LeMay Compatibility Guide

LeMay Bullpup Conversion Kit

Compatibility Guide (Build Fitment)

Quick Links

Start Here

Ready to order? Shop LeMay kits

On this page

Overview (what matters most)

LeMay compatibility is determined by a few key factors. If you confirm these items, you’re 90% of the way there:

  • Upper system: bufferless / charging style determines the correct rear/buttpad setup.
  • Lower fitment: mil-spec forged lowers fit best; some oversized billet features may not.
  • Rear trigger: your AR’s rear trigger must be CURVED (flat-faced rear triggers are not compatible).
  • Handguard: must be M-LOK or KeyMod and at least 6.5″.
Not sure? Before ordering, send us your upper + lower + handguard details and we’ll confirm the correct kit option:
Contact.

Upper systems (bufferless / special)

Choose your buttpad on the Store page based on your upper and charging style.

Bufferless uppers (examples)

  • Foxtrot Mike FM-15
  • PSA JAKL
  • Brownells BRN-180
  • CMMG Dissent
  • Faxon ARAK
  • Matador Arms MAT9

Shop current configurations here: Store

Bufferless BCG kits (examples)

  • Law Tactical ARIC
  • Evolution Weapon Systems

Other supported setups (example)

  • Dead Foot Arms 2.5″ (Rear-charging)
  • Bufferless rear and side charging hybrid

Have a hybrid setup? Send your model names and a photo and we’ll confirm fitment:
Contact.

Lower receiver fitment

Fits: forged mil-spec pattern lowers and most billet lowers.

May not fit: oversize/flared magwells and integrated/oversized trigger guards.

If you’re running a unique billet lower, send the brand/model and a photo:
Contact.

Trigger requirement (IMPORTANT)

Your AR’s rear trigger must be CURVED. Flat-faced rear triggers are not compatible with the LeMay interface.

  • Forward (front) trigger shoe: both curved and flat ergonomic shoes are included—use whichever you prefer up front.
  • Reset spring: adds approximately +1 lb to pull weight.

More technical detail is on the FAQ and Technology pages.

Handguard requirement

LeMay mounts to your handguard using our bracket system.

  • Mounting type: M-LOK or KeyMod
  • Minimum handguard length: 6.5″

If you’re unsure of your handguard length, measure from the rear edge forward and send us a photo:
Contact.

Which buttpad do I choose?

Pick your buttpad option on the Store page based on your upper and charging style. If you’re not sure, don’t guess—send your upper model and we’ll tell you which option to select.

Calibers & magazines

Use what your upper/lower support (e.g., 5.56, .300 BLK, 7.62×39, 9mm, etc.).

Compatible with mil-spec profile stick magazines.

Send your build (we’ll confirm fit)

For the fastest confirmation, include:

  • Upper: brand + model (and charging style)
  • Lower: brand + model (forged/billet)
  • Trigger: confirm rear trigger is curved
  • Handguard: M-LOK/KeyMod + length
  • Barrel & caliber (and any special notes)
  • A quick photo (optional but helpful)

Send it here: Contact AR Force Arms

Want the full technical overview? Technology • Need general questions answered? FAQ