Do Griffin Armament lowers fit PSA uppers?
Griffin Armament lower + PSA upper: yes, they fit
Yes. Griffin Armament AR-15 lowers fit Palmetto State Armory (PSA) AR-15 uppers. Both are AR-15 size receivers. A real mil-spec keeps AR-15 receivers from different makers close, though not exact, and fit problems show up most when the upper and lower come from different makers. We checked them with the rules the AR builder runs.
Fit comes from the same rules the AR builder runs on every part you add. Build data only ranks the setups; it never decides fit. Checked November 10, 2026.
Our take
Most built setup: the Griffin Armament MK2 Stripped lower with the PSA Built Stealth upper.
PSA is one of the most picked upper brands on Griffin Armament lowers.
Griffin Armament makes suppressors, muzzle mounts and sights, all in house in Watertown, Wisconsin.
Founded 2005, Watertown, Wisconsin, Made in USA
PSA sells affordable AR lowers, uppers, BCGs and complete rifles, and it makes them in house from forging to finished part.
Founded 2008, Columbia, South Carolina, Made in USA
Griffin Armament lowers and PSA uppers by platform
Each row is checked on the most built part of that platform from each brand.
| Platform | Fit |
|---|---|
| AR-15 | Yes, they fit |
AR-15: yes, they fit
Both are AR-15 size receivers. The upper is stripped, so the barrel you pick sets the caliber.
Checked on this Griffin Armament lower
Griffin Armament MK2 Stripped Lower Receiver$208.95and this PSA upper
PSA Built Stealth Upper Receiver$99.99Most built Griffin Armament lowers and PSA uppers setups
Ranked by how often builders pick the exact pair. Only pairs our rules pass are listed.
#1Yes, they fit28% of these buildsCheck fit
#2Yes, they fit11% of these buildsCheck fit
#3Yes, they fit4% of these buildsCheck fit
#4Yes, they fit4% of these buildsCheck fit
#5Yes, they fit4% of these buildsCheck fit
#6Yes, they fit4% of these buildsCheck fit
#7Yes, they fit4% of these buildsCheck fit
#8Yes, they fit4% of these buildsCheck fit
What Griffin Armament and PSA say
Griffin Armament: Griffin's MK2 stripped lower comes with left and right bolt catch and release levers and a left side mag release, but not the standard right side mag button.
Griffin Armament: The Griffin MK2 lower takes mil-spec .154 inch trigger pins.
Griffin Armament: Griffin's MK2 ambi stripped lower is built to fit mil-spec lower parts and has a mil-spec fire control pocket.
PSA: PSA owns its supply chain, including Spartan Forging and DC Machine, from forging the receivers to finishing the muzzle brake.
PSA: The KS-47 Gen2 bolt has two lugs reshaped so it feeds from AK magazines.
Fit is judged from the specs retailers list, which can be missing or wrong. Confirm with the manufacturer before you buy, and have a qualified gunsmith check any build before you fire it.
Other uppers builders put on Griffin Armament lowers
- Griffin Armament lowers + BCM uppersMost picked
- Griffin Armament lowers + Geissele uppersSecond most picked
- Griffin Armament lowers + Daniel Defense uppersFourth most picked
- Griffin Armament lowers + Aero uppersFifth most picked
Other lowers under PSA uppers
- PSA lowers + PSA uppersMost picked
- Aero lowers + PSA uppersSecond most picked
- Smith & Wesson lowers + PSA uppersThird most picked
- Wilson Combat lowers + PSA uppersFourth most picked
- Spike's lowers + PSA uppersFifth most picked
- Sharps Bros lowers + PSA uppersSixth most picked
- LMT lowers + PSA uppersEighth most picked
- Anderson lowers + PSA uppersNinth most picked
Griffin Armament lowers and PSA uppers: questions builders ask
Will a PSA upper fit a Griffin Armament lower?
Yes. Griffin Armament AR-15 lowers fit PSA AR-15 uppers. Both are AR-15 size receivers.
Do I need a matched upper and lower?
A real mil-spec keeps AR-15 receivers from different makers close, though not exact, and fit problems show up most when the upper and lower come from different makers.
Why might a PSA upper feel loose or tight on a Griffin Armament lower?
Some play between an AR-15 upper and lower is common, but it can get excessive when the two come from different makers, and a tension screw or an Accu-Wedge takes it up.