Threaded barrel setup for an AR upper?

[ToddM]

Perhaps it's crazy talk, but it seems like the "big" accuracy limitation we keep hearing about with AR platforms is many of the uppers are built too thin, flex too much with a big long bull barrel on them, and the barrel to upper interface has too much slop, variation under bipod loads, heat cycles etc. In addition many of the handguards these days are not built to be stiff, but instead to be ultra lightweight. Sure there's the fact there's more moving parts, and loctime is much slower etc. but those are hard to get away from in a semi.

I've always wondered if it would be possible to do a heavier AR upper, but with a threaded barrel setup where the user just headspaced the barrel, but keeping all the other AR parts. Now we know that slip fit barrels can be accurate, Anschutz, Suhl, etc. do it, but it requires more care and custom machining, cryo fitting etc. that it's not something the average guy is doing. We also know some companies are wringing a lot of accuracy out of AR builds, JP, many custom shops, though I'd guess most are custom machining barrel extensions to be super tight to the individual uppers, etc.

It just seems like there's a market for long range semi's now that more and more shooters are stretching into longer ranges, but we're still working with fittings/interfaces etc. that were designed around being cheap, and field replaceable for a minute of man 600m guns.

 

[brazz04]

I'm guessing this thread will get overrun with "buy better parts" and I can't say I disagree with that motto. My 14.5" 6.5 Grendel with a Krieger barrel and an Aero M4E1 upper is outstandingly accurate...way more accurate than I am as a novice shooter.

Edit to add, 620 loktite is very cheap and effective in taking up minor fitment tolerances.

 

[ToddM]

I suppose that's fair, I've built a few and had a few built by some of the big names in AR's for accuracy, Keystone, JP, Precision Firearms, etc. but we still see guys struggle with issues even when buying top dollar parts. Some of that is the nature of lego guns and the fact they simply are harder to shoot as well as a bolt gun without great fundamentals.

I kind of see it like bolt guns. Sure I can go to GAP, PVA, etc. etc. and get a bolt gun that shoots amazing, and costs a ton, and there's value in that path. However now we also have the option to put top quality pre-fit barrels into a RPR, Savage etc. where costs are still kept reasonable but accuracy is maximised. We're also seeing switch barrel, thread/nut setups for guns that don't come that way, like the Tikka, TRG, Remingtons etc. So there's certainly precedent for maximising accuracy of a platform that isn't full custom. There's no shortage of "putting lipstick on a pig" with high $ part upgrades for lower cost entry level guns to increase accuracy.

 

[srt-4_uk]

So you wanna build an upper with the extension already built in? Honestly surprised it hasn't been done yet.

 

[ToddM]

Yeah basically a very beefy, even more beefy than say the Mega SBU version that was thicker than any other upper I've seen since, with I guess no extension and just a threaded barrel interface and locking nut. The Vltor Mur is 8.7oz with assist, dust cover, etc. The Mega SBU was 14oz stripped in the non-charging handle version, both 7075.

I'd add that additionally I'd want a thick, stiff handguard that was not mounted to the barrel nut in any way, in theory the strongest/stiffest option doing so would be a monolithic upper. So many handguards today are only focused on being the lightest. I was not a fan of the Mega MKM setups (similar to the Aero M4 enhanced, Seekins IRMT, which might be better haven't used either) I had am Mega MMK setup on a JP supermatch barrel for 3 gun and it was a noodle, Honestly the most flex of any handguard I've used since, and you got almost zero options for changing it.