30BR problems...dies, brass or both?

[DanB]

I recently acquired a XP-100 chambered in .30BR...it appears to be a retired silhouette gun. Included in the deal was a seat or RCBS dies,FL, neck and seater). In the die box was one piece of brass. The headstamp was 'RP' around the top side of the case head and 'BR REM' around the bottom side.

Not paying much attention to this case, I proceeded to neck up a few RP 7BR,not turned at all) cases that I had laying around. Turns out that the necks were too thin for the dies to size enough to hold a .308 caliber bullet even after pulling out the expander ball. So I pulled out the case that was in the die box...with a .308' bullet seated in it the neck measured .332'. With the .308' bullet in the necked up 7BR case it measured .327'.

Since I really wanted to shoot this gun I went as far as making .30BR cases from .243W brass...it was a little time consuming but all went well and before long I had twenty nice pieces ready. With the LR primer pocket instead of SR, I backed down a little and started at 32gr H322 and 130gr Hornady SP. I test fired three cases and after four reloads they were fine so I loaded all twenty. The fired necks are a little snug on a virgin bullet so I'll have to watch that carefully and maybe turn them a hair. For the first time out I was pleased to see it shoot into sub-MOA at 100yds with seven of ten rounds under .4'. The other ten are awaiting for a good day to shoot 300yds.

So my question...what to do with the brass problem? Do I continue to make cases from .243 and load accordingly to deal with the LR primer? Do I send the dies back to RCBS but I don't really see where they could help since they are oversize. I plan on just hunting with this gun for the time being...the barrel is a bit on the thin side for my taste so I will rebarrel eventually...do I deal with the brass/die issue at that time?

Thanks for any input.

 

[Eddie Harren]

If you'll send 3 fired cases to Harrell's Precision, they will make you a bump die that will utilize Wilson or Redding bushings and you'll be set for life. The Lapua 6 BR Norma brass will be here soon if not already.

 

[AlNyhus]

DanB: It sounds like what you have is an early version of the 30BR chamber. Those chambers were made for use with the small primer 308BR cases once made by Remington. This brass is a thin walled, full length 308 case with a small primer and large flash hole. They were the 'parent' case that was used to make all calibers of the early BR cases...22, 6mm and 7mm. The .30 cal. version was popular in handgun silhouette for it's bullet weight advantage. The .30 cal. variant was also refered to as a 308X1.5 or the 308 Barnes.

The chambers for the Rem. 308BR brass are significantly smaller at the back end than what Lapua 6BR cases measure. Depending on the reamer specs, cases from these Rem. chambers will normally measure around .465-.467 on a fired case @ .200 ahead of the extractor groove. Unfired cases will be in the .464-.465 range at this same point. These 'early' BR chambers were 1.500 long although some later versions were 1.560...the same length as the Lapua chambers of the 'modern BR case/chamber era'.

Lapua 6BR brass runs around .470 at the same measuring point and can also be a bit bigger up front..at the shoulder/body junction. So depending on the size of the reamer used to cut your chamber, you may or may not be able to use the Lapua case. If you're lucky enough to have a 'big' Rem. BR chamber...the Lapua cases can sometimes work by using a small base die.

Worse case scenario is that you'll need to make cases from the discontinued Rem. 308BR cases. These were long ago discontinued but are still avilable with a bit of searching.

The approach I'd probably take is to have the RCBS f.l. die modified by JLC to take a neck bushing,assuming it sizes the body appropriately now) and use the Remington 7BR brass. Choose a bushing that gives the neck tension you'd like and you'll be set.

Be careful of the neck length on these chambers...a chamber cast would be very helpful. Here's a couple of links that may give some additional info:
http://www.6mmbr.com/30BR.html
http://www.6mmbr.com/compcartridges.html

For what it's worth............-Al

 

[eww1350]

Why not have a gunsmith run a modern 30BR,Robinett) reamer into your exsisting chamber making it compatable with the Lapua brass..??
A gunsmith can cut the chamber by hand while the barrel is still on the action..should cost about $50..usual and customary fee..:,