338 Sherman Build (This Is My Boomstick!)

[truck driver]

Yes, so far, the ONLY bullets I have seen that can keep up with the Berger in terms of velocity, drift, and drop are monos. Accuracy and terminal performance are still open questions.

The only other .338 bullets that even make sense to me are in the 200 grain range.

I'm not sure why it's such an issue in the .338 diameter, but a LOT of .338 bullets seem to be designed with a long bearing surface, which limits velocity potential. That may not make much difference with the larger cased .338's, but it matters when trying to extract efficiency from cases on the smaller end of things.

I've enjoyed your post and I'm impressed that you are taking a case based off the 280 and getting this much performance out of it with .338 cal 250gr bullets.
I'm shooting a 338Wm and haven't tried anything heavier than 210gr out of it and that is a 210gr Nosler PT with RE17 and getting 3023fps out of a 24" M77 Hawkeye.
I have had trouble like you with the 210gr Swift and can't get much over 2900fps with it do to pressure. I think besides the longer bearing surface the brass jacket material also has something to do with it.
I have torture tested Nosler 35 Whelen seconds brass that I used to form 35W/AI brass pushing a 200gr AB to just under 338Wm velocities along with 225gr PT. I use CFE223 in the 35W/AI with great results.
Some where in your post I missed what the case dimensions are for the 338 Sherman and was wondering if you would repost them. I have a M70 I might like to try building one on.

 

[elkaholic]

Case is 2.495" in length and coal to the lands with a 250 Berger is approx. 2.570"....rich

 

[elkaholic]

Case is 2.495" in length and coal to the lands with a 250 Berger is approx. 2.570"....rich

Coal with bullets with less aggressive noses like nosler or hornady are more like 2.4+

 

[truck driver]

Coal with bullets with less aggressive noses like nosler or hornady are more like 2.4+

How much neck do you have for holding bullets? Thinking you could run a reamer in a 338-06 chamber and maybe set the barrel back one thread to clean up the chamber like you would for a 35Whelen/AI.
I have been thinking of getting a reamer for a 338Wm/AI to get a little more out of the old girl with out having to go up to a Rum or Lap.
I like the way the straight case walls and 40*shoulder of the Ackley tames pressure or should I say hides it.

 

[elkaholic]

How much neck do you have for holding bullets? Thinking you could run a reamer in a 338-06 chamber and maybe set the barrel back one thread to clean up the chamber like you would for a 35Whelen/AI.


I have been thinking of getting a reamer for a 338Wm/AI to get a little more out of the old girl with out having to go up to a Rum or Lap.
I like the way the straight case walls and 40*shoulder of the Ackley tames pressure or should I say hides it.

How much neck do you have for holding bullets? Thinking you could run a reamer in a 338-06 chamber and maybe set the barrel back one thread to clean up the chamber like you would for a 35Whelen/AI.
I have been thinking of getting a reamer for a 338Wm/AI to get a little more out of the old girl with out having to go up to a Rum or Lap.
I like the way the straight case walls and 40*shoulder of the Ackley tames pressure or should I say hides it.

 

[elkaholic]

Neck is .323". I do think you could just clean it up
You can call me at 208 755-6723 anytime

 

[truck driver]

Neck is .323". I do think you could just clean it up
You can call me at 208 755-6723 anytime

Thanks for the number and info. What time zone are you in so if I call it won't be late at night or too early in the mourning.

 

[elkaholic]

Pacific

 

[truck driver]

Pacific

Looks like I'm 3hrs ahead of you so I'll watch my time before i call.

 

[benchracer]

I've enjoyed your post and I'm impressed that you are taking a case based off the 280 and getting this much performance out of it with .338 cal 250gr bullets.
I'm shooting a 338Wm and haven't tried anything heavier than 210gr out of it and that is a 210gr Nosler PT with RE17 and getting 3023fps out of a 24" M77 Hawkeye.
I have had trouble like you with the 210gr Swift and can't get much over 2900fps with it do to pressure. I think besides the longer bearing surface the brass jacket material also has something to do with it.
Some where in your post I missed what the case dimensions are for the 338 Sherman and was wondering if you would repost them. I have a M70 I might like to try building one on.

IMO, the keys to 338 Sherman performance have been the introduction of powders and bullets that are a better match to the Sherman case capacity. The .338 WM sits in a no-man's-land in terms of case capacity. It is larger than it needs to be to properly utilize H4350 class powders, and too small to utilize powders like Retumbo or H1000.

I do think RL-26 could be a game changer for the .338 WM and, based on my experience with it in the 338 Sherman, I believe it could work a bit better in the .338 WM. For someone who already has a .338 WM, that is the direction I would go to maximize it.

I think an M70 chambered for 338 Sherman would make for a very nice build. One advantage of the M70 over my Ruger is the availability of a Wyatt's extended box magazine for it.

 

[codyadams]

IMO, the keys to 338 Sherman performance have been the introduction of powders and bullets that are a better match to the Sherman case capacity. The .338 WM sits in a no-man's-land in terms of case capacity. It is larger than it needs to be to properly utilize H4350 class powders, and too small to utilize powders like Retumbo or H1000.

I do think RL-26 could be a game changer for the .338 WM and, based on my experience with it in the 338 Sherman, I believe it could work a bit better in the .338 WM. For someone who already has a .338 WM, that is the direction I would go to maximize it.

I think an M70 chambered for 338 Sherman would make for a very nice build. One advantage of the M70 over my Ruger is the availability of a Wyatt's extended box magazine for it.

The one thing you can do is send your rifle in to CDI and have it fitted with a DBM, they mill out part of the reciever and allow you to load up to 3.600" OAL

 

[codyadams]

This guy

 

[benchracer]

The one thing you can do is send your rifle in to CDI and have it fitted with a DBM, they mill out part of the reciever and allow you to load up to 3.600" OAL

Looks like a VERY good option. GREAT find! Thank you!!

 

[elkaholic]

That makes a Ruger a whole lot more user friendly!