9mm Blazer and FC brass -- poor neck tension and set-backs .

[Samgotit]

Is it me or the brass.

As of late I have notice that Blazer (about 80%) and FC (about 50%) brass will keep way to little neck tension. I put all of my reloaded ammo in 50 or 100 round boxes nose down. I check the primers and push down on each round for set-backs. Blazer and FC fail that finger-pressure test by the percenages listed aboove. With WW, R-R and all the other common brass I have never had a problem with neck tension.

I have randomly measured the bullets I'm using and none are below diameter, and the case mouths after sizing measure fine as well.

I thought it may be a die problem, but I switched out a Hornady die I was using with a Lee, then again with an RCBS. Same results. I tried all three of those dies screwed right down to the top of the shell plate.

Any idea. I'm loading on a Lock-n-Load AP

 

[john16443]

More information may be necessary to offer help. From what I can gather, your sizing die may be doing it's job, but what about your expanding die, seating die and crimping die?

Revolver or semi-auto?



What type of bullets are you trying to load?

What brand of sizing die are you using?

Are you expanding the case mouth prior to bullet seating, and if so, with what type/brand die and how much?

I also use a LNL AP press, are you using a PTX type insert in the powder measure? In other words, are you possibly adding more flare?

What are you using for a seating die? Are you crimping and seating using the same die? If so, I suspect this is where you're having trouble. If you can crimp using a separate die for semi auto's you'd be better off.

What is the final diameter of your round at the top of the case after your crimping operation? Are you crimping more than just to remove the bell?

My thoughts so far are that you may be overcrimping the bullet, and in doing so, inadvertently DECREASING neck tension, not increasing it.

 

[rcmodel]

Measure your expander rod or plug.

For a 9mm, it should be about .3525" to no more then .353".

If it bigger then that, chuck it in a drill and make it so with an emery cloth strip.

rc

 

[kingmt]

I think you may have asked a question to something I ran into last time I loaded 9mm. I never checked to see what happened tho but it was all FC brass that had poor crimps tho.

 

[Samgotit]

I'll get to more measurements tomorrow. It's best I quit for tonight. :banghead:

-------------------------

I just replaced my expander die with a new RCBS that measures .352". I set it to give just the lightest bell.

Same thing.

I went on to check the Hornady seater/crimp die before I replaced it with an RCBS. I reset the Hornady by the book.

Same result with Blazer.

I then replaced my Hornady seater/crimp die with a new RCBS and went exactly by the directions (all the way to the case, then one full turn up. I did it will a Blazer in the shell plate, too. The crimp just removes the bell.

Still get finger-pressure set-backs with Blazer.

All other brass works with no problem.

 

[kingmt]

Your not crimping. Try reading it again.

 

[Samgotit]

I am crimping. The bell is gone. I need neck tension, not a crimp. The crimp does not replace neck tension.

All final rounds end up very near .378" at the case mouth regardless of brass.

---------------------

To answer some of the above questions.

No PTX
Precision Delta Bullets. They measure fine, though.

 

[beatledog7]

Brass is more elastic than lead. When you seat a bullet, the action stretches the brass and to some degree compresses the bullet. If the brass is a bit hard from being worked and the case is not flared/belled enough to allow the bullet to go in with minimal squeezing, the bullet retains its compressed size but the brass springs back, causing a loss of neck tension.

So it's a balancing act. With work-hardened brass, a little more flare can actually enhance neck tension by squeezing the bullet less and also springing back less.

It might be worth a try to pull bullets from a few of the culprit brass and see how much they're compressed. You may be able to achieve a bit more flare, but then again you may not. The brass springs back a bit in the flaring process as well.

 

[1SOW]

Try sizing a few and carefully load them with NO flare, and retest for setback.

What specific bullet are you using??

One thing those headstamps have in common: 9mm FC, Blazer (and Speer) brass are a lot softer than WIN, R&P and PPU brass.

 

[IMtheNRA]

I had the same problem with Speer and Blazer 9mm brass. I use a Hornady LNL press with Hornady dies. I could push the bullet into the case in about 50% of the cartridges loaded with Speer and Blazer.

No problem whatsoever with any other headstamps that I used, including Federal.

I suspect that Blazer and Speer brass are thinner than most other types.

 

[kingmt]

all the way to the case, then one full turn up. I did it will a Blazer in the shell plate, too. The crimp just removes the bell.

If you turn the die up off from the case then your not crimping. If the die doesn't touch the case mouth then it can't crimp it. All your doing is ironing the bell out.

 

[gamestalker]

I don't work with much Blazer, but I do run a lot of FC brass in both .40 & 9mm. I've had a couple now and then that have had marginal neck tension, but only after having been reloaded multiple times, and not specific to FC. Also, I only load jacketed.
As a matter of fact, I recently loaded 250 rounds of .40 of which all was FC, and 250 rounds of 9mm a mix of Win., RP, and FC and some Speer and Starline brass. My Son came back to me with one .40 that had set back, but that brass was pretty much on it's last reloading, so I was actually kind of surprised only 1 out of 250 had a problem. Of the 9mm mixed head stamps, none had a problem.
I think the best thing you could do is, follow RC's advice, he's got the scoop on helping you find the culprit through process of elimination.

 

[777TRUTH]

Had the same problem with 9mm Hornady sizer die. Hornady blamed everything except the die.

Switched back to my Lee 9mm dies and life is good again.

 

[1SOW]

If you turn the die up off from the case then your not crimping. If the die doesn't touch the case mouth then it can't crimp it. All your doing is ironing the bell out.

