Shoot Your Defense Ammo, Duh...

[PappaWheelie]

Eat Crow and Humble Pie, PappaWheelie.

It was only due to coming across a czfirearms.us thread by charlestheforth about a possibly stiffer outer recoil spring (than the highest preload DPM outer) for my "Punching Above Weight" Invisible 15 Round RAMI that I actually shot a half magazine of my carry ammo, with Wifey assisting with location marking of the chosen 7 rounds in order to get an average casing discharge distance.

The good news is that the Wolff Kimber Ultra spring was a clear improvement, dropping the average casing discharge distance by 1.3 feet.

The even better news is that the 6(!) FTFs between my RAMI and my SP-01 Tactical's 12 "rechamberings" showed a strong tendency for a leg of the Xtreme Defender's flat cruciform nose to get hung up on the bottom of the feed ramps of both pistols. I.e., good thing to know before you actually need flawless reliability! It seems the spaces between the cruciform's legs provide opportunity for the nose of the bullet to advance without the associated elevation that a circular face dictates.

https://czfirearms.us/index.php?topic=102671.msg803459#msg803459

Maybe I'm part Scotch, but I had not yet used my more costly carry ammo for "mere target practice." I'm actually surprised in retrospect that my first trials with the DPM springpack and the Xtreme Defender ammo (5 shots, so 4 rechamberings) didn't expose the problem. http://www.czforum.com/forum/index.php?topic=5506.msg23284#msg23284

At any rate, bottom line, I concur with all those who have heretofore advocated doing firing range practice with your latest carry ammo, if you make any change, to verify reliability. Duh...

I've alerted both Underwood Ammo and Lehigh Defense to my experience with their flat cruciform nose bullets and 9mm CZ feed ramp lengths.

In the meantime, in that I have a number of boxes of this ammo, and only need two "chamber only" rounds, I'll experiment with tapering the cruciform legs at various angles to see if a conical angle and intersection diameter combination that would reliably "cam" the nose up onto the ramp can be found.

Thanks again, charlestheforth!

[SI VIS PACEM PARRABELLUM]

I never carry any ammo that I haven't personally tested in the respective firearm(s) that it will be used in. Yes the cost is high when testing defensive rounds but not nearly as costly as finding out that your gun doesn't like that ammo when you really need it to.

[Wobbly]

Loading the same weight (but lower cost) bullet at the same speed can help you duplicate your SD ammo for general purpose range testing like point of aim, getting the feel of the recoil, etc. But nothing will tell you about the ability to feed well like burning up a US Grant's worth of the real stuff.

Sure would like to see a photo of your ammo from several angles. One photo with a random pile like this would do the trick....




PS. Don't feel so bad. I eat a lot of crow. It goes down much easier with ketchup.   

[MadDuner]

My buddies at the range shake their heads and tell me I?m just wasting ?good? ammo....
They could be right.  But at least I KNOW that it works, instead of just hoping that the last change to that spring didn?t ruin my chance of defending myself with defensive +P ammo.

[PappaWheelie]

Sure would like to see a photo of your ammo from several angles. One photo with a random pile like this would do the trick....

Here ya go Wobbly: https://www.underwoodammo.com/collections/defensive-ammo/products/9mm-luger-plus-p-plus-90-grain-xtreme-defender?variant=18785693466681

[daved20319]

I run Gold Dots as defensive ammo, and like you, was hesitant to burn up my expensive ammo just for target practice.  But last year I discovered the LE 50 round boxes were available from SG Ammo for the same price I had been paying for 20 round boxes locally.  Ordered 400 rounds with the express purpose of burning up a couple hundred for a serious function test.  No issues, it functioned just fine in all the 9's I had at the time, but I did learn that it's a lot dirtier than any of the range ammo I'd been using.  Will be doing almost the same thing now that I'm shooting more .45 ACP, but instead of buying Gold Dot ammo, I'll load my own to duplicate factory specs as closely as possible.  A lot cheaper than buying factory ammo, and an important exercise, I already know that one of my .45's is a bit ammo picky.  Later.

Dave

[Wobbly]

Here ya go Wobbly: https://www.underwoodammo.com/collections/defensive-ammo/products/9mm-luger-plus-p-plus-90-grain-xtreme-defender?variant=18785693466681

Wow! Yeah, it's very easy to see now that feeding would be highly dependent upon the random radial placement of the ogive, relative to the gun's feed ramp.

