Barrel constriction, fire lapping, and leading

[Woodtroll]

Folks, I posted this in Veral's section over on Graybeard Outdoors, but thought I'd run it by y'all as well.


I have a stainless Ruger Bisley in .45 Colt that is giving me a fit. It came with a significant barrel constriction just ahead of the forcing cone, and would never shoot as well as I thought it should, and leaded with almost anything I ran through it, even gas-checked bullets. 108 fire-lapping rounds later, ALMOST all of the constriction is removed. I can just BARELY feel it as I push a lead slug down the bore towards the forcing cone. Before, I had to drive it past this point with several licks from a nylon hammer.

Now, the revolver is pretty accurate, giving me several groups 1-1/2" or less at 25 yards. However, it still leads lightly with most of the loads I've tried. The only thing it doesn't lead with is a Lee 300 gr. gas-check RFN (the only GC bullet I have in this caliber). My goal is to have an accurate gun that will not lead, or at least accumulate lead past a certain point. I thought that the barrel might need breaking in or seasoning after the lapping, but I've fired about 60 rounds since lapping with no apparent relief in the leading.

Specifics are: Ruger Bisley 5-1/2" .45, stainless. Chamber throats are 0.4525", forcing cone area at restriction 0.4514-5", muzzle 0.451". The chambers are aligned well with the barrel (checked witha range rod). Bullets I've used are the afore-mentioned Lee, an NEI 270-gr. Keith belonging to a neighbor, and a new LBT 280 WFN that Veral just cut for me. The alloy I'd like to use is wheelweight +1% added tin water quenched, but I've tried mixing 50% pure lead to soften this up, as well as air cooling. Bullets are sized 0.453" and lubed with LBT soft in a Star sizer. The load I'd like to use is 21.5-22 gr. WW296, and a lighter load of Unique/ Universal at 9.0 gr. or so. The load that doesn't lead is the Lee GC, WW quenched, 0.453". Anything else, softer alloy or lighter loads, sized samller at 0.4525", still leaves a smear of lead visible under a bright light in the muzzle (but not lumps, and it is easily removed).

The puzzling thing to me is that the leading is occuring in the last 3-4" or so of bore, and is mostly in the LEADING edge of the rifling and on the top of the lands, although there is a little in the grooves. In other words, the lead seems to be in the area of the land/ groove juncture that should have the most "grip" on the bullet as the rifling tries to impart the spin. It is almost as if the bullet, once spinning, is stripping the rifling slightly in the direction of the rifling twist.

With all that said, might the very small constriction still present be causing these leading problems? I hate to lap much more, as I feel that I'm just prematurely wearing out my barrel. Would a different powder be less likely to lead? I think I have all the mechanics right on this gun, except for the very minor constriction, and am puzzled by this continued leading. I'd like to use the WFN mould exclusively for both light (~900 fps) and heavy (~1100 fps) loads, since it seems most potentially accurate. Any input would be most welcomed.

BTW- the new WFN mould casts and releases perfectly, just like all my other LBT moulds!

Many thanks! Regan

[Bass Ackward]

Regan,

Nice write up. I am going to guess that your bore diameter was .451 before you started since that is what it is at the muzzle.

What area of a rifled barrel do you suppose is the hardest to form correctly and smoothly, especially by hammer forging or buttoning? If you guessed the rifling base groove juncture, you win todays prize.

And where does your leading begin? And if it breaks seal there and blows the lube off, wouldn't you expect to see more leading on the rifling where the force (friction) is being applied to try and rotate the bullet?

So if I read this all correctly, what you are saying is that you are leading in the area of the gun that hasn't been corrected by lapping? Hmmm. What was that question about more lapping again?

[Woodtroll]

Thanks, that's pretty much what I had figured, but I hate to "wear out" the barrel before I even get started. I know that stainless is particularly tough and wear-resistant, but how much fire lapping is too much? Am I likely to go too far with another 24 rounds or so (I try to shoot in groups of 6, to keep any lapping on the cylinder throats even)? Should I use a 0.453" lapping bullet, or size it down to 0.452" or so (the constriction right now seems to be just under 0.4515")?

Thanks again, Regan

[drinks]

Put the LBT mold on E bay and shoot the Lee bullet.

[felix]

You might firelap with a few more rounds, but use the longer boolit for the job with the hope more grit is carried more foward. ... felix

[Char-Gar]

I won't go into the ins and outs, the why and wherefore, but here is what to do to cure your leading problem.

1. Load 200 rounds of factory level loads with cheap jacketed bullets. Surplus 230 45 ACP ball will work just fine.

2. Fire the 200 rounds as fast as you can load and fire. Don't worry about trying to hit anything.

3. As soon as the last round is fired, removed the cylinder, flood the barrel with Shooter's Choice and give it 200 fore and aft strokes with a new bronze bore brush. Keep the brush wet with solvent. Wear gloves as the pistol will be hot.

