AR-15 short stroking? (Or just not working)

KevinB said:
What is Rick's spec?

The M16 is overgassed, it does not need that much to function with M193 or M855, it was done that way for a variety of reasons including proper function in different environments and clean/dirty etc.

While not ATRS, I will give you my thoughts
Our (KAC/KMC) first SR-15's where what some feel as undergassed. The gun was designed in FL, and ran fine with M855 even in cold testing. What happened was folks ran weak ammo in the cold (the original SR-15 gas port was opened up a few thou after complaints about errative function with .223Rem ammo).
I prefer a gun not to be overgassed, I loved the early SR-15 as it was smooth as silk --- however I live in Fl and lube my weapon.
I shot a bunch of guns sent in -- with Wolff (about the weakest ammo available) and cold soaked a few with no major issues -- I did need to lube a few, and in one case needed to replace a carrier key upon inspection that it was leaking.

However the decision above my paygrade was made to open the port up to allow folks to take their $2300 rifle and shoot garbage ammo thru it.

The other aspect on this, is regardless of what ATRS's ammo spec is, its a parts gun, and I would say that you have an ammo issue, or a gas leak. That's my personal feeling.

Reaming a gas port is easy anyway - it would probably be cheaper to buy an 0.090 and 0.092 Reamer from MSC Direct and do it yourself.
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Hmm, thanks for the info. It probably would be easier to try a hotter ammo, like the S&B pr Privi stuff I mentioned, I also hear the Norinco ammo has a bit of bite to it as well.

As for gas leaks, I noticed some carbon buildup on the gas tube where it meets the gas block, so their is some gas bypassing their. the gas key is tight as far as I can tell and it looks like the gas tube has a nice ring around the end, so it seating nicely in the gas key of the carrier so i don't think its bypassing their.

This could be a matter of me running cheap ammo through a high quality barrel as well, although I had an understanding that the Federal AE stuff was average for pressures though.

Ill have to give it some thought, as I will not be able to do anything for a good few months anyways so ill have ots of time to think about it.
 
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Federal AE red box is okay for cheap ammo, the black box is not.

A .223 round from the same manufacturer has most of the same components but how they cut costs is reducing the amount of powder.

That's why the AE black box is almost half the price of the red.
 
Someone on this board checked the difference between the red and black box IIRC. They found that the amount of powder was (near) identical between the two. Although that doesn't necessarily mean it was the same powder (or result in the same pressure), ammunition manufacturers buy powder by the boxcar load and adjust the load to fit their specs between batches.

Federal has stated that there is a difference between the two types, but I think they just have two different boxes and load them from the same pile ;)

added:

'max' in another thread posted this:

I send an email to Federal to make things clear.

They said the difference is the bullet they use.

I send another email asking to be more specific than "the bullet is different" and give more details.

Ill post the answer as soon as I got it.
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http://www.canadiangunnutz.com/forum/archive/index.php/t-820592.html
 
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Think of the money Federal is saving if they load one less grain of powder in the cheaper ammo :cool:

Like I said before, Black Box will not cycle in my AR's but Red will. My bolt actions work well with the Black Box though. ;)
 
I noticed that in lower tempetures that inproper gas ring alignment and over lubercation mixed in with extreme fouling would always cause issue's with this rifle platform...
But then again I just reboot my computer and put on the movie comando. Thus never having to reload or clean my rifles again :p
 
I contacted ATRS and they did confirm that their have been issues with their 20" barrels and the gas ports being undersized. Its being taken care of and ATRS has been great about it.

Although, I do wonder if having an undersized port would make the action a little smoother using hotter ammo, like privy. Just a thought.
 
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