Two things immediately screamed at me. This round would benefit from either...
? Having a plastic piece to fill those huge voids, sort of similar to the Hornady Critical Defense rubber tip, or
? Having more cutaways. Office chairs went to 5 casters in place of 4 to prevent the occasional tip-over. In much the same way, 5 cutaways would mean there'd always be something curved to guide the ogive up the feed ramp.

Thanks but I'm sticking with proven Speer and Federal SD rounds.

 

[PappaWheelie]

Wow! Yeah, it's very easy to see now that feeding would be highly dependent upon the random radial placement of the ogive, relative to the gun's feed ramp.
Two things immediately screamed at me. This round would benefit from either...
? Having a plastic piece to fill those huge voids, sort of similar to the Hornady Critical Defense rubber tip, or
? Having more cutaways. Office chairs went to 5 casters in place of 4 to prevent the occasional tip-over. In much the same way, 5 cutaways would mean there'd always be something curved to guide the ogive up the feed ramp.

I think you meant angular, Wobbly; radial is in the outward direction of a radius
Good points both. Perchance Lehigh Defense will adopt when all is said and done?

Me, I'm sticking with copper for the higher muzzle energies permitted by the lighter (than lead) bullets, and with the industry-best (imho after Frankford Armory impact hammer disassembly of many "store-bought" cartridges) load quality of Kevin Underwood.

If I don't arrive at a "bulletproof" cone angle and truncation diameter for the (480 ft.lbs.) Xtreme Defender, I'll stick with the 105 gr (322 ft.lbs.) Max Expansion
https://www.underwoodammo.com/collections/handgun-ammo/products/9mm-luger-105-grain-maximum-expansion?variant=18785725939769
and the 70 gr (423 ft.lbs.) Max Expansion HERO
https://www.underwoodammo.com/collections/handgun-ammo/products/9mm-luger-105-grain-maximum-expansion?variant=18785725939769
in alternation, 105 gr at the top of the magazine followed by 70 gr, etc. (Xtreme Defender in chamber).

[PappaWheelie]

last year I discovered the LE 50 round boxes were available from SG Ammo for the same price I had been paying for 20 round boxes locally.
Dave

Yeah, SG Ammo typically has the best pricing around: I buy 1000 round boxes of Speer Lawman for target practice for the same price as Walmart sells Winchester White Box! No comparison in quality; the Lawman is FMJ (no powder exposure to lead), the powder is "indoor" quality, and the primers work all the time, unlike WWB.

[HST]

I have shot hundreds of rounds of underwood extreme defender through my P 10 without one failure of any kind and is my preferred carry ammo .
The plus P is the most accurate  ammo i have tested and the lightest recoiling of the bunch , follow up shots are extremely quick and accurate .

[PappaWheelie]

I have shot hundreds of rounds of underwood extreme defender through my P 10 without one failure of any kind and is my preferred carry ammo .
The plus P is the most accurate  ammo i have tested and the lightest recoiling of the bunch , follow up shots are extremely quick and accurate .

Thanks HST, Underwood has responded with "no known problems with CZs and Xtreme Defender" as well, so perhaps my experience was a heavenly amplification of an arguably small risk, but having thoroughly gotten my attention, I've committed to eliminating that risk entirely. I saw with my own eyes the FTF bullets being hung up with a leg "under" the beginning of the ramps of both models, at an alarming 50% frequency.
As a first step, to prove to myself whether the product was "salvageable" as carry ammo, I cobbled a short file section fixtured at 45 degrees to the spindle of my drill press
https://drive.google.com/open?id=1hje4TRHEeRjt82JboHzpUQsEZPjGSXKd
and made up a magazine load of conically bevelled (albeit crudely in terms of surface finish) cruciform wings
https://drive.google.com/open?id=1L5k7lHhGJBGT4vyArWJZQJNHOpKWUNaX
https://drive.google.com/open?id=1h9k1MfiCL19cn2jRSrFT5kqMY3sxti8d
to try alongside my CZ 97 BD through which I also had not yet cycled even a magazine full of Xtreme Defender.

Happy results: No FTFs with the .45 ACP (I shot a whole box, what a sweet gun!); no FTFs with the tapered nose 9mm magazine full. TYJ!
I'll experiment some more with shallower cone angles and larger intersection diameters now that I know this best-in-class (performance-wise) ammo isn't a lost cause.

