Tuning the Gun 101

[uniform64]

Is BCM consistent with their gas ports?

[jerrysimons]

I once got to talk with some engineers from the Mclaren Race Team. We conversed for about 3 hours. I did most of the listening. I can't believe what they go through to get an engine around the track for 500 miles-and believe me, the work is for 500 miles exactly-if that is what the race calls for. Back on topic. IG, since you posted "101" please follow this up with a 102, 103, etc. I (we) appreciate the info.

Indeed perhaps a how-to guide, including ranges of various known factory ammo pressures. Though, this info is already on the board if one does a little searching.

[Iraqgunz]

I'm not going to cook the fish and eat it as well.

IG-
Most EXCELLENT info ,sir.
Might I ask, that you add...again for the new and uninformed...the LENGHTS of each gas system?

[Iraqgunz]

The examples above are based off the 20" rifle and the 14.5"/ 16" carbine. Simply because as stated there is a standard there.

Sticky X 1million

Is it getting too deep into basic tuning to mention different barrel lengths and dwell times with these designated gas systems?

I assume this all for the standard 16" barreled guns; whether rifle or carbine.

[SeriousStudent]

Excellent write up, IG, and much appreciated. I'm printing this and putting it in with my tools and spare parts.

I also stickied the thread. Do you want this to stay in AR General Discussion, or want me to move it to Ar Technical Discussion? Seems like a good fit in either location.

[Whytep38]

Excellent info again, IG.

FYI, my Colt 6520 purchased new in 2010 came with an H2 buffer like their M4/M4A1 carbines, rather than the H buffer like their 6920. Has Colt switched back to the H?

[Iraqgunz]

Not sure to be honest.

Excellent info again, IG.

FYI, my Colt 6520 purchased new in 2010 came with an H2 buffer like their M4/M4A1 carbines, rather than the H buffer like their 6920. Has Colt switched back to the H?

[CoryCop25]

Ammunition is a major factor here as well. If you are shooting non 5.56 loadings you may not be able to run the heavier buffers. Ultimately whatever you choose, you should be ensuring that your weapon will function with all the ammunition that you have in your stock.

Great post!
If I may add to this section about tuning, and ammo selection.
Don't forget to consider cold weather, lubrication and fouling when tuning the rifle to your ammo.
If you tune your rifle to your least powerful loading and the rifle JUST functions when using it, you will begin to have failures when your rifle gets dirty, looses its lubrication or is used in colder weather.
You have to allow for function during these conditions or you will be dealing with a rifle that works great clean and slick but as the day progresses, you will encounter problems.

[Alex V]

In my short experience I try and slow down the cycling rate as much as I can with buffer weight and maintain function. I am not sure if this is the right thought process or not, but it seems to work. I run an H2 in a midlength with shit Russian ammo reliably. I could not detect bolt bounce when running 5.56 (mil pressure) ammo. I assume with higher pressure ammo the gun will run faster, but if I set it up for 5.56 it may not run shit .223 well. I try to set it up for the least common denominator.

I once got to talk with some engineers from the Mclaren Race Team. We conversed for about 3 hours. I did most of the listening. I can't believe what they go through to get an engine around the track for 500 miles-and believe me, the work is for 500 miles exactly-if that is what the race calls for. Back on topic. IG, since you posted "101" please follow this up with a 102, 103, etc. I (we) appreciate the info.

Off topic warning - I ran into 3 McLaren mechanics during the 2006 US Grand Prix in Indy... in a gun store that rented firearms/range in the back lol. Poor Brits without guns... The conversation did not go well as I am a crazed Ferrari Fan

Back to your regularly scheduled program.

[blade_68]

Correct Ejection, brass leaves receiver ejection port..
Clock position get a damn digitally watch and forget.. 0100, 0400 clock ect. ejection bull crap.