Ordered an Aero Precision Grendel upper...

[Calfed]

HI, guys...new member here.

I ordered an Aero Precision 20" Grendel upper and charging handle (during their 18% off Shot show sale) and just received notice that it shipped. This upper does not include the BCG. Aero advised that I should get a Grendel bolt from Ballistic Advantage ($150) and that is the only one guaranteed to work. I've found a Toolcraft Grendel bolt for less than $100 and am wondering if those are GTG.

Anyone have any experience with Toolcraft Grendel bolts?

Also looking for any magazine recommendations (10 round max)

Thanks!

[mdram]

toolcraft is gtg from my readings
iirc they make bolts for many other people, including military

[Harpoon1]

HI, guys...new member here.

I ordered an Aero Precision 20" Grendel upper and charging handle (during their 18% off Shot show sale) and just received notice that it shipped. This upper does not include the BCG. Aero advised that I should get a Grendel bolt from Ballistic Advantage ($150) and that is the only one guaranteed to work. I've found a Toolcraft Grendel bolt for less than $100 and am wondering if those are GTG.

Anyone have any experience with Toolcraft Grendel bolts?

Also looking for any magazine recommendations (10 round max)

Thanks!

Looking for just a bolt? If you can wait a little while or maybe want a spare or two........not a bad idea.

http://www.65grendel.com/forum/showthrea...55-S-amp-H

E-Lander mags from Alexander Arms seem to be the top of the line.......they just got a new shipment in last week. Mine arrived today!

http://www.shopalexanderarms.com/Magazin...der_1.html

C-Products seem to get good reviews.........well, mostly! I just got some from CTD.

https://www.cheaperthandirt.com/product/...7410536.do

[VASCAR2]

Brownell’s has a 6.5 Grendel BCG in stock plus E-Lander and CP ten round mags in stock. Brownell’s has free shipping right now on orders over $49.

A few forum members have used the Brownell’s 6.5 Grendel BCG and appear to be GTG, actually look like Toolcraft. With Brownell’s warranty it is worth comparing prices.

https://www.brownells.com/rifle-parts/bo...05382.aspx

[Calfed]

Looking for just a bolt? If you can wait a little while or maybe want a spare or two........not a bad idea.

http://www.65grendel.com/forum/showthrea...55-S-amp-H

E-Lander mags from Alexander Arms seem to be the top of the line.......they just got a new shipment in last week. Mine arrived today!

http://www.shopalexanderarms.com/Magazin...der_1.html

C-Products seem to get good reviews.........well, mostly! I just got some from CTD.

https://www.cheaperthandirt.com/product/...7410536.do

Nah, need a whole BCG...

E-Lander it is

[Calfed]

Brownell’s has a 6.5 Grendel BCG in stock plus E-Lander and CP ten round mags in stock. Brownell’s has free shipping right now on orders over $49.

A few forum members have used the Brownell’s 6.5 Grendel BCG and appear to be GTG, actually look like Toolcraft. With Brownell’s warranty it is worth comparing prices.

https://www.brownells.com/rifle-parts/bo...05382.aspx

Thanks...looking into it.

[tracker12]

I bought a Toolcraft BCG and it has worked flawlessly with the group buy bolt I bought here.

[sreyemj]

Aero advised that I should get a Grendel bolt from Ballistic Advantage ($150) and that is the only one guaranteed to work.

They just say that because Aero owns Ballistic Advantage, Toolcraft should be gtg.

[Jakegsxr11]

I bought a Toolcraft BCG and it has worked flawlessly with the group buy bolt I bought here.

That's what I did also (5.56 bcg) , mine also works flawlessly.

[Calfed]

Thanks, guys

[Irbuff]

They just say that because Aero owns Ballistic Advantage, Toolcraft should be gtg.

Hmm that is interesting. Didn't know they owned them. Knew they used their barrels but that was it!

[The Profit Joseph Sith]

DONT BUY BROWNELLS!!! search the forum they use a shorter non standard firing pin length. Make sure and get one that uses a standard pin which you can find anywhere. I got standard mil spec bolts and the GB bolts they are gtg.

[Jakegsxr11]

I'm not 100% sure but I think the Toolcraft bcg also uses the shorter firing pin. I bought the 5.56 Toolcraft BCG and used a GB bolt.

[The Profit Joseph Sith]

Im fairly certain the problem enlies with complete BCG's only. I got decent complete MIL-SPEC BCG's with mil spec pins and all. And swapped the bolts by themselves. AIM surplus nitride m16 BCG for like $80 or $90 and bolts from the Group Buy got tons of spare parts as well. Enough to last my lifetime.

[VASCAR2]

The Brownell, Toolcraft, Odin and Larue 6.5 Grendel bolts use a shorter tail which is .01 shorter than the Alexander Arms and most other Grendel bolts (Group Buy Bolt).

The Brownell, Toolcraft, Odin and Larue use shorter firing pins to prevent punctured primers. With the 6.5 Grendel bolt with .136 bolt face AA lengthened the tail of the bolt so a mil spec firing pin could be used. The first time the shorter bolt tail length first showed up was when Odin released their 6.5 Grendel bolts and 6.5 Grendel barrels. Odin’s were getting pierced primers which was traced to the mil spec firing pin in the shorter bolt. I suspect an engineer never thought to add .01 to the length of the bolt even though 5.56/223 use .125 bolt face +or- .001 and Grendel has a .136 bolt face.