4. Take the pistol home, remove the ejector rod and catch the barrel in padded jaws in the vise.

5. Coat tight fitting patches with Semi-Chrome or Flitz metal polish and and polish the bore, change patches and recoat with polish if things get loose. Keep this up for at least a half hour or until your arms feel like they are falling off. You can't polish too much.

6. Clean the barrel good with solvent to remove any excess polish and that is that.

Where you get through, your pistol will no longer lead and be very easy to clean.

You could have done this to start with and saved all of that laping.

[felix]

A good approach! Think of it this way: You cannot ruin a barrel that does not shoot straight (for any reason). The objective is to WEAR it in. Lots, many more than 200 rounds, sometimes a 1000 or more, of high antimony, very low tin boolits will do the same thing, but over time shooting normally. ... felix

[Woodtroll]

Thanks, folks. The gun seems accurate enough now, and my main concern is the leading. I understand the wearing in/ burnishing process, but am not convinced that jacketed bullets would have removed the constriction at the frame threads, which was over 0.002" as best I could measure. Do y'all think that it would have, especially in a stainless barrel?

Thanks for your help! Regan

[VTDW]

Woodtroll,

You got some great input. I have switched to Tungsten Carbide instead of lapping compound for lapping. I proceed very carefully and it always goes well for me. I have several pounds of the stuff left over from when I specialized in thermal composites. You are correct in that most stainless steels and especially those used in rifle barrels are very abrasion resistant.

I will offer to send some to you and only you. I do not recall the micron size of my powder but let's just say it is very minute. Just let me know. Also, how do your prepare your boolits for firelapping?

Dave

p.s. I also use the TC for lapping out my moulds.:castmine:

[Phil]

All very interesting but I would like to ask (not trying to be a smarta$$), why didn't you just send it back to Ruger and have a replacement barrel fit? I've done that with Smiths in years past and they replaced the barrel, no questions asked.

Cheers on a very cold, windy morning,

Phil

[Bass Ackward]

Woody,

You have many ways to go. But at this point, you say the gun shoots to your satisfaction. So the constriction apparently isn't causing any real problems huh?

Just some jacketed even to finish the lapping process and you could be home free.

If you don't want to remove any more metal and simply finish upm, I recommend one of those lapping Kits from Tubbs. They will do with 50 jacketed what it takes maybe 1000 to do. Much cheaper option and the fine aluminum gets down where it needs to to finish the job.

Just one more thing to think about.

[Char-Gar]

Woodstroll... I am going to get hacked off at the knees by Veral fans, who will swear those constrictions are the devils own work when it comes to handgun accuracy....but...for what it is worth, I don't buy it.

I have never had a sixgun ( have had many score) that did not have some constriction where the barrel screws into the frame. Polish the barrel as per my first post and you can peek down the barrel with your naked eye and see them as plain as a rat turdin the sugar bowl.

Constrictions in the rear end of a sixgun barrel do little harm to accuracy asthe lead bullet has plenty of barrel left to recover it shape before it exists the muzzle. Constriction in rifle barrels due to broach cut sight dovetails are another issue althogether. They can destroy accuracy althogether, particularly if it is the front sight dovetail that is the problem.

Leading is not caused by these constrictions. A rough forcing cone and/or rought bore filled with machine hickies are the mechanical reasons for a sixgun to lead. Of course some leading is caused by poor alloy or bullet fit, but that is an ammo issue.

I known I am going against St. Veral. He has a way of stating his opinions as fact and use selected data to back him up.

I have forty five years experience loading and shooting cast bullets is sixguns and have learned enough to trust my own experience over what I read.

Now folks are going to line up and tell me how accuracy improved after they fire lapped their sixguns. I don't doubt the truth in that, but the accuracy improvment did not come from removing the constrictions but from smoothing the barrel and removing the mico-machine hickies. The same could have been done by my original procedure and or recutting the forcing cone, or by firing lots of high-antimony cast bullets as Felix suggests.

Fire lapping removes metal in ways and places you may not want. It is an equal opportunity abrasive..not a good thing... IMHO.

[Woodtroll]

I appreciate all the input, I'm learning a lot!

I didn't send the revolver back because of the shipping expense, because most of the large-bore Rugers are like this and I wouldn't expect much different from a replacement barrel, and primarily because I'm a tinkerer and learn from things as I work on them (hence my presence on this board!).

The gun seems to be grouping to MY accuracy potential right now, but there's always room for improvement. My main gripe with it at this point is that it still shows some minor leading.

