VZ 58 Pistol SBR Project - what do I need to know?

[RSR]

Froggy -- don't know either way on the M92 Krinks.  I just figured it was something super simple like not wanting to manufacture custom HGs for a short barreled rifle...  I would like to think that factory designers and engineers think about stuff like ballistic performance throughout entire range of intended use, but I'm somewhat a skeptic in this regard.

[Atl_Matt]

Great insights guys. I don't know that I'm fully on board with the need for 10" barrels for the 7.62x39 round. Totally different deal with the 556 - it's designed to yaw and frag at the crenallation and needs velocity to do that reliably. Never heard that about the AK round - basically it's heading straight through - with an FMJ you get a .30 cal hole - with SP you get something bigger. Barrier penetration I totally get but terminal ballistics - guess we're back to more is better (velocity) arguments. Anyway, great insights from all. I still wouldn't want to be on the business end of my Krink. Matt

[RSR]

Penetration through steel in particular is a function of velocity.  Trajectory is a function of velocity as are both energy and momentum.  All matter in different ways -- velocity, high velocity, is what makes rifle rounds superior to pistol rounds and why militaries no shoot 500+ grain bullets out of standard issue rifles like they did turn of the last century (to be clear -- referencing 1900s, not 2000s).

In particular w/ 7.62x39 FMJs -- the lead core rounds, which are all we have here in the US after the AP ban, the bullet jacket length and shape by and large stayed the same.  To account for heavier lead vs lighter steel (by a given unit of volume), 7.62x39 FMJ rounds began leaving airspace in the tip of the bullet.  For 7.62x39 FMJ to deposit full energy in the human body, the bullet needs to yaw/tumble.  With steel core 7.62x39 FMJs, this really only occurred when striking bone.  With lead core and hollow tip, this yawng/tumbling occurs due to unbalanced bullet with heavier base.  However, velocity greatly assists this in occurring -- for instance, some lead core 7.62x39 FMJ will have internal core move forward to aid tumbling (like 5.45 7n6), some will have the hollow nose cave in/dent resulting in yawing then tumbling, and some the bullet will not have any change and just tumble...  The first two scenarios generally result in significant tumbling within the first 3-4", and velocity is significant in ensuring this bullet deformation/displacement occurs.  The third is largely what happens with excessively thick jackets and/or at lower velocities and usually tumbles within 6-8".  It's worth noting that all are better than the 10-12" where the steel cored 7.62x39 would usually tumble, but you obviously want the bullet to tumble sooner rather than later.  (Note: All of these are what was seen in gel block testing...)


If you're talking about Russian-made HPs or SPs velocity matters there too as there needs to be sufficient force to overcome the thicker and stronger steel jackets (vs usual copper jackets). 

Though overly simple in regards to not accounting for stretch cavities, the lower velocity you go the more 7.62x39 just punches a .30 cal hole not too far removed from a 9mm FMJ...
A good read on stretch cavity from Dr. Gary Roberts -- main takeaway/point is that stretch cavity does not reliably produce incapacitating wounds:

The tissue surrounding the permanent cavity is briefly pushed laterally aside as it is centrifugally driven radially outward by the projectile?s passage. The empty space normally occupied by the momentarily displaced tissue surrounding the wound track, is called the temporary cavity. The temporary cavity quickly subsides as the elastic recoil of the stretched tissue returns it towards the wound track. The tissue that was stretched by the temporary cavity may be injured and is analogous to an area of blunt trauma surrounding the permanent crush cavity. The degree of injury produced by temporary cavitation is quite variable, erratic, and highly dependent on anatomic and physiologic considerations. Many flexible, elastic soft tissues such as muscle, bowel wall, skin, blood vessels, and empty hollow organs are good energy absorbers and are highly resistant to the blunt trauma and contusion caused by the stretch of temporary cavitation. Inelastic tissues such as the liver, kidney, spleen, pancreas, brain, and completely full fluid or gas filled hollow organs, such as the bladder, are highly susceptible to severe permanent splitting, tearing, and rupture due to temporary cavitation insults. Projectiles are traveling at their maximum velocity when they initially strike and then slow as they travel through tissue. In spite of this, the maximum temporary cavity is not always found at the surface where the projectile is at its highest velocity, but often deeper in the tissue after it has slowed considerably. The maximum temporary cavitation is usually coincidental with that of maximum bullet yaw, deformation, or fragmentation, but not necessarily maximum projectile velocity.

