.308, 155s, and a 22-inch barrel...

[Grump]

What speeds should be reasonably attainable with these in a .308...in a 22-inch barrel?

Sierra's book has a reputation for being a bit conservative. It shows max speed of 2900 fps out of a 26-inch Savage barrel using IMR-4064, and a max speed of 100 fps slower at 2800 fps for Varget loads. I also see many shooters loading 1-2 grains MORE than the Sierra published max to get their 2950-3000 fps with 155s.

I know many barrels in .308 tend to lose 15-25 fps per inch you go shorter, but how do these two specific powders do with 155s?

Thanks!

 

[loadedround]

For what it's worth. The current #14 Speer Manual shows a 150 gr bullet with a max load of 47.0 gr of IMR 4064 @ 2814 fps out of a 22" barrel.

 

[USSR]

Grump,

Most of the Palma shooters are getting atleast 2950fps with their 155gr bullets, but with long barrels. The Sierra reloading manuals are extremely conservative, and I would expect you could reach 2900fps with judicious reloading in your 22" barrel.

Don

 

[Bart B.]

Grump, it depends on your barrel's chamber bore and groove diameters, case weight and how tight the case neck grips the bullet; all keeping the peak pressure at no more than SAAMI peak levels. I doubt you'll get more than 2800 fps without getting up into unsafe pressure levels.

I wouldn't get concerned about driving 155's from a 22 inch barrel as fast as possible. Typically, the fastest one can drive any bullet with decent pressures is rarely the most accurate load. If the highest muzzle velocity is possible, you'll do better with IMR 4895 or Varget powder; IMR4064's a bit slow for 155's in a .308 Win. case.

But your definition of "reasonably attainable" velocities may well be different that others. What are you willing to sacrifice to get that velocity if pressure is really to high for your safety and those around you (whom you may be forcing to sacrifice something) when you shoot that ammo?

 

[GooseGestapo]

What BartB said.

I've gotten best performance from H4895, Reloader 15, and BL-C2/Win748 from the .308.

IMR4064 and Varget will give good accuracy, but no better than the ones above. Velocity is ususally a tad lower for these two also.

Any of the first three listed above will likely give you over 2,900fps, if your barrel is "average".

However, every barrel is "individual", and some are slower, some are faster than others. I wouldn't get hung up over the velocities though....

FWIW; my brother has a pre-'64 Win Mod 70 FW, that with a book max load of H4895 shoots MOA or better for 3-shots (he's a hunter, not shooter or competitor) with a Nosler 150 partition. It chrono's just over 2,900fps on several different chrono's at 50-100degF. He's taken quite a few elk with it as he lives in Nevada. (Also a LOT of deer,and a few prararie dogs) This year it's going sheep hunting as he drew his "once in a lifetime" sheep tag this year. With a Leupold scope he considers it a "do it all" gun. Who's to argue with success...........Although he shoots a 110gr HP at the pd's loaded to hit same POI as the 150's.......

Me ?, I prefer the .30/06. I can easily get 3.000fps and with some component combinations, over 3,100fps- but, I prefer sub-moa, so ususally around 3,000. Same powders, BTW....... but all my '06's have 24" tubes.

 

[ForneyRider]

I hit 2930fps with 24in Douglas barrel in a VZ24 custom.
I used 150gr Nosler BT's with 46gr IMR 4064, CCI 200 primer, and Win brass. IIRC, Max load was 48gr in Lyman book for 150gr BT, and the max load for 155's is 46.5gr.

I had 2.8in OAL.

I've been told and read that 4895 is the powder to use for 308 Win and 8x57 Win. But I use 4064 for 308 and Varget for 8x57.

The VZ24 running 3-9 Tasco and 2-stage trigger was able to get bullet holes to touch. And the M98 Mauser was able to get 150gr Sierra Pro-Hunters bullet holes to touch with a Zeiss scope and 2-stage trigger.

 

[45ACPUSER]

Each bbl is a rule unto itself; ergo you will never know till YOU chrono the loads in your gun! The Sierra book uses FEDERAL brass to work up their data. I would suggest using Win or Lapua brass.

Here is proof of what a bbl can and can not do! I had shot out of my stock 700 308 BHA 175gr Match ammo for benchmark of a constant. My reloads using the 175 were running right below 45gr of Varget and getting better velocity. I had my 700 rebuilt.....with truing etc and a Mike Rock 5R bbl. Now, here is the proof. I chrono'd the same lot of BHA ammo out of 22" bbl and was getting same velocity...with 4 less inches.........now....with a match chamber......my 175gr reloads use 43.6gr of Varget nearly 1.5gr less powder and getting the velocity......so this is my personal proof of each gun is a run unto itself......YOU NEVER KNOW TILL YOU CHRONO the loads..otherwise you are just pissing in the wind....

 

[JDGray]

Running 155gr SMKs, my accuracy load is with 43.6gr varget. 2725 fps out of my 20" Savage, 10FP.

I've had good luck with Varget, and havn't tried any other powder. The above load gives me .580" 5 shot groups @ 100yrds