copper fouling

[wareagle1]

I seem to be getting about 9 rounds out of my 7mm rem mag before I have to clean and use a copper remover(sweets 7.62). I get .5 moa or under, up until this point, then it just puts them all over the place. I'm shooting CT ballistic tips pushing 3200 fps but I'm going back to reg ballistic tips because I did not see any improvement in the Copper fouling.
Does this seem about right?, or is there something I can do to reduce the fouling.

 

[JD338]

Sounds like you have a rough bore.
Try some JB'b paste to smooth it out.

JD338

 

[steve4102]

Are you allowing the barrel to cool completely between rounds or are the last of your nine shots fired in a hot barrel?

 

[wareagle1]

3 shots 2 minutes apart, then 5 minutes before the next threw shots and then another 5 minutes before the last three

 

[Guy Miner]

Factory barrel?

Have had the same problem myself with high-velocity factory rifles. The bores tend to be pretty rough. They'll shoot well enough for a few shots, then may often start getting so badly copper fouled it goes to pieces. I used those "Final Finish" fire-lapping bullets from Tubb, and they helped smooth the barrel of my old 7mm mag Sendero, but it still fouled too badly for use at matches where there is no time to clean.

JB Bore paste, particularly in the throat area can help. It is a very mild abrasive.

Ultimately though - you may have to treat yourself to a nice smooth, hand lapped custom barrel from Krieger, Lilja, Rock or one of the others. Oh darn, I hate it when I have to upgrade to a custom barrel... :grin:

 

[wareagle1]

it's not quite on the level of a Krieger, Lilja, Rock but it's a douglass witch should be better than a factory

 

[coyotetrapper]

With CT bullets I bet it isn't copper fouling in 9 shots? Do you have a synthetic stock? Some are more prone to exspansion than others, those with a bedding block are much better than those without.

Savages lower end synthetcis are so flimsy that you can flex them with the action removed.

By all over the place what do you mean exactly? Also sweets is a very harsh cleaner, I would switch to barnes or montana extreme will remove the lublox from those CT"s or copper just as well and with less corrosive action.

Is your 7mm new? How many rounds have you put through it? I find the best accuracy in larger bores comes after 60-70 have been put down the barrel?

 

[wareagle1]

coyotetrapper, the stock is a Bell & Carlson thumbhole premier . By all over the place, I guess I mean 1.5 inch groups, witch really isn't to bad., But those first 9 shots of .5 moa are really nice. It has had about 100 rounds put through it

 

[Guy Miner]

Dang - I'm surprised that the Douglas is fouling like that. Figured you had a factory barrel for sure.

Sweets is my go-to copper remover when I've got bad copper fouling. If that's not working.... Hmmm... Now, if it only has 100 rds through it, it may not be fully broken in. Sometimes the chambering reamer leaves some very fine marks when it's cutting, particularly if it's a little dull. Those marks, right at the throat area can cause the bullet jacket material to strip away, and will keep fouling until they are polished out. Consider aggressively using JB Bore Paste in that area, and consider those Final Finish bullets for fire lapping that area.

Good luck! Guy