Bullet setback help pls.

[Thompsoncustom]

I'm having problems completely eliminating bullet setback in my lee 102gr bullets. bullets are sized to .3565 and even with flare set to the point of shaving the bullet the more I chamber the bullet the more it just keeps pushing it further down.
9mm OAL is 1.045

Any ideas on what I'm doing wrong? Thanks Dan

[Dan Cash]

canlure the cases to meet the base of a fully seated bullet. Either that or get a different bullet. You don't say what pistol you are feeding so perhaps there is something there that could be adjusted. Does the pistol do this with full metal jacket bullets?

[prs]

9mm must be a honey to reload. Sounds like your brass may be springing back after full length resizing or maybe your internal sizer is a bit too large. In 38/357, 45 Colt, and 45ACP I carefully set the depth of the internal sizer to that when the boolit is seated to get OAL its base is sitting right at the end of the internally sized area. That sort of leaves a slight wasp-waisted area to help resist bullet set back. Not at all sure that can apply to 9mm though.

prs

[Thompsoncustom]

Gun is a CZ 75b and I don't have a problem with any of the other bullets I reload/cast this is the only one with set back problems.

[MtGun44]

Size bigger.

Bill

[jimb16]

+1 size larger. You'll get better "neck tension" that way and it should stop the setback.

[prs]

Is there a handloader's device that canalures the cases as described in second response. That is pretty much the same principle as what I described in the third response. Anyway, a better boolit to case fit seems to be the need.

prs

[fredj338]

Are you sizing properly? What brass? Check the dia of your expander, it should be no more than 0.354" or a bit less. Some brass, like RP, very thin, & setback can be an issue. Over crimping can cause a loss of neck tension. The taper crimp should just finish the case off, no more.

[243winxb]

Lee U Carbide Small Base Sizing Die 9mm Luger. http://www.midwayusa.com/product/386755/lee-u-carbide-small-base-sizing-die-9mm-luger "These dies undersize brass between .002" and .003" smaller than other Lee Carbide Sizing dies."

[Wayne Smith]

The Lyman M die, properly used, will create a ledge for the boolit to sit on to make sure it is straight. This may solve the problem. Otherwise I agree, check the size of your expander.

[Thompsoncustom]

Size bigger.

Not an option. .3565 is as big as I can go without having problems chambering. This gun has a really tight chamber.

As far as crimp goes for the longest time I didn't use any crimp at all and now I use just enough to remove the bell in the case and that's it. I thought about adding more crimp to help hold the bullet but I've always relied solely on neck tension.


Lee U Carbide Small Base Sizing Die 9mm Luger. http://www.midwayusa.com/product/386...-die-9mm-luger "These dies undersize brass between .002" and .003" smaller than other Lee Carbide Sizing dies."

Ya I've heard about the U dies and that was one of the first things at came to mind after I ran into this problem and probably the route I'll end up going I just wanted to make sure there wasn't something I was doing wrong or missing.


Are you sizing properly? What brass? Check the dia of your expander, it should be no more than 0.354" or a bit less. Some brass, like RP, very thin, & setback can be an issue. Over crimping can cause a loss of neck tension. The taper crimp should just finish the case off, no more.

I sure think I'm sizing correctly but I can't say for sure. Using all Lee dies and the sizing die almost hits the shell plate when at the top of the stroke. Brass is all mixed. I'll take a look at the expander plug as I have never tore that die apart before.

[MtGun44]

Then polish down the expander to a couple thousandths smaller than it
is now. Proper taper crimp will help, but neck tension is necessary.

Bill

[243winxb]

The bearing surface may have an effection on your 102gr bullet, if a lot shorter than the other bullets. The 9mm case tapes, so the deeper you seat a bullet, shorter COL, the more neck tension you will have. But to deep, and you may have feeding problems. This is when sizing with a carbide die. http://i338.photobucket.com/albums/n420/joe1944usa/Firearms%20%20and%20%20Reloading/9MMLuger1.jpg

[mroliver77]

Try "blueprinting" or documenting every aspect of your load. Measure your fired brass, resized brass, after the expander die has been used, the expander die etc. Something is out of kilter and putting it on paper might help you to see it. Most reloaders just assume that the die maker has done all the setup and while true the die needs to work on all brass bullets and guns. Most dies oversize brass then rely on the expander to push it back open. The less we move the brass the better.

You might want to sort your brass too at least until you figure this out. It might shed light on your problem. .002 neck tension really holds on to a boolit if all else is correct.


J

[Thompsoncustom]

Pulled the expander plug and it appears to be .354 is that ok? I took some 400grit and just polished it a little more to make it smooth than anything else. also tired adding a good amount of crimp but that made no difference.

Is there a measurement I can safely take my expander plug down to that it will still work fine on all 9mm bullets?

I think I'll take you advise Mr.Oliver and write some more of this stuff down, The brass doesn't seem to matter as once fired or 10+ fired brass they both seem to have setback. And alot of setback I'm not just talking a thousand or two if I keep chambering this round it will pound it all the way back into the case.

Resized case measures .372 on the outside close to the mouth, can almost start the bullet just needs a touch of flare before it will start without shaving.

[Thompsoncustom]

Well made some progress. Turned the expander plug down to .350 and added .005 crimp and now I can chamber the rounds once without bullet set back. So it appears i'm headed in the right direction, now can I take to much of the expander plug?

[mroliver77]

You need to measure the ID of a sized case. There should be at least .002 tension the whole length of the boolit body. Is the enough straight case to hold your boolit? Is your expander straight? Any chance of borrowing another set of dies?
J

[Thompsoncustom]

well it's .349 to .350 the length on the bullet and get smaller farther down but this bullet doesn't seat past the .349 point. This is on a resized case but not expanded.


is the enough straight case to hold your boolit? Is your expander straight?
I'm not really sure. Might be able to get ahold of another set of dies from a cousin a state away just won't be anytime soon. I could always buy different dies but I do want to just throw money at it if it may or may not work.

The bullet is seat .174 in the case according to quickload.