What caliber for new LR-308 build?

[balttigger]

Just got a new upper & lower from Gibbz Arms for an LR-308.

Was looking at building a 6.5 PRC since I have a 6.5CM in a bolt gun and wanted something with a little more 'umph'. I even considered a .300 WSM. Then I tried to find a bolt with a .540 bolt face.

You would think with the upcoming popularity of the PRC cartridges, someone would make bolts to fit them.

So now I am stuck with calibers that use the standard .308 bolt. I am looking at 338 Federal, 375 Raptor or ???

I will want it to be deer capable out to 400, maybe 500 yards and also trying to keep the per shot cost under 3 bucks/pew.

Suggestions?

 

[4g64loser]

Talk to the good folks at VA Silent Arsenal about your wants. They do this. I don't really have a desire for such a gasgun as I am a certified bolt gun snob but the guys from their shop shoot some of the same events and their stuff is on point.

 

[erwos]

Should have bought a 6.5 Grendel upper instead.

If ammo cost is an issue and you don't reload, go 308. 500 and in is nothing for a good 308 gun. I'm not sure where you're gonna find a 500yd deer shot anywhere near here, though...

 

[GunBum]

Magnum bolt face bolts are available, but cost a left nut and right arm….

https://www.kakindustry.com/lr-308-parts/magnum/kak-industry-head-mag

 

[tundramuscle03]

I'm debating whether or not to switch out barrels on my .308 AR to match my 6mm Creedmoor bolt gun...

 

[balttigger]

Should have bought a 6.5 Grendel upper instead.

If ammo cost is an issue and you don't reload, go 308. 500 and in is nothing for a good 308 gun. I'm not sure where you're gonna find a 500yd deer shot anywhere near here, though...

Already have a Grendel. The 500yd distance was more for possible future endeavors.

 

[alucard0822]

308 and 6.5CM are pretty simple to build, and not a lot of problems, but the further away you get from those two or a few variants of them, the more you run into problems with cartridge length, bolt dimensions and gas tuning. Have seen some WSM builds, they run into those problems, and usually getting stuck with shorter OAL and lighter bullets at higher velocity if you plan on feeding from a mag. Out to 500yds or so a good heavy 308 or 6.5CM is within range for power, but I would be more worried about precision in the sub 2MOA-ish ethical kill zone at that range.

 

[teratos]

I would be more worried about precision in the sub 2MOA-ish ethical kill zone at that range.

The sub 2MOA kill zone does not apply to socialists....correct?

 

[steves1911]

Why not just 308?

 

[alucard0822]

The sub 2MOA kill zone does not apply to socialists....correct?

Hunters should always respect animals and take them ethically to minimize suffering. Hunting people...not so much

 

[balttigger]

Why not just 308?

I already have a 308, 6.5CM, 6.5 Grendel, 7mm-08, 243, 22-250 and a few others. I want to build something different.

What I really want is a barrel in 277 Sig Fury, but I doubt we will see commercial barrels available any time in the near-mid future.

 

[teratos]

Hunters should always respect animals and take them ethically to minimize suffering. Hunting people...not so much

My feelings exactly.

 

[steves1911]

I already have a 308, 6.5CM, 6.5 Grendel, 7mm-08, 243, 22-250 and a few others. I want to build something different.

What I really want is a barrel in 277 Sig Fury, but I doubt we will see commercial barrels available any time in the near-mid future.

Fair enough.... do you reload? 25 creedmoor with a fast enough twist to run the 135gr berger could be a lot of fun...or a 22 creedmoor

 

[Biggfoot44]

Do you want Different , or Different that overlaps what you already have ?

Actually Different would be .358 Win .

 

[balttigger]

I decided on a 300WSM from DeadShot barrels. Magnum length gas tube w/ an adjustable gas block.

 

[DaemonAssassin]

8.6BLK looks a bit interesting, if you are willing to wait for barrels and muzzle devices.

 

[calicojack]

Should have bought a 6.5 Grendel upper instead.

Yes sir!

 

[lazarus]

308 and 6.5CM are pretty simple to build, and not a lot of problems, but the further away you get from those two or a few variants of them, the more you run into problems with cartridge length, bolt dimensions and gas tuning. Have seen some WSM builds, they run into those problems, and usually getting stuck with shorter OAL and lighter bullets at higher velocity if you plan on feeding from a mag. Out to 500yds or so a good heavy 308 or 6.5CM is within range for power, but I would be more worried about precision in the sub 2MOA-ish ethical kill zone at that range.

