.223, .300 Blackout, 7.62x39 and .50 Beowulf

I only have 223/556 right now and am building another 223. After that I want a 300 Blackout and a 22LR. 6.5 Grendel would be after those. From there I have no clue.

I've only built one outside the service, a 16" copy of the 10" CAR's I helped the Cav. recon unit build, cal. 5.56. I do want to put a .300 BO on the AR I just got today, and a can.

None other than 223/5.56 currently. The 6.5 Grendel is the only thing that interests me and I may well add an upper for that round sometime in the next year.

I have now put together a 16 inch 5.56 carbine and a 16 inch 300 blackout.

I have learned to do my research, especially on the length of the gas system. I really like the BO but the 5.56 is like the foundation AR. I feel like you have to have one in 5.56/.223 just because of ammo availability.

I may forget a few I've built for customers, but I personally own or have owned 22LR, 17WSM, 17 rem, 17Mach IV(disaster), 20 Prac, 204R, 223rem, 223wylde, 5.56x45, 223AI, 6x45, 243wssm, 25 wssm, 6.5 Grendel, 264 LBC, 6.8SPC, 277 wolverine, 7 valk, 300blk, x39, 450 Bush, 458Soc, 50beo.

Personally, the 223 wylde and 5.56 make the most sense for a general purpose "joyful" rifle. The mid-bores like the 25-45, 6x45, 6-6.8, 243lbc, 6.8spc, 6.5 grendel/264 LBC really are the most versatile. I love shooting the 458 soc out of the AR, just as I love the 458win mag in a bolt repeater and the 45-70 in a levergun, but the heavy weights really do lack in versatility - too much recoil for small game, and not really any better performance on mid-sized game like whitetails and hogs than the 6.8/6.5's, so unless you're going after short range bison, the big bore AR's are just a novelty. The x39 and 300black are cartridges which don't interest me any more. The trajectory is weak, so they fall short on deer/hogs compared to the 6.8/6.5's, but they don't yet hit as hard as the 450/458/50... Kinda like a full size truck with a 6 cylinder, they'll get you to work well enough, but when you really need to work, you'll find a weakness. The WSSM's were an absolute joy, AR-10/LR-308 performance out of an AR-15, but it's also hard to call the Dtech (oly) uppers true AR-15's, since so little about them is transferable. If the brass were 1) more available, and 2) much, much better, I'd still be shooting the 243wssm, but until then, I'm content to run 243win DPMS GII and 6.5creed LR-308 customs instead.

Have plans for a 300 blackout.

Favorite AR-15 I have...easy the 7mm Valkyrie. BY FAR the most versatile cartridge inside the AR-15 platform.

CarJunkieLS1 said:

Favorite AR-15 I have...easy the 7mm Valkyrie. BY FAR the most versatile cartridge inside the AR-15 platform.

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I get more out of the 25wssm, and don't have to spend hours on hours forming brass, and factory ammo can be found on the shelf. That's the crippling aspect of the 7 Valkyrie for me, it's an impressive round, but it's not so great to warrant the annoying amount of brass prep.

My favorite round in the ar is the .458 Socom, i didnt build the upper for that one (tho ive taken it apart a few times, and replaced the hanguard now).

My 6.5Grendel is my favorite upper that ive built. 100gr balistic tips at 2700ish do wonders on our goats, and the guns light and handy. Even with a relatively heavy lower build.

Ive done 4 .223 uppers and 2 .300aac uppers, but those were all mostly refining my personal preference in parts and feel. Ive gone thru 1/2 dozen grips for the same reason, and if i dont sell my AR soon ill probably go through a few stocks.

Im assuming the 7Valk uses a larger dia bolt and barrel extension, or some other method for increasing the strength of the bolt lugs? I wonder if the bolt and extension could be used with the big bores to allow for higher pressure loadings.

