Parts for SR-762 builds

[eunichron]

Primary Arms discount on the SR-762 lowers is up again. $69.99 while they last. I have all the receivers I need for the builds I want, so I won't be purchasing more.

I did finally get a response from Ruger customer service regarding parts availability. They only confirmed that they no longer have parts available for purchase, and that any Armalite upper should mate with their lower.

A few of the parts I ordered from Numrich/Gun Parts Corp arrived today. Pivot pins and bolt catch roll pins. The pivot pins are Ruger OEM part #NS01066 and measure at 1.3500" long, not including the head. They are .2745" wide. This matches dimensions I've seen for Armalite pins. I think it is safe to say any Armalite compatible pins are good to go for these Ruger lowers.

The bolt catch roll pin is listed in the manual for both the SR-556 and SR-762, and it measures within spec for a standard AR15 bolt catch roll pin. I paid $7 each for these Ruger OEM pins, don't pay that much. Use whatever you can salvage from a parts kit or order them from McMaster-Carr (3/32" x 1/2" coiled spring pin part #91598A204).

Next steps will be ordering one each of the Stag10 and DB10 uppers and some more Armalite small parts to see how they match up.

[Armed Eye Doc]

You are giving some excellent information on a large frame receiver that will be useful for some unknown lurker in the future.  You are what this forum is about.

[Armed Eye Doc]

Diamondback DB10 and Ruger SR762 will mate to each other and cycle.  I was not in a place to test fire though.

Top is a Ruger upper on a DB lower.  Bottom is reversed.

[98Z5V]

Good info!  So, you won't get any info from Matrix Aerospace about these now, because they changed their own design.  However,Matrix made all those uppers and lowers for Ruger,  from 2013 to 2018.  With that said, you can follow what other Matrix owners had to do to complete their receiver sets and get them running.

Here's my .338 Federal Matrix gun:

 

[Belt Fed]

The takedown pin on the last Aero lower i built was too short. it still worked but does not come even with the hole.

Edited October 12 by Belt Fed

[eunichron]

On 10/11/2026 at 3:51 PM, Armed Eye Doc said:

Diamondback DB10 and Ruger SR762 will mate to each other and cycle.  I was not in a place to test fire though.

Top is a Ruger upper on a DB lower.  Bottom is reversed.

Excellent!

My only update is that I have no updates at the moment. Great to have confirmation on the DB10 upper, but they're out of stock on the website at the moment, so I haven't been able to get an order in. I have a Stag 10 upper on order that's estimated to ship in the next few weeks. I've been finishing up some AR15 builds while I wait on stock notifications.

[98Z5V]

I've got a couple STAGs and one Matrix.  The Matrix was identical to the SR-762.  I can mate them together next week and see if they fit.