AR Comp Powder

[KMart]

Now that AR Comp has been out a while, I am interested in what some of you have observed while using this powder.

I have been using it in a 223 using 69 gr SMK and 75 Gr Hornady HPBT bullets out of a bolt gun. The barrel is a 26" 1x8 twist McGowan SS. I get good accuracy and excellent velocity with both bullets. 3100 fps with the 69's with some groups in the .2's. About 3050 with the 75's and some groups in the .3's.

What seems to be a problem is how bad the barrel copper fouls with this powder.
When I shoot the 69's with benchmark powder, there is hardly any copper. Only 1 or 2 patches with KG-12 and the copper is gone
With the 69's and AR Comp it takes 7-8 patches to get the copper out.

What have you all seen with the AR Comp?

 

[KMart]

Not many users of AR Comp. Has anybody noticed increased copper fouling with this powder?

 

[Michaël T]

i use it in my 6mm Fat Rat (ar15)with satern barrel and have no excessive copper fouling i am using hornady, berger bullets
two patches with shooters choice to clean out carbon deposit and clean she is after 60 rounds fired

 

[jlc204]

I've been testing AR-COMP in my 204 Ruger. I've definitely noticed an increase in carbon over Benchmark, and now that you mention it, it takes more patches with KG-12 to get the copper out also, than it does with Benchmark. Although, I'm getting higher velocity. Maybe that has something to do with it?

 

[KMart]

I notice more carbon with all Alliant powders. The copper is what what has been concerning me. I was wondering too about the increased velocity with the heavier bullets.

 

[amamnn]

How can you tell that more copper is being stripped from your jackets and not that you have less layering of carbon/copper and etc. if you don't use a borescope (since it was not mentioned) to actually see what's going on inside the barrel?

I've found several instances of layering that resulted in "clean" patches when in fact there was still copper in the barrel. Without a borescope I would have thought the barrel was clean. The reverse is also true. Using a cleaner burning powder or finding the right pressure to get the best from a powder made patches seem to reveal more copper in the barrel, when the fact was that I was getting less layering. You always get jacket stripping in factory barrels at the gas port in an AR. How much are you really getting out?

Unless you start with a clean barrel and are SURE it's clean all this talk of copper stripping or carbon residue is just so much gunsmoke....you don't know what you left behind last time you cleaned.....and being sure takes a borescope. It seems doubtful that a powder would cause more jacket to be laid in the rifling of the bore, but it sure could be burning differently and layering less. These days you can get a Vision Optics fiber optic borescope for less than a name brand riflescope or you can take your "clean" rifle to almost any good gunsmith and have a look through his borescope. What you see will no doubt surprise you.