6.5 Grendel Gas Port Sizes

[Shivesy]

I have gathered some information about gas port diameters that I thought I would share with this forum. These 3 examples are all 6.5 AR barrels. I am sure these examples are not written in stone but I have personally used #1 and #3 with success. I am using factory Hornady A-Max and SST 123gr ammo and H3 buffer.

#1) 20" Barrel Rifle Length Gas Systen. (.093)
#2) 16" Barrel Mid Length Gas System. (.078)
#3) 16" Barrel Carbine Gas System. (.062)

[sneaky one]

Thanks for the good data Shivesy- I'm sure someone will broadcast their thoughts on this. I have a co-worker that bought 2 rifle uppers recently , and is having the same port diam. issue-I thought that this was the problem= he doesn't know that yet-he is lost on this. One runs fine-yet the same as the other won't run . Same parts-same same all around. One for the hubby-& 1 for the wife deal here. I will set him on this course -of diam. inspections. Thanks shiv.!

[Flyby]

What tools are you using to measure the gas port? Never had to mess with one, even on the 300 Blackout. Are they pin gauges? Where best to get them? And if you want to expand a gas port, there must be sized bits to do so?

I have a machinist I use to thread barrels and such, I'm sure he could check it. Its a little of a drive to get to him.

[ricsmall]

Flyby, Just use a drill index. I have one that is 1/64th increments, so it pretty well covers everything. Find the correct one for the port and you have it.