.40 S&W Brass Bulge, Normal?

[G11354]

I bought my first handgun (M&P 40) about a year ago and decided to start re loading for it. Bought some bulk once fired .40 S&W brass and after re-sizing noticed the brass has a very slight bulge near the head of the case and that the bulge uniformly surrounds the case.

Brass drops in barrel freely same as my factory new "Hornady Critical Defense" rounds would.

Is this normal in .40 S&W brass and are these shells re loadable?

 

[Deshooter]

There is a history of brass fired from Glocks to have this bulge. I believe Lee makes a die called the bulge buster specifically for this condition.

 

[Curator]

G11354:

Are you sure your sizing die goes all the way to the shell holder when you de-cap/re-size? If not this is what is causing the small bulge at the base. If the sized cases drop easily into your barrel's chamber, you are good to go. A "Glock-bulge" will not go all around the base but be only on one side. Your sizing die may be re-sizing a bit more than necessary for your gun since they are made for every gun in that chambering. I do not reload cases with a "Glock-bulge" due to concerns about the strength of the bulged area after resizing.

A tip about utilizing "bulk-once-fired" .40 S&W brass: sort them by head stamp before reloading them. Carefully check and adjust bullet seating and taper-crimp as necessary for each lot of head stamps. Different case manufacturers often have slightly different case mouth thickness and the taper-crimp die may need to be "tweaked" slightly to prevent bullet set-back upon feeding/chambering. Failing to do so has resulted in more than a few Ka-BOOMs.

 

[G11354]

Appreciate the input.

Im using a "lee" 4 die set. I managed to find some shells I fired from my pistol and they show the same slight bulge.

The brass does drop in and out of barrel freely.

 

[omgtkk]

Lee makes a kit expressly to address this. Its called.....wait for it....the bulge buster. Its a kit that is used with the factory crimp die and allows you to push the casing entirely through the die to resize the base bulge. It works on .40 & .45, but not 9mm due to the slight taper on that case. Costs around $20. I just used mine this weekend as I loaded a few 45's

 

[Curator]

If your sized brass drops in and out of your chamber easily, you don't need to do anything to it. ALL brass bulges slightly at the head since the chamber diameters are nearly always a few thousandths larger.

 

[gamestalker]

Glock brass will have a bulge, but it is only on one side of the brass, where the barrel is poorly supported.

If you have brass with a radial bulge it is either due not completely resizing down the shell holder, or, it's brass that has been exposed to excessive pressures and may blow the next time it is fired.

GS

 

[sexybeast]

Is this normal in .40 S&W brass and are these shells re loadable?

Yes it is normal, yes it is reloadable, and you don't have to remove it if it will chamber as it most likely return.
There usually is a bulge all the way around and your sizing die will remove most of it. You "don't" have to "bulge bust" unless it won't chamber.
But inspect your brass for cracks!

 

[HighExpert]

+1 on the bulge buster. I have found a little lube and a single stage press works great. Brass like new.

 

[Rico567]

I have gotten range pickups of .40 S&W brass that has obviously been fired through Glocks (as evidenced by the firing pin mark, which is quite distinctive), and some of these, but by no means a lot, have a bulge. My Lee size die has always taken these out, and when such cases (with a visible bulge) go through the size die, it can be felt.
The strange thing is that of the half-dozen Glocks I have shot and reloaded for, not one has ever left a bulge that I've ever been able to tell. I gather that .45 hasn't ever been a problem anyway, but I load my .40s fairly warm, developing about 1100 - 1150 fps using H. Universal. No bulges, ever.

 

[Matt Dillon]

Do you check your finished rounds in a case gauge?

 

[Rico567]

I used a case gauge until I discovered the Lee Factory Crimp Die (the one for pistols that has the carbide size ring incorporated into a crimp die. This die takes the finished round to standard outside case diameter, no matter what has happened in the seating die. For a while, I still used the case gauge, but after several thousand rounds and I got none that wouldn't drop in, I quit using them.

 

[RealGun]

The FCD still does not address the case head area that the OP mentions. It is "normal" for cases to look like the description unless following the advice to routinely run all 40 brass through a Bulge Buster or Redding G-Rx, the former being the least expensive and also working with .45 ACP. I have both and certainly admire the Redding as a good tool.

I prefer using a gauge rather than a barrel, because I have multiple 40s and need to load to a standard.

 

[2 Horse]

It's normal, the case should be .423 give or take a couple of thou at the case head.
The lee die sizes the case body to .416 or so. The ring or bulge is where the carbide insert stops. This is what your looking at