https://primaryandsecondary.com/basic-wound-ballistic-terminal-performance-facts/

[RSR]

*Again, if you want to handload, I would imagine there are faster burning powders you could use to create a much superior cartridge for SBR use than commercial loadings.  Or if you want to just spew flames, then you have the commercial load option too... 
I do wonder about how the presumably larger gas port would perform w/ custom loads though.  Presumably more recoil would be subjected to the gun. Unlike ARs with buffers and recoil springs of varying weights, VZ58s only really have the gas port size to control recoil...

[CitizenPete]

Great insights guys. I don't know that I'm fully on board with the need for 10" barrels for the 7.62x39 round. Totally different deal with the 556 - it's designed to yaw and frag at the crenallation and needs velocity to do that reliably. Never heard that about the AK round - basically it's heading straight through - with an FMJ you get a .30 cal hole - with SP you get something bigger. Barrier penetration I totally get but terminal ballistics - guess we're back to more is better (velocity) arguments. Anyway, great insights from all. I still wouldn't want to be on the business end of my Krink. Matt

As your aware,  7.62x39 ballistic specifications are based on 16" barrels. 

Terminal ballistics depend on the bullet included in the cartridge -- for example:

M43 FMJ  steel core, yes for the most part in tissue, "it's heading straight through - with an FMJ you get a .30 cal hole";   

M67 FMJ lead core flat bottom (a.k.a.: Yugo surplus) yaws at about 1-3" and creates a massive wound channel (based on ballistic gel tests); 

Ulyanovsk with 8M3 FMJ HP LCB (hollow point lead core boat tail) fragments quite well;
etc..

https://www.youtube.com/watch?v=QrS-kya8xVA

[RSR]

CP is correct.

One thing to note is copper.

The Yugo surplus is copper jacketed with a lead core and hollow nose, but FMJ bullet.  It also has a flat base which puts weight slightly further to the rear.

Golden Tiger for instance has a thinner steel (actually -- bimetal, mild steel that's copper washed) jacket than what most of the Russian stuff does -- mainly barnaul (bears and wolf) and tula.  Steel jackets are stronger than copper, which means they require greater forces for optimal yawing...
However, GT also has a boat tail bullet which results in slightly less weight bias to the rear.  While the BT bullet does result in better accuracy beyond 200 yards than flat base, it does that at a tradeoff for bullet tumbling efficiency at all ranges.  But the higher velocity of GT and the thinner jacket seem to totally negate that design caveat in testing I've seen.  My personal take is accuracy/hitting a target coming as a first consideration with terminal effectiveness secondary...

The US soft point in that wound track image is copper jacketed as well, probably the winchester soft point actually.  I would not expect Russian steel case to perform as well -- add another inch or so to initial wound track most likely, all else should be roughly equal -- there's also been discussion that the Russian lead used is harder than what american manufacturers use though I know of no reliable testing occurring on that...

EDIT: I don't know of this type of info for 7.62x39, but found this interesting in regards to bullet performance at different velocities -- also important in considering the effective range as it relates to velocity of the bullet you're using; also would be worth knowing at which velocities you get expansion and not just fragmentation as well -- no doubt related, but different...:

Penetration and Fragmentation are key to the .223/5.56 ammo. Bullets that penetrate 10-12” or higher are usually preferred. Generally FMJ bullets begin to fragment at 2500-2700 fps or higher. OTM/BTHP/SMK bullets generally begin to fragment at 2200-2300 fps or higher. Soft Point (SP) Ammo generally begins to fragment at 2000 fps or higher. Ballistic Tip (BT) ammo generally begins to fragment at 1900 fps or higher.

