Could lube solve this problem?

[drklynoon]

Background info: Four revolvers .32 S&W Long, .315 chamber throats, .3115 barrel but only at the muzzle and thread squeeze area. I'm shooting .314 bollits Water dropped W W's in it and am getting some significant leading at speeds from 600 FPS to 750 FPS. Due to the muzzle being tight as well as the barrel throat I am unsure if fire lapping will help so My question is: Are there any lubes that have better characteristics of fighting poor boolit fit at slow speeds? I'm currently using 50/50 to no avail.

[Pat I.]

Try it without quenching the bullets.

[338RemUltraMag]

Could also try shooting pure lead with 2% tin, may help obturate the boolit to the bore.

[btroj]

Where is the leading and how tight is the thread choke?
I bet getting rid of the thread choke would help. A tight muzzle isn't bad at all. A taper from breech to muzzle is actually a good thing, if not overly severe.

[drklynoon]

Pat, By quenching I assume you mean oil quenching. The water drop makes them pretty durn hard. I should have explained the leading a little better. I am not seeing any flashing on the front of the cylinder but am getting a lot of buildup around the throat of the barrel. Some of this may be due to the bullets being .0025 over groove diameter but if I drop the boolit size down it will be sloppy in the cylinder throats.
338, I don't keep much pure lead around but I do see merit in your comment. I appreciate it. I'm definitely not looking for a quick fix, so to speak but am hoping that someone has had similar problems and found a lube type that helped or some advice that could help focus this hazy brain o' mine.

[Dan Cash]

I would make that six shooter some one else's problem and get a different one for myself.

[drklynoon]

Well Dan it's actually 4 revolvers all of the same make and technically they are someone elses problem, they are my dads. I may try 338's suggestion and try a softer bullet.
btroj, The only way I know of getting rid of the throat choke is fire lapping. I've gone through the search function and threads about fire lapping are disjointed at best. I have gleaned that if done incorrectly fire lapping can ruin a gun. If you know of a way to fire lap a .32 long It would be greatly appreciated.

[Pat I.]

Pat, By quenching I assume you mean oil quenching.

If you drop them in water that's quenching too. Drop the bullets on a towel instead of in the water and see if it helps. You could try some different lube, I like LBT Blue, but always go for the free and easy things first.

[drklynoon]

Pat, I like the idea of trying a softer boolit. I personally use Lyman Moly for everything but these guns have been getting 50/50 alox. We have some loads worked up to try today but unless a better option surfaces, trying a softer boolit sounds like a smart option.

[btroj]

Fire lapping can be a problem if done wrong. Done right it can work miracles on a gun like you have.

[drklynoon]

That is what I have gathered but it is extremely difficult to navigate between what is right and what is wrong. The reading suggests many "methods" for gritting a bullet some jacketed some lead. It also seems to be load sensitive and every caliber has specific needs. As such, I have found little reliable information on lapping a .32 long. I'd love to give it a try but am hesitant due to the inconsistencies with methods and the vagueness of instruction for some of the "kits." If someone had info to a "kit" that was explicit and specific to the .32 long I'd jump on it but I haven't found it yet.

[btroj]

I use 320 grit Clover brand compound. Bullets should be soft, 25/75 WW/lead would be good. Bullets need to be embedded pretty well with compound. Shoot a very light load, just enough to get bullet thru barrel. I shoot into a berm so I can be sure the bullet exits the barrel.
Use fired cases that are not sized. Bullets need to be bigger than barrel.
Shoot 6 or so and clean. See how it slugs. I stop well short of where I want to end up and shoot some regular loads. I can remove more but I can't put it back.
Done this way it will clear up the thread choke and not overly enlarge rest of barrel.

[geargnasher]

First, quit shooting hard boolits at popgun pressures. Try soft, like a 50/50 mix of unpainted, stick-on wheel weights and regular clippy weights with maybe a pinch (1/2%) of tin added, and AIR COOL them. Play around with the loadings, fast powder, slower powder, different charge weights, and only if you totally fail to fix the problem would I worry about correcting the guns.

You can fire lap or hand lap the thread choke out of a revolver barrel. I've done it both ways and firelapping is by far the simplest and easiest. The concept is simple: Embed the driving bands of boolits with abrasive grit such as valve grinding compound, coarse like 240 or 320 is good to start with as the silicon carbide is very brittle and crushes to finer and finer particles under pressure. Use boolits that are reasonably soft, no harder than air-cooled wheel weight metal (12-14 bhn), preferably softer for what you're doing. Use light loads, something that will barely get the boolit out of the barrel. I like about 2-3 grains of Red Dot or Bullseye for most stuff like .45 Colt and .357 Magnum, check load data for .32 and maybe only a grain of either of those would be sufficient. Take two steel plates that are FLAT, preferably machined, smear Clover compound on them and roll the boolit lightly between for two full minutes. Don't put so much pressure that you deform the boolit or make it smaller, just keep embedding the grit in it. Make about a dozen. Use old, tired brass that you won't cry over losing. Load with the light charge of fast powder, and put a tuft of Dacron to lightly fill the empty space under the boolit, this will compact behind the boolit and form a better dynamic gas seal to keep from blowing out the grit in the loose spots in the barrel. You can fill the lube grooves with valve-grinding compound as well, it seems to help. Make sure that your lapping boolits don't get rolled smaller than the largest groove dimension, or swaged smaller when seated in the case. If necessary, only use fired brass and unsized castings, or what ever combo and tooling you deem necessary to obtain the ends of having a large enough lap entering the barrel. If the lap is undersized, it won't cut the grooves well enough.

