Lets talk new AR15 cartridges

My next new AR caliber is going to be off the AR-10. That will be the .45 Raptor. Also legal in the straight wall states.

Big Horn Armory has apparently done the same thing for the .500 S&W round as the .45 Raptor did to the .460 S&W. It seems BHA has made their .500 proprietary.

Fine Figure of a Man said:

The 6.8spc not a bad round, the 6.5 Grendel is just a little better in every aspect IMO.

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Except when it isn't I bet dollars to doughnuts that the 6.8 SPC would be more reliable and have a longer service life in automatic weapons.

Varminterror said:

Can you elaborate a bit on this?

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If you start looking at ballistics tables the 6.8 outperforms the 6.5 out to around the 2-300yds, after that the 6.5 does better, and while both can reach out to 1000yds, you're
a) losing a lot of performance, and, more importantly
B) I'm not confident taking an offhand or poorly supported shot at greater than 400 yds.

I'm not saying the 6.8 won't go to say 500yds, but that wasn't what it was designed for. It was designed for hitting really hard out of shorter barrel rifles at short to medium ranges.

@greyling22 - how long have you been hunting with these two? And shooting past 300yrds with them? Which bullets?

Goosey said:

I bet dollars to doughnuts that the 6.8 SPC would be more reliable and have a longer service life in automatic weapons.

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I doubt that will matter to the OP in choosing a cartridge for deer.

BigBore44 said:

View attachment 835866 I went with BCA fluted HBAR 7.62x39 during a good sale. Paired with a PSA MOE EPT STR lower. Really cheap to plink with. Cheaper to hunt with than just about any other medium bore cartridge. All the accuracy I need. Many pigs will fall to this rifle starting in a few weeks.

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I also went with 7.62x39.

I put mine together using a stripped Aero lower with a PSA LPK with enhanced FCG. Complete PSA upper with Boyd’s laminated furniture. C Products 20rd mag, 30mm Simmons 1-6x scope mounted in a Giselle style knockoff mount.

It is quite accurate and very mild recoil.




I also have a 16” .300BLK that is also very accurate and a good choice for short to medium range shots on deer however if I would have bought my x39 first I would not have bought the .300.


Anderson stripped lower with enhanced PSA LPK, A2 stock, MOE grip, SOTA upper, Nikon P-300BLK 2-7x scope.

Very good shooting rifle but gets very little time in the field after I put the x39 together.

brutus51 said:

Never heard of the 7mm Valkrie, what is it and is ammunition available?

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It’s a Wildcat, no, ammo isn’t available. Brass can be made from many common .473” nominal case head short action cartridges, but 6.5x47 Lapua brand brass is the proprietor’s recommendation - which does hold true. It’s a series of cutting the necks off, bumping the shoulder back, expanding and neck reaming/turning (multiple times each, especially depending on your brass source choice), necking, trimming, annealing and final fireforming.

In other words, it’s a hell of a lot of work to make brass. A guy really needs to 1) want it bad, and 2) have a powered neck reamer/turner.

It shoots a heavier better bc and sd bullet faster than the 6.8, using the same barrel length. 90% of what a 7mm08 can do in the smaller lighter platform.

I had an AR in .358 WSSM. Launched a 200 grain at about 2,850 IIRC. Really hard hitting with very moderate recoil. Works with standard r mags

It would be an awesome factory round

I'm wondering does anyone neck down the thumpers. I would imagine a 6 or 6.5 bushmaster would be a screamer.

mavracer said:

I'm wondering does anyone neck down the thumpers. I would imagine a 6 or 6.5 bushmaster would be a screamer.