NOTE: .223/5.56 ammo, whether it is FMJ, OTM/BTHP/SMK, SP, BT, generally fragment upon impact because the bullets have a thin jacket. There are exceptions however, such as the Barnes DPX, which look like BTHP ammo, and also some of the Bonded Soft Point Ammo like the Federal Bonded Ammo, Nosler Partition, and the Hornady TAP Barrier. These bullets have a thicker jacked and they mushroom out like traditional HP ammo.

Source: https://www.ar15.com/archive/topic.html?b=3&f=16&t=281405

[RSR]

Couldn't find this earlier but here you go: http://www.ar15.com/forums/t_4_54/96834_.html

Posted: 5/14/2007 12:14:44 PM EDT [Last Edit: 5/15/2007 7:00:28 AM EDT by Zhukov]
This was posted over on Tacticalforums.com a month ago, and I've added it to the FAQ. Just posting it here to let everyone know...


ALL CONTENT OF THIS POST IS COURTESY OF DOCTOR GARY ROBERTS, AND IS HOSTED ORIGINALLY AT Tacticalforums.com. I have saved it off here in case it disappears off of their servers.

5.45x39

The 5.45 x 39 mm Russian M74 53 gr FMJ boat-tailed bullet has a copper-plated steel jacket surrounding an unhardened steel core and a small 5 mm long empty air-space under the bullet nose. Its typical muzzle velocity is 3066 f/s. In contrast to the older 7.62 x 39 mm Russian M43 Type PS which it replaced, the 5.45 x 39 mm M74 53 gr FMJ commonly exhibits very early yaw in tissue, at approximately 2.75", but no deformation or fragmentation. In both uncomplicated extremity and torso wounds, the very early yaw allows the bullet to travel sideways through the body, increasing permanent tissue destruction and temporary cavitation effects. A small punctate entrance wound is present and the exit wound may be punctate, oblong, or stellate depending on the bullet yaw angle on exit. Penetration is approximately 21.6?. 5.45 x 39 mm M74 is a lot like an early yawing 5.56 mm bullet that does not fragment--for example M995, but without the AP capability. Good fragmenting 5.56 mm bullets, like the Hornady 75 gr or Nosler 77 gr OTM?s, are superior to 5.45 x 39 mm. I am unaware of any good terminal ballistic testing on commercial 5.45 x 39 mm loads.

7.62x39

In discussing 7.62x39 mm FMJ, the question is always which one, as their characteristics are highly variable.

In fact, there is a bit of a controversy brewing in some of the AAR?s coming in from OCONUS on the effectiveness of 7.62 x 39 mm ammunition. Initially, this appears somewhat strange, as there may be more forensic data available regarding wounds caused by the Russian 7.62 x 39 mm FMJ than for any other rifle cartridge. The original 7.62 x 39 mm Russian M43 Type PS 120.5 gr FMJ boat-tail bullet has a copper-plated steel jacket covering a large steel core and a typical muzzle velocity of 2340 f/s. In tissue, it typically travels approximately 9.8 to 10.6" point forward before beginning significant yaw. Most uncomplicated wounds of the torso and extremities have small punctate entrance and exit wounds and exhibit minimal internal tissue disruption since the bullet does not deform or fragment and usually exits before yaw occurs. Total penetration is around 29.1?. WDMET (Wound Data and Munitions Effectiveness Team) collected extensive forensic data on over 700 7.62 x 39 mm gunshot wounds during the Viet Nam war. The predominant feature of this cartridge is the MINIMAL amount of damage it produces in soft tissue wounds, on par with FMJ handgun wounds such as those produced by 9 mm M882 ball. We also have extensive law enforcement data, as this cartridge has been used extensively in illicit activity. For example, in the 17 January 1988 Stockton school shooting, 30 of 35 kids who were shot lived. Of the five that died, all were shot in critical structure--head, heart, spine, aorta and none had damage to any organ not directly hit by a bullet.

