Pushback

[chief99]

Starting loading 380's today for my wife's P238. Loading 95 gr. jacketed Mag Tech bullets with starting load , 2.9 grs. of HP38. Shot 21 rds. , loads cycled good , no problems. Oal, 0.985 . Problem , at least 3 rds. seem there was to much flare and I got a push back problem. I'm using a taper crimp and FCD. Checking every round for push back. Using once fired brass . Bullet seating die is set for the right Oal but does not feel like it getting enough crimp on the bullet.

 

[blarby]

Bench test at 5 and 10.

Or, bench test them with one good hard push, and measure what should be zero pushback.

 

[Walkalong]

Neck tension holds the bullet in place in an auto cartridge like .380, 9MM, etc. No amount of crimp will cure it, and excess crimp can hurt neck tension.

Reduce the flare to a minimum. "Crimp" just enough to remove the bell, or maybe .001 more.

If you still get setback, try it without the FCD. If that doesn't help, try not flaring them. If you don't get setback then, the expander is too large. If you do still get setback, the sizer is too large.

 

[gahunter12]

^^^^^This. I agree with Walkalong 100%. Case tension is the key.

 

[rcmodel]

+1 too.

Your most likely problem using Lee dies is the powder-through expander is not only rough as a cob, but also too big.

Take it out, and work in down in a drill with Emory cloth until it is only a hard slip fit inside a sized case.

That will insure you are not over-expanding the sized brass and losing all neck tension.

In any case, there is no possible way you should EVER be able to push a seated round deeper in the case with your bare hand without hurting yourself trying.

The 'push test' against a bench is a total waste of time.
Nobody can push hard enough with bare hands to test proper neck tension.

rc

 

[Rule3]

In any case, there is no possible way you should EVER be able to push a seated round deeper in the case with your bare hand without hurting yourself trying.

The 'push test' against a bench is a total waste of time.
Nobody can push hard enough with bare hands to test proper neck tension.

rc

How else would you test them?

 

[joneb]

I have extra flare/expander stems for a few cartridges that I load, some get modified a bit to fit my needs.

 

[rcmodel]

How else would you test them?

1. Make a mark around the bullet/ case mouth joint with a sharpy pin.

2. Then chamber that round 2-3 times and see if the ink mark is still there.

If it is inside the case, you have a problem with case neck tension.

But I can assure you that the force needed to prevent bullet set-back in a semi-auto pistol is much more then you can test with your bare, tender fingers pushing on it!!

The difference is like pushing a hammer back an inch with your thumb.
Or hitting your thumb with a hammer from an inch away.

You can push as hard as you can with your thumb without it hurting on a bullet.

But that is a different force then when the slide slams the round out of the mag into the feed ramp, going faster then you can watch it move.

rc

 

[rfwobbly]

I'm using a taper crimp and FCD.

With taper crimp, some is good, but more is NOT better. On top of everything else already mentioned above, you need to set the FCD aside. There's no need to 2 taper crimp operations.

 

[moxie]

rc,

Agree the "press test" is not as good as actually chambering rounds. But the press test, at least for me, has the virtue of being easy to do and effective. If my ammo passes my press test, there's never been any setback. To each his/her own.

chief99,

Best advice is toss the FCD off the closest bridge. It seems almost axiomatic that the FCD is involved when people have these neck tension issues. Do as Walkalong says in post #3. Flare just barely enough to allow the bullet to sit in the case. The "crimp" step should actually be just removing that flare, not really crimping the case into the bullet. Just enough to allow the round to chamber easily. The "plunk test" is a good way to make sure.

 

[Rule3]

I put on a leather glove and push with the heel of my hand, then hit my hand with the hammer

Seriously though the pushing with the hand on the bench certainly has been a long time "suggestion" on the interweb.

 

[UziLand]

I prefer to tap test. That is taping the bullet (about as hard as I can with one hand) on soft wood. Of course this doesn,t include soft points. I have never had a problem with pistol cases. Have had problems with 7.62x39 due to the violent action, especially with xtreme bullets which are short and have no cannelure. I see no reason to double crimp a 380 and agree it could be your problem.

