advice on 308 AR upper and lower

[JTNieman]

Rainer AR-10 18" brl or a CMMG CHF 18"

Those have mid-length gas systems don't they?

I'm just asking cause I learned the hard way that the Armalite-pattern rifle-length gas tubes are about 0.33" longer than the KAC/DPMS-pattern ones.

They are. I'm sticking with the greatest number of standard AR15 parts as possible. Shouldn't be hard at all.

That's awesome. I'd be -very- interested in your build.

My dad wants an AR rifle but wants a 308 .. so he figures hey, AR10. He's adverse to spending over a grand though, so... yea, going to have to see what I can get hooked up. Probably just gonna build it for him and gift it. He just wants it for some fun target shooting, not a lot, and hunting.

I don't give a fuck how many training course ninjas say it won't hold up to hard battle rattle course of fire or if they have to clear malfs on occasion because of ... whatever. It won't likely see the number of rounds in one training weekend after it's whole service life in my dad's hands.

[RickOShea]

Ruh-roh.....Checkout this thread that just announced that a company called Handl Defense is coming out with a 308 PMAG compatible lower for the SCAR...for $300.

http://fnforum.net/forums/fn-scar-17s/30502-scar-lower-receiver-made-7075-aluminum-accepts-magpul-308-pmags.html

[Regular Guy]

Ruh-roh.....Checkout this thread that just announced that a company called Handl Defense is coming out with a 308 PMAG compatible lower for the SCAR...for $300.

http://fnforum.net/forums/fn-scar-17s/30502-scar-lower-receiver-made-7075-aluminum-accepts-magpul-308-pmags.html

That is interesting. I'm still going to build my own. I believe the big problem with the DPMS was the use of 4140 for the barrel. It ran fine until is got hot. Once it was hot, the chamber expands and tightens then FTE. At least that's my theory. I have ZERO intrinsic evidence. However, when it was relatively cool and using commerical ammo with PMags, titties. It also ran fine with C-Products mags. It never failed to feed.

This go around I'm going to get a CHF brl or a Noveske. If this build is not acceptable to me, I'm going to get a SCAR with the PMag lower is it's not unobtainium.

[MacWa77ace]

Back on short list.

[Gunmetal Crew Chief]

Ruh-roh.....Checkout this thread that just announced that a company called Handl Defense is coming out with a 308 PMAG compatible lower for the SCAR...for $300.

http://fnforum.net/forums/fn-scar-17s/30502-scar-lower-receiver-made-7075-aluminum-accepts-magpul-308-pmags.html

That is interesting. I'm still going to build my own. I believe the big problem with the DPMS was the use of 4140 for the barrel. It ran fine until is got hot. Once it was hot, the chamber expands and tightens then FTE. At least that's my theory. I have ZERO intrinsic evidence. However, when it was relatively cool and using commerical ammo with PMags, titties. It also ran fine with C-Products mags. It never failed to feed.

This go around I'm going to get a CHF brl or a Noveske. If this build is not acceptable to me, I'm going to get a SCAR with the PMag lower is it's not unobtainium.

If they were using 4140 for a barrel, they were retarded. Its a ChromeMoly Steel, granted, and that gives certain advantages, but at the same time, it isnt meant for barrel building....Bike Frame, Clutch parts, even Receivers, but not where heat is going to build up like that. However, it doesn't stop a lot of companies from using it. Its one of the cheapest steels available...and in my opinion, not suitable for barrels. 4150 is better for a barrel, and the non chrome lined thing with DPMS makes me sick. Why on earth...well anyways...I always look to Noveske if I want to know what smart gun builders are using...416r Stainless type. Thats a niiiiice barrel steel.

[RickOShea]

This go around I'm going to get a CHF brl or a Noveske. If this build is not acceptable to me, I'm going to get a SCAR with the PMag lower is it's not unobtainium.

Yeah, I like the CHF 16" barrel that came on my LMT.....But, it's just soooo damn heavy.

I got an 18.5" chrome-lined Criterion barrel that weighs 1lb 3oz less, that I'm going to send to DBMG and have them do their MWS conversion on it, so it'll work on the LMT quick-change barrel system.

I put that same barrel (18.5", CL, Criterion) on my M1A about seven years ago, and have been "tickled-shitless" with it's quality and performance (it was noticable more accurate than the 22" stainless steel barrel that came on the rifle).

[Regular Guy]

This go around I'm going to get a CHF brl or a Noveske. If this build is not acceptable to me, I'm going to get a SCAR with the PMag lower is it's not unobtainium.

Yeah, I like the CHF 16" barrel that came on my LMT.....But, it's just soooo damn heavy.

I got an 18.5" chrome-lined Criterion barrel that weighs 1lb 3oz less, that I'm going to send to DBMG and have them do their MWS conversion on it, so it'll work on the LMT quick-change barrel system.

I put that same barrel (18.5", CL, Criterion) on my M1A about seven years ago, and have been "tickled-shitless" with it's quality and performance (it was noticable more accurate than the 22" stainless steel barrel that came on the rifle).

I'm liking the Rainer brls and they get good reviews. The CMMG CHF brls are not out yet, if ever, considering CMMG has kick ass ideas that they can't get off the ground. I don't blame them, they don't have a massive do anything budget.
I'm going to find a brl that is a good balance of strength and weight. Nice thing is that there is more interest in AR-10s and more competition for our AR-10 dollarz. My weight goal is 9lbs.

