9mm loading issues......

[bcp477]

I wanted to share a solution to a problem I have been having lately. In my 9mm pistols, I shoot mostly 0.357" dia. boolits. Mind you, all three of my pistols will do just fine with 0.356"...but , I have found these particular boolits easily available from several different sources (at a good price) ... and they function perfectly in my pistols. They just happen to be designed for the 38 special, or 38 LC, I forget which. They are 125 grain, RNFP "cowboy" boolits, sized to 0.357".

The problem I have been having is that, in roughly 2 to 5 of every 50 I load, when seating the boolits, I get a rather pronounced bulge on one side of the case.....large enough that the finished rounds won't chamber. This is weird, because it only happens less than 10% of the time....and I can't figure out why. I have finally come to the conclusion that it must be due to odd brass. I use range brass exclusively for my 9mm loading, so I get all manner of headstamps. I have tried to correlate the problem to a particular brand....or just the "foreign" brass, etc....but it happens with all the brands I've used.

Of course, I have checked for and eliminated such things as out of spec dies, excessive wear on the dies, etc. It seems to really be a brass issue.

My loading routine includes flaring the brass with a 38 special expander insert (in my 9mm die)....and only using my taper crimp die to straighten out the case mouth after seating the boolits, no further crimp than that.

Since I am unwilling to toss out what are probably several thousand foreign made cases in my stash.....and I don't wish to get into measuring the case wall thicknesses, etc. before loading.... and I refuse to throw out perfectly good ammo (with only a case bulde preventing use)....I came to the conclusion that the best way to deal with this is to adopt a "fix" AFTER the rounds are loaded.

It dawned on me that running the offending loaded rounds part way into an appropriately sized case sizing die might "iron out" the bulge, without squeezing the cast boolit down in diameter, so as to render it undersized. Obviously, I could simply run the loaded rounds into a 9mm case sizing die (with the decapper removed)....but that would SEVERELY swage down the bullet. So, that is no solution.

But, how about a die for another cartridge, that has a suitable diameter ? A search of my loading manuals seemed to indicate that a 38 ACP die might be just the ticket. The spec'd OD of those cases is 0.384". Running a bulged 9mm round part way into such a die might well, I reasoned, iron out the bulge enough to allow chambering, without too much squeezing of the boolit.

Long story short.....it works ! The 38 acp die, with decapper removed, fixes the bulge with only less than 0.001" change in the boolit dia.

I have now "fixed" all of my saved up bulged rounds....pulled some of the boolits and measured them....and test fired about 50. Seems I stumbled on a pretty good solution, which only cost me $26.

Anyway, there it is......hopefully it will be of help to someone else with the same problem.

(Sorry, but I have no pictures to post.....as I forgot to take any. I just "fixed" all of my wonky rounds, without thinking of saving any for pictures.)

[Ed_Shot]

Do you measure the length of your brass "before" you prime it? I separate my 9MM by head stamp and trash any shorter than .747. It's not uncommon to find some at .740. The short brass is not getting expanded "as much" which will cause problems when you seat.

[bcp477]

Hmmm, interesting. I'll give that a look.

Thanks.

[Bohica793]

A pronounced bulge on only one side of the case makes me suspect a boolit that is out of round or not sized properly.

[bedbugbilly]

How are the slugs when you seat - any chance they may be tilted a touch and when you seat, a bulge forms?

I cast a Lee 356-120 TC to load in my 9mm. they drop at around .358 so for the 9mm, I size 'em to .357. (For 38 Spl. I load them "as cast"). You don't mention what dies you are using nor what your OAL is that you are loading to..

I'm just thinking "out loud" so bear with me . . . If you have 9mm cases (trimmed or not) that are different lengths - when you expand, the mouth should be expanded equally around the circumference. Naturally, a longer case would be wider at the top of the mouth over a shorter on. If your slug enters the case mouth of the shorter case "equally" - i.e. not tipped - it should still be equal all the way around, not causing a bulge. (in theory). That is what is making me wonder if you slug is being seated square to the case mouth or if there could be a slight "tilt" to it?

I flare my cases the very minimum to just let the slug "stick" when placed on the mouth and then I seat. Even so, on my 38 spl. when I load it with a longer RN 160 gr lead slug cast in an original Winchester mold, I have to watch to make sure that the slug is "in line" with the case and not canted in any direction before I move it up into the seating die. I have never bulged a case but I can see how it could happen.

I would also check the slugs just to make sure they are concentric and not off spec. Take a number of measurements. If you can pull one out of the bulged case, see if there is any indication that it could be out of spec. At least you should be able to eliminate that as a potential problem.

