9mm Issues

[RL-Photo]

I'm having some trouble with crimping/neck tension on my 9mm loads. I am using 124 gr rn extremes in a Hornady LNL AP with Hornady taper dies. I have included pictures below of my cases. They are sorted by headstamp but I am having trouble/inconsistencies across most brands. Standard process of tumbling brass, first stage decaps and resizes, second stage expands case mouth to ~.384, powder charge, seat/crimp die to 1.150". Im having 2 problems, the first is inconsistent COAL's, ranging from 1.147-1.160+, I have measured the xtremes and they aren't that inconsistent in lengths. Second problem is the major one, as you can see below I am getting major setback when doing the "press test". This problem is intermittent, I can load 500 with no problem, then can't get them to hold tension. I have to push pretty hard to get them to move, but others won't move if pressed firmly. The measurement at the case mouth after seating/crimping is consistently .377" which is very close to factory rounds I measure, and smaller than the .380" listed in my manual. I have tried resetting the dies step by step as the instructions say. If I try and bring the crimp down further it starts to look more like a roll crimp. Needless to say I am quite frustrated at this point. I've had this issue with my .223 as well. Any held would be appreciated...

 

[WILWORK4GUNS]

Over expanding the case mouth?
It should be fairly snug seating the bullet - even before the crimp.
Looks like there is a bit of outward flare in the last pic.... Which would be over flared.
Try backing off the expanding die until you can just get the bullet to press in without shaving the jacket off. This will cause less stress on the brass as well.
I use a collet crimp on all rifle cases.

 

[bohica793]

Over expanding the case mouth?
It should be fairly snug seating the bullet - even before the crimp.
Looks like there is a bit of outward flare in the last pic.... Which would be over flared.
Try backing off the expanding die until you can just get the bullet to press in without shaving the jacket off. This will cause less stress on the brass as well.
I use a collet crimp on all rifle cases.

^^^^This. The picture clearly indicates that the expander is is overflairing the the case. I think if you measure, you may find the overflaired case is slightly longer than the other as well, which could be exaggerating the problem.

 

[TennJeep1618]

I agree with both above. Flare the cases just enough for the bullet to sit upright on the expanded case before seating and make sure the brass doesn't shave the bullet while seating. I also like to use the Lee Factory Crimp die for handgun rounds, as it will "resize" the case after seating the bullet. Also note that plated bullets can be very sensitive to over-crimping. That's one of the reasons I went to coated bullets.

Just FYI, you'll still probably see .003-.005" variation in COAL, but it won't matter.

Also, here is an interesting podcast about sorting by headstamp: http://www.triangletactical.net/2016/07/31/junk-science-sort-pistol-brass-headstamp-reloading/

 

[ChrisC]

Flare looks fine. Might be a sizing issue. Resize the problem round again making sure the sizing die has only about a paper thin gap between it and the shell holder. It is crucial in a tapered round such as the 9mm. From looking at the picture, it looks like a partially sized brass. It is also a good idea to check the carbide ring for cracks once in a while

 

[SCTaylor]

Also note that plated bullets can be very sensitive to over-crimping. That's one of the reasons I went to coated bullets.

In my experience both are sensitive to over-crimping. Did you find coated are more forgiving?

RL - It appears your brass is not being sized far enough down, as others noted. If you look at the change in coloration at the bottom of the case, the color change is 7 mm from the bottom of the case. With my 650 & Lee sizing die, it is only ~4-mm above the bottom of the case. 9mm is a tapered case, if the die is not going down far enough then the full resizing operation is not complete, leaving the neck too "open". I also shoot for a .375-.376 crimp. But the crimp is dependent on the bullet, load a few with tighter crimps, pull the bullet to see if the plating is indented (proper) or cut (no bueno).

The LNL AP is a 5 station tool head correct? Any reason you are running the seat & crimp in one die?

 

[16gauge]

Definite short sizing at least on the case pictured. I agree with Tenn Jeep the Lee factory crimp die is invaluable. Easy to set the amount of crimp and best of all it resizes the cartridge as it comes out of the die, so if you over crimp it will smooth out the case and insure that it will feed with no problems.

