Question on reloading a case that is shorter than the book says

[Corkster]

I bought some once fired brass (300 Win Mag) from the Gun Broker site, the brass in question was from a batch of Hornady custom factory loads. I turns out it's Frontier brass, but from what I understand, it's good quality stuff and Hornady uses several different manufactures of brass for their custom loads. After tumbling the brass I wondered if it might need to be trimmed. According to the several reloading manuals I have, it should be trimmed to 2.610" in length, however, my brass is 2.590" on average. I don't get it! I have yet to get once fired stuff that is undersize. Anybody else ever run into this? Should I reload it, would it be safe to shoot? Maybe after I fired it it would stretch out a bit...? HELP!

 

[ReloaderFred]

It's perfectly safe to shoot as is. You'll just have to adjust for the crimp, if you choose to use one. Don't worry about it being shorter than the book says. The only danger is when it's longer, and reaches the throat of the chamber, which will drastically increase pressures.



Hope this helps.

Fred

 

[Bullet]

You need to resize it before measuring to see if it needs trimmed.

 

[steve4102]

You need to resize it before measuring to see if it needs trimmed.

Yes, and don't forget you need to FL size someone else's brass.

 

[highlander 5]

the brass will stretch .005-.010" when resized but if your measurement is correct you are plenty safe

 

[NCsmitty]

All previous posts are good info. FL size it and check an empty case in your chamber for fit on a closed bolt.

NCsmitty

 

[Corkster]

O.K. so I resized them and gained a few thousandths, to put me at 2.595, still not 2.610. What is the consensus O.K. to reload and shoot?

 

[FieroCDSP]

Should be okay. Your OAL is your determining factor here. Whether your case is longer or shorter than book listed, using the same OAL will net you the same volume inside the case, which is the important figure in the kaboom equasion. The crimp setting will have to be altered, though, as the crimper will need to meet the case deeper on a short case than a longer one. This is why you set your crimp before your seating depth.

Put a freshly sized (short) case in and run it into your seating die. Crank the die down until it contacts your neck firmly. Since you're dealing with a resized case that hasn't been flared to take a bullet, your crimp will likely be right around that point if tapered, a bit deeper if rolled. Do a couple of test seatings to figure the rest of the adjustment out.

 

[rcmodel]

I probably wouldn't crimp .300 WinMag in the first place, but that's just me.

rcmodel

 

[bullseye308]

IF it was me and IF I was going to crimp, I would find the short one and trim them all to match, that way they will all grow up together. If you're not gonna crimp it shouldn't matter.

 

[Bullet]

The listed trim length is 2.610, your resized brass measures 2.595.

So you’re .015 under trim length.

I say load’em and shoot’em.


.

 

[Corkster]

Thanks Gentlemen,
I will load them as they are, no crimp and to suggested C.O.L. I'll let you know how they shoot and stretch.