Bulging Brass

Prairie Man

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I am reloading 9MM, I've noticed 11 out of a 160 rounds, the brass is bulging at the base of the casing not fully going into the barrel. The brass I'm using should be once fired factory rounds. I have just converted my Dillon 550B to 9MM, did I do something wrong?
 
If you can take the gun apart, drop a reload in the chamber , it should bottom out. If it don't seat the bullet a bit deeper,crimp a bit more maybe, not much, just enough.
The ammo is close to perfect, as only a small number is causing the problem.
 
To expand on Pete's posting, is your sizing die set to make contact with your shell plate???

Glock chambers can be more than generous, and tend to bulge 1/4 of the brass just ahead of the extractor groove. Most die sets can tame the 9mm bulge, but some brass will be lost.
 
If your once fired brass was fired in a Glock or other loose chambered gun, it can bulge enough to be out of spec and not fit in guns with tight chambers.

A lot of my reloads were too bulged to fit in a case gauge until I bought a Lee factory crimp die. In addition to crimping, it resizes the case further down than a regular sizing die. After I got the FCD I only have about 1 in 250 rounds that's too bulged to fit the case gauge. They're only about $20 and well worth the money in my opinion.

As others have said, this might just be your normal sizing die not screwed down enough. Double check it and the instructions that came with it.
 
Dillon dies leave the glock bulge in the case. My 9mm case gage hasn't arrived yet, but the finished ammunition fit's the glock chamber fine - I just don't know if it'll cause chambering issues if used in other pistols.

Do you use the Lee FCD on a progressive press? If so, do you still size in Station 1 using a sizing-only die and then use the FCD in the last station to both resize (getting rid of the bulge) & crimp?
 
CanFire said:
Do you use the Lee FCD on a progressive press? If so, do you still size in Station 1 using a sizing-only die and then use the FCD in the last station to both resize (getting rid of the bulge) & crimp?

That's exactly what I do. Well, I decap in station 1 too :D
 
I use the LEE fcd in 9mm and .45 ACP and I am very please with the results. My .45 has very tight match spec chamber and before I had a factory crimp die I was lucky if I could get 200 rnds through the gun before it needed its chamber cleaned.
 
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