What is happening?

[FISH4BUGS]

I am loading on a Dillon 550b cast 356402's sized 356 w/ Magma Lube w/ 4.3 gr 231 in mixed 9mm brass (all commercial - no processed military). Many of the loaded rounds will slide into and out of a Dillon Guage and function flawlessly in all my sub machineguns and pistols.
HOWEVER, after loading, some of them DO NOT guage correctly and will not go all the way down into the guage. They are ever so slightly oversized apparently.
I don't know what is causing this. Same bullet, same sizer die, same eveything except the brass.
Could it be that I need to sort my brass by brand? Could it be that the bullet, when seated, "fattens" the overall outside diameter of the brass because the brass is thicker?
Most of them don't seem to be a problem in full auto in the MAC and the S&W 76, (they have generous chambers) but the UZI doesn't particularly like them nor do the pistols.
If it IS the brass, how can I save hundreds of loaded rounds?....WITHOUT disassembling them for components?
HELP!

[ph4570]

I suspect you are on to it -- some brass is thicker. However, I would not have thought a .356 boolit would cause the issue even with some thicker brass. If that is the case maybe shoot up the fat loaded ammo in the larger chambered MAC and then sort brass for future loads.

There are those more much expert than I on brass thickness as a function of headstamp. Perhaps if you indicate which headstamps are problematic (assuming they sort out that way) someone else can comment on thickness variance between headstamps.

[scrapcan]

See if you have Amerc brass mixed in. I have noticed that this brass is dimensional different than most brass.

As for the loaded rounds if you can narrow it down to a certain brand of brass, sort that out and use it in on of the generous chambers. You could try a factory crimp die.

[243winxb]

The web area of the brass may have expanded in the gun with the largest diameter chamber. Most FLRS dies do not size the web area. Plus your load could be on the hot side for a lead bullet. The mould makes a 120gr bullet if i remember correctly, but when checking the weight as the bullet drops from the mould, it may be more heavy then 120, so a reduction in powder might be in order. OR the rounds that dont fit the gauge, try giving them a little more taper crimp. Thats my guess.

[cabezaverde]

I have been playing around with a similar problem in 9mm.

Boolit and brass combination that causes the boolit to be sized down when crimped enough to chamber.

So far, I have found out that Federal 9MM brass is thinner and more accommodating. I have read that R-P is also, but have not checked any.

[Larry Gibson]

FISH4BUGS

674310]I am loading on a Dillon 550b cast 356402's sized 356 w/ Magma Lube w/ 4.3 gr 231 in mixed 9mm brass (all commercial - no processed military). Many of the loaded rounds will slide into and out of a Dillon Guage and function flawlessly in all my sub machineguns and pistols.
HOWEVER, after loading, some of them DO NOT guage correctly and will not go all the way down into the guage. They are ever so slightly oversized apparently.

The gauge is made to minimum specs. Odds are your chmabers aren't. The question is do the non-gauging rounds chamber in your subguns and handguns. If they do then don't worry about and go shoot.

I've been loading 9mm for a multiple of handguns and subguns since '68 and have yet to gauge a single round of 9mm. A great many of them were with 356402 sized .356. Also my cases were a great variety of everything including military. I never did have a chambering problem.

Larry Gibson

[FISH4BUGS]

I have tried to fire the ones that are not guaging properly and they are not allowing the bolt to close on some of the rounds.
One poster mentioned a factory crimp die. Would that size the case back down to where it would fit? I have never used one and it sounds interesting. I guess it would be in station 4 in the Dillon 550?
I'll take a look at the brass and see if there is some pattern to it. I hope it isn't one brand or the other because it is already hard enough to sort military out of the bunch, and now I have to sort by head stamp?
UGH!

[snaggdit]

Factory crimp dies will iron out a fat spot from seating the boolit. Problem is they do so by swaging down the boolit. Could lead to leading. Use cautiously.

[JIMinPHX]

Maybe your sizing die is not down far enough & rounds that have previously been shot in a loose chamber are a bit too ft from being fireformed, while round that were previously shot in a tight chamber never got big enough to cause a problem.

[lylejb]

How about case length?

I had a problem in .45acp with an occasional long case, would allow too much crimp to be applied. This would cause the case to bulge. Often, this was small enough it was difficult to see, but the pistol would find it every time!!

I trimed the brass, and adjusted the crimp to that length, problem solved.

[kamikaze1a]

Lee Factory Crimp Die will correct the problem. But as was mentioned, it sizes the bullets a bit too. As I understand, it's called a "Factory" crimp die because the cartridge manufacturers use a similar process...

[Ricochet]

My understanding is that they size the cartridge to maximum nominal dimensions for the cartridge. They've fixed some bothersome cartridge chambering problems for me. I haven't pulled boolits to measure them, but haven't noticed problems from using the Carbide Factory Crimp Dies. I've gone to using them routinely for my pistol cartridges.

[MtGun44]

9mm brass seems to have a LOT more variation than any other caliber I load.
Some has mouths so thick it seems almost double some of the more 'mormal' stuff.

Bill

[FISH4BUGS]

I went to a machine gun shoot at a friend's house in rural New Hampshire (a wonderful place to live in case you didn't know) and I discussed this issue wth some others. They had another possiblity - that some of these 9mm's have ALREADY been fired in guns with generous chambers (MACs UZI's etc.) and when they get resized they cannot be resized down enough towards the base of the case. THAT is what is causing the problems.
One suggested roll sizing all my 9mm brass and GUARANTEED that will take care of the issue.
Now to start digging in about roll sizing. Lots to learn. Burned up most of the ammo this weekend so more to cast, size and lube and reload around a thousand 9mm's.
Anyone with experience with roll sizers?

[finishman2000]

certain guns are more fickle than others, esp 9mm. play around with the crimp....back it off some and it will work out. I had the same problem and now all cases work in all guns.

[243winxb]

http://www.wolfbullets.com/rollsize.htm Some feel that roll sizing 223 & 308 brass can weaken the brass and cause ruputred cases. Redding makes GRX push thru die for 40 S&W. Here a 9mm die. http://egw-guns.com/store/index.php?main_page=product_info&products_id=40 The drawing of 9mm showes the rim at .394" and the web at .391" so i am guessing a push thru die would not work??

[243winxb]

They had another possiblity - that some of these 9mm's have ALREADY been fired in guns with generous chambers (MACs UZI's etc.) and when they get resized they cannot be resized down enough towards the base of the case. THAT is what is causing the problems. This is what i said in post #4
The web area of the brass may have expanded in the gun with the largest diameter chamber. Most FLRS dies do not size the web area. Dont over look other possibilities. OAL to long or bullets to fat. Taking measurement of the loaded rounds and compare should give the correct answer.