I am considering a build, and there seem to be many players that aren't compatible with each other....

As a general rule my assumptions from reading are:


1.  Buy a matched upper and lower from a single vendor, as many uppers and lowers aren't compatible, even if they are "DPMS pattern" and take PMAGS.

2.  Any DPMS pattern Bolt carrier group should be fine for any DPMS pattern upper/lower combo, regardless of brand?

3.  Stocks are just like the Armalite AR10 -  we use the same receiver extensions, just need specific size buffers and springs for the .308 variants.


Where does the majority of "incompatibility" come in?

Adding to the confusion, there are several new entrants to the market with receiver sets in particular, that are "DPMS" compatible, but don't seem to fit with DPMS receivers if you mix and match.

From your other assumptions, they appear reasonable, but there have also been instances where the rails on the bolt carrier are impacting the Receiver Extension threads in the lower, when the gun had the correct buffer and spring for an AR10.

It's an example of tolerance stack across multiple machine shops, with a gigantic question mark as to how many of them are running off the the same prints for AR10 receiver groups, BCG's, barrel extensions, threads, magazine catch location in relation to center of bore for the BCG, fire control group pin locations in reference to the BCG, reamer prints and tolerances, let alone materials selection.

In the end, you accept the total risk as a consumer that forcing these parts together is going to result in magic when you pull the trigger.

This is why I describe the AR10 parts market as a minefield that has to be negotiated carefully.  I've been watching this forum, and I'm seeing out of battery firings (How is that even possible?), pirced and blown primers, mags that don't work that were specifically meant to work in SR25 pattern guns, and a lot of DIY builds that simply don't cycle, Fail To Eject, etc.

It's an interesting thing to watch unfold, after having been into AR10's for so long.  Keep in mind, I had plenty of problems with off-the-shelf DPMS LR-308's and LR-260's, which were extractor and tight chamber related.

So I was thinking of selling my Armalite AR10T, and doing a build on a DPMS pattern, just to stay more "current", and have PMAG options.

Perhaps I should be happy with what I have?

It actually works, and shoots well, doesn't it?  If you want a lighter gun, consider the AR10A as a base model.

You could also buy a GII.  All depends on what you want to do.

Yep, it does.  However, it doesn't like to run suppressed very long before it starts really choking.  I imagine it needs some gas regulation when suppressed.

Armalite SASS kit, with their adjustable gas block.  It does use an .875" gas block though.  Armalite SASS Kit

I would be down for a "compatible" sticky thread.
I'm hoping for a Aero matched set on Black Friday.

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Two start off with we have two different patterns.   The Armalite AR10 pattern and then DPMS AR10/LR308 Pattern, they are different.   If we could get all the different manufactures on the same page or some kind of standard like they did for the AR15 in mil speck, so everything would be the same and interchange.

Wolf

I can almost buy a dedicated rifle for that money.

There are way more than that, and receiver compatibility within SR25 magazine compatibility is only diverging, not aligning.

1955-1962

* Original Armalite AR10 from the 1950's, to include Dutch, Sudanese, Portuguese rifles, many of which were imported back into the US, a few as complete rifles, and others as parts kits.  More of a collector's market.





1993

* Knight's SR-25, designed in conjunction with Gene Stoner himself. Introduced in 1993, using commonality with existing AR15 parts for ease, the SR25 entered into the market.  The biggest difference between the SR25 and original AR10's is the BCG, which has a narrower tail so it can be used with AR15 diameter RE tubes.  The fire control group is also patterned after the AR15, which has some distinctions from the original coil sprung AR10 hammer.





1996
* Eagle Arms (who acquired the Armalite name) EA-10 and AR-10's, with modified M14 mags.  Karl Lewis of LMT did much of the work on the Eagle Arms/Armalite AR10, using an SR25 upper receiver for a test bed.  Introduced during the time of the Clinton AWB, they had to source surplus magazines, since new mags could not be manufactured for civilian use, unless they were limited to 10rd or less capacity.   Armalite History





2003-2006

* Bushmaster introduced a Rock River licensed design in 2004, called the BAR-10.  It ran on FAL mags, but was discontinued in 2005, only to be revived as the RRA LAR-8 a few years later.



* DPMS, saw the demand in the market, and introduced an economy LR-308 rifle series in 2004 right before the sunset of the Clinton AWB, using a BCG and magazine patterned off the SR25, but a different set of cheap 6000 series receivers that don't work with the SR25.  The original magazines were of a translucent color, polymer, and limited to 10rd capacity, which was fine with the 24" bull barrel LR-308 rifle.  With the AWB sunset, the .308 AR market started to rapidly expand around this design, with several C Products sources as an OEM manufacturer for DPMS magazines.



