Home Forums Hunting & Shooting AR and Tactical Rifles AR10 build question

I am building a AR10 rifle and I purchased this upper/lower: http://www.slickguns.com/product/aero-precision-m5-ar-10-matched-set-225

I've built several AR15 rifles but not a AR10 and I know AR10's are their own animal, anyways from my research it seems like the Armalite gas system might be better but I'm not sure if it will work on a DPMS style build.

If it matters I will probably have it chambered in .308, maybe 6.5 grendel creedmoor. I was originally going to build a 243 but I haven't read many positive reviews for the chambering in a AR10.

Edit to add: I am leaning towards a rifle length gas system and a 18"-20" barrel.
Thanks!

I'm not an expert, but have 2 DPMS LR uppers in .243 and .260, and have worked on them a bit.

It seems like you already get the difference in DPMS and Armalite platforms, most of the parts don't interchange. RRA is it's own platform as well. DPMS is the most common and what I have.

6.5 Grendel is an AR 15 chambering, You could do .260 or 6.5 creedmoor with the LR-308 platform. I have a Black hole weaponry barrel on the 260, a dpms on the 243. If I build another down the line I'll probably do a Lilja. Some companies either sell the bolt with their barrel for correct headspace or require you to send one in.

I would do rifle length gas, even with 18" barrel, it is said to cycle the action smoother. I would also get an adjustable gas block, many of these .308 based chamberings lead to over-gassed rifles that need to be tuned down for proper cycling and to be easier on brass.

And keep in mind these are heavy. If you want a particular weight for carrying you need to consider that when picking your barrel contour and handguard.

I would spend my money on the trigger and barrel over the other stuff if budget is a concern. Stocks and handguards are easy to upgrade later. I like Geissele SSA-e the best in my AR15s.

Thanks for the info, I meant the creedmoor in my original post.

How do you like the 243 in an AR10?

I looked at Black Hole today for barrels and I was going to call them to ask them a few questions, are you happy with the one they made you for your .260?

I dig Geissele, I use the G2S but I've been using their lower end ALG triggers and I like those too.

I've had the 260 for a few months, but haven't ran it much. I sold the scope I had on it and haven't used it since, but plan to soon. I had to radius (polish the corners) the extractor b/c it was chewing up case rims at first. I also had to turn the gas block down nearly closed with it to get it cycling properly. I have only put 30 something rounds through it, no loads so I don't know yet on accuracy. The bore did feel smooth and clean up easily though.

I picked up the 243 as a complete upper, it has a standard gas block on it but it functions fine. It's the LR 243 lite hunter, with the lighter contour 20" barrel and carbon fiber FF tube. It doesn't seem too too picky, last time out I found loads for 95 sst and 85 sierra gk in mixed brass that shoot MOA or a little better.

What do you mean by Armalite gas system? They and the DPMS are essentially the same thing. The Armalite gas tubes are a tad bit longer but are pretty much interchangeable with DPMS stuff.

Go with a rifle length gas system for any barrel length greater than 16".

I thought DPMS uses a ar15 gas tube and armalite has their own..

Armalite's are a tad bit longer but either will work. I have an armalite tube on my DPMS pattern Lilja.

Is it an Armalite A or B lower?
http://www.thetruthaboutguns.com/2012/01/foghorn/new-from-armalite-ar-10a/

The Armalite AR10 B was designed and sold during the 1994 to 2004 Assault Weapons Ban. They used modified M-14 magazines to get around the 10 round magazine limit. Armalite also produced their own AR10 B magazines during and after the ban.

Armalite is now selling the AR10 A lower which is also their original AR10 lower. The AR10 A lowers will accept original Armalite magazines and the new PMag magazines that can be used in DPMS 308's.

It's also my understanding that the Armalite A uppers will fit on the DPMS style lowers. I cannot tell you if the Armalite B uppers will also fit. I'm sure someone who knows will help us out.

kwg

The Armalite upper will fit on a DPMS lower but the DPMS upper want fit on a Armalite upper due to the radius at the butt end of the upper. There will be a gap at the rear of the upper to lower fit when putting a Armalite upper on a DPMS lower. There is a picture some where that shows the fit but I am unable to locate it.

Found it...



Here is some good info on the 308 AR compatibility

http://308ar.com/compatibility.htm

I have a matched upper/lower from Aero Precision.



Looks like the gas system is interchangeable so I think I'm good for now. I'll probably have some more questions, thanks all!

That is a DPMS style upper with a High Rail. You will need a handguard with a matching rail and a AR15 gas tube. There is 2 different DPMS style uppers a high and low rail. This is why I ordered all my upper and lower parts from Aero.

Thanks for the intel!

Here is what I was looking for to show the difference between the tall and short uppers.

https://troyind.com/sites/troyind.com/files/rtc-attachments/DPMS_RECEIVERS_COMPARE.pdf

Thanks!