Really, that's about it. Keep the grit off of the gun's show surfaces, off your hands, and off of the outside of the cases. Clean the pistol, including chambers and cylinder base pin, after every cylinder full. Check to see how the muzzle looks. When you begin to see wear approaching the muzzle (shiny, clean metal), consider stopping there. Check the restriction at the barrel/frame junction often by cleaning and slugging the barrel both directions, and when the thread choke falls below half a thousandth you might be close to done. Finish the job by lapping the forcing cone with a brass lap and then a tight patch coated in fine lapping compound, about 100 fast strokes through the bore using a muzzle protector cone.

Gear

[drklynoon]

Thanks btroj and gear. Fire lapping seems pretty straight forward when it is layed out like this. I appreciate it. Gear, as far as boolit hardness goes, in other guns of similar velocities I have found WD WW's to be more accurate and less apt to lead. I have heard it many ways some prefer linotype boolits and others straight lead w/ a little tin. I suppose I have become a little to ridgid w/ the WD WW's and should try other hardness's when I run into trouble.

[btroj]

Slower often needs a softer bullet. Poor fit, which you develop due to thread choke, needs a softer bullet.
Nothing leads like a hard, undersized bullet.
Softer can swell back up after the thread choke if pressure is still high enough. Hard won't do that.
This is all part of the learning process.

Fire lapping can be scary at first. Go slow. You can always remove more. Clean all the grit off everything well.

[geargnasher]

Thanks btroj and gear. Fire lapping seems pretty straight forward when it is layed out like this. I appreciate it. Gear, as far as boolit hardness goes, in other guns of similar velocities I have found WD WW's to be more accurate and less apt to lead. I have heard it many ways some prefer linotype boolits and others straight lead w/ a little tin. I suppose I have become a little to ridgid w/ the WD WW's and should try other hardness's when I run into trouble.

Boxed yourself in with a wall built of one or two experiences, eh? :) Cast boolits will bite you in the butt if you do that, try to keep an open mind and really THINK about what is going on inside the gun with regard to pressure/time curve, alloy strength, gun dimensions at different points in the boolit's path, and never forget there's high-pressure gas that WILL take the path of least resistance if given half a chance, and it will erode and deposit boolit dust in the bore if you let it. Stop the leaks by perfecting dynamic fit, and you'll stop the leading. Linotype isn't any good for anything at my house except for adding a little antimony to a weak alloy.

Gear

[drklynoon]

Yeah Btroj, we will see if he is willing to fire lap. Yesterday a new load with 100 gr rn's was tried with some fair success. I like the idea and would love to gain the experience. There is some question as to the grit of the valve lapping compoound on hand so this will be figured out first after that we will see.
Gear, I would say a few more than a few experiences have shown me that a harder boolit can reduce gas cutting and general leading; however, you are correct in your assertion that softer boolits can obturate with greater success. different people have different methods and I definitely appreciate an outside point of view. For the better part of 15 years I have shot mostly around 800 FPS and above; although, that measurement is not indicative of pressure which has it's own effect on a boolit. Thanks for the input guys. It is appreciated.

[btroj]

I specifically bought silicon carbide Clover brand compound. I wanted to know exactly what I was using.
Hard bullets CAN stop leading, if initial pressure is high and fit is good.
Notice Gear mentioned dynamic fit. The fit of the bullet is changing as it travels down your large in the middle bore. It is snug at the breech then gets lose. Hard lead isn't swelling to keep up a good dynamic fit, especially at your low velocities and pressures. A softer bullet may be able to keep expanding to keep a seal in the bore. Your bullet is allowing as to blow by, hence the leading.
Get rid of the thread choke. The silicon carbide breaks down as it goes thru the bore. Give a bit of a taper. This is good as the bullet is always going into something tighter, not loser. Keeps the seal due to good dynamic fit.

Remember, fits not a one time thing. Fit must continue thru the entire firing process. In your example it is poor in the mid section of the barrel. Fire lapping fixes it permanently. A softer bullet matched to a powder charge and burn rate can help overcome it also.

Harder is not always better.

[drklynoon]

Word Btroj, I'm with you on all of that. When I had posted the question I had just found out about the choke point. Up until then we had been running under the assumption of just big cylinders and small barrel. I hadn't thought through the entire process with the new information yet. I agree harder is not always better. I normally only shoot WW's and have caught flak for it for some time. Some say too hard many say too soft. I have found that you have to have some parameters to work within if you are gonna remain sane lol. I'd love to try a AC WW boolit in these guns now just to see how it performs. At these pressures I remain dubious that the boolit will swell to fill the center section of the barrel; however, we have not had any leading in this section as of yet and the accuracy on some of these guns has been a pleasant surprise. I really appreciate your advice it has been invaluable.

[geargnasher]

The only voice of real authority on the subject of alloy strength and hardness is your particular, individual gun.

Often, with a little experimentation with load, boolit design, and static fit, one can shoot a broad range of alloy with success. In fact, I recommend trying everything from near pure to straight linotype in their pistols, and try to get each one to work WELL, that way you understand exactly what works best and exactly why.

I think you'll find that hardness/toughness is generally a quality that promotes accuracy, even at lower velocities, but I think you'll also find that it's more difficult to get to shoot cleanly and well in any revolver that isn't near perfect dimensionally, and you won't notice the difference much inside of 25 yards anyway with most guns. A quality, scoped .44 Magnum shot from a good rest can certainly tell the difference in a few BHN points or a one percent change in antimony content, groups will change by a matter of inches at 100 yards. The effect will be far less dramatic or even noticeable with less potentially accurate guns at close range.

So again, harder is not always better because not all guns are created equal. Some of the "lesser" guns need a more forgiving alloy to keep from leading up, and you probably won't notice any decrease in accuracy going slightly softer anyway. What you need is spring, not hard/brittle.

Gear