I don’t think there is anything mechanically wrong with the Brownell, Toolcraft, Odin or Larue bolts but just a difference to be aware of incase you ruin a bolt. You just need to match your firing pin to your bolt, there is .01 difference in mil spec FP and the shorter firing pin.

[Kswhitetails]

My BCM 5.56 bolt measures: 2.7970 and pin 3.2765

Monster Group Buy Bolt: 2.8120 and pin 3.2770

Larue Grendel Bolt : 2.8005 and pin 3.2700

Larue 5.56 bolt: 2.8000 and pin 3.2780

Given these measurements, the only bolt appearing long is my monster bolt, which uses the same length pin.

I need someone to help me make sense of this. I understand the purpose of shortening the bolt and pin, but my data doesn't bear it out. I'm not of a machinist's background though, so I may be unable to read the data correctly.

come to think of it, I didn't get a pin with the GB bolt, so is there a possibility I need a longer one to use with it? I haven't had any FTFir yet...

[VASCAR2]

With a 2.810 long bolt you need a mil spec length firing pin. The 223/5.56 bolt with the designed bolt face depth of .125 +or- .001 are 2.800. When Bill Alexander adopted the .136 bolt face depth he added .01 to the length of the tail of the bolt so his 6.5 Grendel bolts would accept a standard milspec firing pin.


When other manufactures of the 6.5 Grendel barrels started releasing barrels and their own non sourced AA bolts they used a shorter overall length bolt exactly like the 5.56/223. These manufacturers using .136 bolt face and 2.800 length bolt decided to use a shorter firing pin to preclude having pierced primers. It is not difficult to shorten a mil spec firing pin to work with a Brownell, Toolcraft, Odin or Larue bolt. If you try to use your shorter firing pin with your Group Buy Monter bolt you might encounter failure to fire due to insufficient firing pin protrusion.


Just another nuance associated with the 6.5 Grendel. Another confusing thing is the slight differences in length due to allowable tolerances. I don’t know the specified length of Milspec AR-15 firing pin.

I measured my Group Buy Monster bolt overall length at 2.812

I’m using a PSA Freedom Nitride bolt carrier & firing pin overall length 3.278

I measured my PSA Premium 5.56 bolt overall length 2.800 - 2.780

I measured the firing pin from Premium Bolt 3.278

Here is a thread with a lot of information on the Brownell’s 6.5 Grendel BCG with pictures and lengths.

http://www.65grendel.com/forum/showthrea...rier/page2

It’s possible Larue is sending a full length firing pin with his 2.800 length bolts. I read Larue used a 2.800 bolt but I’ve never seen where anyone measured their firing pin. The pierced primers may not occur as frequently with thicker CCI 41 or CCI 450 primers compared to thinner cup CCI 400 or WSR primers when using a full length firing pin.

I never thought to try and measure the firing pin protrusion on my 6.5 Grendel bolt but I previously measured the bolt face depth and it measured .136. My 5.56/223 bolt face was .125 and I didn’t think to measure the firing pin protrusion on it either. I don’t know the specified protrusion for an AR-15. I could do the math on my bolts but know the exact spec.

[Kswhitetails]

Funny, after looking at the data again, it just so happens that somehow that particular pin is the longest of the batch. (Honestly don't remember the source of that firing pin)

So, what that means is that as long as I'm using a SAAMI chamber, and an AA spec bolt, then everything else should work? (I'm not arguing headspace/go-no go, always check these for yourself yadda yadda) But it sounds like as long as there's nothing out of Bill's specified measurements with the Grendel chamber or bolt, then the rest of the pieces should work as intended. Why have there been so many folks changing things to make this even more complicated...

So, because the Grendel bolt is .11 deeper in the face, he added .1 to the tail of the bolt to account for the length of the standard mil-spec firing pin in an effort to further the interchangeability of the Grendel to existing ar15 parts systems?

[VASCAR2]

Yes Kswhitetails, actually .01 difference 2.810 for AA spec bolt and 2.800 on 5.56 bolt and Larue. I haven’t read any reports of pierced primers with Larue 6.5 Grendel’s but this issue came to light after Odin released their 6.5 Grendel and there were frequent reports of pierced primers. The pierced primers were the result of 2.800 bolt .136 bolt face depth and milspec length firing pins.


Maybe Larue’s tolerences are tight enough that this issue has not appeared with his barrels and bolts. Like I added to my previous post I don’t know the specified firing pin protrusion for an AR-15. If your rifle functions and no pierced primers great. If a forum member is getting pierced primers this could be the issue.

[VASCAR2]

Here is a link to an earlier thread where the short Odin bolt .2800 was encountered using a mil spec firing pin with resulting pierced primers.

http://www.65grendel.com/forum/showthrea...-New-Build


Honestly I think the 2.800 bolt length with .136 bolt face depth is either an oversight when gearing up for production or no concern about trying to maintain parts compatibility.