Lengthing Throat to Prevent Over Pressure AR Comp

[lee1000]

I have a Savage FTR 308 and it has a short throat, this seems to be common with this rifle. I would like to get as much velocity out of this rifle using AR-Comp (more available than Varget) but I'm currently limited by pressure. I'm close to 1000 yard velocities but not quite there (about 70 fps short).

With the bullet on the lands OAL (Tip to head) is 2.816 (min is 2.810 per manuals). I loaded up rounds to 2.810. Bullet is Nosler Custom Comp.

Would it be worth taking it to a gunsmith to have the throat lengthened? How much velocity would I gain if I did?

 

[Steve Blair]

What's the bullet?

 

[lee1000]

What's the bullet?

175 gr Nosler Customer Comp
41.4 to 44.2 Grains of AR Comp

 

[243winxb]

Throat http://riflemansjournal.blogspot.com/2011/01/cartridges-1000-yard-308-case-capacity.html

 

[lee1000]

Throat http://riflemansjournal.blogspot.com/2011/01/cartridges-1000-yard-308-case-capacity.html

Thank you, very interesting article.

 

[Steve Blair]

Your ideal freebore would only be about .040" longer for that bullet. Donovan is right on both counts. You could benefit somewhat from a longer freebore and are probably about max for AR-COMP. You could benefit more from another powder at that bullet weight.

 

[lee1000]

Your ideal freebore would only be about .040" longer for that bullet. Donovan is right on both counts. You could benefit somewhat from a longer freebore and are probably about max for AR-COMP. You could benefit more from another powder at that bullet weight.

Yes, I've been looking for a keg of Varget but been able to find any. A local store has some 1 pounders for $40 but I'm paying that.

I went with AR Comp because I had read how temperature stable it was but like you said, I'm getting close to max. Are they still shipping kegs of Varget? Can you recommend a powder that is fairly temp stable?

 

[Steve Blair]

Unfortunately, all your candidate powders are in high demand. Don't pay $40/lb but keep your eyes open and be ready to buy when you see what you want.

 

[lee1000]

Can you recommend a powder that is fairly temp stable?

They all are when your in the middle of a good accuracy node. Just some a little better then others.

You could also "point" the Nosler's and gain a little more ballistics....

Donovan

good point