While out shooting some 40 S&W recently, I noticed that some of the FMJ bullets were starting to set back in the case. Luckily, I found the problem before a ka-boom happened. I wouldn't want a series of problem rounds to cause someone to inadvertently (and unjustly) blame my G22 for the ka-boom.

After some investigation, back home, testing ALL of my loaded 40 stuff, I found that all of the problem rounds would push back into the case with light, finger squeezing pressure. All of these were rounds loaded with PD 165gr FMJ, in the older Federal brass. No other bullet in that brass, would move, even under considerably more force. This only happened in what appears to be a much older version of that brand brass. The newer stuff has a different font/stamping and never had the same problem. All of the bullets were .400, just like the other brands on hand, and all of the brass was sized, seated and crimped on the same dies, Hornady.

After a little more experimenting, I found that older R-P brass had the same problem...only with these bullets. But, these PD bullets would hold tight in all other brass that I tried. Blazer Brass,Winchester and S&B all worked very well. So, now I need to separate brass just to use with these 40 cal, PD bullets.
I have 1000's of other PD bullets in other calibers and never had a problem with them. I am thinking about calling them to see if they had a bad batch some time ago that they caught later on, maybe a taper on the bearing surface or something. But any of the ones that I checked looked to be in spec.

Weird, huh?

I like my .40 sizing die to size the case down so far that I can see exactly where the base of the bullet is in the loaded cartridge. If yours is not doing that, I'd replace the sizing die. I'm not worried about maximizing case life, but I don't want that bullet to move, especially under finger pressure. Of the pistol calibers I load, the .40 has the least margin for error, in several respects.

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Science plus Art

Listen to this^^^^^^^^^^^^^^^^^^

If the bullets "worked" in 4 other types of brass then it does not seem there is a problem with the bullet?

As mentioned something seems to me going on with the sizing die and/or flaring and/or crimping.

Just a good opportunity to plug the LFCD that so many dislike.

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Still Running Against the Wind

Slightly undersized bullet + thin walled brass?

I had this problem with practically all bullets when I first started loading .40 S&W. The problem was with the RCBS sizing die. And no amount of crimp with the Lee Factory Crimp Die would fix it. I bought the U-Die from EGW and that immediately solved all my problems. I think the U-Die is actually a Lee product but I live 20 minutes from EGW so I just drove over there to buy one. If you load .40 S&W, you gotta have a U-Die.

Dave Sinko

I, too, have had this problem. Improperly machined sizing dies were the culpret........from one of the best die makers. They replaced for free.

WILDPIG

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I ain't from around here.

I actually use the LFCD on all of my auto rounds.

I was kinda thinking along the lines of thin walled brass at work today. I haven't checked for that yet. Since it seems to pretty old brass, this makes sense to me, to be a possibility.

I have a lee sizing die and the egw u die which is a lee die but sizes down bit further not much difference. I also used a lee factory crimp die with good results.

old federal brass was known for being on the thin side and kaboomed in glocks and other poor chamber guns would toss it and use newer stuff. I have loaded newer federal brass without problems. not all brass is the same some minor die adjustments maybe needed when running different brass from another. for best results sort the brass and adjust as needed.

Before I would toss the sizing die, I would measure the O.D. of the resized cases to see if they are within spec.. If that is OK, the next thing I would look at would be the expander plug, which should be at least .003" smaller than the bullet diameter. Being .001"-.002" smaller still is not a bad thing. Bell the case mouth the minimum amount necessary to start the bullet.

First measure before you buy new equipment.

Bruce

This is one of the reasons I like to use lead. I can use .402/.403 that chambers well but has the tight fit that allows you to clearly see the base of the bullet thru the case. Cast is about half the price too.

It makes for a dirty gun but I clean them after every use anyway, my mentor, Senior Chief Kirchgessner drilled into us if your going to trust your life to a mechanical device you better make sure it is in the best shape you can get it.

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Shoot fast & live long
Warren

How about if it is just the one brand/batch of old brass, get rid of that and just use the brass that works?? Not like there is a shortage of 40 SW brass.

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Still Running Against the Wind

IIRC, Federal changed internal dimensions on their .40 S&W brass around 18-19 yrs or so ago. They beefed up the web in the new design. The old headstamp is "FC" and the new one is "FEDERAL". I'd mic the bullets at the base and see what diameter they are vs other brands. Is 165gr the lightest bullet you shoot? That could be part of why you only see the issue with that bullet as the bearing surface is shorter than 180grs.

I might also check the brass length and see if the brass has flowed and has thinned out the case wall. I would want to know these bits before I tossed the old brass just so I had that knowledge for the future.

Hastily spouted for your befuddlement.