Improving the ES and SD: 147 gr RN Berrys over N320

[Clint007]

Hi guys. My  latest load project is 147 gr RN Berrys over N320.  I'm not really happy with the shot to shot velocity consistency. It's the same with several CZ, not particular to one gun.  I'm testing using new STarline brass, which is what I use for major matches. Current estimate is 3.4 gr giving me an average of 865 fps but with too much ES and SD. Don't have the numbers handy but bring that later...

Wondering if I'm expanding incorrectly. This bullet is 0.356 diameter. I seat at 1.150".

How would you expand the case for this bullet for best performance?  I have both the Lyman M die, and a Lee expander die with plugs with 0.353, 0.354, 0.356, and 0.357 diameters.  And I can expand less of the mouth and use the powder funnel to flare instead, if I want.  The Lyman M die, when seated to a point that flares the mouth nicely, is about the same depth as the bullet seats at 1.150".   I measured this long bullet and case, to make sure I'm not pinching at the inside taper of the case. That seems not to be the issue. Plus Wobbly has posted this 1.150" length as appropriate for this bullet....so I don't think that's it.

Also, what are the negatives to consider with under-expanding (run out/problematic seating, pressure spikes?) and over-expanding (set back?)?

Thanks as always for sharing your wisdom and experience.

C

[Wobbly]

Plus Wobbly has posted this 1.150" length as appropriate for this bullet.... so I don't think that's it.

Oh sure ! Go ahead. Drag me straight into the middle of this ! 


Several thoughts... not that I'm big on 147gr or any kind of expert.

• I've fallen in love with deeper seating since that OAL was last described. I now think the easiest way anyone can help themselves is by deeper bullet seating. The object being tighter bullet holding... so that chamber pressure is allowed to build before bullet release.

• Deeper seating is always a concern with 147gr since the bullet is physically longer and will collide with the internal shape of the 9mm case. That point remains, so deeper seating has to be done with care.

• I know bullets are almost impossible to get right now, but jacketed always shoot better than plated. I've recently been impressed with RMR Match Winner 147gr, and they fit quite nicely into the CZ chamber. For mixed brass, I'm using an OAL of 1.110" with these.

Current estimate is 3.4 gr giving me an average of 365 fps but with too much ES and SD. Don't have the numbers handy but bring that later...

• 365 fps just can't be right. Maybe 865 ? Please check that.

• In my experience the one advantage Berry do have is the rounded base, which can eliminate the need for a lot of case mouth belling. We did experiments here years ago seating Berry with zero belling and it worked out well. These experiments were "one-off" since we were investigating what the Taper Crimp looked like. We never tried this in full-production mode. But the point is made... belling can be reduced when using Berry.

• My concern with the long OAL and the deep-acting "M expanders" is this: is the bullet being firmly held ? So I'd be looking at exactly how the Taper Crimp Die interacts with the case mouth and neck. A simple flare can be eliminated with a simple TC Die. But when you start distorting the case further down the neck, does the TC Die close that up too ? I don't think all TC Dies reach down the side wall to do that. Some investigation is required.  In other words, the M expanders solve one issue, but did they solve one simply to create another ?

• Working on the above, I might want to go only with a simple 0.353" expander and slight flare. Then, if seating without disturbing the plating was an issue,... maybe a Seating Die with a built-in bullet guide... like the Hornady.


I have other thoughts, but I need my coffee now.

 

[SoCal]

Have you double checked to make sure it plunks and spins in your barrel, it could be your barrel requires a shorter OAL?

[Clint007]

Yep, they plunk nice and easy in the barrel and spin and pop up when I shake the barrel lightly. It’s not on the lands.

Wobbly, thank you. Yes, 865, sorry, posted that last night after a full more-vexing-than-average work day. I choose to set the slowest round to be 865, to ensure I make power factor (850) at any match.  I see you guys posting your data and I see single digit ES and SD, and I’m seeing SDs in the 20-30, and ES of 80-90 fps currenty. Accuracy is okay, but I don’t have a Ransom rest to really explore that in detail. But my normal measured freestyle accuracy at 30-50 feet is just fine.

I actually have some of those RMR 147 gr match winner bullets. At least enough to test certainly and use for major matches. But I have more of the 147 gr Berry's RN and will be practicing with those.  If some modest effort to tighten up my ES and SD (the accuracy is just fine, BTW) on the Berrys doesn’t work work, I’ll try those RMRs instead.  But I’m thinking it’s something I’m doing on the press. I’ve quadruple checked my charge drops…I even using a trickler to hand charge 20 rounds with exactly the same amount of powder, using my very sensitive scale, and the ES and SD issues persisted. Of all the variables at play, the expansion process is one I hadn’t looked into the most so that’s the current area of enquiry.  I even checked the concentricity of my expansion plug wondering if I had a lemon or something.  Nope, it’s fine.

I flare just enough to allow the Berry's to not fall off the shellplate as the shellplate autorotates. It is, indeed, a tiny flare compared to what I had to do with coated lead bullets (which I no longer shoot). I am using a Lee Taper Crimp die set to just remove this bell, I mic the case mouth during this setup process and periodically, and all rounds plonk easily into the barrel or a case gauge.

