[BLFields]

I have begun a course of fire lapping the barrel of a Colt .45 SAA. So far I have fired 54 lapping bullets through the bore. I still have streaks in the bore which I suppose is lead. But it is not much as before. Accuracy has improved as has velocity somewhat. However, when I push a copper scrubber wrapped brush through the bore, I can feel it hitting and removing the streaks and at the forcing cone I push out flakes and slivers of lead.

So, my question is this: when do I know I've gotten all the benefit there is to get from the fire lapping? At some point can I expect the barrel to be completely free from streaks? Will there come a time when there will be no more lead particles coming out of the forcing cone? Or, on the other hand, will these things continue notwithstanding a smooth, uniform bore?

Another question: can these streaks be lube and not lead? How can I tell? Like most Colt .45 SAAs, the chamber throats are much larger than the bore in my gun and so I use 0.454 or 0.455 bullets for a 0.451 bore. The forcing cone has a lot of work to do and I am wondering whether all of the flakes, chips, and slivers of lead are from the forcing cone and nothing of consequence is coming from the barrel. How does a shooter figure these things out?

 

[MikeG]

Slug it. That will tell you how smooth the bore is, and whether there are any constrictions.

 

[nachogrande]

Identify the true problem first, then fix it.

Knowing when to START might be the real problem. Did you happen to be shooting cast? It sounds to me like lead fouling (lead flakes), but you mentioned copper??? I WOULD stop wasting your $ with fire lapping until the barrel is good and clean & you know what's what. A look see with a bore scope might be a good start. Good luck.

 

[BLFields]

MikeG,
I have slugged the barrel numerous times.

Nachogrande,
Copper jacketed bullets in a Colt .45 SAA? Heresy.

 

[MikeG]

If the slugs go through without any resistance under the forcing cone or other tight spots, then I would not lap any more. Not with conventional abrasive, anyway.

I have been playing around lapping with 'bore paste' and it does seem to shine a barrel up just dandy. 10 or 20 rounds with your favorite 'bore paste' or the Remington bore cleaner that has the steel ball in the bottle might be all you need to do the final smoothing.

Do make sure the cylinder throats are not smaller than the groove diameter.

Good luck and let us know how it progresses.

 

[Jim_B]

I have begun a course of fire lapping the barrel of a Colt .45 SAA. So far I have fired 54 lapping bullets through the bore. I still have streaks in the bore which I suppose is lead. But it is not much as before. Accuracy has improved as has velocity somewhat. However, when I push a copper scrubber wrapped brush through the bore, I can feel it hitting and removing the streaks and at the forcing cone I push out flakes and slivers of lead.

Fire-lapping to remove lead? Seems a bit extreme. Why not just use Lead-Away cloth? That stuff seems to work for me every time.

 

[Tater]

Fire-lapping to remove lead? Seems a bit extreme. Why not just use Lead-Away cloth? That stuff seems to work for me every time.

Or some penetrating oil and a brass brush wrapped in copper chore boy strands....

 

[BLFields]

Jim B & Tater,

I'm not using the lapping process to remove lead. After a session at the range shooting lead bullets I see the streaks. I use a Chore Boy wrapped copper brush to remove the streaks as any normal person would. The question with regard to the streaks was whether the streaks are lead or whether they could be lube. I am trying to assess where I am in the lapping process.

So far I have not see the "lube star" at the muzzle which means, as I understand it, that the lube is not reaching the end of the barrel for whatever reason.

 

[Dollar Bill]

Jim B & Tater,

I'm not using the lapping process to remove lead. After a session at the range shooting lead bullets I see the streaks. I use a Chore Boy wrapped copper brush to remove the streaks as any normal person would. The question with regard to the streaks was whether the streaks are lead or whether they could be lube. I am trying to assess where I am in the lapping process.

So far I have not see the "lube star" at the muzzle which means, as I understand it, that the lube is not reaching the end of the barrel for whatever reason.

I don't normally see a lube star with my cast bullet loads shooting Keith style bullets and White Lube BAC, or any other lube for that matter. I do get that nice star with all my BPCR loads though. Honestly, the lube star, while it does show you still have lube at that point, can also be considered as an indication you have too much lube!

Streaks of lube in the bore would indicate you're getting gas cutting at the base of the bullet, cutting all the way to the lube groove. Not a good sign. I would suspect you're still seeing some leading.

Leading towards the muzzle occurs from lube failure. Leading starting more towards the breech end is bullet fit / alloy issue / possibly a rough forcing cone.

So, IMO, it's best to determine what all is going on before proceeding further with fire lapping. I am not a proponent of fire lapping as any of the above issues can be fixed by other means, particularly the forcing cone which has been mentioned twice now. It's a common gunsmith task to ream forcing cones to smooth them out. I also recut them to 11 degrees for better results with cast bullets. Generally, fire lapping will not fix forcing cone issues.

 

[MikeG]

Push a patch through it. The solvent will take out powder fouling, lube, etc., but not likely the lead.

Push a brush through it. Lead will come out in little shiny flakes.

If there is no constriction and you are still getting leading, you may have a different problem to solve (bullet fit, hardness, chamber throats, etc.).

Hope that helps.

 

[BLFields]

Dollar Bill & MikeG,
Thanks, the comments are helpful. My Colt has large throats (0.456, 0.457) with a bore diameter of 0.451 so I have been shooting 0.453 and 0.454 bullets with a BHN of 15. Perhaps I need something softer, maybe around 12. I have some bullets on the way that are 0.4555 and we will see how those do but they will also be BHN 15.

I have cut the forcing cone to 11 deg. (I think it was already at 11 deg., but I tried to smooth things out because it looked a little rough.) Nevertheless, I am still picking up significant leading at in the forcing cone although the first few inches of the actual barrel look good. The constriction I had was about 2/3 rds of the way down the barrel and that is what I have trying to lap out. And that is where I continue to see streaks.

 

[MikeG]

The constriction may not be quite gone yet, then, if you are still getting leading halfway down the barrel. Can you feel any difference in that area pushing or pulling a tight patch through it?

 

[BLFields]

No, I can't. The constriction was not severe and I estimated it at something on the order of .0005". I could push a 0.443" pin gage through the entire length of the barrel but it was obvious that it took more effort to push it through at area. Given the streaking, I am concluding that it is still there but has been reduced.

Given the flaking of lead at the throat, perhaps the way to proceed is to get a lapping 11 deg. brass plug and try to smooth out that area. However, I am always going to have to deal with the large throats but I thought I'd try every other solution to get a decent shooter and turn to getting a new cylinder as a last resort. Colt has no plans to ever reduce the size of these throats and so, given the lack of availability of Colt cylinders, I'll have to get one made from scratch. I'd like to avoid that expense if at all possible.

 

[emp1952]

SAA leading

I have a Ruger Blackhawk s/n is below 200 No transfer bar safety. when I started shooting it I wanted to only use keith style swc gas checked bullets. Circa 1972

I found annoying leading, fouling problems with this Ruger. Copper fouling was coming from the gas checks. Occasionally I would find a gas check on the ground in front of me. I additionally had one flyer out of every six shots. After much trial and error I found that the cylinder bore for one of the chambers did not line up quite right. When the timing dog clicked in and locked the cylinder I could push my cleaning rod down the barrel and at the forcing cone I would hit the edge of the cylinder. Upon notifying Ruger they immediately paid to have it shipped back to them and I don't know if they reworked the timing grove for that chamber or they provided a new cylinder. Thousands of rounds later it has never given me reason to complain again.

I offer this anecdote just to show that all kinds of things could be at play. Don't settle on one thing without eliminating other possibilities.