New Model 12 LRPV ammunition advice needed.

[chrisbaker42]

Just picked up a nice new .223 LRPV with 1 in 7 twist and would love to get as much advice as I can on best ammunition both factory and reloading suggestions.

[SlowTrigger]

With a 1 in 7, 77 gr. factory loads would probably be the best. Federal Premium GMM or could try Fiocchi 77s.

[adam38654]

Federal gold match with 69 and 77gr sierra matchking. But fiochi 77g is pretty good for the money.

Reloading the heavy twist like 77 grain sierra matchking, 75 gr amax, and the 80's also.

I have also read of surprising accuracy from the lighter 52/53 grain bulllets in faster twist barrels but they wont buck the wind as well farther out.

[chrisbaker42]

Many thanks for the advice so far.

[arnie]

That barrel will handle 80 grain bullets also .They have way better bc than the 77 does .

[darkker]

MV = Muzzle velocity

RPM = MV * 720 /Twist

Remember that bullet weight isn't important for twist, it's a generalized rule for length. The 75gr Amax is notably longer than the 77gr SMK. I called all the majors some years ago and inquired about RPM limits for the .224 bullets. Sierra and Nosler match bullets have the thickest jackets, and can withstand roughly 320,000 RPM. Hornady and the rest(didn't talk to Berger) are more like 290,000 RPM, but your particular barrel smoothness will play a large role in the ultimate number.

You may find that the shorter, thus lighter weight and thinner jacketed varmint bullets, will come apart if you fire them quickly.

[chrisbaker42]

I now have a selection to start building loads for ranging from 75gr hornady to 80gr and 90gr Bergers, I will report back with any successes.

[Scott Evans]

MV =

You may find that the shorter, thus lighter weight and thinner jacketed varmint bullets, will come apart if you fire them quickly.

Depends. Some are made for high velocity/high spin rate, some are not. Sierra will tell you if they are for std vel or high.

I just loaded some 224 40 Blitzkings to 336K RPM worked fine. I've shot 6mm 70 Blitzkings at 342K and they worked great. 6mm 70TNT had to be kept below ~290K and didn't tolerate a dirty barrel. 204 39g BK's were fragile for me. It just depends. The high spin rate makes for some serious splat factor on PD's.

[darkker]

Yes, it always depends.
The original TNT's have a spec'd RPM limit of @ 240,000 rpm, but as I said, barrel dependant.
The SMK's and Blitz's have the thickest jackets, not the others.
If you want I can link my OP from another forum with the particulars I got from the MFGRs.

[Scott Evans]

Yes, it always depends.
The original TNT's have a spec'd RPM limit of @ 240,000 rpm, but as I said, barrel dependant.
The SMK's and Blitz's have the thickest jackets, not the others.
If you want I can link my OP from another forum with the particulars I got from the MFGRs.

That'd be cool info to see.