Copper Fouling?

[35whelen375]

Hello, I am kinda stumped, In my Remington 700 .308 WIN and shooting the 168 Barnes TSX.

I bore sighted my Zeiss HD5 Conquest 3-15x42, then shot at 25 yards the scope seemed to track very well, I clean the Barrel and the next day moved to 100 yards and only needed to adjust 1 minute down and 1 minute left, 2 shots, I put another 2 shots, 1.8-2" high at 100 for my 200 zero- both those shots were touching, I then moved to the 200 yard target to confirm the zero, and flinched on the first at 200 from a dang guy with a big muzzle break next to me so I shrugged that one off, and did my next shot, but it hit 2" low at 200, I shot another and it was the same 2" low, shot a forth and same thing 2" low, I moved back to 100 yards and my point of impact from the 1.8" high was now right on the bull- WTH?? copper fouling? I have read both good and bad, but just wondering if that might be the case, or need to clean after say 4 to 5 shots?

 

[blacknzr1]

I had a copper problem the other day. it made the groups bigger. but not off target.

but easy to check clean it and see what happens.

check scope mounts etc

 

[Dr. Vette]

You cleaned it. As a result, your point of impact changed until the barrel fouled again and you returned to a consistent point.

I was out shooting two rifles of the same caliber, same maker, but different bullets on Wednesday. Each had been cleaned a couple of days prior with BoreTech Eliminator, though one needed the copper cleaner from them too. One of them settled back in on the 3rd shot, the other needed until the 6th before it was consistent again.

This is a normal thing to have happen. A clean barrel shoots different than a fouled barrel, and if you had any leftover oil or cleaner in the barrel that too will affect the point of impact.

Leave it alone now until end of season. Mine won't be cleaned until January or February at this point. The one that only took 3 shots to settle in had at least 50 rounds through it from load development and other shooting and is shooting Barnes TTSX bullets. Oh, and that's NOT the one that needed the copper cleaner. This rifle had the cleanest bore I've ever had the pleasure of cleaning despite the number of rounds it's seen.