U use Lee 4 die sets for my 38s and 0mm. (Please don't think I'm advocating that they are better than any other brand - everyone has their preferences.) I seat and then crimp so it is two different operations. If I read you post correctly, I think you are doing that as well. A lot of people don't like Lee's FCD but I have never had a problem with it "swaging" my lead slug diameter down. The carbide mouth of the FCD insures that the loaded cartridge is within specs. Once in a very great while, I have a loaded cartridge that I may feel a little resistance when I move it up in to the die, but I find no evidence of "swaging" the slug and every cartridge is checked in a "cartridge gauge" before I place it in the box. The die gives a nice taper crimp - on the 38's, using the FCD in that die set, it gives a nice rolled crimp.

You may have done it already, but checked the rounds that you have the bulge in carefully to see if there is any chance the slug was canted when going through the seating die. I use "range brass" as well and I don't separate by head stamp - I just load them up. Another thing to try, is since you are using a 38 spl expander in you 9mm - try putting the 9mm expander back in and see what happens.

Good luck and I hope you can get it figured out. A Lee FCD isn't that expensive (Titan has good prices on them) and you might want to try one out as your crimp die. If you don't like it, you can always peddle it to some on here.

[garym1a2]

I use the Lee factory crimp in 9mm and on 40's that don't pass the chamber test I run.

[mj2evans]

Is the bulge only with millitary brass? If so I think mil brass is a little thicker in 9mm vs commercial.

[bcp477]

I originally thought that the problem was canted boolits.....seemed obvious that it must be that. That is, in part, the reason I use the 38 special flare insert. That makes it possible to insert the boolit with (only) finger pressure, up to the lube band. Thus, I can ensure that they are straight ...and they stay positioned, until they enter the seating die.

I still think it possible (perhaps probable) that the problem is canted boolits - perhaps the few that exhibit the problem are getting canted as the boolit seater plug makes contact with the boolit nose. I'm not sure, but I intend to keep at the problem.

The problem was worse (that is, it happened more often) when I was still using the 9mm flare insert.

Since the 38 acp die is working well to fix the problem rounds, I am no longer as concerned about it as I once was. Nevertheless, I will continue to work on the problem.

Thanks for the ideas and suggestions.

[runfiverun]

makes me suspect you need a tick more flair and to hold the boolit straighter when going into the die.
the bulge is from the tipped boolit being straightened out on it's way down.

[bcp477]

More flare I don't know about......any MORE flare and the cases will be big enough for 40 cal boolits. But, I think you are on to something as regards the bulge.

Here is the scenario :

1) The boolit is placed into the mouth of the case, as straight as possible. This was much more difficult when I used the 9mm flare insert (as the flare was much less). Now, with the larger flare, it is easier, but not foolproof. This accounts for the fact that the incidence of the problem has decreased in frequency, after going to the larger flare insert.

2) The round is slid into position in the shellholder, on the press, for final seating. If not careful, the base of the round in the shellholder can be slightly out of position, such that the CASE (and thus, the boolit which was inserted straight) are contacted by the seater plug at a slight angle. This then pushes the boolit into a tilted position (relative to the case).....after which the case straightens up as it enters the seater die body (which it must do). But, the boolit is now canted or tilted, relative to the case. Seating the boolit then causes the bulge, just before the boolit straightens up as it reaches the fully seated position.

3) This scenario is not helped by the fact that I load with a hand press, so the whole setup is really never in a true vertical orientation in use.

4) There is just enough play in the fit of the case in the shellholder (which must be there to allow smooth insertion and withdrawl of the brass)....to allow everything to get slightly out of kilter sometimes.

5) Ah Hah !!! It all starts to make sense...



So, the obvious solution is either a mounted press.....or much more care in the operation of seating the boolits. As a stop gap, I have the 38acp die to fix my screwups.

A possible improvement might be a seater plug with a flat end, rather than the cupped end that is standard (but only for flat-nosed boolits, of course).

Dagnabbit, things were certainly much easier when I was loading only 38 Special...and shooting only revolvers !!!

Ah........the "good 'ole days".....

[Larry Gibson]

Try backing the FL die off so the cases are sized just enough to chamber in your pistol. No need to FL size completely.

Continue to use the .38 SPL expander with the .357 sized bullets.

Use a bit epoxy in the seating stem to make the contour fit the cowboy bullets FP concentrically.

Larry Gibson

[captaint]

I was gonna say - Isn't anybody going to ask about the seater punch?? Does it match the boolit ??
Has the OP looked ?? Just a random question.... Mike

[bcp477]

I was gonna say - Isn't anybody going to ask about the seater punch?? Does it match the boolit ??
Has the OP looked ?? Just a random question.... Mike



The seater plug indeed does not match the nose shape of these particular boolits. The boolits are round nose/ flat point (with a moderate sized meplat)....and the seater plug is the standard type, with an internal shape very similar to a parabola. Of course, the plug was designed for predominately round nose boolits, which is the shape original to the 9mm cartridge.

I do not want to modify the (only ) seater plug I have, because I do load RN pills as well. So, I have ordered a spare seater plug for my seater die, which I will fill in with epoxy, to make it more suitable for flat nose boolits.

Thanks everybody for your help. I think that the problem is now in hand.