Copper Wash

[161]

I had never heard of copper wash causing cast boolits the lead before coming to this site. My question is if copper wash causes lead fouling why do we use copper gas-checks?

[captaint]

Gas checks, living on the base of the boolit, is less likely to leave copper behind than a copper jacket. IMO the gas checks are there to protect the base from melting and letting gas blow past the boolit. Normally the gas checks are reserved for higher pressure, higher speed loads, rifle or pistol. IMO, the copper left in the bore will actually drag lead off the sides of our boolits, causing problems. enjoy Mike

[blackthorn]

"Gas checks, living on the base of the boolit, is less likely to leave copper behind than a copper jacket. IMO the gas checks are there to protect the base from melting"
(The base [or any other part of the bullet] does NOT melt! If there is room for the gases to pass the edge/end of the bullet [i.e. small bullet or defect in the base edge] it will cut tiny bits of lead off and those tiny bits are then ironed onto the interior of the bore as the rest of the bullet passes!)
"and letting gas blow past the boolit. Normally the gas checks are reserved for higher pressure, higher speed loads, rifle or pistol. IMO, the copper left in the bore will actually drag lead off the sides of our boolits, causing problems."
(right, that is exactly what happens!).
"enjoy Mike"

[williamwaco]

The gas checks are also riding on a thin film of lubricant which is not present with jacketed bullets.

[BAGTIC]

I believe... Gas checks do not prevent leading They remove leading They function like the scraper rings on a diesel engine. Any lead that has tranferred from the lead surface of the bullet as it passes through the barrel is scraped off by the gas check bringing up the rear leaving the bore clean in preparation for the next round.

[Bret4207]

There's "a copper wash" and then there "copper fouling". It really depends on the gun but a slight copper wash may not cause problems, in other guns it will. If you get copper (jacket) fouling then you may as well forget cast till you fix that sewer pipe. Jacket fouling that might abrade a jacket bullet in passing and do no harm to accuracy ( no help either!) will usually cause major issues with cast, ending up in a shards of lead alloy clinging to the bore.

It all depends on just what you have.

[mpmarty]

The copper deposited in bores is analogous to tinning a solder joint in preparation to actually soldering the joint. It improves adhesion.

[JeffinNZ]

I believe... Gas checks do not prevent leading They remove leading They function like the scraper rings on a diesel engine. Any lead that has tranferred from the lead surface of the bullet as it passes through the barrel is scraped off by the gas check bringing up the rear leaving the bore clean in preparation for the next round.

I disagree. A gas check creates a much tougher seal on the base of the boolit strengthening and preventing leading.

[williamwaco]

I believe... Gas checks do not prevent leading They remove leading They function like the scraper rings on a diesel engine. Any lead that has tranferred from the lead surface of the bullet as it passes through the barrel is scraped off by the gas check bringing up the rear leaving the bore clean in preparation for the next round.




Those two are not mutually exclusive. I agree without reservation that gaschecks remove pre-existing leading. They have become my favorite cleaning mechanism. I always carry a few to the range and If the loads I am testing lead the bore, I can shoot a couple of gas checks through it and it will be squeeky clean.

That does not mean that they do not also prevent leading.

Although it would be very difficult to test. I wonder if anyone has ever had leading problems with gas check loads?

[runfiverun]

gas checks are called so cause thats what they do.
the scraping is a by product and may or may not happen.