UL

 

[steve4102]

Your OAL is to long.

You do not have enough bullet to case contact.

Reduce OAL and increase neck tension by seating the bullet deeper into the case.

 

[Henry45]

What Steve said.. I load for my wife's P238 with 231, 2.9-3.1 g and OAL is .970. Never a problem with setback.. Do what RC said. Mark the bullet, and chamber it. You should be able to see where the problem lies..

 

[gamestalker]

I actually came up with a method of measuring lbs. of neck tension. Using a dedicated SS press, I use my trigger scale and hook it at the same marked spot on the handle of the press. Then using the seating die, I measure how many lbs. it takes to move the bullet on a several pieces of once fired brass.

Obviously this works for measuring neck tension, but I haven't found a weight that represents brass with inadequate neck tension yet. I need to give this some more thought and research before I can fully apply it as a functional method.

I'm also using the same process to measure primer seating resistance, but again, the only aspect I've established, is how to weigh the amount of resistance for a good primer pocket, and have yet determined what weight represents a loose pocket.

But at least I'm part way there.

GS

 

[Peter M. Eick]

It occurred to me that I could do a very simple test using a bathroom scale and my drill press. If you chucked up the round in the press in a shell holder or even just in the chuck, you could put the scale on the work table and then simple push it in using the press.

I never thought of doing that before. I will have to experiment next time I pull the machinist vice off the drill press.

 

[Walkalong]

Iowegan over on the Ruger forum has a neat way to check neck tension.

http://rugerforum.net/reloading/65863-lee-fcd-pistol-not-rifle-virtue-vice.html#post818426

I ordered some springs, but haven't set it up yet.

 

[moxie]

Agree with his conclusions re the evil nature of the FCD. As I've said, toss them off the nearest bridge. Even if they might (!) work OK with jacketed bullets, what's the point of re-crimping?? As for lead...squish.

Do not agree with his statement that the crimp contributes to 10% of the case neck tension. It doesn't contribute to tension at all. Rather, it is a totally separate mechanical operation that physically pushes (crimps) the case into the cannelure, helping to prevent movement of the bullet. Case neck tension is the friction fit that occurs because the case's internal diameter is a bit smaller than the bullet's outside diameter. The crimp might add 10% or so to the process of keeping the bullet locked into place, but not via case neck tension. Crimp works in addition to tension. As he does point out, overcrimp ruins tension and can buckle the case.

Despite this technical disagreement, the author gets big kudos from me for doing such a thorough test. Nice work!

 

[steve4102]

Even if they might (!) work OK with jacketed bullets, what's the point of re-crimping?? As for lead...squish.

Have you used the Lee Factory Crimp die in the 380 ACP, or are you just repeating what you have heard/read?

I have and I do, never anything even close to a "Squish".

If you are getting your 380 lead bullets "Squished" with the Lee Factory Crimp die, then you are either misusing the die, or it is defective. If you do not have a 380 FCD then.....

 

[moxie]

Never have had a .380. Not sure why the dies for it would be different. Are you getting decent accuracy? Happy it's working out for you.

 

[steve4102]

Are you getting decent accuracy?

This is my wife's new Kimber Micro at 15 yards rested, using Crimson lazer sights and Lee 102gr HI-TEK coated lead. Crimped with the Lee Factory Crimp die.



These are the bullets.

 

[moxie]

Obviously working for you! Thanks.

 

[chief99]

Thanks for all the advice on my pushback problem with loading the 380. The problem has been solved. I took Walkalong's advice and did away with the flare and the FCD , then I did the RCmodel sharpie test on several rounds 2 0r 3 repeats. Walla ! No pushback . Shot a box today , cycled well and very accurate. That's why I love this forum . You ask a question and you learn . Thanks !

 

[PapaG]

Had rounds push back over time at work....loading up my LCP each day. Noticed after a week or so that the top round looked a little short. Learned to rotate the rounds in the magazine so that none were used more than twice and then would take them to the range and recycle (shoot) them. These were factory rounds.
Mentioned it on another forum and was flamed as it "couldn't happen". Won't mention the forum but they rarely take "the high road".