Another carbon build up question

[WANTASHOOT]

I am some what stumped. I think there is a very simple explanation.

I have been playing with my .223 in a Ruger A-bolt and my .250Savage in a Ruger 77MkII. I use Varget in both loads the 223 gets 26.4g and the 250 gets 35.5g.

I have noticed much more carbon build up in the barrel of the A-bolt .223.
Could this be caused by the quality of the barrel? I dont have a borescope but the barrels both look good to the naked eye. Or could it be something else.

 

[BoydAllen]

Differences in load peak pressure could be the reason. Hotter loads generally burn cleaner.What weight bullets are we talking about? Doesn't Browning make the A-Bolt.

 

[WANTASHOOT]

I new the ruger/browning mistake would be caught. Unfortunatly I realized I had made the mistake about 10 minutes into my 5 hour trip and would not have computer access untill this morning.

As for my .223 I am shooting LC Brass with 26.4g of Varget with a 60g V-Max. I had about 40 rounds down the barrel when I noticed the carbon fouling. Primarily in the first 4 inches of the bore. I had to scrub with a nylon brush to get it out.

In the 250 I am shooting Remington brass with 35.5g of Varget and 87g Speer spt. It also had about 40 rounds down the barrel. It cleaned up with about 8 or 10 patches with Butches bore shine.