Which AR-15 stocks fit which buffer tubes?
The stock slides onto or bolts over the buffer tube, so the tube decides which stocks fit. There are three common tube types: carbine, A5 and rifle.
The Short Answer
- Collapsible carbine stocks fit carbine tubes, and most also fit the slightly longer A5 tube.
- Fixed rifle stocks like the A2 and the Magpul PRS need a rifle-length tube and rifle buffer.
- Carbine tubes also come in two diameters: mil-spec (1.148") and commercial (1.168"). Buy a stock made for the diameter of your tube.
Buffer System and Stock
Every buffer kit we list, checked against every stock.
Palmetto State Armory Carbine Buffer Kit
- Fits Magpul MOE SL Carbine Stock · Palmetto State Armory Classic M4 Stock · Bravo Company Gunfighter Stock Mod 0 · Magpul CTR Carbine Stock · B5 Systems Bravo Stock · Magpul UBR Gen2 Collapsible Stock
- Won't fit Generic A2 Fixed Rifle Stock · Magpul PRS Gen3 Precision Stock · Magpul MOE Rifle Stock This stock fits rifle buffer tubes, but the buffer kit is a carbine tube.
Aero Precision Carbine Buffer Kit, H Buffer
- Fits Magpul MOE SL Carbine Stock · Palmetto State Armory Classic M4 Stock · Bravo Company Gunfighter Stock Mod 0 · Magpul CTR Carbine Stock · B5 Systems Bravo Stock · Magpul UBR Gen2 Collapsible Stock
- Won't fit Generic A2 Fixed Rifle Stock · Magpul PRS Gen3 Precision Stock · Magpul MOE Rifle Stock This stock fits rifle buffer tubes, but the buffer kit is a carbine tube.
VLTOR A5 Receiver Extension System
- Fits Magpul MOE SL Carbine Stock · Palmetto State Armory Classic M4 Stock · Bravo Company Gunfighter Stock Mod 0 · Magpul CTR Carbine Stock · B5 Systems Bravo Stock
- Won't fit Generic A2 Fixed Rifle Stock · Magpul PRS Gen3 Precision Stock · Magpul MOE Rifle Stock This stock fits rifle buffer tubes, but the buffer kit is an A5 tube.
- Won't fit Magpul UBR Gen2 Collapsible Stock This stock fits carbine buffer tubes, but the buffer kit is an A5 tube.
Aero Precision Rifle Buffer Kit (A2)
- Fits Generic A2 Fixed Rifle Stock · Magpul PRS Gen3 Precision Stock · Magpul MOE Rifle Stock
- Won't fit Magpul MOE SL Carbine Stock · Palmetto State Armory Classic M4 Stock · Bravo Company Gunfighter Stock Mod 0 · Magpul CTR Carbine Stock · B5 Systems Bravo Stock This stock fits carbine or A5 buffer tubes, but the buffer kit is a rifle tube.
- Won't fit Magpul UBR Gen2 Collapsible Stock This stock fits carbine buffer tubes, but the buffer kit is a rifle tube.
Parts Worth a Look
Our picks from the AR-15 catalog, with the lowest price we list (prices last checked Oct 4, 2026).
Buffer System
Budget Pick
Palmetto State Armory Carbine Buffer Kit
Carbine tube · H buffer
Complete carbine kit with an H buffer, which suits most 16" builds.
$34.99 at Palmetto State Armory (sample price)
Best Value
Aero Precision Carbine Buffer Kit, H Buffer
Carbine tube · H buffer · Staked castle nut
Arrives with the castle nut ready to stake. Fewer steps, same fit.
$52.99 at Primary Arms (sample price)
Premium Pick
VLTOR A5 Receiver Extension System
A5 tube · A5H2 buffer
Longer spring and buffer for a softer, more reliable cycle. Fits carbine stocks.
$109.99 at Brownells (sample price)
Stock
Budget Pick
Palmetto State Armory Classic M4 Stock
Collapsible · Mil-spec diameter
Basic M4 stock. Works, and is easy to upgrade later.
$19.99 at Palmetto State Armory (sample price)
Best Value
Magpul MOE SL Carbine Stock
Collapsible · Mil-spec diameter · QD socket
Slim, snag-free, and fits both carbine and A5 tubes.
$49.95 at Primary Arms (sample price)
Premium Pick
Bravo Company Gunfighter Stock Mod 0
Collapsible · QD sling mounts
Ambi QD sockets and a solid cheek weld.
$59.95 at Brownells (sample price)
Start from a Complete Build
Every part already checked to fit. Open one in the builder and swap anything you like.
Sources
Updated Oct 5, 2026.