Welcome to the frustrating world of " No MilSpec guidelines for LFAR's"  ( LFAR's Large Frame AR's )

I say LFAR's because of the many different patterns used.

I would post pics of your various LFAR's.... I ask just to be sure you are talking about a DPMS GII "small frame model "

The DPMS GII is a small frame 308. Not a lot of interchangable parts. Triggers, mags, yes... but a lot of the other parts are proprietary.

If your DPMS DP10 308 is this... https://dpmsinc.com/dpms-dp10-18-mid-length-308-win-1-10-stainless-steel-classic-rifle.html
It probably is a PSA, just rebranded DPMS.... Those you can readily get parts from PSA.

LR-308's lots of companies make parts for these... but again make sure the parts work for that "Brand"

High Rail v. low rail.... they are talking about the height of the rail on the upper.  

And even this can be a chore... since PSA uses a rail height in between high and low.


Some examples of proprietary parts... bolt catch, mag catch, uppers or lowers ( subtle BCG heights in context to the lowers buffer bore axis ) pushdown pin lengths and positions...

Parts differences specific to the different "patterns"... different barrel nut thread pitches, subtle measured differences between a Armalite v. DPMS bcg, gas tube lengths protrusion into the upper.


The list can go on and on.

So, please post pics of your LFAR's ( can I say that any more with a DPMS GII ? )

Than way we can help steer you into the correct direction.

Can you tell if your barrels bore is chrome lined ? ( The linked description says " Chrome Lined Nitride Coated").... not really important, but if it is chrome lined, please post pics of any markings on the barrel.


For the DPMS-DP10... if your lower is stamped with "West Columbia, SC", I am 99.9% sure it is a PSA PA10 "pattern"
I say 99.9% only because some of the DPMS models say.... Upper ..." Receiver Style: DR10 Flat top with Feed Ramps"  and some say "Receiver Style: PA10 Flat top with Feed Ramps"
But, I seriously doubt PSA would make a different upper for their own PSA proprietary lower.  

When I say PSA pattern... that is because of some of those subtle differences.... IMHO, it would be best to buy parts from PSA or "DPMS"

Bolt catch will be PSA specific for these.

PSA ( CURRENT DPMS )  uppers and lowers ONLY fit each other.. not a bad thing since you should be able to buy any PSA PA10 / PA65 upper and use them.

I know the pivot pin on a PSA is longer then some other brand LFAR's.

DPMS pattern BCG's and barrels are GTG.

All Typical AR15 triggers all work.

Handgrip wise.... ERGO, PSA, and Magpul MIAD GEN 1.1 Grip Kit – TYPE 2, have all worked for me... some of the other Magpul grips with a beavertail, do NOT fit properly, there will be a gap at the beavertail end.

As for the PSA rail height... it is right in between low and high. Most people just us a low free float handguard.

The DPMS Gen II is a different beast unto itself. Parts for these are pretty danged hard to find.

Shorter and lighter lower, BCG unto itself, ejection port door unto itself, barrel and upper unto itself.... all sorts of proprietary parts.  Did I mention unto itself ?

GenII BCG in the middle. LFAR on top ... AR15 on the bottom

On a side note... Armalite AR10 parts seem to be getting harder and harder to find.

I would stock up on spare parts as needed for your AR10 Armalite.

Interesting it is Chrome Lined barrel.  PSA has used FN CHF CL barrels on and off during its PA10 production.

Quote... and I should have been more specific.
"as far as the gen ii, it is a highrail. i measured from the pics...its exactly .210"

I don't know if the .210 thing applies to the Gen II... it does to the DPMS LR308.  But I think the Gen II has a different diameter barrel nut, so a common LR308 free float tube won't work.

FWIW, even the charging handle on the Gen II is proprietary.


BE VERY CAREFUL who you order Gen II parts from, they are that rare... and some will try to rip you off or steal your CC info.

Fine looking Gen II !

LaRue trigger ?

I "think" I have one of the DPMS LR308 Broom handle barrels in queue for a PSA build ( Lol , never enough time, the older I get..... and to many irons in the fire )