leading problem headache........

[Ackley]

First of all,I'm new here at the forum.Been a shooter for 50 years.Here's the headache I'm having.I've got a 57 Smith mountain gun in 41 mag.No matter what I've tried in the way of lead bullets,I get leading.I've tried anywhere from BHN 12 tru 22.Plain base,gas check.High velocity lube,orange magic even black powder lube.I've shot .410 diameter thru .411 bullets and my chamber throats measure .411.

Actually,I've run out of options of what to try.Any ideas ?? Thanks for any repies.

[Down South]

Have you slugged the bore and what does it measure?

[shooting on a shoestring]

Welcome aboard Ackley.

I think you would get flooded with posts if this was in the Wheelgun and Hand Cannon section a little farther down the list.

I noticed like Down South a critical piece of info is your bore diameter. If it is larger than your throats, you will have leading. Also, I notice you have .411 throats, but the largest boolit you've tried is .411. Could you go to 412? I shoot the largest boolits I can chamber, a little thumb pressure is fine for me if I have to.

Also, I've had very good luck with 2400 behind boolits that tend to lead for me. I've occasionally completely done away with leading and even cleaned up some previous leading by shooting a 2400 load.

One other thing that I would want to know is where is the leading in the bore? Is it just past the forcing cone? Just towards the muzzle? All the length of the barrel? Is this a stainless gun? And last of all is this an EDM rifled Smith?

Inquiring minds.....are just full of questions.

[462]

Ackley,
Welcome. You've arrived at the best forum.

Your post brings to mind my first one.

1. Slug the groove.
2. Where is the leading? Throats? Forcing cone? First part of the barrel? The last part of the barrel? The entire barrel?
3. What are the loads?

[Ackley]

The leading is just in front of the forcing cone.I started with unique and the leading was totally horrible.I switched to 2400 and that helped,but not nearly enough.This is a blued gun.

[runfiverun]

restriction under the frame........
lap it.

[Daves1]

Please explain restriction under the frame.

[Down South]

Please explain restriction under the frame. Where the barrel screws into the frame is a common place to have restriction in a revolver. This can many times be (felt) by slugging the bore which needs to be done anyway for us to have a better idea of just what the problem may be. The measurements of both the cylinder throats and bore are important for proper bullet fit.

[Daves1]

So when Runfiverun says to lap it, he's talking about only lapping the barrel where it screws into the frame, correct? And how would you go about lapping it? What technique?

[Cadillo]

So when Runfiverun says to lap it, he's talking about only lapping the barrel where it screws into the frame, correct?


If you detect that there is a constriction in the area where the barrel is screwed into the frame, it means that when the barrel was scewed into place, it was a tight fit and that tightness squeezed the barrel down constricting the bore as it was tightened into place. If I confirmed that condition in my gun, I would firelap the barrel until the constriction was reduced to the point that it was no longer a factor.

No, I have not yet had to do this, so I am not speaking from experience, but rather just stating how I would approach the problem. Perhaps someone else here has actually confronted and solved this problem for themselves. If so, I would like to hear their input in this regard.

[Daves1]

Embed lapping compound into boolits and shoot till restriction is gone? How many shots approximately to accomplish this?

[stubshaft]

You can either fire lap or pour a lap and push it back and forth in the barrel until the restriction is gone. There is no way of telling how many boolits OR laps will be needed.

[Rex]

Doesn't Lead Bullet Technology offer a fire lapping kit?
Rex

[wiljen]

Brownells or midway carry one made by wheeler

[runfiverun]

some valve lapping compound and some cast boolits,light loads.
the alternative is to paper patch about 20 rounds with printer paper and use those that will hold the lapping compound rather well finish up with about 20-30 plain paper for a final finish.
works on old mili rifles too.

[HORNET]

Try with 320 grit lapping compound or finer on a cast boolit. I believe that's what the kits start at, then move to finer for finishing. Fire a few, then retest, repeat as needed. Don't get too enthusiastic too fast, it's easier to take more off than to grow it back on (Don't ask how I know). There's a little more discussion here: http://castboolits.gunloads.com/showthread.php?t=78901 . Or you can do a search on Firelapping. It's been discussed at length.

[Lloyd Smale]

could be a restriction or a cylinder that is slightly out of time with the barrel. For a rough look take a bullet and drive it down the barrel and back into the cylinder and see if it gets damaged on one side or the other when it goes into the cylinder. A slight missalignment cant be told like this but a bad one will show up. Also drive a bullet through your barrel and check the size without going into the cylinder and it will show if you have a restiction where the barrel is screwed into the frame. my experiences with smiths usually will show its an alignment problem more often then a restriction. Rugers are just he oposite. A restriction can be lapped out but if its a timing problem it will need a trip back to the factory.

[Down South]

The thread starter needs to determine exactly where the problem is first. It could be a number of other things causing his leading problem. Fire lappigg should only be done if it is determined that there is a constiction.

[dubber123]

I'm running about 90+% of the S&W's I have slugged as having a noticeable restriction at the frame. 4 out of 5 I believe is the current count. Using 320 grit, and ACWW boolits, it is taking around 48 shots to completely remove the constriction. All guns have ben blued, not sure how much different stainless would be. The difference in fouling after lapping is amazing, with a noticeable increase in accuracy to boot. Like has been stated, do some checking first, but if it's a constriction, don't be afraid to lap.

[Daves1]

Great thread, lots of good information. Thanks