Grendel bolt indentification

[dice55]

I ordered a 6.5 Grendel BCG from Bear Creek, after receiving its unmarked and I compared the bolt to a .223 standard bolt. I cannot for the life of me see the difference. Im told its the depth of the bolt face head .136 to .124. is that the only way? Since my upper hasn't arrived yet I cant test . I.m wondering if the .223 bcg will chamber the 6.5 round? I will scribe the bolt accordingly once I comfirm. Any help is appreciated.

[LtDan]

OK the diameter of a Grendel bolt is the same as the 7.62/39 or AK round. It is quite a bit larger than the 223/556 bolt. Even though they are physically the same size on outward dimensions. The difference in the Grendel bolts has to do with the depth of the face of the bolt. The AK round used a .124" depth as do some Grendel's this at one time was called Type 1 the true Grendel bolt is deeper and it measures about .136" and earlier was known as a type 2. You really need to know what your barrel is supposed to use and use the proper bolt

[grayfox]

who makes your barrel? the biggest thing is that your bolt face depth needs to match what the barrel was cut for (pardon the dangling preposition).
yes, the inner diameter is larger as LtDan writes, the ejector is clear of the outer rim-face whereas the 223/556, well that ejector cuts into the outer rim-face-steel.

2 differences in Grendel bolts which can come into play. first is the face depth which hopefully should be 0.136 +/- 0.001 (some bolts, so-called type 1's, have the 0.124 or 5 depth). second is the bolt overall length which a real type 2 bolt is 0.011 longer than the 223/556 bolt. The normal 556 bolt is IIRC 2.800" long. The real Grendel with a 0.136 face depth needs to be 2.810-2.811" (again give or take a thou) from the front edge of the bolt rim-face to the end of the tail.

One important item: Toolcraft at one time made the shorter bolt (556 length or 2.800) and paired it with a shorter firing pin (not 556 std length) and a 0.136 face depth... if you have that combo of bolt/firing pin then keep them together and they will work fine in a chamber set for a 0.136 face depth. It's far better to have the std 556 pin and the longer-tail grendel bolt IMO. I think Toolcraft is now doing the (correct) bolt length and std firing pin but it's a good idea to measure yours and verify.

here's a thread that has some good info in it:

http://www.65grendel.com/forum/archive/index.php/t-18437.html

also, in the bolt face infographic thread - this section of forum - you will see how Bill A beefed up the extractor to handle the Grr case vice just using a 556 extractor.

[grayfox]

Dice, I re-read your post, and if your bolt from BCA is the same length as a standard 223/556 there's a good chance it is the toolcraft one I wrote about, that uses a shortened firing pin (shorter than the 223/556 pin) and 556 bolt length. Best to use a caliper to check -- you need one of those anyway, Amazon has a few not too expensive and gtg.
So, if that is the case, then for a 0.136-style chamber those two should work ok but you must keep the firing pin and that bolt together, they won't work with other standard parts b/c of the sizing changes that TC did.

[dice55]

IMG_9417agJPG.png
6.5 bcg on right .223 on left? dosen'tb except a 7.62x39 round. both ID of the inside of the bolt face is the same 9.70. a 7.62x39 is 11.10 . I just measured with calipers

[grayfox]

take them out of the carrier, separate the firing pin and measure both bolt lengths by themselves.
btw, I'm more used to measurements in inches....
your post confuses me, which one will seat the 7.62/39 round?

[grayfox]

are maybe both of them 223 bolts?
9.70 mm = 0.381 inches, sounds like a 223 round...

[HuntTXhogs]

[sneaky one]

Be wary of the brands that were not here 5+ years ago- maybe not proven yet.


Keep looking, investigating.

[FLshooter]

Take a 6.5 grendal case and if it fits on the end of the bolt,it’s the right one.

[FLshooter]

[A5BLASTER]

Take a 6.5 grendal case and if it fits on the end of the bolt,it’s the right one.

Negative ghost rider.

It could fit and have the wrong face depth.

This is why I only buy my bolts from this forum's group buy or from PF. It's also why I only buy sammi chambered barrel's.

Doing it this way I have never had problems, like so many guys seem too keep having.

[kpswihart]

It may be that the pics are difficult for me to judge, but it looks like the rims of the bolts are the same, or similar, thickness. The Grendel rim should be noticeably thinner. Not sure what you have, but fairly sure it is not a Grendel. I'm sure measurements are available here somewhere, or some more knowledgeable members may know off hand. I'd send back to BCA, or have it positively identified and used as a spare.

[grayfox]

The 6.5 G Monster bolt compared to a NiB 556 bolt. Note around the ejector, the 556 ejector clearly cuts into the rim, whereas the Grendel bolt does not. There is a small space between the ejector and the rim.

The Monster bolt measures 2.812", which is a nominal 0.011 longer than a 556 bolt.

20190704_102005.jpg

20190704_102144.jpg

[BCHunter]

Looking at your pics. That is not a 6.5 bolt, the ejector protrudes into the rim and the rim is to thick to be grendel