A5 Buffer Spacer for AR-15 or AR-10 JP Silent Captured Spring

This precision-machined spacer is designed to fill the excess void encountered when running an A5 buffer system with a JP Silent Captured Spring. Unlike the factory white polymer insert—which must be cut down, is difficult to hold, and nearly impossible to cut square—this spacer is machined to exact length for a perfect fit right out of the box.

Manufactured from aluminum, this insert will not compress, deform, or bind inside the buffer tube. Its rigid construction ensures smooth installation and removal during cleaning and maintenance, eliminating the frustration of polymer spacers that can hang up or wear over time.

Features:

Purpose-built for A5 buffer systems using JP Silent Captured Springs
Precision-machined aluminum for exact fit and alignment
Eliminates the need to cut factory polymer spacers
Will not compress, deform, or bind in the buffer tube
Smooth insertion and removal for easy maintenance
No rattling or slop left between the JPSC and the BCG

*** All our measurements and checks were done using a Forward Controls Designed A5 Buffer tube assembly*****

Why a Dedicated Adapter Matters

If you’ve upgraded to the A5 Buffer System, you know it’s the gold standard for smoothing out the AR-15’s recoil impulse. But because the A5 tube is roughly ¾" longer than a standard carbine tube, dropping in a standard JP Silent Captured Spring (SCS) will result in over-travel, potentially damaging your receiver or causing catastrophic malfunctions.

The "Quarters" vs. The MTE Adapter

You’ll see "hacks" online suggesting you just stack $1.75 in quarters at the bottom of your tube. Here is why we machine a dedicated solution instead:

Dimensional Stability: Plastic spacers can compress over time under the heat and constant battering of a 6.5 Creedmoor or 6 ARC. Our 6061-T6 aluminum adapter will never compress, ensuring your bolt travel remains consistent for the life of the rifle.

Concentricity: Unlike a stack of coins that can shift and rattle, the MTE Adapter is machined to a precise diameter that centers itself perfectly in the buffer tube. This keeps the JP SCS rod perfectly aligned with the bolt carrier, reducing friction and wear.

Weight & Harmonics: We’ve optimized the weight of the adapter to ensure it doesn't add unnecessary reciprocating mass. It stays seated at the rear of the tube, providing a solid, silent foundation for the spring to work against.