 

[RL-Photo]

I'm pretty sure the suggestions on sizing die not being in the right position could help, though it's strange that I haven't adjusted that die in sometime and hadn't run into that problem all the time. As far as over expanding the case, I knew it was possible to do this and it would shave the case but I would have thought that the taper crimp would close the bell back. Does it only close the case back in a small area and not all the way down the case? As far using a seating die and a crimp die separately I am certainly not opposed but that's how the set was sold, wouldn't have guessed it wouldn't have worked. TennJeep on those Lee FCD's, I thought they would actually crimp the case which could effect the bullet indexing on the casemouth?

 

[oneshot]

What expender are you using . I have had this before and it was the expender. just my 5 cents

 

[RL-Photo]

I am using the hornady expander die that came with the 3 die set, I actually made the flare a little greater on the because I was thinking my problem was the bullets were getting swagged by not having enough bell. I will back it out a little tonight, lower my sizing die and update the pictures and measurements

 

[bobinbusan]

Keep us in the loop of fixing your problem, thanks :hat:

 

[RL-Photo]

So let me start off with thanking everyone for their input, really appreciate the participation and info. I was able to get back on the bench tonight and here is what I did and found... I tried only changing one thing at a time to help figure out what had the greatest effect. I started by reducing the flare on the expanding die to .380 (wall thickness averages 0.011) which was interesting because thats what the case measured before being resized. Just changing the flare did not fix my problem so my second change was adjusting the sizing die to as small of a gap between the shellpate and base of the die as I could. I think this is where I found my fix (until I get the Lee FCD) This brought the OD of the cases to .371" (again wall thickness average of 0.011). I brought the crimp in a little more than I had it before in order to pass the press test, OD after seating and "crimping" was 0.373". Ironically this process seemed to decrease my std. deviation of COAL as well. I have included pictures of some bullets I pulled from the final loads that were able to pass the press test, sorry for the noses being mangled I don't have a pullet puller, had to use pliers. I have a slight ring that I am assuming is the crimp in the bullet. For comparison I pulled a bullet from a 115gr WCC WB and a 135gr WCC HP. There is no sign on crimp on the WB but a significant crimp on the HP. I am still going to get the Lee FCD and run all of these through them to smooth everything out. But overall am happy with such a quick fix, crossing my fingers...

 

[Va boy]

I have read 9mm cases should be segregated by mfg as they are more finicky than other calibers. I have noticed WCC cases to be thicker or heavier than say, Federal, etc. I personally don't separate my cases and have no problems. As someone said earlier, expand the case mouth only enough to get the bullet to sit upright. I've noticed on my LNL AP if I dont keep cases riding along in all stations, my last couple rounds' COAL differs from the others, I guess due to the tipping of the shell plate as all pressure is on one side only when the last few cases come around. Also, watch the shell plate center bolt as mine loosens occasionally

 

[Mouser]

Maybe I'm not understanding something...I run a Lee turret and have a 4 die set...the 4th die is a crimp die so it is just a matter of setting it to the proper depth...so are you running a 3 die set? I do flare my cases slightly to accept the bullet easier and the amount of flare should not matter except that flaring shortens case life...the more the flare, the fewer loads you can get out of a case. The only thing that could/should impact OAL is not seating completely or looseness in your dies...cant think if anything else. Really, once you lock down you should be golden and very consistent....looseness is what Id be looking for first, alignment second...make sure your press is fully extended each and every time and you should be consistant, even if you are off...it should be the same on every case to .001".

Also, keep in mind that one can introduce variation with your measuring devices too...calipers have to be dialed to a consistant spot and perpendicular to the surface you are measuring....this is actually difficult on OAL measurements and I find that I have to be careful and precise as I can get a longer reading if my calipers are off a little bit...and rezeroed periodically to ensure you don't have slippage in the calipers giving you false readings... a micrometer can be over tightened and is even more difficult not to introduce human variation but most people I know use calipers, not micrometers.