However, not all 7.62 x 39 mm FMJ bullets are of the original steel core construction. Significantly increased tissue damage is produced by the early yaw seen with several 7.62 x 39 mm FMJ lead core bullets, including:

-- Yugoslavian M67 124 gr FMJ, flat based, copper-jacketed, lead core bullet which travels only 3.5" in tissue before yawing

-- Chinese (PRC) 7.62 x 39 mm 123 gr FMJ, copper-jacketed, lead core bullets which begin their yaw after only 2 to 2.5" of travel in tissue.

-- Czech and several types of Western commercially produced lead core 7.62 x 39 mm FMJ yaw within the first 2 to 3 inches of travel in tissue.

In both uncomplicated extremity and torso wounds, the very early yaw of these lead core 7.62 x 39 mm FMJ bullets allow the projectiles to travel sideways through the body, substantially increasing permanent tissue destruction and temporary cavitation effects compared to the standard 7.62 x 39 mm Russian M43 Type PS 120.5 gr FMJ. These early yawing lead core 7.62 x 39 mm FMJ bullets cause wounds very similar to the 5.45 x 39 mm Russian M74 53 gr FMJ bullets, however, the larger size of the 7.62 x 39 mm bullets results in a bigger permanent cavity compared to 5.45 x 39 mm bullets.

The differences in terminal effects seen in recent combat with 7.62 x 39 mm FMJ wounds can likely be explained by the different terminal effects caused by the various types of FMJ construction.

When one moves to a expanding/fragmenting design in 7.62 x 39 mm, terminal performance is significantly enhanced. The best 7.62 x 39 mm loads we have tested to date are the Winchester 123 gr JSP (X76239) and the Lapua 125 gr JSP. Out of a 16? barrel they perform somewhat like lightweight .30-30 loads:

Lap 125 gr JSP
Bare Gelatin: vel=2316 f/s, pen=17.3?, RD=.62?, RL=.43?, RW=122.6 gr
Car Windshield: vel=2323 f/s, pen=14.8?, RD=.60?, RL=.40?, RW=110.6 gr

Win 123 gr JSP
Bare Gel: vel=2253 f/s, pen=14.4?, rd=0.56?, rw=90.1gr
Pretty much the same results when going through car windshields.

Of note, most of the ?cheap? Russian JHP/JSP ammunition offers poor terminal performance. The one that seems to work is the 7.62x39mm Saspan 124 gr JHP (Ulyanovsk Machinery Plant; 8M3 bullet); from a 16? AKMS the data is:

BG: vel=2297 f/s, pen=15.0?, Max TC=10cm@18cm, RD=0.63?, RW=100.5gr"

Because of the larger permanent cavity and greater bullet mass, the 7.62 x 39 mm JSP?s offer somewhat better performance than the .223 bonded JSP?s, like the Trophy Bonded Bearclaw use in the Federal Tactical loads. These 7.62 x 39 mm JSP loads are a good choice for use against car windows and should also be outstanding for hunting deer and other similar size game.

7.62x54R

The 7.62 x 54 mm Russian M1898/1908 Type L 148 gr FMJ hollow based bullet has a copper-plated steel jacket covering a lead core and a typical muzzle velocity of just under 2800 f/s. These bullets generally travel point forward for 6" or so, causing minimal tissue damage. The bullets then yaw, turning 180 degrees and continuing base forward for a total penetration in excess of 20? without further yaw. In uncomplicated extremity wounds, the bullets will frequently exit before yawing, causing little tissue disruption and small punctate entrance and exit wounds. If the bullets yaw while still traveling in tissue, in the thick torso for example, the permanent and temporary cavity are increased while the bullets travels sideways, resulting in a greater amount of crushed tissue and extensive damage to inelastic tissue. Exit wounds may be punctate, oblong, or stellate depending on the yaw angle of the bullets on exit. The wounds from the 7.62 x 54 mm are nearly identical to similar size U.S. bullets, including: the original pre-WWI spitzer .30-06 FMJ loading, pre-WWII .30-06 M1 ball, WWII .30-06 M2 ball, .30-06 M72 Match, 7.62 x 51 mm M59 FMJ, current 7.62 x 51 mm M80 ball load, and 7.62 x 51 mm M118 SB (Match). All of this ball ammo has nearly identical the terminal performance with a relatively long neck and single yaw cycle. The 7.62 x 54 mm Type L FMJ is still in wide use with PK machine guns and may be found being used in obsolete, but rugged M1891/30 Mosin-Nagant rifles.

