Free throat distance for 6BR?

[shadowdrak]

I recently did a search on here looking for a free-throat distance and found that 0.070" was the ideal distance for reaming. Now my gunsmith said that won't be enough free-throat for Berger 105g. VLD,because I'll be seating the bullets deeper and taking up powder capacity and compressing) and that I should go with 0.113" of a free-throat.

I'm rebarreling my Rem. 700 PSS in 308 to 6BR. and plan on shooting 87g. Vmax on up to 105g. VLD and Amax. I mostly plan on the 105's but would like to use the 87's as well.

What would be the ideal free-throat for my needs? Thanks for any help you guys can provide.

 

[billmo]

I went with a .104 freebore on my 6BR and it is working well with the 105 - 108 gr. bullets. I can seat at 1.400 just kissing the lands with the 105 gr. Berger VLDs. I have not loaded any light bullets yet so I don't know how they will pan out. Bill

 

[billmo]

Good advise man. Dave built my reamer. Fine product. Bill

 

[shadowdrak]

Great advice guys. Gave him a call, but he was on the other line, and will call me back. I was only a little hestitant with the gunsmith, who does great work, but usually works on tactical and varmint guns and what I get out of it is this is the first time he is reaming for the 6BR with specific specifications regarding bullet weights to be used. I'm sure Dave will give great advice in that regard. Thanks.

 

[treeman]

1+ for .113 freebore my ptg 6br reamer has this amount of free bore. I shoot sierra 107's and they are up out of the doughnut and shoot really well.______treeman

 

[shadowdrak]

Finally talked to David. After explaining to him what I wanted to do, he was saying to go with a free bore of 0.085" and after shooting several hundred rounds and getting throat erosion, I would have to switch over to 105s exclusively. I got some 105g. Amax yesterday and decided to seat them as if I had a 0.113" free bore. Those 105s are sure long, because with that free bore the base of the bullet was really down in there,about halfway between the shoulder and neck). I guess my best bet is to go with a .104" free bore and that will seem to be a happy medium for 87s and 105s with enough room to get erosion and still be good for a while with both weights.

 

[rcw3]

The 105 A-Max bullets have a very long bearing surface relative to some of the other 105-108 gr bullets, and therein lies the dilemma with throating. Throat it for the 105 A Max bullets, then put a Berger 105 VLD in there and you will have a lot less neck holding onto the bullet. Throat it for the Berger 105 VLD's and then put a 105 A-Max in there and the bullet will sit way back further into the case. Ahh - where to find that optimum balance point?

Robert Whitley

 

[niceone]

mmmmmm i like both 87v max and 105 amax ???????????

 

[Tim_in_TN]

I have a .104" and wouldn`t change a thing. Very accomodating.

 

[shadowdrak]

The .104" free bore sounds the best bet to me. Gives the ability to easily shoot 87s seated and 105s seated a little deep, but after several hundred rounds and some throat erosion, I'll probably just go with the 105s exclusively,depending on the amount of erosion and seating depth for the 87s).

 

[Ackman]

My 6BR has 0 freebore. Touching the lands an 87VMax has it's boattail taper right at the neck/shoulder junction.....the base extends about .110" below that. Freebore of .100" + should work fine with that bullet.

 

[jdfletch]

I talked with Dave Kiff about shooting the 105-108 bullets exclusively. He recommended a 0.104" freebore. Two barrels were cut with that reamer. At 0.020" off the lands, a 105 AMAX seats such that the boat tail - shank junction is just above the neck-shoulder junction of the case. The base is obviously deeper, but 30.6gr Varget is not compressed. The 105 Bergers seated 0.015" in are fine, as are the 107 Sierras at 0.020" off.

Russ Theurer has one of the barrels and as noted in another post it is quite the hammer. 6BR NRA Prone Rifle

I would not hesitate to go with a 0.104" freebore if you want to shoot the 105gr class bullets.

Doug