What caused a ring of lead?

[tomme boy]

Are you inside turning your brass to size? I have seen where this lenaves a sharp ridge on the inside when the brass has been fired and sized a few times. That junction of where it was reamed is pushed into the neck. That would cause a ring but it should be shot out the barrel when fired.

Or just go back to jacketedfor awhile to wear in the throat more a revisit ccastata later time. Myself, i would get a regulr palma reamer, or bisly and have it clean up the neck and throat.

[Krag 1901]

Very weird problem. From the pix of the size of the rings, they don't look like bore size to me? They looked much bigger than .300-.312? Measure them and see what has a similar dia in your chamber?

[DougGuy]

I have the same issue with a Ruger Blackhawk 10/40. The problem is most evident in the .40 cylinder. I suspect that the edge on which the case headspaces is slicing a little bit of lead and PC when the round is fired. With cleaned chambers, I can usually fire the first 6 rounds, and from then on the rounds no longer fit. After picking the little rings out of the chamber, I can fire 6 more rounds. I have fiddled with RN, TC, Keith SWC shapes, as well as different sizing. All works well with plated or FMJ bullets, but nothing cast. With the 10mm cylinder, I finally found a NOE WFN that works ok. An ongoing struggle. I also am considering contacting Doug Guy to see what he can do.
Loren

Not to steer the thread, but to offer my findings to compare with all the hypothesis already put forth concerning the OP.

After having the cylinder in hand, it is discovered that 5 of the throats are a smooth .4025" from the front, right down to the burr at the chamber mouth which is present in all 6 chambers, and the pin gage stops on the burr with a resounding "plunk!" Where have we heard that before?

The 6th chamber is just the slightest bit snug on the pin gage but it will go part way if I force it.

Using a fine grit borazon stone should remove only the burr and leave the throat diameter unchanged. Should fix this one right up.

[rockshooter]

excellent! looking forward to trying it!
Loren

[Wm Cook]

So I’m new to the lead ring problem thing. New as of a couple weeks’ worth of experience. This is close enough to Elginrunner’s problem that I though I could draft the topic.

This is a Ruger American, 7.62x39, #2 Lyman (about 16bhn). The barrel has exactly 12 rounds through it. All lubed not PC'd. All were seated .015 away from jam length. Which means all were riding the groove. Those 12 were shot while scanning for sub sonic velocity using Red Dot, Unique and H4227 with bullet weights of 155, 165, 185 and 200. This could be considered as a worse case situation since no jacketed bullets were ever fired through the barrel and two of the four bullets fired had their base inside the case. Case's were chamfered, not expanded and not crimped. Best case is that being a fresh cut chamber the burrs from the factory cut was picking up the lead. Maybe 20 to 50 round of jacketed bullets through the barrel may iron things out. Maybe.

Groove at muzzle is .3100 and bore measures .3020. After the chamber it measures .3134 and it tapers to .310 around .225 upstream. The transfer from the chamber cut for the case looks like a sharp 45 degrees.

SAAMI shows the case length to be 1.524, the Ruger’s chamber is cut to 1.569. That leaves a .045 gap. The neck of the case + bullet (Lapua case) is .3432 and the chamber neck is cut at what looks to be .3365 which is a very sloppy .033. But it’s a factory mass produced rifle and not a benchrest rig.

After 12 round there was a 360 degree ring of lead at the end of the chamber where the case cut ends. I didn't look at the chamber until I finished the velocity check so the entire ring could have been caused by only one of the bullets or it could have been accumulative.

I was able to clean out some of the ring by brushing. I’m left with about 1/3 of the ring looking like a solid ramp from the case lip forward at the 6:00 position. And it won’t come out. The current plan is to buy a Ruger barrel nut wrench and a set of gauges, unscrew the barrel, clean it up and retry with those bullets that leave the base in the neck. If anyone has any other ideas I would appreciate it.

As a side note I looked at my K Hornet which has about 1000 cast round through it and it is immaculately clean. I sold a lot of my other cast rifles so I didn't have anything to compare to. If I said anything really stupid in the above post please forgive me.