The Czech 7.62 x 54 mm LPS 148 gr FMJ has a similar wound profile to the 7.62 x 54 mm Russian M1898/1908 Type L 148 gr FMJ, except the bullet begins to yaw much earlier, at around 2.4? to 3? of travel through tissue. As a result, wound effects are signficantly increased compared to the Type L bullet; the very early yaw initiation increases permanent tissue destruction and temporary cavitation effects compared to the standard 7.62 x 54 mm Russian FMJ. A small punctate entrance wound is present and the exit wound may be punctate, oblong, or stellate depending on the bullet yaw angle on exit. Penetration of these bullets is in excess of 20?.

The specialized 7.62 x 54 mm Wolff 200 gr FMJ sniper ammo for the Dragunov SVD is an exception to the above wounding effects, as this ammo acts more like M852/M118LR. These Russian sniper bullets typically have a muzzle velocity approaching 2600 f/s and travel approximately 5" point forward before beginning to deform, yaw, flatten, and fragment. Approximately 60% of the bullet weight is lost to the multiple fragments which spread radially outward from the primary bullet path. The multiply perforated tissue is unable to resist the stretch induced by temporary cavitation and extensive tissue destruction occurs. Uncomplicated extremity and torso wounds would likely exhibit a small punctate entrance wound. If the bullet exits before deforming or yawing, minimal tissue disruption will occur and a small punctate exit wound will be present. After the bullet yaws, deforms, and fragments, tissue destruction is greatly increased; torso wounds are often fatal and exit wounds may exhibit large tissue defects. If the bullets fail to fragment, then they act just like the FMJ's described above.

[Atl_Matt]

Many thanks to both RSR and CP. Got schooled on AK ammo characteristics by some incredible sources of information. Truly appreciated. Best, Matt

[RSR]

Cross posting this here to VZ58 boards as well.

Just fyi -- was VERY PLEASANTLY SURPRISED to see this. 

SG Ammo is now selling an 8M3 effect 7.62x39 hp load they custom ordered from Tula/Uly: http://www.sgammo.com/product/tula/1000-round-case-762x39-8m3-124-grain-hollow-point-ammo-made-ulyanovsk-cartridge-works-u

They also have 100 round lots as well: http://www.sgammo.com/product/tula/100-round-box-762x39-8m3-124-grain-hollow-point-ammo-made-ulyanovsk-cartridge-works-ul0

[MeatAxe]

Cross posting this here to VZ58 boards as well.

Just fyi -- was VERY PLEASANTLY SURPRISED to see this. 

SG Ammo is now selling an 8M3 effect 7.62x39 hp load they custom ordered from Tula/Uly: http://www.sgammo.com/product/tula/1000-round-case-762x39-8m3-124-grain-hollow-point-ammo-made-ulyanovsk-cartridge-works-u

They also have 100 round lots as well: http://www.sgammo.com/product/tula/100-round-box-762x39-8m3-124-grain-hollow-point-ammo-made-ulyanovsk-cartridge-works-ul0

Before I get too excited, I'd like to see some ballistics gel tests of this new production "8M3."

The usual Tula HPs available these days (also manufactured by Ulyanovsk) look identical to 8M3, down to the pre-fail cuts on the jacket inside the hollow tip, but they zip through pork shoulders like FMJ ammo, with no expansion or fragmentation.

[RSR]

No doubt you can see if these are 8m3 w/ just water jugs.  I might order a small pack to test, but i maxed out my ammo budget for the next six months prior to the election...  Once i shoot off my non-lacquer hps, I'll likely replace them w/ this... 