* CMMG began offering receivers that were compatible with DPMS receivers, as well as some marginal G3 magazine compatible uppers and lowers that saw limited interest from the market.



* DPMS introduced the AP4, with a lower height 1913 rail on the upper, ejection port door, and FA/brass deflector, causing the growing handguard after market to have to diversify even more from Armalite vs. DPMS upper receiver thread patterns by accommodating the new rail height.  This carbine won the NRA's Golden Bullseye Award of the year.



2007-2008

* Fulton Armory began offering their FAR-10, using what appeared to be a lot of DPMS components, but with higher standards of QC, fit, and finish, using high end Krieger and Criterion barrels.



* Rock River Arms introduced the LAR-8, using FAL mags, a much longer receiver set, longer BCG, longer charge handle, and unique barrel nut threads that were seen on the Bushmaster BAR-10.  They changed the charge handle to a traditional latch design, but retained the ambi bolt catch and FAL magazine compatibility.



* JP Enterprises began manufacturing the LRP-07, starting with their own billet receiver set, bolt carrier, and DPMS bolts.



* Patriot Ordnance Factory added the P308 to their line-up, using different pin lengths and dimensions with their uppers/lowers, and their op-rod system design from the POF-15.



2009

* LMT expanded their modular rifle line to include a new 7.62x51 MWS, which later won the contract for the British L129A1 DM system.  Karl Lewis's background in the industry spans decades of AR15/M16/AR10 component manufacturing, engineering, and collaborative effort with other major names in the AR15 and AR10 market.  The monolithic upper receiver design taken from the AR15 MRP offers continuous rail, and also has a quick barrel change system representing significant advancements in the AR15/AR10 market that set LMT apart from the competition.  Other innovative features are found in the gas system, as well as the bolt, which uses dual ejector springs for increased reliability and spring longevity.



* Iron Ridge Arms began making billet receiver sets based on the SR25/DPMS BCG, which evolved into the IRA-X .308 rifle.



* LWRC introduced the op-rod driven 7.62 NATO REPR with proprietary receivers, handguard, and BCG.



* Mega Machine introduced the MA-10 with their own billet set as a foundation, but relying on DPMS or Armalite BCG/barrel compatibility, and DPMS/KAC upper receiver thread/barrel nut interface.



* H&K Introduced the HK417 & MR762, which are op-rod driven 7.62 NATO rifles using all unique H&K components throughout the guns.



* LaRue introduced the OBR 7.62 as an entirely new approach to upper receiver and handguard interface, eliminating any contact between the barrel nut and handguard.  LaRue also spec'd out his own magazine, BCG, and gas system optimized for Surefire Suppressor use.  The OBR also has a continuous 12 o'clock rail to mitigate mounting of optics, clip-on Thermal Weapon Sights, and other devices based on a lot of input from military customers in the SOF community.  The new PredatOBR represents a series of innovative features, including tool less handguard removal.



* Colt introduced the Colt 901-16S Modular system with .308 upper receiver group.  This rifle will accept a standard AR15 upper, with a mag well insert so it can convert from 7.62 NATO to 5.56 NATO.



2010-2013

* GA Precision introduced the GAP-10, based on POF/Hogue receivers/Handguard, with high end Bartlein barrel.



* Remington introduced the R-25 (this is really a Freedom Group Consortium DPMS receiver set, BCG, and Remington barrel)



* Bushmaster, under Freedom Group ownership, introduced the .308 ORC, using DPMS-type receivers and BCG, with a Bushmaster chrome lined barrel.



* Smith & Wesson introduced the M&P-10, with totally divergent bolt and barrel extension geometry.



* Sig Introduced the SiG-716.



* Christensen Arms introduced their own receiver set, and production guns with carbon fiber wrapped barrels.



* Windham Weaponry (the former Bushmaster) introduced the SRC308.



2014
* Freedom Group introduced the GII through the "DPMS" brand name.  This is the most revolutionary development in the AR10 market since its introduction in 1955, in my opinion.



* Lancer introduced a revolutionary L-30 .308 rifle, incorporating many features reducing weight, offering modular magazine well, and an extended 1913 top rail.



* Seekins Precision introduced the SP10 .308, with some of the finest machining, fit, feel, and lightening cuts on the receivers.



* Aero Precision is now offering their own forged receiver set.



* PSA has introduced their own receiver set.



The highlighted companies have maintained a specific standard for them internally, without much regard for compatibility outside of their area of control.  There never is going to be standardization in the AR10 market.

no Sig or LWRC?  better than me, I'd of missed half of that

http://308ar.com/compatibility.htm  I found this site useful when I was planning my .308 AR build.



http://megaarms.com/maten/compatibility/  There's some good info on Mega's Ma Ten page.

I might trade mine for a DPMS G2 if the long-term feedback on them is good.

Sig 716, near the bottom

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