firing pin

[ulmapache]

Dumb question here....does the grendel take a different firing pin? Are the firing pins caliber specific? Or will the pin from any bcg repair kit work...thx...

[mdram]

it should use any mil spec firing pin

BUT at one time toolcraft was using a shorter pin

what bolt do you have? what bcg?

[lazyengineer]

Any pin will work. There are some renditions that take their own firing pin, but are rare. The standard is called Gen II, and it's pretty rare to see anything else anymore. Unless you're looking at buying something old and used, it will be Gen II and any pin will work.

[A5BLASTER]

It should take a mil spec length fireing pin.

Toolcraft at one time when they first got into the grendel had complete bcg's that the fireing pin was of diffrent length because they didn't make their grendel bolts too spec length.

From what I have seen this has been fixed.

Long as your bolt has a .136 bolt face depth it will use a mil spec length fireing pin.

[Lastrites]

Odin used a shorter FP, don't know if they still do or not.

[ulmapache]

Type II build....so I suppose it will work...picked up a master rebuild kit from Cryptic with all the small stuff...roll pins, cam, firing pin etc... Black Rain Arms for the extractor...(Alexander arms wanted 18 bucks to ship the extractor and pin...NOT!!!! And no other shipping options were offered.) Waiting on the bolt...then can start building the upper...

[LRRPF52]

A real Grendel bolt is designed to be compatible with standard Mil-Std firing pins, not that there are many of those outside of a few companies.

Remember that there is no set of specs that describes the misnomer, "Type II". Nobody in the industry can tell you what "Type II" means for this reason.

An AR15 Grendel bolt has a deeper bolt face depth to allow for a stronger extractor lip, a different extractor pin location, and a different extractor shelf depth to compensate for extractor snap-over inside the constraints of the AR15 barrel extension Inner Diameter (ID). A Grendel bolt also is longer at 2.810" to bring more tail into the overall length so that Mil-Std length firing pins will not have excessive firing pin protrusion.

Some companies recognized the need for a deeper bolt face depth and spec'd their bolts out that way, but failed to accommodate the standard firing pin parts supply by using a 2.800" bolt length.

The best thing to have is a Grendel bolt with 2.810" OAL, .136" face depth, a certain grade of 9310 alloy heat treated correctly and batch-tested with destructive testing and MPI (not HPT non-destructive).

I like the AA firing pins that have a triangular cross section. That's an interesting improvement to the AR15 firing pin design, not that there have been many problems with FPs once they dropped the heavy head pins from the early AR15 Model 601, which was prone to slam-firing from pin inertia.