FAQ

FREQUENTLY ASKED QUESTIONS

 
 
 
 
 
Why can’t I find your piston carrier for sale? I would like to purchase one for my other manufacturer’s piston system.
We do not sell our patented piston carriers for use with other manufacturers piston systems. Our patented piston carrier is exclusive to our company and is specifically designed for our piston systems specifications and tolerances. Piston carriers are not drop in carriers like your AR-15 Direct Impingement Carriers; therefore, each manufacturer’s piston carriers are not compatible with each other.
 
 
Do you offer a .308/AR-10/7.62x51 piston conversion system?
We do not offer a piston conversion for the .308/AR-10/7.62x51 rifles.
 
 
If an item is in stock what is your turn around on shipping time?
For small item(s) that are in stock, they ship usually in 1-2 business days, if shipped through USPS. Uppers and piston conversions can take anywhere between 4 to 7 days to ship, this gives us time to build and test fire, so we know when it leaves our workshop it's in working order. Back Orders will ship as soon as product(s) are available within 1 to 2 business days.
 

What do you recommend for buffer and spring set-up for your piston uppers?
Recommended Buffer Weights and Springs are as followed:
  • 7.62x39 CAPS and L.P.R. CARBINE
    • Standard Buffer and Carbine Spring
    • H2 Buffer and Carbine Spring
  • 7.62x39 CAPS and L.P.R. MID-LENGTH
    • Standard Carbine Buffer and Spring
  • 7.62x39 SPARTAN CARBINE
    • Standard Buffer and Carbine Spring
    • H2 Buffer and Carbine Spring 
  • 5.56 CAPS and L.P.R. CARBINE
    • Standard Buffer and Carbine Spring
    • H2 Buffer and Carbine Spring
  • 5.56 CAPS and L.P.R. MID-LENGTH
    • Standard Carbine Buffer and Spring
  • 5.56 SPARTAN CARBINE
    • Standard Buffer and Carbine Spring
    • H2 Buffer and Carbine Spring
  • 300 BLACKOUT
    • H2 Buffer and Carbine Spring

Do you sell an end-user drop in piston conversions?
At this time, we do not sell end-user install piston conversions. Our quality control has been to do in-house conversions because there are times that op rods have to be adjusted for optimal length due to the tolerances that are allowed with barrels, uppers, and other associated parts. If these parts are on the opposite end of mil-spec then we have to custom fit an op rod which will allow your system to run at optimal performance. We check headspace and gas port sizes. When a gas port is under gassed we open it, if it is over gassed we add a reducer. When a customer's upper leaves our workshop it's as if we built it as a piston upper from the ground up, and shoots right out of the box.
 
 
Do you charge for the install of the Piston Conversion Kits?
No, we do installs and testing for free as part of our customer service. When you buy the piston conversion kit you will be charged shipping cost at that time and that cost is used to return ship your upper back to you after we retrofit the piston system. However, if you send us your upper in parts and we have to assemble it we do charge $20.00 gunsmithing fee.
 
 
What calibers will your AR-15 piston conversions system work with?
5.56x45, 7.62x39, 5.45x39, 6.8 SPC, 6.5 Grendel

  
The polymer-based integrated buffer in the bolt carriers, how often do they need to be replaced?
We chose the highest quality polymer on the market today to utilize in our carriers. The polymer we chose has outstanding abrasion resistance, low coefficient of friction, self-lubricating, chemical and stress cracking resistance, and another key characteristic is impact strength. The polymer is an extremely tough product that is used for applications that require durability, high impact and/or abrasive wear resistance. We have been running this carrier since 2009 with no damage to the integrated polymer buffer, nor have we ever had to replace the integrated buffer on any of our customer's piston system set- ups nor our direct impingement carriers. Our Carrier Buffer Technology is a patented product that is EXCLUSIVE to Black Rifle Arms. The integrated polymer buffers are easily removed and can be replaced with another in a matter of minutes. Black Rifle Arms bolt carrier polymer buffers have a Lifetime Limited Warranty against manufacturer defects or damage during normal use. Warranty is void due to modification, misuse, or by damage due to mishandling.
 
 
How do I go about getting my bolt carrier's buffer replaced if I do damage it?
Bolt carrier buffers are an add on product when a customer purchases a direct impingement bolt carrier, a gas piston upper and/or gas piston conversion. Due to our bolt carriers with buffer technology being a proprietary patented product, we have had to provide a policy to protect our patent due to numerous parties trying to buy just the bolt carrier buffer to modify their non Black Rifle Arms bolt carriers.

BUFFER POLICY:
Please contact the dealer you bought your bolt carrier from and provide them with proof of purchase rather by an Invoice # or a picture of your bolt carrier
If you purchased your bolt carrier from Black Rifle Arms directly please contact us with your name and or Invoice # so we can look you up in the system.
If we can't find you in our system you will need to provide proof by way of taking a picture of the bolt carrier with buffer technology and sending us an email. Please contact us at our CONTACT US page at, so
somebody can assist you. We apologize for this inconvenience, but we are working hard to protect our technology through Patent rights.