You asked for 8m3 spec 762x39 ammo, SGAmmo delivered. Here at SGAmmo we love 7.62x39 ammo (and guns), and over the years had a large number of requests to locate 8M3 spec ammo that had gone extinct back around 2002. We went to the manufacturer and importer of UCW ammo and put our $$$ where our mouth is and had it custom made for our clients. This ammo features the 8M3 124 grain hollow point projectile, a polymer coated steel case (UCW no longer offers lacquered case), and mil-spec sealant applied to the case mouth and primer pocket to water-proof the cartridge. The projectile has a magnetic bi-metal jacket covering a lead core. The manufacturer is OJSC "The Ulyanovsk Cartridge Works". The importer is 'Tulammo USA Inc'. This product SKU is exclusively distributed by SGAmmo.com thru the end of 2017. We hope you enjoy this retro 7.62x39 ammo option that we had resurrected.

FWIW, SG Ammo is always transparently honest in all my dealings with them...  For instance, they sold a bunch of Golden Tiger .223 ammo earlier this year.  It turned out that GT used hard 5.45x39 primers instead of buying the softer .223 primers from Tula (apparently the only maker of commercial spec .223 primers in Russia...).  Price for that ammo was around .24 or .25 cents per round prior to knowing about the primer issue. 
SG Ammo once becoming aware purchased back all the ammo at full refund and and paid for returned shipping.  As they can't send back to russia, they then repacked as loose bulk and sold it as "hard-primer" 5.56 with mods needing made to get it to be run reliably outlined.  And they sold it at a loss for somewhere around 15 cents per round IIRC... 
That's the caliber of folks you're dealing with and I really doubt they'd compromise their reputation to misrepresent stuff like you see from some folks at gunshows who represent every modern 124 gr hp as "8M3"... 

Also, the fact that Tula themselves places 8m3 on the package should be telling that it's something special.  Case box is also marked "hunting ammo" which I don't recall seeing on standard HP boxes.

[RSR]

Full thread link:
http://www.akfiles.com/forums/showthread.php?t=289444&page=4

Found this: http://www.akfiles.com/forums/showpost.php?p=3700188&postcount=84

Hi Guys

Fun thread, just going to jump in here once then I am back to pushing papers in the SGAmmo warehouse. I may not address questions or may find my way back here in time.

This stuff came in yesterday morning, no I have not been sitting on a stash of this stuff in hopes of making extra on, LOL. We got one container 1,000,000 rounds, and it is selling well at the start.

My cost on this ammo is $215 per 1000, it costs a $10 a 1000 more than normal to get the sealed primer and case mouth, but IMO its worth it, so less the odd chance for a price drop from Russia or the importer cutting their commission I'm not budging on the price. There may be other good deals come along though if your main concern is only price, this is a busienss of very low profit margins that is made up for by high sales volume. If you look at what I really make on that is not much, $239.50 minus 3% to credit card and a ball-park figure of 2% costs for box, tape, labor to pick, check and pack the order, its about $12 to $13 net profit that ends up in my pocked for my return on the investment to make this happen. Not a lot of margin to work with for the guys hoping for a big price drop, Sorry.

I had Tulammo who is the main importer for TCW and UCW ammo to the USA make this happen (by paying them a lot of $$$ to do it). Part of the PO is that they do not take other vendors orders for this in 2017, even if they did I doubt anyone would sell it for less, the margin just is not there to work with. The ammo is made by Ulyanovsk, not Tula, I just added a 7th picture to the listing showing that marking on the case.

I sectioned a couple bullets somewhat crudely and there are slight partitions within the jacket, I am not sure if there are 3 or 4 or 5 but they are visible right were the core meets the jacket even if you just use a flashlight and close eye to look into the hollow point.

Is 8m3 really any better than a soft point of any other hollow point? I am not sure on that. Internet legend would lead you to believe it is and hundreds of people asked me for this every year, so I coughed up the cash to make it happen for them. I am sure there will be debate as to if this is 'Real 8M3' or not, or does it perform the same as the stuff that is 15 to 20 years old, etc etc, I will leave that top the public to discuss but Ulyanovsk says this is real 8M3 and they are the original manufacturer and owner of that trademark / and projectile patent so that is good enough for me. My goal was just to give the client what they were asking for, if it is really any better I will leave that to you to decide. Neat ammo though, I had actually had a dream of having this ammo made for the past few years, glad it finally materialized

Thank you
Sam Gabbert
SGAmmo Owner

Interesting post following that does a good job summarizing uses: http://www.akfiles.com/forums/showpost.php?p=3700485&postcount=93

First of all, thank you very much for trying and succeeding at getting this made and imported for us. I truly do appreciate that SGAmmo tries so hard to please a fickle consumer base, which so many gun owners really are.

