SAAMI Grendel Barrel Makers?

[65Whelen]

The X-Caliber is one company who offers both SAAMI 6.5 Grendel or 264 LBC with either .125 or .136 bolt. It’s kind of hard to make a blanket statement as to how an X-Caliber barrel will come configured.

When I ordered my X-Caliber barrel I made sure I was getting a SAAMI chamber with a .136 bolt via e-mail. They even cut the chamber to my bolt that I sent them. I was very happy with it.

Boy this thread did go off the tracks somewhere. Focus people focus.

[BluntForceTrauma]

I’m no machinist but I think it is cheaper to mass produce a traditional throat compared to a compound throat.

I'm no machinist, either, so I asked Faxon about this regarding the barrels they make for me.

They said, "Nah, drillin' a hole is drillin' a hole." Drilling with one reamer is the same as drilling with another reamer. I know that my reamer cost is the same as any other reamer.

We've heard that the compound throat is more expensive, but it seems to be one of those "urban myths."

[ricsmall]

I'm no machinist, either, so I asked Faxon about this regarding the barrels they make for me.

They said, "Nah, drillin' a hole is drillin' a hole." Drilling with one reamer is the same as drilling with another reamer. I know that my reamer cost is the same as any other reamer.

We've heard that the compound throat is more expensive, but it seems to be one of those "urban myths."

You hit it dead on, John. A reamer is a reamer. No additional cost in producing one over the other. And to answer another question early in this thread. A manufacturer can buy the SAAMI reamers from the tool maker and make and sell the barrels without paying fees. His fees are paid when he renews his ffl’s.

[NugginFutz]

Velocity is all about burning the powder. If the length of the barrel burns all the powder in the load and extra inch or 4 will not give you anything more. Now if you feel the longer barrel stabilizes the bullet better then accuracy "may" be improved. IMHO there are to many other variables that go into an accurate barrel to just think about length.

One thing that could be interesting is does a SAAMI barrel produce higher velocities vice other 65G spec ones.

I have seen no correlation between a SAAMI chambers vs All Others, where it comes to muzzle velocities. All other factors being equal, I believe that variations in velocity have much more to do with the bore geometry than anything else.

I have a pair of 264 LBCs from BHW, and a 6.5 Grendel (SAAMI) from Larue Tactical.

My 18 and 22" BHWs use a proprietary polygonal rifling (Caudle 3P) and have exhibited higher than average velocities with factory ammo and comparable hand loads, as reported by others.

The 18" Larue, on the other hand, runs very fast. Almost as fast as my 22" BHW. (Tested with Hornady American Gunner and Hornady Black factory ammunition). It appears to have traditional Enfield style rifling, but I cannot confirm this. I'm not sure if this is typical of the Larue barrels, but it certainly surprised me.

[Harpoon1]

New to the forum, playing catch up with Grendel, trying to wrap my head around the variables.

The earlier list shows "Ballistic Advantage" using a SAAMI chamber, but BA says its a "type 2"?

What am I missing?

http://ballisticadvantage.com/18-inch-65...arrel.html

[VASCAR2]

Blame Black Hole Weaponry, BHW sold 264 LBC barrels chambered to use 7.62X39 bolts with a bolt face Depth of .125. Later BHW chambered 264 LBC barrels chambered to use 6.5 Grendel bolts with .136 bolt face Depth. To alleviate confusion BHW designsted barrels chambered to use .125 X39 bolts as Type I, barrels chambered to use .136 bolt face 6.5 Grendel bolts as Type II. Other manufactures and vendors have started to identify their barrels as Type II if they are chambered to use 6.5/Grendel bolts with .136 bolt.

If this isn’t bad enough Satern/Liberty released a chamber called Grendel II which also shoots 6.5 Grendel ammunition.

[Harpoon1]

Blame Black Hole Weaponry, BHW sold 264 LBC barrels chambered to use 7.62X39 bolts with a bolt face Depth of .125. Later BHW chambered 264 LBC barrels chambered to use 6.5 Grendel bolts with .136 bolt face Depth. To alleviate confusion BHW designsted barrels chambered to use .125 X39 bolts as Type I, barrels chambered to use .136 bolt face 6.5 Grendel bolts as Type II. Other manufactures and vendors have started to identify their barrels as Type II if they are chambered to use 6.5/Grendel bolts with .136 bolt.

If this isn’t bad enough Satern/Liberty released a chamber called Grendel II which also shoots 6.5 Grendel ammunition.

Vascar2,

Sorry, was that for me?

So BA has a SAAMI chamber but, they say its a "type 2" barrel because it takes the .136 bolt?

[VASCAR2]

That’s correct, Harpoon1, wasn’t trying to rant. My career caused me to give lengthy replies, to many reports over the years I guess. Ballistic Advantage uses SAAMI Spec chamber and are very popular 6.5 Grendel barrels.

[Harpoon1]

Vascar2,

Oh....I didn't take it as a rant. Thanks for clearing that up, it was a big help.

[zcostilla]

Two inches isn't much of a difference. Some people report that their 16" barrels get more velocity than their 18" barrels. Other things play a factor such as rifling twist and type. If you are talking about a 4 inch difference, you could make a pretty good "rule of thumb" estimate. One average that I read from Klem was "It will be about 25fps for each inch of barrel."


LRRPF52 also said once that "There isn't a linear rule for muzzle velocity and barrel length, but rather a curved rule. As the barrel gets past 20", the increase per inch produces less speed, although each barrel has its own characteristics."

I wanted a 20” barrel because I prefer the way a rifle length gas system cycles. But I couldn’t pass up the Bear Creek Arsenal sale for Black Friday to get the barrel for my first Grendel.

Getting back to OP’s post, also was confused by the different specs for both barrels and bolts. Mostly, by the fact that some would advertise as a true SAAMI chambering but use a 0.125” bolt face depth.