copper fouling
- Thread starter 49willys
- Start date
Proabably so. Most bullet jackets are gilding metal, which is actually a form of "low brass", meaning low zinc content. About 5%. Too little to look yellow colored. I expect the various manufacturers have small differences in the alloys they order because they feel it gives them one advantage or another.
There are also electroplated bullets. These usually have pure copper, and it typically has greater friction than the low brass, so they can't be shot as fast in most guns. If you were shooting those, then you may find other makes of bullets do better.
If your barrel is prone to fouling, you can firelap it with very low loads of abrasive impregnated bullets. If you are happy with the accuracy you may not want to do more than polish the bore, in which case the Tubbs Final Finish product might be a good choice. But, in general, smoothing reduces fouling.
You can also go to using moly-coated bullets. That's not as fashionable as it once was, but it really does cut fouling down.
There are also electroplated bullets. These usually have pure copper, and it typically has greater friction than the low brass, so they can't be shot as fast in most guns. If you were shooting those, then you may find other makes of bullets do better.
If your barrel is prone to fouling, you can firelap it with very low loads of abrasive impregnated bullets. If you are happy with the accuracy you may not want to do more than polish the bore, in which case the Tubbs Final Finish product might be a good choice. But, in general, smoothing reduces fouling.
You can also go to using moly-coated bullets. That's not as fashionable as it once was, but it really does cut fouling down.
Some barrels shoot more accurate after being copper fouled. When that happens, the micro size pits in the bore are filled with copper and subsequent shots have little or no jacket material scraped off unevenly and they are not unbalanced enough to impair accuracy.
It is a barrel issue. The shallower those pits are or the smoother the bore finish, the less fouling there is. But there's a limit. When those tiny pits and rough spots get smaller than about .000010" in size/depth (less than a 10 micro inch finish in the barrel making business), more copper fouling happens. Top quality barrel makers like a 14 to 16 micro inch finish which seems to copper foul the least.
It is a barrel issue. The shallower those pits are or the smoother the bore finish, the less fouling there is. But there's a limit. When those tiny pits and rough spots get smaller than about .000010" in size/depth (less than a 10 micro inch finish in the barrel making business), more copper fouling happens. Top quality barrel makers like a 14 to 16 micro inch finish which seems to copper foul the least.
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Based on the barrels I've used I'd say more barrel than bullet.
My Shilen-barreled Remington 700 is almost impossible to foul heavily no matter what brand of bullets I use. I've tried Barnes, Sierra, Hornady & Nosler they were all similar.
My Enfields are the exact opposite! I have one that was unfired until I unwrapped it (apart from factory proofing), &n the other was shot god only knows how many times. Both of them will show jacket fouling after just a few rounds. Those bullets have been British MkVII ball, South African R1M3Z, Hornady, Speer, & Sierra. They all fouled about the same.
My FAL is about 1/2 way in between, some fouling happening but not as much as the Enfields, that has had bullets from Sierra, Nosler, Speer, South Africa & Brazil. They were also very similar to each other.
My Shilen-barreled Remington 700 is almost impossible to foul heavily no matter what brand of bullets I use. I've tried Barnes, Sierra, Hornady & Nosler they were all similar.
My Enfields are the exact opposite! I have one that was unfired until I unwrapped it (apart from factory proofing), &n the other was shot god only knows how many times. Both of them will show jacket fouling after just a few rounds. Those bullets have been British MkVII ball, South African R1M3Z, Hornady, Speer, & Sierra. They all fouled about the same.
My FAL is about 1/2 way in between, some fouling happening but not as much as the Enfields, that has had bullets from Sierra, Nosler, Speer, South Africa & Brazil. They were also very similar to each other.
I can't tell you much about why one of my rifles foul more than another. But for example my factory Rem. 700 shoots the 222 with a 50gr. bullet around 3/8". About one time a year I notice that the groups will open up a bit. I have noticed the cleaning patch doesn't move smoothly through the barrel. That is the time when I will take a 22 mop with a patch on it so it's tight and apply a small amount of JB cleaning compound on the patch. I will push it back and fourth through the barrel just enough to smooth it out. Then I clean all of it out and will notice quite a difference on the friction pushing a cleaning patch through. My theory is constant smooth friction is better than having hot spots or tight spots.