Y'alls comments on constrictions, lapping, and bore condition make sense, and confirm my own jumbled thinking in some areas. I especially don't want to wear my throat or forcing cone any more to get the rest of the bore in shape. I failed to mention in my first post that I had recut the forcing cone, but of course that did not go deep enough to remove all the constriction. I will say that I am one of the ones that will swear that lapping helped accuracy tremendously, as will others, but the specific mechanism for the improvement (whether constriction removal or polishing the roughness in the bore) I cannot determine for myself.

So, no heartache or hurt feelings on my part at all. I'm here to learn, and that's why I posted- to hear other ideas and opinions. I appreciate y'all taking the time to help me out and offer suggestions!

[44man]

The only question I have is how shooting 200 jacketed bullets will help if the bore picks up copper fouling in the first few shots and the bullet no longer rides clean steel? I would clean out the copper after ONE shot and do that for at least 20 to 50 rounds. Then clean after every 4 to 6 after that.
Then what lube was used? Could it be that it is not doing it's job because it is too hard? (Or too slippery, lube should not be "slick".)
I am a firm believer that too highly polished a bore is not good for cast. Yes, it makes it harder for lead to stick but the boolit should get some "bite" from the bore. Wearing off the sharp edges of tool marks is all that is needed. To make a bore like a mirror does not aid accuracy. I would put up with a little leading if the gun shoots tight groups. This will improve as the gun is shot.
I have had too many brand new revolvers that never leaded. My BFR's do not lead and did not lead from the first shots unless I tried LLA. My Vaquero never leaded after opening the throats and it has never been shot with jacketed. I shoot for months without cleaning with no loss of accuracy. All of the guns in my safe are dirty!
The problem of a little leading is overblown. As long as groups do not change, forget about it. Lead that is not soldered to the steel will shoot out ahead of the next boolit and will not build up any more then what is there from the first shot.
Has anyone ever considered that a little lead can provide a better bore seal and actually prevent more leading?
Unlike the old, dead soft .38 wadcutters and poor lube that would fill the grooves over the tops and even lead the outside of the gun, I have no problem with those easy to push out specks left in the bore.

[felix]

44man, of course. your burnishing method using condoms is the ultimate way to break in a barrel. But, it is way overkill for the run-of-the-mill gun. For example, your friend's 45-70 that he brought over. Shot good enough right out of the box, suggesting that any additional barrel effort would not improve its intended purpose. ... felix

[44man]

True, Felix, and I would only do it for a really rough barrel or a BR barrel. I have not seen a really bad barrel since the first Spanish ones. Bore restrictions are another story though and should be fixed. The quality of barrels today are just fine. For super accuracy up to and beyond 1000 yd's, it is very important to clean up a bore. But have you noticed how many guys are shooting 25 yd's? Unrealistic with magnum revolvers. My slingshot will do as good as some of those groups. But then, some guys are happy with 2" groups at 25 yd's. I am not one of them and want less then 1" at 50 yd's.
We get too anal over a little leading. I don't think there is any way to prevent ALL of it. Have to learn to live with it and be happy.

[Char-Gar]

44man... I am not technical or scientific enough to explain it but the combination of the 200 quick rounds and the resulting heat does the job. The at the range cleaning job removes 100% of the jacketed bullet fouling.

I am not anal about a little lead, but a smooth, highly polished sixgun barrel is a true delight. It shoots better, shoots better longer and is a breeze to clean.

[44man]

Charger, are you SURE it is highly polished or just nice and smooth? There is a difference!
A super polish works great for jacketed bullets and bench rest rifles but not so good for cast.

[Woodtroll]

Folks, I sincerely appreciate your input, and have enjoyed the discussion.


VTDW- PM sent, thanks!


Take care, friends. Regan

[Four Fingers of Death]

My 586 always leaded, just forward of the barrel/frame juncture. Shoots excellent groups, still leads,PITA, but always accurate. I scrub it out when I get keen, but mostly leave it. It never has had many J bullets through it (well used when I bought it in 1985, blooms on the cylinder, etc, lots of use before I got it and I reckon it has had about 80k lead 38s through it since I bought it. I have counted 60K commercial loads through it by my records of purchases, and I cast a lottttt!

Still leads, still shoots ok, go figure? I have a 38, 2x44s, 2x45Convertibles, 38Super Auto, 9mm, they don't lead, even my NMSBH and it has had a lot of truely evil loads through it.

[VTDW]

Folks, I sincerely appreciate your input, and have enjoyed the discussion.


VTDW- PM sent, thanks!


Take care, friends. Regan

Woodtroll,

These guys are really good!!! I love this forum:castmine:

Dave