So, do I need to expand at all? Can I just flare a little and skip the neck expansion step altogether? The expansion seems to be adding about 0.002” to the ID of the upper case. That’s what I found…does that sound right?

Wobbly, how deep are you seating the 147 RN Berry then?   Or, rather, what's the proper way to determine just how deep the Berrys 147 RN can seat without pinching the case wall? Take a fired Starline case that accepts the bullet without too much effort, and see where it stops with very light insertion pressure? I can then mark or measure the OAL, then compare that to the push test derived max OAL length.  Up to now I have set the bullet back from the max OAL, but hereafter I can use the other end of that range as my reference point. Maybe 0.010” up from pinching the case wall? 0.015”?

Would very slight eccentricity of bullet seating cause this without affecting accuracy that much?  I modified my Dillon seating anvil to stop dimpling the tip of the bullet during seating, I drilled it out so there is no pressure on the tip but rather on the ogive. My concentricity seems fine, though...

Thanks

C

[Wobbly]

If some modest effort to tighten up my ES and SD (the accuracy is just fine, BTW) on the Berrys doesn’t work work, I’ll try those RMRs instead.  But I’m thinking it’s something I’m doing on the press. I’ve quadruple checked my charge drops…I even using a trickler to hand charge 20 rounds with exactly the same amount of powder, using my very sensitive scale, and the ES and SD issues persisted. Of all the variables at play, the expansion process is one I hadn’t looked into the most so that’s the current area of enquiry.  I even checked the concentricity of my expansion plug wondering if I had a lemon or something.  Nope, it’s fine.

The biggest contributor is not using all the same brass. After that is different amounts of powder and different OALs. Have you actually weighed 30 consecutive drops from your powder measure ? There could be variations.

I flare just enough to allow the Berry's to not fall off the shellplate as the shellplate auto-rotates. It is, indeed, a tiny flare compared to what I had to do with coated lead bullets (which I no longer shoot). I am using a Lee Taper Crimp die set to just remove this bell, I mic the case mouth during this setup process and periodically, and all rounds plonk easily into the barrel or a case gauge.

Well, if it measures and tests good, I really can't improve upon that.

Wobbly, how deep are you seating the 147 RN Berry then? Or, rather, what's the proper way to determine just how deep the Berrys 147 RN can seat without pinching the case wall? Take a fired Starline case that accepts the bullet without too much effort, and see where it stops with very light insertion pressure? I can then mark or measure the OAL, then compare that to the push test derived max OAL length.  Up to now I have set the bullet back from the max OAL, but hereafter I can use the other end of that range as my reference point. Maybe 0.010” up from pinching the case wall? 0.015”?

I really haven't run Berry 147's since I did that testing, and that was 4-5 years ago. So I can't answer your question directly. But read on...

After searching through this much brass...



...I finally found 1 single StarLine case and measured it. It looks like you can seat down to a depth of roughly 0.320" before you get into the wedge. (With Berry, it will actually be maybe 0.040" more than that due to the bullet's base radius.) To get this number I set my caliper to 0.356" and inserted the inside measuring tines. That left a small mark on the case interior where the interior ramp starts.


Then I took my caliper and made a simple depth measurement to the scribed mark.


That means with a 0.670" long Berry bullet (as listed in the Bullet Length thread), you could conceivably seat as short as 1.100" and not even be near touching. Using an OAL of 1.120" would give you 0.300" of bullet engagement, which should be more than enough.

Would very slight eccentricity of bullet seating cause this without affecting accuracy that much?  I modified my Dillon seating anvil to stop dimpling the tip of the bullet during seating, I drilled it out so there is no pressure on the tip but rather on the ogive. My concentricity seems fine, though...

Yes you're correct, however eccentricity is one thing deeper seating works to eliminate. Of course, it could also get out of whack after slamming into the feed ramp.

RN should center fairly well, but you can remove the RN anvil and try a bullet in it by hand. The anvil should not allow any side-to-side.

To check eccentricity on a finished round, simply roll it on a counter top. Eccentricity shows up as a bullet wobble as the cartridge rolls.

[Clint007]

Thank you very much. I will continue.....

[Clint007]

Using a 147 RN Berrys and fired mixed brass and Starline, I pushed the bullet into the cases until they stopped naturally (I and there is a clear and unambiguous stop when you do that). I assume that's where the case wall starts to narrow.  Similar to your test, Wobbly, I found that ~0.300" was the shortest depth before the bullet stopped. There was some variation obviously.  All but one of the 25 cases I tested, if crimped at that point, would be between 1.030-1.070. That's with no setback or safety factor.  I found ONE case (out of about 25) that was more than this, but all were well under 1.100". So by my calcs I can, as you suggested, with a margin for protection, I could go 1.120-1.130" safely

The Lyman M die expands about that same depth, actually...about 0.300".

