Re-barreling .308 to something big?

[HunterMann]

The 338 Federal provides decent trajectory and penetration. But if you are looking for pure blunt force trauma in your "heavy thumper" then a 9.3mm-08 or .375-08 should deliver. There are plenty of bullets to choose from. I like 375's, but I don't design cartridges. The slightly smaller diameter 9.3 might give you better shoulder and neck options. Good luck, have fun, and stay safe!

 

[waspocrew]

What about opening up the bolt face to a magnum bolt and going with a 338 or 358 WSM? With the short action, you'll probably have some COAL restriction, but might be worth looking into.

 

[bamban]

Here is an eye opener for a 308.

 

[marksman1941]

Here is an eye opener for a 308.
View attachment 487597

Holy cow. I don't think I'd be ballsy enough to run it that hot. My 168's hit 2750, but I haven't tried getting a 200 that high

 

[bamban]

Holy cow. I don't think I'd be ballsy enough to run it that hot. My 168's hit 2750, but I haven't tried getting a 200 that high

Not my load. A member at SH who goes by Montana Marine did lots of work on 308 Win and 30-06

 

[akmtnhnt]

Here is an eye opener for a 308.
View attachment 487597

Speaking of Bubba's ****in hot hand loads, those are right around 80kpsi. So, ya...

 

[marksman1941]

Speaking of Bubba's ****in hot hand loads, those are right around 80kpsi. So, ya...

No doubt. My current 308 wouldn't shoot a 190gr smk inside a 4" group (which surprised and appalled me) even with a 1:10 twist so I gave up on heavies for that barrel. I would certainly like a big boomer but not one that's pushing that far beyond the bounds of the cartridge design.

 

[marksman1941]

What about opening up the bolt face to a magnum bolt and going with a 338 or 358 WSM? With the short action, you'll probably have some COAL restriction, but might be worth looking into.

I hadn't considered changing up the bolt face much. I don't have any experience with the wsm family and didn't have them on my radar. I'll do some research there.

 

[comfisherman]

Good question. I shoot a 20" barrel, but the cartridge was designed around the 16" barrel and gets 100% burn at that length. These handgun powders burn quickly. H110 and 300 MP are the best so far. I can get 2900 fps with 200gr barnes and accurate #9.
With the 308 coal, you have miles to seat the bullet out of the case and still fit in any mag or box.
I load on the upper end, but get 3-4 firings before primer pockets are loose.
View attachment 487565

How does it feed from the bottom metal?

I'm in a similar place, I've got a couple donor guns (kimber and a seven) in 308 for building a bigger bore small thumper for my wife. The easy button is jes for 358 or 338, but the minimal bore gains doesn't offset the decrease in Bullet selection.

The 45 raptor looks good but when I talk to various builders they all end up with an aic mag to keep the 250 grain projectiles from nose diving.

Big bore 308 bolt face is a quandary.

 

[comfisherman]

Speaking of Bubba's ****in hot hand loads, those are right around 80kpsi. So, ya...

Yeah... those numbers are pretty close to my 20 inch 300 wsm. The ever elusive forum magnum.

 

[Dean2]

Take and stuff a 286 grain, 9.3 Oryx in the 308 case and you will have about as big a Thumper as you are capable of getting on a 308 case and short action rifle. Anything over 375, you are at the point of diminishing returns, as you don't have enough COAL or capacity for heavier and longer bullets.

 

[marksman1941]

How does it feed from the bottom metal?

I'm in a similar place, I've got a couple donor guns (kimber and a seven) in 308 for building a bigger bore small thumper for my wife. The easy button is jes for 358 or 338, but the minimal bore gains doesn't offset the decrease in Bullet selection.

The 45 raptor looks good but when I talk to various builders they all end up with an aic mag to keep the 250 grain projectiles from nose diving.

Big bore 308 bolt face is a quandary.

That's the exact quandary I am discovering. I'm glad I'm not the first to encounter it. I haven't spent much time chasing down 45 raptor information yet, so it's good to know that folks have had to do some work to make it run.

My rifle is currently in a heavy chassis. If I go this rebore route, I'll be buying a new stock and bottom metal for the action and dropping a new barreled action into the chassis. so it's not out of the question to upgrade to an AIC mag system when I start collecting parts for it if I did the raptor

 

[comfisherman]

If you do the mag route the raptor gets positive feedback, basically a bolt action 4570 with 452 bullets.

My conundrum is balancing power and recoil. I could easily swap a bolt face and make a 375wsm.... but know in a 13lop manners, with a light contur 16 inch barrel on a model 7 or kimber it kills both ways. 308 powder column seems like as big as I can go.

The 375 raptor looks good but, the 452 bullet selection is vast and cheap... the 375 not. Most modern 375 bullets like 375 have launch speeds as well.

I've come full circle and just stuck with a slightly fast twist 308...

 

[akdad]

Do the Gibbs thing on a 358!!!
I didn't ever look at the energy of the 358 I have one in a blr because it was a friends favorite all around rifle so I chased it down and bought it when he passed. I always thought it was a decent increase.