Platform accuracy might not be an issue, but you do run in to field accuracy issues. Needs to be a pretty good rest and very good conditions and a very accurate distance measure with good known dope and calculation to make me comfortable considering a shot on a deer at that distance. If it was a suitably powerful cartridge and accurate gun, sure maybe a Moose with the MUCH bigger kill box.

I am aware some people do take shots that far. I am also reasonably confident they make a lot more misses/bad hits than those decent marksmen taking 300yd shots...

Really just about anything past 400yds starts getting super iffy. One of the hot magnums or PRCs really only stretches your legs an extra 40-80yds vs something like a .308 when it comes to field accuracy. Gravity and wind still impact the bullet, just a little less because of the lower drag and higher velocity.

Just compared to a .308, at 500yds, a typical 300PRC loading has 4-7 inches less drop than a typical .308 150-168gr tipped round and only about an inch less drift in a slow cross wind. It still has ~44 inches of drop and 2.5" of drift.

Anyway, that aside, you are pretty limited to just .308 based cartridges for an AR-10/308. I've heard mostly of problems and $$$ trying to get WSM cartridges to work with them. If you need something with more oomph in a semi-auto platform, I think you need to go the customer route of an AR-3006 or AR-300WM platform. You may be able to find something in 300PRC, but probably custom. You could likely get something in .25-06 if you really wanted something that can get to 500yds in a serious hurry. Probably isn't going to be THAT much more expensive and it is almost certainly going to be more reliable.

All that said, for my "reach out and touch things" platform, I am seriously considering a 300WSM, though in a bolt gun. Those fat, short little cartridges just have a lot of issues feeding. But I like the better potential accuracy, ease of reloading, slightly lower recoil, shorter action and more efficient combustion compared to a 300WM. Even if it means a round less capacity and a bit finickier reloading. You get in to those kind of powder capacities, and it is saving you a cool 10-15 cents per round in the reduced powder for similar muzzle energies.

 

[alucard0822]

Platform accuracy might not be an issue, but you do run in to field accuracy issues. Needs to be a pretty good rest and very good conditions and a very accurate distance measure with good known dope and calculation to make me comfortable considering a shot on a deer at that distance. If it was a suitably powerful cartridge and accurate gun, sure maybe a Moose with the MUCH bigger kill box.

I am aware some people do take shots that far. I am also reasonably confident they make a lot more misses/bad hits than those decent marksmen taking 300yd shots...

Really just about anything past 400yds starts getting super iffy. One of the hot magnums or PRCs really only stretches your legs an extra 40-80yds vs something like a .308 when it comes to field accuracy. Gravity and wind still impact the bullet, just a little less because of the lower drag and higher velocity.

Just compared to a .308, at 500yds, a typical 300PRC loading has 4-7 inches less drop than a typical .308 150-168gr tipped round and only about an inch less drift in a slow cross wind. It still has ~44 inches of drop and 2.5" of drift.

Anyway, that aside, you are pretty limited to just .308 based cartridges for an AR-10/308. I've heard mostly of problems and $$$ trying to get WSM cartridges to work with them. If you need something with more oomph in a semi-auto platform, I think you need to go the customer route of an AR-3006 or AR-300WM platform. You may be able to find something in 300PRC, but probably custom. You could likely get something in .25-06 if you really wanted something that can get to 500yds in a serious hurry. Probably isn't going to be THAT much more expensive and it is almost certainly going to be more reliable.

All that said, for my "reach out and touch things" platform, I am seriously considering a 300WSM, though in a bolt gun. Those fat, short little cartridges just have a lot of issues feeding. But I like the better potential accuracy, ease of reloading, slightly lower recoil, shorter action and more efficient combustion compared to a 300WM. Even if it means a round less capacity and a bit finickier reloading. You get in to those kind of powder capacities, and it is saving you a cool 10-15 cents per round in the reduced powder for similar muzzle energies.

Agreed, I love AR10/AR308s, but once you start getting away from 308 based OAL/head dimensions the problems escalate quickly. I have been eyeballing the PRC calibers, pretty much take what they got right with magnum calibers and tuning them to run heavy bullets. The 300PRC with 200+gr match bullets looks incredible, but not in an AR10 platform. Most of my hunting experience is with varmints, small kill box, pretty much any supersonic bullet will do the job, but wind drift and range have to be dead on. The difference between 300 yards and 400 yards is huge, 500 even more, if your range is off just a few yards, even with really fast calibers you won't hit, or worse an injured animal ends up limping away.

 

[303_enfield]

260 rem, nice 130g pill and you save powder.