Exactly what your supposed to do with 9mm Luger.

 

[Steve C]

Not putting on enough crimp. Removing the case bell is not crimping. Add a little more crimp by turning your seating (or crimping die) in a 1/3 turn or so and then test the results with thumb pressure to the back of the case and the nose into the side of the bench. Repeat increasing crimp until you are satisfied with the bullet hold.

 

[PO2Hammer]

Too much expansion and/or flare.

I use 9mm FC brass quite a bit. I skip the expanding/flaring die altogether and go straight from sizing/priming to bullet seating. No crimp because it's not needed. Bullet tension is excellent.

I think if you let the bullet do most or all of the case mouth expanding you get the best ammunition overall and bullet tension.

If you're going to use an expander die, do like RC said and make sure it's not too big.

I notice 9mm FC brass sizes with much less force than Win and other brands. Maybe it's on the soft side or the thin side, that could be adding to your trouble.

I would recommend making dummy rounds, no powder or primer, and feed them into your gun from the magazine and measure them before and after for set back. I think it's a lot more realistic test for set back.

 

[918v]

Not putting on enough crimp

Crimp does not hold bullets in place.

 

[[email protected]]

I have ran into the same problem with remington brass in .380 and 40s&w. I tried not flaring the brass, as well as an overdose in crimping but I couldnot get enough neck tension to keep the bullet from being set back. I now save remington brass for oversized cast bullets. I have heard that remington brass is thinner and when it is resized the internal diameter is larger. I mostly load 40s&w with either federal or cci brass using berrys or cast bullets and I never had an issue with too little neck tension with them. The remington brass I was going to use in 40s&w was nickle plated and I was going to load some hornady xtps. All my pistol dies are lee dies. I also load on the lnl press. As some have said, crimp is not a substitute for proper neck tension, in a semi auto round. From what you said it seems that you sould set that headstamp brass aside to use with cast bullets that run a little larger in size. The bullets I used for .380acp were berrys and although they are advertised as being .356 in diameter, I was unable to get enough neck tension with remington brass, but win brass worked fine. To answer your question it is my opinion from what you said it is your brass and you get an A++ for checking your ammo for problems before firing it.

 

[1SOW]

Steve C:

Removing the case bell is not crimping. Add a little more crimp by turning your seating (or crimping die) in a 1/3 turn or so and then test the results with thumb pressure

9mm is tapered straight wall case. The taper crimp is measured (not tested by finger pressure) within 1/16" of the case mouth. Approximately .377" depending on case-wall thickness is a good "taper crimp". .376 is fine for jacketted rds, but may be too much for .356 dia plated rds in thick cases.
The issue here is primarily the ability to "feed and chamber smoothly", NOT retention.

If you "crimp" much more than that, you are driving the case into the bullet jacket/plating, and are damaging the bullet. Pull the bullet and you can clearly see the results of excessive crimps.

Case neck tension (SIZING) is 99% of what holds the bullet in the case.

 

[mizer67]

Your die isn't sizing the brass enough to give you enough neck tension with that brass, if it's screwed all the way down.

If the die is in spec. and you can't get sufficient tension, then you could try a EGW-U die, which is undersized and will give you more neck tension than a standard die. They're not too pricey and work well with work hardened or thin brass.

 

[918v]

The U die won't give any extra neck tension. All it does is size the base more.

 

[Steve C]

The OP is having set back problems. In in my experience with reloading 1000's of 9mm a year using a wide assortment of brass including plenty of the type he is having an issue with, that usually means that not enough crimp is being applied. If you don't think crimp holds the bullet enough to prevent set back then so be it. All he has to do is try what I suggest. If it doesn't work for him then he's out 10 minutes of his time a couple rounds no worse off and a little more knowledgeable for the experience. Won't hurt my feelings any. He can then go and spend money and time trying to solve his problem by obtaining a new expander, etc.

All I try to do is offer solutions that worked for me to problems that I had encountered 30 years ago when I was young and inexperience.

 

[Blue68f100]

When I run into weak neck tension I do not use the expander die. If you have the inside of the the mouth champhered the bullets will load just fine if they are not flat bottom bullets. Most jacketed bullets have a small radius on the bottom so they load just fine. Or you can get another expander plug and turn it down using a drill press like RC said. In some cases you can just buy the under sized ones.

 

[popper]

If it is soft brass, a couple of size and expand sesions should harden it. If it is thin brass, the sizer may not be reducing it enough, won't make any diff. what the expander does.

 

[1SOW]

The OP is having set back problems. In in my experience with reloading 1000's of 9mm a year using a wide assortment of brass including plenty of the type he is having an issue with, that usually means that not enough crimp is being applied. If you don't think crimp holds the bullet enough to prevent set back then so be it.

Your statement is true as far as it goes. Two results: 1. You create a depression/ledge in the bullet that absolutely stops set-back. 2. You damage the bullet/jacket/plating.

The 30K or so 9mm Luger I've loaded for comp., haven't had set back problems and the bullets were not damaged.

Read the loading manuals and other publications that tell HOW to load 380, 9mm Luger, 40cal and 45ACP "pistol" straight wall cases. They will all say the same. Sizing, not taper crimp, retains the bullet.
If the case is worn out, it won't give enough tension to retain the bullet firmly.

I'm honestly not trying to be argumentative here.
New reloaders read these threads. They need to follow the published procedures for reloading semi-auto straight-wall cartridges.