Thanks for any advice. Bill

[sigep1764]

Go to your dentist and ask him for an old dental pick, the stainless kind. That thing will dig that ring out no problem.

[jsizemore]

In the old days we would get carbon/lead hump built up at the case mouth bullet junction in our chamber of our 22lr. It would make chambering a bit tough and accuracy would go to heck because the lube could be scraped off and/or the lead bullet sized smaller. The trick was to cut the rim off a fired case and cut teeth in the mouth of the case like a hole saw. Epoxy/glue that rascal on a jag and cut that mess out of the chamber of your rifle. No need to use a bunch of force and mess up you homemade saw. No reason you couldn't do the same with a centerfire lead shooter. Still got to use some solvent to get the last bit out but the bulk amount is easily removed.

[Wm Cook]

Thanks for both of those suggestions. I have a dental pick but it wasn’t long enough to reach the chamber case mouth cut. I modified it and added an extension and I could reach it but even factoring in the distance from the lead lump to a point on the action it wasn’t easy finding where to scratch. Haven’t given up on that since the tool and the concept is solid.

Same with the sawed off case neck and epoxying it to a jag. Gotta think of a way to stick it to a jag. I am glue/epoxy stupid.

What do you think about grinding some 1/4” round stock to a one sided lip and heating the tip with a propane torch? Even if it’s just close it may heat the area near the lump enough to let me move the lump of alloy.

Or how about plugging the barrel in front of the chamber and putting in a table spoon of something (Kroil?) and soak the lump long enough to loosen the alloy from the steel chamber. Thanks for the suggestions, Bill.

[onelight]

Might try a brass rod like a brazing rod , filed or hammered to shape to make a scraper that won't damage the barrel.

[jsizemore]

Might try a brass rod like a brazing rod , filed or hammered to shape to make a scraper that won't damage the barrel.

You got that right. A fired case fits your chamber. A little hand work with a file, cut off tool or hacksaw and some glue takes care of the problem with little chance of messing your chamber.

[Wm Cook]

Maybe use one of the Sinclair action cleaning tools like their lug cleaner or their chamber mop. Probably the chamber mop. Pull the cotton stuff off the chamber mop end and glue/glass bed the case neck to the spiraled mop stem. Score the mouth of the cut off neck and cut the lump out. If I get that far today I’ll post a picture.

In jacketed benchrest we were always fanatical about cleaning that area. Used to use a 35/9mm brush to clean up residue.

I wonder what caused the lead buildup?

[tomme boy]

Look up the vinegar and hydrogen peroxide mix for removing lead. It will take care of it no problem

[Wm Cook]

I was worried about unwanted side effects with the hydrogen peroxide vinegar mix.

https://castboolits.gunloads.com/sho...-Lead-in-Bores

Here is the case neck saw tooth design. Unfortunately it didn’t get the lip clean. Going to plan B and I’ll pull the barrel and solder iron melt the buildup and wipe it clean. Can’t reach it with the action in place.




Thanks, Bill.

[tomme boy]

Stuff ear plugs in the bore just past the ring. Then fill the chamber just enough to cover the ring. Let sit just long enough to soften it. Then repeat if necessary. Just clean it well with water after each time.

If you had some mercury I would say use that instead. But not many people have that anymore.

[Wm Cook]

Thanks. I’m going to give that a try. I usually vary the ratio of Hp/vinegar based on the situation. On this I may try a 1/3 to 2/3 mix. I like the idea of ear plugs. Bill.

[popper]

First time with that problem in a CVA BO. Lead rings attached to the case when ejected. 145gr GC PC slick sided mould, pushed hard. Gap between mouth and bore. Anything that gets shaved sticks there and 'soldered' to mouth. Didn't see them until cleaning cases and a bunch dropped off. Not a complete 'circle' as the case sits in the chamber loose until firing, alloy squeezed into space, then GC comes along and clips it.