Fire Lapping a revolver

[JAMESGR]

Has anyone had trouble while fire lapping a revolver??? I'm trying to fire lap the barrel of a Rossi Model # R97104 and the cylinder will not rotate after three (3) rounds are fired. I have to disassemble the cylinder and clean it. From the post I have read and the Beartooth Bullet Guide there is NO, ZERO, reference to this happening. Cleaning is preformed after 6-12 rounds fired but no mention of the cylinder not rotating. Is this common and something I should just know??? Cylinder throats are .358; breech end of the barrel is .348; muzzle end of the barrel is .349. Measured using minus pin gauges. The pistol barrel has five grooves; I don't have a micrometer that measures five groove barrel slugs; six grooves I could measure. I am just trying to get the barrel the same diameter through the entire length. Everything I have read states that the muzzle end of the barrel should be the same diameter as the breech end of the barrel or slightly smaller. Anyway,is this a common problem?? Thanks you.

[Mitch]

i have more questions than anything else.oce ypou unload the gun is the cylinder still jamed? i do not know what method you are useing.I have the feeling your loaded fire lap cases are on the big side and not seating all the way into the cylinder or maybe just one chamber.

Ok did you have problems with the revolver leading the barrel or poor accuracy?L]I am not sure how deep the rifleing is on a rossi.checking for a thread or some sort of constiction with a pin gage is ok.but if you did not slug the barrel you may be doing more damage than good if the groove dia is correct already.manmy guns shoot just fine with .001 taper the wrong way.at long as the cylinder throat to barrel relatioinship is right

[Texas by God]

Fire lapping loads are supposed to be very light. Are you sure your primers aren't backing out causing the cylinder to bind?

Sent from my SAMSUNG-SM-G930A using Tapatalk

[Gtek]

Cut a soda can open and make strips about 3/8" wide and 2" long. Measure can material with MICROMETER and then wrap pushed slug with strip pinching in one hand and measuring with the other. Measure OD and subtract twice the thickness of the strip, there's your real close boolit OD. Bore diameter is something interesting to know but groove is what you are after. Cylinder locking up is hard to tell from here, I put the compound in the throat not on the boolits. Push one in throat deep enough to clear cone area, push back out. Have cut rod to correct length, in to flush on muzzle and back out. That's where I start, then all the way through from front checking for thread choke forward of cone. With that I usually have a good idea where, what, and how much.

[megasupermagnum]

Has anyone had trouble while fire lapping a revolver??? I'm trying to fire lap the barrel of a Rossi Model # R97104 and the cylinder will not rotate after three (3) rounds are fired. I have to disassemble the cylinder and clean it. From the post I have read and the Beartooth Bullet Guide there is NO, ZERO, reference to this happening. Cleaning is preformed after 6-12 rounds fired but no mention of the cylinder not rotating. Is this common and something I should just know??? Cylinder throats are .358; breech end of the barrel is .348; muzzle end of the barrel is .349. Measured using minus pin gauges. The pistol barrel has five grooves; I don't have a micrometer that measures five groove barrel slugs; six grooves I could measure. I am just trying to get the barrel the same diameter through the entire length. Everything I have read states that the muzzle end of the barrel should be the same diameter as the breech end of the barrel or slightly smaller. Anyway,is this a common problem?? Thanks you.

Groove diameter is the more important measurements to determine if your throats are large enough, but pin gauges are the correct tool to measure thread choke (restriction where the barrel threads into the frame). I can tell you from experience that .001" or less of a thread choke will have a minimal impact on how a revolver shoots. This is assuming your throats are large enough. As you say, ideal would be same, or slightly smaller at the muzzle with no restrictions or variations in the barrel.

As for the revolver binding, I've never heard of it happening in so few shots. You are sure it is junk getting into the cylinder/crane and not the primers backing out from light loads? If so, a dab of grease should catch all the junk and keep it from going where it shouldn't.

[JAMESGR]

Mitch, gun has poor accuracy. The Bearthooth Bullet Guide stated that the cases should be some that were fired in the pistol and not resized. I checked the cylinder fit of the cases before loading and they fit. The cylinder would not rotate even after the cases were removed.

Texas By God, Primers not backing out. Powder charge is only 1.3 grains of Bulleye. I put a small (less than a grain) piece of TP on top of the powder charge to keep in in contact with the primer. I am seating the bullets as far into the case as I can. This is recommended.

Gtek, are you putting the slug into the middle of the strip? Are you putting the compound in the cylinder throats or the forcing cone area of the barrel? You stated throat but I'm not sure how that works getting it into the barrel. If into the cone area how are you getting an even layer? I have thought about putting it into the barrel but I don't know how to get an even layer.
Thanks, I hope my responses make sense.

[JAMESGR]

Megasupermagnum, I didn't intend to skip your response, just got carried away, I hadn't thought about putting grease in the cylinder/crane area. That's a good idea to try. It's one of those "why didn't I think of that" moments. Thank you.

[Don1357]

Sounds like you have a different problem than the one you think you are having. The issue may not be related to the last thing you were doing with the revolver when it started happening.

[Mal Paso]

The cylinder gap may be too tight. I had a Colt that would fire 3 rounds before binding on burned powder kernels between the barrel and cylinder. Less than .004" cylinder gap can be a problem.

You might want to have a gunsmith look it over. It sounds like a lot of problems for one gun, you might get some better insight.

[Gtek]

Wrap the slug 90 degrees with strip on slug, pinch with thumb and index finger, grab 90 degrees with needle nose, whatever, just get close to slug and wrapped tight then measure. Compound, swing cylinder out and took 90 degree needle nose, pinched cotton ball and worked compound into ball. Swabbed in and out of barrel about a 1/2" in applying light coat. Yes, a pin gauge will show you thread choke, but if you have bore choke one would think you also have groove choke. Wad cutter length to flush and back out to measure. You need to think things can go very slow (Ruger SS) or very fast (Rossi ?), you don't know. It can be a very laborious, little shooting and lots of measuring!

[mdi]

Nearly impossible to troubleshoot problem long distance via the written word. If we had the gun in our hands we would be able to tell you, so here's another WAG. Besides the primers staying out and binding, my second thought was gunky dirt. When I tried fire lapping, I used some store bought "lapping" bullets and loaded them extra light. These shot really dirty. A cylinder full and I had sooty grit/gunk all over my hands and the gun frame. Perhaps your fire lapping loads are so dirty they bind/gunk up your gun so badly it has to be disassembled and cleaned...

[JAMESGR]

Thanks Mal, I used a feeler gauge and my cylinder gap is .005" a .006" will not even start to enter the gap.

Thanks mdi, mine are shooting dirty to. I'm going to enlarge the flash hole in some cases maybe this will keep the primer in place. Also, going to use a little grease on the cylinder/crane area, the ejector rod opening, and under the ejector. Hopefully, this will keep the gunk from locking the cylinder rotation

Thanks Gtek, I'm going to use your method to put compound into the barrel. It's worth a shot !!!

[Petrol & Powder]

Is the cylinder rotation problem occurring while the spent casings are still in the cylinder?
If so, the primers may be backing out due to low powered loads used for fire lapping.

If the cylinder is binding without the casings in the gun, then I would look for the abrasive compound migrating into the cylinder arbor/yoke area.