RRA 6.5 Grendel barrel/upper ?

[Rebels010]

Does anyone know if RRA ever made a 6.5 grendel barrel and/or upper? Looking to buy a rifle and that’s the MFG he states but not sure I was aware of them making Grendel stuff.

[FLshooter]

It’s far as I know RRA never made 6.5 Grendel uppers.

[VASCAR2]

RRA has never sold any 6.5 Grendel AR-15’s but they used to be a top seller of stripped (mid to late 90’s early 2000’s) uppers and lowers. Most of RRA barrels were sourced from Wilson Arms which are currently sold chambered in 6.5 Grendel by JSE. Someone might have one that looks factory RRA but is probably a parts gun. You can call RRA and they can tell you via the serial number whether the lower was stripped, assembled lower or complete firearm when it left the factory.

[Rebels010]

Yeah, I don’t think he is trying to mislead anyone, just doesn’t know/can’t accurately remember the barrel MFG. price is fair no matter who the MFG is, but I don’t want to get a type 1 bolt/chamber. Anyway I can compare my bolt visually to it and tell the difference?

[VASCAR2]

If you have a caliper just lay it across the face and use the tip going into the breach face to measure the depth. The bolt will either measure .136 +or- .001 or .125 +or- .001. The .136 is the standard 6.5 Grendel bolt face depth or commonly referred to as Type II. If the measurement is close to .125 then the bolt is commonly used in 7.62x39 and is Type I. On most 6.5 Grendel bolts the length from the tail to the face of the lugs is 2.810 inches plus or minus around .002.

The AR-15 5.56/223 bolts measure 2.800 inches but since AA added .01 to the depth of the bolt face and AA added .01 to the length of the bolt to use standard mil spec firing pins. A couple manufacturers have used 2.800 length bolts and use shorter firing pins. Odin Works and Brownell’s are reportedly using 2.800 length bolts.

The critical dimension is the firing pin protrusion. The firing pin protrusion standard is .028-.036 inches or a tolerance of .008 inches. If the firing pin is out of spec you can get pierced primers or slam fires. If the firing pin protrusion is to short you might experience failure to fire.

If you have several AR-15’s I would be very careful to keep the same firing pin with the same bolt.