8m3's real world performance characteristics exhibit a lot of what we like in a round that is intended to be used against people and some smaller game (the aforementioned coyotes, little FL white tails, small hogs, etc). Generally a short wound neck, early upset, reliable and impressive fragmentation, and rarely penetrates hydrolic mediums more than a foot. Dr. Gary Roberts has a very high opinion of the bullet as it's one of only two imported rounds in 7.62x39 that perform as well as we'd want in a social encounter (the other being the unicorn Lapua 125gr JSP). The fact that it was also cheap enough to train with made 8m3 a fine choice back in the day.

Fast forward a decade and a half and there really hasn't been a publicized modern test of the stuff outside of Dr. Roberts' limited work. I would be perfectly happy to donate a box of 8HP, 8m3 "effect", and the new 8m3 you're importing to someone willing to test them properly. I'll be in touch with my local ATF tech branch to talk shop about other things and I'll bring this up to see if they're bored enough to be interested.

Are there better rounds for hunting? Sure. Most modern rounds are better suited to penetrating the thicker bones and meat of larger deer and hog to destroy the important stuff without annihilating good meat. Are there better rounds for defeating auto glass? Yup, most bonded core rounds like Fed Fusion do well, as does SST and the Lapua JSP. Are there better rounds against lightly garbed people or small deer/hog/'yote when preserving meat and pelts is not the goal? Maybe not. Hornady's SST is arguably the most versatile around in this caliber, but even it doesn't fragment as impressively as ye olde Uly 8m3 "effect", certainly not after such a short wound neck.

I look forward to seeing this new import tested. It would be awesome to have another great option on the market that is good enough to use and cheap enough to practice with.

Edit: random fun fact, Uly 8m3 more closely matches Leupold's 300 Blackout reticle than Hornady SST, Federal Fusion, and Golden Tiger.

And some pics here, but don't recall my AK files UN or if I have one... Will try to access later.
http://www.akfiles.com/forums/showpost.php?p=3714321&postcount=134

hronograph data: 46F, 70% humidity 30.0" HG, 10 shots, chronograph 10 feet from muzzle.
High: 2460
Low: 2380
AVG: 2426
ES: 80
SD: 25

Two failures to fire on first strike, but this lower has a trigger specifically NOT for steel cased "surplus" ammo. I've never had issues with other "flavors" of steel cased at 80F, but this time I did. The cold may have contributed to the lighter than normal strikes as they were within the first four shots. There were NO failure to feed or other malfunctions for the rest of the test.

Group was around 2MOA for 7 of the 10 shots, but I'm sure the low (X ring) was pulled, and also one of the two low-left. The third low-left I'm unsure of.

Only recovered fragment (lead, no jacket found) was in the third jug and weighed 3.6 gr.

Upper was a PSA "sale" (cheaper than I could build it), 16", Aimpoint Comp2.

This may be labeled as "hunting" ammunition, but I wouldn't want to hunt anything I wanted to eat!

And his reply to a couple Qs:

I don't recall saying it was a "definitive test". People had asked for some initial data, I supplied it. YMMV

I changed the lower, no more malfunctions of any kind.

Yes, FMJ will blow up a water jug, but it doesn't create birdshot size holes when it exits.

Merry Christmas!

[MeatAxe]

No doubt you can see if these are 8m3 w/ just water jugs.  I might order a small pack to test, but i maxed out my ammo budget for the next six months prior to the election...  Once i shoot off my non-lacquer hps, I'll likely replace them w/ this... 

