98Z5V

Not even. My scope is as low as it can get, too.

I blast the externals, completely. Whatever happens to get taken off the inside is a bonus. I paint the whole thing, inside and out. EDIT: that includes the receiver threads. This is for Cerakote, not Duracoat.

Well, barrel length will always be personal preference, but with that (your) criteria, I don't know if I'd go 20" on it. 300~600, you can probably do with a 16" barrel, rather easily. The .338 Fed isn't going to have the distance that a heavy .308 Win load would - you're using the same case, necked up and using heavier projectiles... less case capacity, pushing a heavier projo. I can't see the .338 Fed keeping up with the .308 Win at longer distances. You'll still be pushing a 200~225gr projectile at 2,200~2,400 fps. But, 300~600 should be easy for it. 18" would be as long as I'd wanna go, for sure, if it were me. .30-cal muzzle devices usually add around 2" to the barrel length, too. Something to keep in mind. There are newer (lots of!) muzzle devices out there that are shorter, as well. The reasons for me going 16" on the barrel - for now, until I can cut it down more - are because I'll be carrying it, shooting it to 300, max of 400, and I don't want it to be a super-heavy rifle. Needs to be maneuverable.

It still comes down to this, for this cartridge - that might have been overlooked in my long post. What's the intention for this rifle, and at what range, man? That will definitely guide the recommendations on what you should order. Over anything else. My rifle is gonna be a Fatass Texas pig-gun. I don't see myself taking any fatass hog shot beyond 300 yards, at all. That drives my build, right there, and my barrel selection and build criteria.

You come out here, and my Arizona Ninjas will manage to shoot the fuk out of the PVC. I think the PVC is bullet-magnetized or something... These guys will test it, that's for damn sure... My steel-framed target was fine at 100 yards, until Mike decided that he could shoot his 10mm pistol at 100 yards... The steel frame was full of holes after THAT range trip... <lmao> Don't MAKE me take pictures of the target frame, Mike. I'm just sayin'...

5.56 shiit here, and I've got tons of experience with those... 1:9" twist is great for 55gr. 1:9" twist does okay up to about 62gr. The max a 1:9" twist can handle is 68/69gr, and it's just above it's capabilitiles for precision shooting. Will it get it done? Yeah, it can, but it comes down to the barrel manufacturer that that point. Most times, not optimal, though. You hit that peak shooting 69gr in your 1:9" barrel, that was sighted with 55gr ammo... That's what got you, with your recent tests. I have 3 stainless match barrels for 5.56 guns that are .223 Wylde chamber, 1:8" twist. one 16", one 18", and one 20". Those bastards are WICKED with 68/69gr match projectiles. Fucking ridiculous. They won't outshoot the 20" YHM steel-barreled 1:7" heavy barrel gun with 75/77gr ammo though, for distance. That thing is a freak with 75s and 77s. Total freak, all the way to 800 yards - yes Ed, you just read that... Pull that shiit with a 5.56 gun, stud. The Hornady 75 BTHPs are slightly more accurate over the Sierra 77gr OTM/BTHPs through that gun. The 18" Wylde chamber 1:8" twist is the best overall performer, though. That rifle eats anything, with ridiculous accuracy. I've got 55gr Hornady FMJ-BT loads that hit just as well as the 75gr Hornady BTHP loads do, at 100 and 200. Fucking stupid accurate rifle - but it's all about the barrel. For you, pokey, it's all about the barrel - and twist rate.

You won't know until you can't hit at 800m... I'm just sayin'...

You can't overstabilize a heavy round. You can come in under, though, on a heavy round, and not stabilize it. Slow-twist barrel. You can overstabilize a light round, and it'll fragment long before it reaches any target. Shoot a 5.56 36-grain Barnes Varmint Grenade through a 20" 1:7" twist barrel...

YOU determine that. Can you outshoot your rifle in it's Hogue Overmold stock? Is the stock your limiting factor?... YOU need to determine that - and since you just picked it up today, you don't know that yet... I know I've said this before, but you need to shoot your rifle... Determine what you need once you can outshoot it...

Different gun, man - no threaded barrel. Sweet chassis, though - I've been looking at those for awhile.

I'm lost on your post. You're building a rifle, so you're only gonna have glitches in it if you build them in - you won't have to deal with any crazy effed-up factory stuff, because it's all on you. Don't buy a DPMS .338 Fed full rifle - DPMS chambers are too unpredictable, with tight and not-tight chambers. You're not going through them for the barrel anyway, so that's a non-issue. Very few other manufacturers make a full .338 Fed complete gun, so that's out, too. For DPMS pattern or AR-10 pattern rifles, on a self-build - with these two receiver sets as the examples - you're only talking about which receiver set you're gonna buy. Nothing more. Which one is more aesthetically appealing to you? Go with that one... The barrel length choice is still unanswered, for this cartridge - why 18" or 20", on .338 Fed? What are you using this for, and at what distance?