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Look at mad dog weapons systems, they make some pretty hot wildcats based on .473” cases. The problem with necking down a 450 bushmaster or 458 soccom is they have to be run at lower pressure due to the bolt thrust being to much for the small AR15 locking lugs. The MDWS wildcats use a proprietary bolt with different lug geometry to be able to go up to 60,000 psi.

someguy2800 said:

Look at mad dog weapons systems, they make some pretty hot wildcats based on .473” cases. The problem with necking down a 450 bushmaster or 458 soccom is they have to be run at lower pressure due to the bolt thrust being to much for the small AR15 locking lugs. The MDWS wildcats use a proprietary bolt with different lug geometry to be able to go up to 60,000 psi.

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Thanks, enjoyed the read. Varmintterror's 7 valk would be awesome but do sound like a lot of work. I think my lazy butt would just live with a 1/2# heavier AR10 in 7mm08.

I’ve had a 6.5 Grendel and 6mm AR Turbo 40 (uses the Grendel case) for 4 or 5 years and have yet to have a feed or magazine issue. That said, I use 5 round magazines for both and that may help. I think the issue was early on and for the most part those issues have been resolved.

mavracer said:

Thanks, enjoyed the read. Varmintterror's 7 valk would be awesome but do sound like a lot of work. I think my lazy butt would just live with a 1/2# heavier AR10 in 7mm08.

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Your doing pretty darn good if you manage to build a comparible AR10 that is only half a pound heavier. I would say more like 2 pounds when similarly outfitted.

brutus51 said:

Interesting but what does it do that the 6.8SPC doesn't?

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Take hours to prep brass.

It shoots a little flatter, but until paper starts shooting for me, the 6.8 or 6.5 is worth more in my safe.

My lazy butt is able to buy brass already converted to 7mm Valkyrie...so it loads just like any other round for me. I always shoot with a brass catcher so I don't lose brass and the Lapua brass lasts for a very long time.

Correct that is uses a proprietary bolt and barrel extension and they have been proofed to take over 70k psi. MDWS has only had one bolt/expansion fail and it was the 358 Yeti that they make. The loads being shot according to quickload was over 75k psi.

Also MDWS is doing rounds based off of the 6.8 SPC case. From 20 cal all the way up to 30 cal. The 20 cal and 6mm version are currently in testing. I'm gonna be a tester for the 25 cal version

someguy2800 said:

Your doing pretty darn good if you manage to build a comparible AR10 that is only half a pound heavier. I would say more like 2 pounds when similarly outfitted.

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Maybe think about a .45 Raptor for that AR10. 300 gr @ 2200 fps would put a smile on my face.

earlthegoat2 said:

Maybe think about a .45 Raptor for that AR10. 300 gr @ 2200 fps would put a smile on my face.

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I’m thinking about it. If I can’t sell mine I will probably rebarrel it to 45 raptor. I already have a 444 marlin and a 45-70 so I have no idea why I would need that other than when people ask me what I have it for I can say “velociraptors of course.”

A 10 round mag full of 300 grain xtp mags does sound like a good water jug blower upper. At the same time so would a 250 xtp from a 450 bushmaster.

I am sort of surprised 45 Raptor is not more capable than 2200 fps with a 300gr. 450BM will push a 300gr bullet to over 1900fps. I would have thought 45 Raptor would have gotten more velocity given how much longer that case is and higher pressure it operates at.

mcb said:

I am sort of surprised 45 Raptor is not more capable than 2200 fps with a 300gr. 450BM will push a 300gr bullet to over 1900fps. I would have thought 45 Raptor would have gotten more velocity given how much longer that case is and higher pressure it operates at.

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That’s the gap I can’t close to justify a 45 Raptor. A “regular” customer of mine has been prodding me to try one of my own so he could see it, I just can’t convince myself I could do anything more with a 45 Raptor than I can with a .458 Socom. Faster and flatter, sure, and it’s really not so different than comparing my standard pressure vs. Marlin Only 45-70 loads I shoot - but the “big difference” for me is the fact my 1895 shoots both with a smile, whereas I’d have to slap 2lbs more rifle together to get the same improvement from a 458 AR-15 to an LFAR 45 Raptor.