Do PSA lowers fit YHM uppers?
PSA lower + YHM upper: yes, they fit
Yes. Palmetto State Armory (PSA) AR-15 lowers fit Yankee Hill Machine (YHM) 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 October 31, 2026.
Our take
Most built setup: the PSA BLEM Classic Stealth Lower with the YHM A3 upper.
About 1 in 60 PSA lowers in our builds carries a YHM upper.
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
Yankee Hill Machine (YHM) makes suppressors, handguards, muzzle devices and gas blocks at fair prices, from a family shop in western Massachusetts.
Founded 1951, Easthampton, Massachusetts, Made in USA
PSA lowers and YHM 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.
Checked on this PSA lower
Palmetto State Armory BLEM PSA Classic Stealth Lowerout of stockand this YHM upper
Yankee Hill Machine A3 Upper Receiver$121.75Most built PSA lowers and YHM uppers setups
Ranked by how often builders pick the exact pair. Only pairs our rules pass are listed.
#1Yes, they fit23% of these buildsCheck fit
#2Yes, they fit14% of these buildsCheck fit
#3Yes, they fit6% of these buildsCheck fit
#4Yes, they fit5% of these buildsCheck fit
#5Yes, they fit5% of these buildsCheck fit
#6Yes, they fit5% of these buildsCheck fit
#7Yes, they fit5% of these buildsCheck fit
#8Yes, they fit3% of these buildsCheck fit
What PSA and YHM say
PSA: PSA owns its supply chain, including Spartan Forging and DC Machine, from forging the receivers to finishing the muzzle brake.
YHM: YHM sells complete and stripped uppers and lowers, plus its own carbines.
YHM: The lower in YHM's billet receiver set fits all standard parts except a trigger guard, has a built in tension screw and takes every generation of PMAG.
YHM: YHM's A3 upper has M4 style feed ramps and T marks, and accepts standard upper parts and mil-spec lower receivers.
YHM: YHM's stripped A3 upper comes without the forward assist and dust cover, while the A3 upper assembly includes both.
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 PSA lowers
- PSA lowers + PSA uppersMost picked
- PSA lowers + BCM uppersSecond most picked
- PSA lowers + Aero uppersThird most picked
- PSA lowers + TacFire uppersFourth most picked
- PSA lowers + Geissele uppersFifth most picked
- PSA lowers + Radical uppersSixth most picked
- PSA lowers + Daniel Defense uppersSeventh most picked
- PSA lowers + Wilson Combat uppersEighth most picked
Other lowers under YHM uppers
- Aero lowers + YHM uppersSecond most picked
- YHM lowers + YHM uppersThird most picked
PSA lowers and YHM uppers: questions builders ask
Will a YHM upper fit a PSA lower?
Yes. PSA AR-15 lowers fit YHM 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 YHM upper feel loose or tight on a PSA 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.