I ran 19 rounds past a chrono using the M-die expanded Starline brass. This was an earlier batch I'd made up at the original OAL of 1.150" and 3.40 gr of N320 average. I also had a clean gun but put 20 rounds through it before this chrono run. My ES and SD were better than priors but still not super.  I want those single digit values I've seen you all post!

I will next try them at 1.125" and also, probably, a batch of the RMR Match Winners 147 gr and whatever length I determine from research.

SP-01 Shadow
3.4 gr N320
1.150" OAL
Average 878
High 893
Low 858
ES 35
SD 11.3

C

[George16]

As suggested in previous posts, why don’t you try using a single headstamp for your load development? Pick about twenty of your star line brass, load them up by weighing each drop and crimp them just to remove the bell.

I bet you’ll get single digit SD using this process. It’s not hard to get single digit process with N320. It’s the best 9mm powder for my minor loads for competition.

[Clint007]

This was just that, all brand new Starline.  I’ll be using once fired Starline for next run....

C

[Clint007]

Is pushing a bullet into a fired case until it comes to a ready stop a reasonable way to determine where the internal case starts to narrow?

I did this with a couple dozen mixed brass to try to determine the max Safe seating Depth....the range was broad on this mixed brass collection, but based on this, adding 0.015 to the extreme value, I figured I could safely load the RMR 147 Match Winner flat nose to 1.105 and be safe. I added a n additional 0.005 for margin and will test some at 1.110. A]which, I’m very pleased with myself for saying, is a totally independent validation of Wobbly’s Above OAL for this bullet. I already did the push test with same cases and that’ll easily work for the length end.

Yep, with 147 bullets your OAL options tighten up significantly.   

C

[DesertRatR]

How does N320 meter? Just asking, as I know nothing about it. I believe metering consistency matters.

I have not (yet) loaded 9 mm. I have loaded a lot of 200 gr and 230 gr 45 ACP (lead, jacketed, plated) on top of Unique, 700X, Titegroup, and Bullseye. My chronograph data consistently shows Titegroup provides the smallest SD and ES, out of my several barrels. I have also verified by drop test (dropping and weighing 50 individual loads all the same weight, typically 4.0 gr for test purposes, of each powder, then running the numbers on the weight) that TG comes in with the smallest weight SD. It makes sense that lower weight SD translates to lower MV SD, everything else being equal. So if N320 meters well and you get low weight variance I'd look elsewhere for the solution. Just a thought. 

I also load only Starline brass, having learned the hard way to skip range brass. 

[George16]

N320 meters very well. It’s very clean compared to Sport Pistol and TiteGroup. I have done load development for all three powders but chose to stick with Sport Pistol for these reasons:
- N320 is the cleanest while Titegroup is the dirtiest while Sport Pistol is in between
- Sport Pistol is cheaper than N320 yet almost as clean
- Sport Pistol is considered the poor man’s N320 due to its lower price compared to N320 yet has the same qualities
- Sport Pistol was formulated for coated bullets according to the manufacturer, titegroup is too hot for coated bullets

Of all these three powders, N320 has the smallest SD followed by Sport Pistol. I still have about 8# of titegroup but I’ll only load it as a last resort.

Load your 147 as short as you can manage. I load RMR 147 TCFP to 1.101-1.104” OAL for my shadow 2 and X5.

Here’s my chrono data from last year load development.
3.4 Gr N320 @ 1.101-1.104” OAL

HI - 874
LO - 864
AVE - 872
ES - 10
SD - 4
PF - 128.18
OAL - 1.101-1.104

If you don’t like your N320, I’ll trade you my remaining titegroup 

[Wobbly]

So if N320 meters well and you get low weight variance I'd look elsewhere for the solution. Just a thought. 

I quite agree.

• Are you running a return spring on your Dillon powder bar ? You may be simply suffering from lack of "consistent density" issues.



Some people use office rubber bands, but a more permanent solution is to use the stock Dillon powder measure return spring, and soften its effect by adding 3/4" in operational length of small dia, stiff wire. Gem clip, mechanics wire, safety wire, what ever. So if you start with 1 to 1-1/8" length of wire and turn the ends up, you should be good to go. (I'll be glad to make one for you, if needed.) There's probably a Dillon return spring in your spare parts kit right now.

• I know you have a Dillon, and it's a great machine, but you still can't use the first 10 drops because all powder measures need time to settle down to a consistent powder density. Without that, no one can ever achieve consistent powder weights.

• The chrono is also suspect. When was the last time you changed your battery, cleaned your lenses, or tried leaning the chrono toward the light ? Position and strength of the light has a HUGE effect on readings. I used to get better diffused light about 4-5PM, but I realized one day that the surrounding tree canopy has filled in. Now I need to shoot about 1-2PM while the light is coming through the tree tops, rather than waiting on the horizon to do the light dispersion.

Just some ideas.

[Wobbly]

For your reading pleasure....

This thread made me realize that a lot of people did not understand how all this was done. So what used to be an obscure addendum to the Max OAL article has now been moved to a place of equal prominence within the Directory. Take a look.

https://czfirearms.us/index.php?topic=111500.0

[nicky]

Nice job as usual.