[RickOShea]

That's the one thing that I don't get about LMT. They've had their rifle out for a few years now, and they offer 16", 18" & 20" barrels, in either CM or SS.....But they're all in the uber heavy-weight profile.

I've read that a lot of guys just send their LMT barrels to places like ADCO, to have them turned down and reprofiled.

[Gunmetal Crew Chief]

Why on earth doesnt anyone ever use G10 for grips on assualt rifles or even use it for rail systems? Its lightweight, strong as certain kinds of aluminum, and easily machined. Plus it comes in a ton of colors. Hmmm...

[RickOShea]

Why on earth doesnt anyone ever use G10 for grips on assualt rifles or even use it for rail systems? Its lightweight, strong as certain kinds of aluminum, and easily machined. Plus it comes in a ton of colors. Hmmm...

http://www.g10grips.com/pages/g10-ar15-m16-grips.php

[Domino]

I am really happy with my DPMS LR-308. It gets sub MOA accuracy and it has been 100% reliable for the ~1,000 rounds I have put through it. Some people trash the DPMS Rifles but I have had no complaints from mine, only praises. As you can probably tell, I could care less what the gun snobs say as long as my rifle performs as it is intended because that is what really matters. I doubt any other .308 autoloader could shoot as well as the LR-308 or AR-10 style weapons. I say go for it.

Have you shot much surplus or dirty stuff through it yet, Dom?

I remember that RG said his shot great with commercial .308, but would choke on him with the cheap stuff.

ETA: IIRC, RG also said that the DPMS mags weren't that great, and that running it with P-Mags helped.

I haven't shot any surplus thorugh it primarily because it costs as much or more than the Russian (Barnaul) ammo. I trust the Barnual more than surplus because it is consistant new production ammo that is non-corrosive. It shoots the stuff just fine, fired over 400 rounds of the Silver Bear 145g SP with no failures and it stays around 2 MOA. If I want to stock up on cheap ammo, that is the stuff I am going to get. Honestly, I don't really see the point in shooting the cheapest surplus through an accurate platform like the AR. If I wanted to shoot surplus, I would have gone with a PTR-91 GI and I would advise others do the same.

[Regular Guy]

. If I wanted to shoot surplus, I would have gone with a PTR-91 GI and I would advise others do the same.

And you'd be giving damn good advice. I'd have kept mine but 3 shoulder surgeries means I need something with a little better recoil management as opposed to a rifle that actually increases it.

I'm kidding, my big problem was I couldn't get a stock that would fit me.

[RickOShea]

I haven't shot any surplus thorugh it primarily because it costs as much or more than the Russian (Barnaul) ammo. I trust the Barnual more than surplus because it is consistant new production ammo that is non-corrosive. It shoots the stuff just fine, fired over 400 rounds of the Silver Bear 145g SP with no failures and it stays around 2 MOA. If I want to stock up on cheap ammo, that is the stuff I am going to get. Honestly, I don't really see the point in shooting the cheapest surplus through an accurate platform like the AR. If I wanted to shoot surplus, I would have gone with a PTR-91 GI and I would advise others do the same.

I get really good groups with South African surplus (can't find much of that anymore) and German DM-111 surplus ball.

[thechin]

I was rocking german DAG for awhile but was having too many issues like spit casings and FTE.

These days I stick with steel and zinc cased from brown and silver bear.

[RickOShea]

I guess that's why the description says "non-reloadable".

[kdxman]

Here is another option for the 308 ar style
http://www.gaprecision.net/ga-precision ... p-10-.html
Its a little pricey but like every thing you get what you pay for
Also I would check out this sight
http://www.snipershide.com/forum/ubbthr ... =35&page=1
Its has a lot of good info on gas guns

[Blacksmith]

Ruh-roh.....Checkout this thread that just announced that a company called Handl Defense is coming out with a 308 PMAG compatible lower for the SCAR...for $300.

http://fnforum.net/forums/fn-scar-17s/30502-scar-lower-receiver-made-7075-aluminum-accepts-magpul-308-pmags.html

That is interesting. I'm still going to build my own. I believe the big problem with the DPMS was the use of 4140 for the barrel. It ran fine until is got hot. Once it was hot, the chamber expands and tightens then FTE. At least that's my theory. I have ZERO intrinsic evidence. However, when it was relatively cool and using commerical ammo with PMags, titties. It also ran fine with C-Products mags. It never failed to feed.

This go around I'm going to get a CHF brl or a Noveske. If this build is not acceptable to me, I'm going to get a SCAR with the PMag lower is it's not unobtainium.

If they were using 4140 for a barrel, they were retarded. Its a ChromeMoly Steel, granted, and that gives certain advantages, but at the same time, it isnt meant for barrel building....Bike Frame, Clutch parts, even Receivers, but not where heat is going to build up like that. However, it doesn't stop a lot of companies from using it. Its one of the cheapest steels available...and in my opinion, not suitable for barrels.

This is total bullshit. Tons of makers use 4140 steel for barrels and it works just fine.

Specific heat capacity: (BTU/lb-F):
4140= .113
4150 (military grade) =.114

Yeah that extra .001 is really going to make a huge difference and make it so much easier to heat up 4140 barrel.



4150 is better. Military grade is better.
4140 works and is cheaper so you can pay less and get marginally lesser quality product.
The differences in performance are negligible and the shooters likely enough to notice the difference are the ones who spend so much money on shooting ammo that they are going to buy a better barrel than the 4150 military grade anyway.