Why does one 300 ultra mag brass not fit into 2 different guns

[capture]

I have 2 300 ultra mag gun one Christensen arms and one HS Precision. Reloading ammo and found out that if I reload a case from one shot by the HS it will not go into my Christensen but the HS will take both. Action on the Christensen is a Remington and the action on the HS is Pro 2000. Any thoughts out there?

 

[Bigeclipse]

I have 2 300 ultra mag gun one Christensen arms and one HS Precision. Reloading ammo and found out that if I reload a case from one shot by the HS it will not go into my Christensen but the HS will take both. Action on the Christensen is a Remington and the action on the HS is Pro 2000. Any thoughts out there?

different sized chambers...in order to use one reload in multiple rifles you will have to make sure to full-length resize the brass...this could include bumping the shoulder back a bit.

 

[MudRunner2005]

BigE is correct. You might wanna buy 2 different boxes of new brass, and keep them seperated as to which one goes to which. Every gun has a different chamber, even if they were made 1 after the other, with the same reamer and tooling.

 

[Canadian Bushman]

BigE is correct. You might wanna buy 2 different boxes of new brass, and keep them seperated as to which one goes to which. Every gun has a different chamber, even if they were made 1 after the other, with the same reamer and tooling.

+1

If you use the same brass for both you will be overworking the brass. Something i would stay away from in the 300 RUM

 

[g0rd0]

a good way to keep your brass separate is to use 2 differant brands of brass

 

[BountyHunter]

Keeping the brass separate for two guns does not solve the problem of die adjustment each time or buying another sizing die. However, it helps ID which brass goes in which gun.

You can use one die for both guns if you do not want to buy a separate sizing die.

However, you must measure the shoulder on brass coming out of both guns.

Take the shortest brass and set your die up to just bump the shoulder on that brass then buy a set of Skip Otto die shims from Sinclair international. Normally $12.49

http://www.sinclairintl.com/reloadi...es/skip-s-die-shim-kit-7-8-14--prod33197.aspx

Take what size shim you need to just bump the shoulder on the longer brass.

So if the shoulder on the longer brass is .005 longer just put the .005 shim under your die and you should be good. You might have to play with .001 shim up or down to get it correct.

You can find dimension variance in shellholder heights too, that is why I put a separate shellholder in each die box and only use that shellholder with that set of dies.

 

[Wachsmann]

I have seen some similar problem on my neck sized brass compared to my full length sizeded brass. one die is a redding and other is an RCBS (neck sizer). The neck sized fits tight into my rifle. I measured off the shoulder and see about a .004 thousands difference between the two. I have been tring to figure out how to get the shoulder bumped down slightly more but I am camming over on the die pretty hard as it is now. I'm pretty sure this is the difference between how the dies are cut/made. Does the shims go under the die as you screw it down into the press or where. I would think if I used a shim in this location you would actually have less shoulder bump. Is my thinking correct?

 

[BountyHunter]

Yes the shims go under the die. If you are flush with the top of the shell holder then get a smith to take .010 off the bottom of the die. I have had to do that several times. Another fix is a set of riding competition she'll holders that are on .002 increments that will do the same thing

 

[capture]

Thanks for your help I will try the shims.

 

[Deleted member 46119]

I load for 4 300RUMs.

The brass lots are all separate for each rifle.

Hall E, custom - mine
Rem 700 BDL - mine, for sale.
Custom LR Bench Rifle on a R700 action - mine
Christensen Arms Carbon Barrel - buddies

The longest/loosest chamber is the CA. The tightest is the Rem BDL.

Sounds like yours is opposite where the CA is tighter than the other.

I'm blessed that sizing just to bump for the Rem is very accurate in all the others so I don't have to change the FL sizer, the fl sized cases are still longer than new. Of course the BR is neck sized until it can't be.