[SI VIS PACEM PARRABELLUM]

Shot placement is key period.I'll stick with traditional defensive ammo.There is NO magic bullet.

[Joe L]

I gave up on defensive specific ammo and just loaded all the home 9mm's with Atlanta Arms 115 JHP, same as I practice and shoot matches with.  I couldn't deal with the zero change from switching ammo and the cost of fancy ammo.  I am still carrying a .40 cal Kahr until my holster for the P-10C with optic arrives.  An 1100 fps JHP is good enough for me in the 9mm.  I am not in a high risk area, until the next presidential election, anyway.   
Joe

[PappaWheelie]

I'll experiment some more with shallower cone angles and larger intersection diameters now that I know this best-in-class (performance-wise) ammo isn't a lost cause.

I made up a larger cutting surface using a chunk* of a body file (VERY coarse single cut) with "ends" trial and error ground (flat) until parallel within 0.001" for secure holding in my inherited (tool and die maker father-in-law custom-made) machinist's vise, and mounted same, with cardboard shims to protect the vise jaw finish, at an "eyeball" 30 degrees to horizontal.
https://drive.google.com/open?id=1BZHtOd-Kwr7GThZ0lHT2Pv4OKwVbjf_P
I processed 32 rounds of Xtreme Defender, having clamped a giant washer to the drill press table as a travel stop that, in conjunction with vertically locked spindle, would produce a cone intersection (with the flat nose) approximately at the base of the cruciform flutes.
I then used a #4 Swiss Pattern (quite fine) rectangular file chunk held parallel to the body file by means of two-sided tape and swabbed with Amsoil Severe Gear as "cutting fluid" to prevent loading up, and touched up the conical surface in a 2nd pass. Cycle time for each cartridge was ~1 minute/cut so it took just over an hour to process all the rounds, an extended magazine full (14) for the RAMI and a magazine full for the SP-01 (18).
https://drive.google.com/open?id=1_mGqISTPAHJcKzs7X9WGYWss-TcAYnJA
https://drive.google.com/open?id=1dYsB_OnfmeybIMvzR10YlT4FpWRl4AmO
https://drive.google.com/open?id=1CEu4DixK712CDNTNnzb2ozhGSB_q7A8L

Then came the tryout: the SP-01 cycled flawlessly. The RAMI suffered one FTF mid-magazine where the cartridge held the slide open with virtually horizontal attitude, the bullet nose center (rather than a leg of the crucifix) itself stuck on the bottom edge of the ramp!

Huge improvement (vs. every other cycle), but not good enough. The time it would take to complete the chambering operation by racking the slide (after recognition of the problem) could conceivably be lethal.

My thoughts at this time are:
1.) it wasn't the cone angle; I'll make up a couple of magfulls with reduced intersection diameter and retry.
2.) it wasn't my normal (softened corners) carry magazine; these should be interchangeable, functionally, but there's bound to be some piece-to-piece variation. One of the above mags will be my carry mag next time.
3.) it shouldn't be the strengthened recoil spring based on casing discharge distance still being, at 9.51 feet, 3.5 feet above the CGW ideal target of 6 feet.
4.) the Xtreme Defender cartridge's measured length is 28.25mm, 0.85mm shorter than Speer Lawman's measured length of 29.1mm, typical of industry practice's shortening of hollow points. If for whatever reason a longer cartridge is needed for reliable feeding of pointy-nosed cartridges, the ideal fix would come from the factory although the few cartridges required for carry could conceivably be lengthened with for example a Frankford Arsenal impact hammer and then re-pressed to the new target length.
5.) a little dab of extreme pressure lube on the bottom of the feed ramp, and conceivably a film of Lucas Gun Oil on the noses of the carry ammo might make the critical difference.
I'm open to suggestions for what might be needed to "reliable-ize" this ammo completely. I've heard all of the "stick with old school ammo" suggestions I'll need for a good bit, btw, so please don't offer more of the same, it's off-topic.


*to break a file cleanly, grind a groove across one face, chuck it in a vise just below the groove, and pull towards the groove. The stress concentration at the tooth tips is so great (b/c of thin sections at max distance from the "neutral axis" that the file snaps with remarkably low effort compared to a slab of steel with comparable section.

[PappaWheelie]

Woke up this morning wondering if "limp wristing" might be an issue: stay tuned, I'm going to shoot a magazine of unmodified Xtreme Defender in each pistol with deliberately "locked wrists" in comparison with a magazine with "not so much."