What handguards and/or rails will work with the piston system?
List of handguards or rails that work with our piston systems without modifications. 
 
With the CAPS and Spartan Piston System Extended Rails ARE NOT Compatible with our piston systems.

There may be other Handguards or Rails that are compatible that we are not aware of, but this is a list of rails we have used in our piston builds. 

Spartan Carbine Piston System:
Midwest Industries Gen2 Drop In Handguard
Midwest Industries Gen2 SS-Series 2 Piece FF
Midwest Industries Gen2 Two Piece FF
Midwest Industries SS Serious Drop In
Midwest Industries K-Series Keymod Drop In
Troy Alpha
Troy Bravo
M-Lok
Troy Vtac Alpha
Magpul MOE
Samson Evolution Rail 
Rainier Arms Force Rail
Daniel Defense Omega Piston Rail
Diamondhead VRS Drop-In Rail
Fortis REV Rail
Rainier Evolution Rail
556 Tactical Evolution Rail

Spartan Mid-Length Piston System:
Midwest Industries Gen2 SS-Series 2 Piece FF
Midwest Industries Gen2 Two Piece FF
Troy Alpha
Troy Bravo
Troy M-Lok
Troy Vtac Alpha
Magpul MOE
Samson Evolution Rail 
Rainier Arms Force Rail
Fortis REV Rail
Rainier Arms Evolution Rail
556 Tactical Evolution Rail

C.A.P.S. Carbine Piston System:
Midwest Industries Gen2 Drop In Handguard
Midwest Industries Gen2 SS-Series 2 Piece FF
Midwest Industries Gen2 Two Piece FF
Midwest Industries SS-Series Drop In
Midwest Industries K-Series Keymod Drop In
Troy Alpha
Troy Bravo
Troy M-Lok
Troy Vtac Alpha
Magpul MOE
Samson Evolution Rail 
Daniel Defense Omega Piston Rail
Diamondhead VRS Drop-In Rail
Fortis REV Rail
Rainier Arms Evolution Rail
556 Tactical Evolution Rail

C.A.P.S. Mid-Length Piston System: 
Midwest Industries Gen2 SS-Series 2 Piece FF
Midwest Industries Gen2 Two Piece FF
Troy Alpha
Troy Bravo
Troy M-Lok
Troy Vtac Alpha
Magpul MOE
Samson Evolution Rail 
Rainier Arms Force Rail
Fortis REV Rail
Rainier Arms Evolution Rail
556 Tactical Evolution Rail

Low Profile Piston System:
Samson Evolution Rail
Rainier Evolution Rail
556 Tactical Rail
Rainier Arms Force Rail
Aero Precision Enhanced M-Lok Rail, Gen 2 (REQUIRES OUR PISTON COMPATIBLE BARREL NUT, sold by us as a call in)
Aero Precision Enhanced Keymod Rail, Gen 2  (REQUIRES OUR PISTON COMPATIBLE BARREL NUT, sold by us as a call in)
Aero Precision Quad Rail, Gen 2  (REQUIRES OUR PISTON COMPATIBLE BARREL NUT, sold by us as a call in)
Aero Precision Quantum M-Lok Rail, Gen 2 (REQUIRES OUR PISTON COMPATIBLE BARREL NUT, sold by us as a call in)
Aero Precision Quantum Keymod Rail, Gen 2  (REQUIRES OUR PISTON COMPATIBLE BARREL NUT, sold by us as a call in)
 
 
My upper has a pinned and welded muzzle device, can I send the upper to you for the piston conversion?
No, you will need to remove it yourself or find a reputable gunsmith/armorer for removal. At that time, you can send the upper in for the piston conversion. If your state requires a permanently attached flash suppressor/muzzle brake you will need a reputable gunsmith/armorer to permanently attach it to be legally compliant.
 
 
Why does your piston system not utilize the spring behind the bolt like other piston systems?
Our system was designed to utilize the bolt rings which are mil spec. We tested our system with the spring behind the bolt and found it made no difference in cam pin wear, and felt it was an extra non-mil spec part that would need replacing. We have countless hours of R&D, so please DO NOT allow another company to replace your bolt rings with a non-mil spec spring that is not needed for the functioning of the Black Rifle Arms piston system.
 
 
What is your warranty on the piston conversion systems?Black Rifle Arms has a Lifetime Warranty on the gas piston system against manufacturing defects. All warranties are void due to misuse, neglect, improper installation, modifications, or consequential damages and will not be covered by our Limited Lifetime Warranty.
 
 
Can you convert an upper with your piston system that utilizes a bull or pencil barrel?
No, our piston system only works with a barrel with a gas block journal diameter of .750” and a barrel shoulder at least 1.9" in length.
 
 
Does your piston system work with other gas lengths other than the carbine?
Yes, our piston conversions work with pistol, carbine, mid-length and rifle length gas systems. As we grow we continue to add new products to our product line to include different gas lengths; however, if you have a pistol, mid-length or rifle gas length upper you can send it in for a piston conversion.