I have built a lot of 5.56 AR uppers. I have a couple in .22LR. I used to have one in .458 SOCOM.
I own two rifles in .300 Blackout, but both of them are bolt guns. And I am happy I went that way.

The only thing that really interests me in an AR is 6.5 Gendel. I have a feeling that some time in the not to distant future I will give that a try.

Hard to beat the .223, cheap to shoot, accurate, low recoil. I have also tried 6.5grendel and 6.8spc, kept the 6.8. I have a 300blk pistol I just finished which is a lot of fun at the range but it basically has no other purpose. Back in July at the range a fellow let me shoot his 458socom carbine which was rather impressive but I'm not sure I need one.

I prefer original recipe 223/5.56. As far as best practices, only buy good gas blocks (or just use standard FSB), and take advantage of PSA sales.

I have an old Rock River Coyote Rifle I bought years ago with a 223 Wylde chamber. Its been primarily my 3-gun rifle and I have done a little bit of varmint hunting with it. Doesn't really have the right optics on it for serious ground hog hunting. The Leupold Mark 4 CQ/T 1-3 x 14mm works great for 3-gun and carbine matches despite the 20-inch barrel. I love the ACE stock. The gas block is a bit of a chunk that could really be replaced since I no longer run iron sights on it.



Two years ago I built a 300BO from parts. The scope is a Burris MTAC 1-4 x 24mm. Used it for a carbine match or two that summer for fun and then hunted deer with it in the 2016-17 season. Did not take a deer with it but carried it a lot, got my deer(2) with a revolver that season. It will be getting an AAC 762-SDN-6 later this year when the paper work clears. Probably use it for some coyote hunting as soon as deer season is out this year.



This summer I picked up a factory 450 Bushmaster upper kit, 20-inch barrel and put it on a DPMS A2 lower I had built. Since it was going to be my hunting rifle this year I topped it with a Vortex Viper HS 2.5-10 x 44mm. I spent the summer working up various loads for 450BM, My 450 has never fired a single round of factory ammunition through it. I settled on a 275gr Barnes TSX bullets for hunting season this year. Unfortunately it has been a dismal hunting season for me this year and the only shoot-able deer I have seen in rifle season I managed to miss. He was one of the largest buck (10pt) we have seen on the cameras and it was a shot I probably should not have taken at all (buck fever). At least it was a clean miss. Two more weekends of hunting to redeem myself remain. In all the load work I did this summer I did manage to come up with a really good subsonic 405gr 450BM loads. I just need to find a good suppressor to go on the rifle and the money rolling up hill to buy it.



Right now 450 Bushmaster has to be my favorite but I think when the suppressor comes in 300 BO is going to get a lot of trigger time. I plan on putting 51 tooth flash hiders on both the 300 BO and the 223 rifle to see how 223 super sonic sounds suppressed. My next AR pattern rifle is probably going to be a DPMS Gen II rifle but we'll see.

I have only .223 caliber AR's. If I want to thump I prefer the WWI and WWII rifles that I own.

Varminterror said:

I get more out of the 25wssm, and don't have to spend hours on hours forming brass, and factory ammo can be found on the shelf. That's the crippling aspect of the 7 Valkyrie for me, it's an impressive round, but it's not so great to warrant the annoying amount of brass prep.

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I don't have to form brass I can buy formed brass that is ready to load. Its just like loading any other caliber to me.

BTW have you found any 25 WSSM brass or ammo in the last 2-3 years...and a .257 caliber more versatile than a 7mm...OK whatever you say. I can order 100 Valkyrie cases and have them in a few weeks, plus the Lapua cases last 15+ firings. Don't see any WSSM cases lasting half that.

I have heard the Hornady is making WSSM brass now so that is good news.

.223/5.56 only here. Never saw the need for a precision AR in another caliber. If I'm going longer range I'm grabbing a bolt gun.

6.5 Grendel, .224 Valkyrie, et all get royally smoked by similar cartridges that don't need to be made to work in an AR.