With 18" or 20" on the barrel, you can go rifle gas, and it's gonna run. Don't do midlength gas if going that length. Why 18" of 20" though, on this cartridge?

Matrix Aerospace is who makes the upper and lower receivers for the Ruger SR762...

Here's who to hit for the Matrix stuff - it's not Matrix themselves. Chris is the main dealer for them: http://www.centralfloridafirearms.com/ You'll find his handguards there. As far as Matrix over Aero - both being aerospace machinists - you can't go wrong with either. I have two AP sets and the Matrix set. The basic question comes down to "do I like the DPMS-cut better, or do I like the AR-10-cut better?" Really, it comes to that. I can't even tell you how many AP 5.56 sets I have - I'd literally have to count them all. "Many" would be the appropriate description as of right now, and there's MANY. The two 308 sets I have are flawless, because that's how they do it. The Matrix set equals those AP sets in every single way, I like mine, and I'll probably try to find another .308AR variant to built, just to buy another Matrix set. Both are really, really good, so it honestly comes down to "what cut is better..." No kidding.

I'm with him - mine is very good. You need to mod it Ed - I've posted about that before. EDIT - hit these threads, fool... This only reminds me that I need to fucking get it going, and paint this thing already...

KNS pin set and Geissele triggers don't mix. That's Bill Geissele's call, and he knows what's best for his triggers. The only thing I run KNS pin sets on are the two blowback-operated pistol-caliber ARs, and the Can Cannon. Nothing else has them. Rifle recoil system - any A1 receiver extension will do. Don't waste the money on stuff marketed as "A2" and end up throwing parts away. Standard AR15 Rifle Receiver Extension for the PRS. That stock comes with it's own screw. Buffer - pick a 308AR buffer. Or, get one from HeavyBuffers, for the 308ARs. Any DPMS-high compatible handguard will work on the AP receiver set. Don't limit yourself. Chris, same guy that sells the Matrix Aerospace receiver sets, has some really nice, inexpensive handguards that will do the trick, without alot of money out of pocket - I bought one with my Matrix set, and I like it enough that I'll be picking up another one for another AP set build. It's good. 330 Fed build, and you're asking about gas system - but you haven't stated what length of barrel you'll be having made by X-Caliber. Barrel length will be the factor. I WAS doing a 14.5" 338 Fed barrel, but switched it to a 16" for now. Bought a brake that I thought I'd like, but it's SHORT. 14.5" barrel still won't make minimum-legal with it. In light of that, I'll go 16" for now, find a permanent brake I like later, then send the barrel to ADCO to get cut down for that specific brake, and still get 16.1" overall. I went midlength gas on that barrel.

Holy shiit, that is awesome! I didn't need to see this...

^^^ Thanks for that clarification, on why you called it that - That would make sense for the OP, considering what he needs to get rolling. We're well aware of the two trigger offerings from ALG D, as well as the Spikes Nib trigger. Shiit, I had a Spike's Nib trigger in mid-2010, and 3 or 4 ACT setups in different rifles. The ACT is superior to the Spikes NiB.

Nigel Tufnel is my hero - he IS the reason all my shiit goes to 11...

^^^ That's excellent!

In relation to that Drew, I left this part out - when I was composing the new, unrelated post, it wouldn't show the attachment of the old pic in my draft - it would appear there after posting it. That's when I'd go back and edit the old pic out. I guess what I'm trying to say - there wasn't a watch to catch it doing that, when composing the message - it attached itself once the post was made.

One thing I noticed - posting pics into a reply. Later, make another reply to something completely different, and it automatically attached the same pic onto that new reply, from a previous, unrelated post. I had to go back in there and edit it out. Working from a desktop. It did that 3 different times, so it's a glitch in the software somewhere...

Match it off the rear tab on your upper receiver... If you measure it out and it's high profile based on the measurements, then get a high-profile compatible rail or handguard system.

That's good - keep 'em together from the same manufacturer, in this build-game. Whatever weird, proprietary parts that PSA has for their upper and lower sets, get those. Everything else shouldn't matter. Run an Armalite buffer system if you'll be building a collapsible stock. I've found that there can be issues trying to mix "x" carbine receiver extension with someone else's cheap "DPMS LR308 carbine buffer - compatible" and so forth. With a 20" barrel, will you be running a rifle stock and not collapsible?

What brand of magazines are you using? Brand, and capacity...