You asked for 8m3 spec 762x39 ammo, SGAmmo delivered. Here at SGAmmo we love 7.62x39 ammo (and guns), and over the years had a large number of requests to locate 8M3 spec ammo that had gone extinct back around 2002. We went to the manufacturer and importer of UCW ammo and put our $$$ where our mouth is and had it custom made for our clients. This ammo features the 8M3 124 grain hollow point projectile, a polymer coated steel case (UCW no longer offers lacquered case), and mil-spec sealant applied to the case mouth and primer pocket to water-proof the cartridge. The projectile has a magnetic bi-metal jacket covering a lead core. The manufacturer is OJSC "The Ulyanovsk Cartridge Works". The importer is 'Tulammo USA Inc'. This product SKU is exclusively distributed by SGAmmo.com thru the end of 2017. We hope you enjoy this retro 7.62x39 ammo option that we had resurrected.

FWIW, SG Ammo is always transparently honest in all my dealings with them...  For instance, they sold a bunch of Golden Tiger .223 ammo earlier this year.  It turned out that GT used hard 5.45x39 primers instead of buying the softer .223 primers from Tula (apparently the only maker of commercial spec .223 primers in Russia...).  Price for that ammo was around .24 or .25 cents per round prior to knowing about the primer issue. 
SG Ammo once becoming aware purchased back all the ammo at full refund and and paid for returned shipping.  As they can't send back to russia, they then repacked as loose bulk and sold it as "hard-primer" 5.56 with mods needing made to get it to be run reliably outlined.  And they sold it at a loss for somewhere around 15 cents per round IIRC... 
That's the caliber of folks you're dealing with and I really doubt they'd compromise their reputation to misrepresent stuff like you see from some folks at gunshows who represent every modern 124 gr hp as "8M3"... 

Also, the fact that Tula themselves places 8m3 on the package should be telling that it's something special.  Case box is also marked "hunting ammo" which I don't recall seeing on standard HP boxes.

I don't doubt SG Ammo (they've always been a pleasure to deal with), but they aren't the ones manufacturing the ammo.

A few years ago (@ 2012), when I was searching for more of the dwindling supply of 1990s vintage 8M3 "Effect" rounds and Sapsan-branded 8M3, I contacted SG Ammo and the guy (Sam?) told me at the time that honest to goodness 8M3 ammo hadn't been imported in over 10 years, even though a lot of people were claiming that both Tula and Wolf Military Classic current production HPs were 8M3.

I then got a hold of the head guy at Tula in the US and he claimed that 90% of the Tula HPs being imported were 8M3 bullets...well I tested various lots of Tula 122 & 124gr HP (which look identical) over a couple of years by firing them into pork shoulders and NONE of them expanded with the fabled explosive effects of 8M3. Those Tula HPs just zipped through like FMJ. So, the Tula guy was full of !@##.

On the other hand, I will say that the 124 gr Tula SPs blew up the pork shoulders pretty well, almost on par with Hornady SSTs and Z Max rounds. These are good hunting rounds, but I would suspect that authentic 8M3, with its fragmentation potential and less penetration, would make better self-defense rounds.

So while I'm hopeful that SG Ammo is getting bona fide 8M3 from Tula (and I even ordered a case -- can't go wrong at that price regardless), I want to either see a ballistics gel test, or do a test myself in pork shoulders, before I start it buying cheap and stacking deep.

As of now, vintage 8M3 is going for about the same price as new production SST, even though it's been kicking around in god knows what conditions for 20 odd years, so I would really like to see new production 8M3 at SG's low prices.

[MeatAxe]

RE: the OP, I think the easiest way to go is just take a Vz58 pistol and put an arm brace on it. That way, you don't have to go through the paperwork, $200 tax, time and energy, not to mention putting your name and address front and center before the BATF.

Also, legally, you can't take an SBR across state lines without writing for and obtaining permission from the BATF, unlike a pistol, which you can take just about anywhere.

The Vz58 pistol, like AK pistols in the arm brace configuration, will make excellent vehicle guns.

[RSR]

Why you may not want to go w/ the 7.6" barreled compact in 5.56, instead opting for 11.9" or 16.2":

https://youtu.be/gwPiINDF9zA