642-1 Trigger Gets Ultra Heavy During Shooting Session

[willie]

Powder residue, lubricant, and lead particles have formed crud that now causes friction impeding cylinder rotation. Crud gets under extractor star and pushes star back against that part of frame called firewall. Use a toothbrush to clean under star. Then clean front of cylinder. Note the most forward screw on the side plate. Removing screw permits you to withdraw crane with cylinder from frame. Do this and separate cylinder from crane. Wipe down.

J frame snubs have a "too short" extractor rod. Even when rod is pushed all the way back, cases will not clear the cylinder. Improper technique cases them to hang up because the short rod will not eject cases with enough force to clear cylinder. The result is crud under the star. You must hold the revolver straight up and down and then thrust the rod back vigorously with force. This technique will eject cases neatly because gravity is assisting.

Your ammo is the culprit. If you have a large supply, you may be able to work around the problem. Start with a clean barrel. Before shooting, apply a very thin film of grease in the barrel. This lube can be any parts house grease. Wheel bearing grease is cheap and useful. Thin means the bore appears shiny. Johnson's Paste Wax will work too. It is my first choice. Shoot and check for leading. Reapply. This is a giant pain in the ass.

I have removed lead by shooting jacketed bullets through a leaded bore. This is a final step after removing most of it. Easiest way is using a short section of cleaning rod with a brass bristle brush attached. Install rod in electric drill. S&W techs would use this method.

Using jacketed bullets to remove lead is an old trick. I no longer do this. I have very likely owned more handguns than any hobbyist here. One thing that means is that I fucked up more handguns than the rest of you nice folks. Think twice before blowing out lead by firing a jacketed bullet over it.

[camsdaddy]

Does it always happen on the same hole in the cylinder?

[Half Moon]

Since it occurs unloaded but then disappears, it's probably not a cleaning problem. Though keeping a revolver clean definitely helps prevent issues!

It might be a loose or wrong screw in the side plate allowing the cylinder to shift under certain circumstances. Make sure the screws are snug (but not over tightened either). The forward most screw that retains the cylinder crane must be the right length as well and is typically fitted. Too long and the cylinder will open stiffly. Too short and the cylinder can wobble in the frame and cause intermittent issues like you describe. If you had the side plate off to install the springs you may have shuffled the the side plate screws around. You may need to check that.

I don't think it's THE issue but the PPU lead hollow point ammo is VERY dirty leaving much powder residue. The lead is also very soft causes a lot of leading. Which is a shame. The price is very attractive. I've got most of a case I bought a year or two ago that I won't use now that I've tried a couple boxes. Wasted money trying to save money...

[03RN]

Powder residue, lubricant, and lead particles have formed crud that now causes friction impeding cylinder rotation. Crud gets under extractor star and pushes star back against that part of frame called firewall. Use a toothbrush to clean under star. Then clean front of cylinder. Note the most forward screw on the side plate. Removing screw permits you to withdraw crane with cylinder from frame. Do this and separate cylinder from crane. Wipe down.

J frame snubs have a "too short" extractor rod. Even when rod is pushed all the way back, cases will not clear the cylinder. Improper technique cases them to hang up because the short rod will not eject cases with enough force to clear cylinder. The result is crud under the star. You must hold the revolver straight up and down and then thrust the rod back vigorously with force. This technique will eject cases neatly because gravity is assisting.

Your ammo is the culprit. If you have a large supply, you may be able to work around the problem. Start with a clean barrel. Before shooting, apply a very thin film of grease in the barrel. This lube can be any parts house grease. Wheel bearing grease is cheap and useful. Thin means the bore appears shiny. Johnson's Paste Wax will work too. It is my first choice. Shoot and check for leading. Reapply. This is a giant pain in the ass.

I have removed lead by shooting jacketed bullets through a leaded bore. This is a final step after removing most of it. Easiest way is using a short section of cleaning rod with a brass bristle brush attached. Install rod in electric drill. S&W techs would use this method.

Using jacketed bullets to remove lead is an old trick. I no longer do this. I have very likely owned more handguns than any hobbyist here. One thing that means is that I fucked up more handguns than the rest of you nice folks. Think twice before blowing out lead by firing a jacketed bullet over it.

Wax or grease in the barrel can increase pressure to danger levels.

I also used to shoot jacketed bullets to remove lead untill someone showed me how it actually just spreads it out and makes it harder to remove.

Now i just use copper choreboy and it takes no longer than normal shooting

[Dave J]

Take a close look at the cylinder to forcing cone gap. If you own a set of feeler gauges, measure it, and see if it's square. That's the point on the gun that heats up the fastest. If there's insufficient gap, thermal expansion can cause drag between the forcing cone and the cylinder, or jam the cylinder back into the breech face.

Not saying that's necessarily what's wrong with yours, just something I experienced with a rescued K-frame once.

[willie]

03RN is correct that wax or grease can increase pressure. Note that when shooting lead bullets with conventional lube the bore becomes coated with a thin layer of grease. The old Lyman lube of yesteryear would do this to a high degree. The entire revolver would become messy. A common component of bullet lube is alox grease. Others contain the common Lucas grease found in auto parts stores. It is one component. Many wadcutter designs have several grease grooves. To reduce mess from lube one can insert lead shot into lube holes in size dies used in lubrisizers. In this way fewer grease grooves are filled. A most common lube is the old NRA formula having 50% alox grease and 50% beeswax. In this example we are putting coating the bore with a grease/wax mixture.

[Rex G]

A feeler gauge can reveal if the cylinder is too close to the forcing cone. Lead or lube can make this factor worse.

Heat expansion can be a factor. There is nothing new about excessive heat expansion, or warping, due to improper heat treatment during the manufacturing process. I have dealt with this in two different auto-loading pistols. The part must, quite simply, be replaced.

Debris can become trapped, and then stick, under the extractor star, but this will not normally fall out, on its own, so will not normally get better, as the weapon cools. This debris can start to become a factor, when one dumps the first empties, no matter how clean the weapon was, before firing. One now-deceased ‘smith, and one ‘smith that should still be with us, have cut clearance spaces, to mitigate the effects of grunge under the extractor star. My two earliest-manufactured GP100 revolvers were made with this feature, at the factory, when Ruger still really cared. (Late Eighties to early Nineties.) One of my newer GP100 revolvers will grunge-up really quickly, with dirty-burning ammo, due to its tight tolerances.

Keep in mind that a double or triple diagnosis can exist. There can be more than one cause, and that is before we get to shooter errors, as mentioned by DB. Revolvers are simple, but shooting them well is not so simple. An on-scene, experienced coach/mentor can be very helpful.

[Spartan1980]

Lead build up was significant inside the barrel and I spent way too much time getting it off tonight. This is after only 150 rounds of 158 grain PPU semi wadcutter ammo. I am sure the lead was clogging the rifling which would explain the key holes.

PPU lead .38 loads are some of the worst lead fouling loads I've ever seen. This is likely your problem.

Make sure during shooting you keep an eye under the extractor star (between reloads) for reasons mentioned. To clean the barrel a copper Chore Boy pad can be cut with scissors and the some of the strands wrapped around a bronze brush. It will "slice" that lead right out. A cylinder full of jacketed loads will push out whats left in the corners of the grooves but a brushing with this will get almost all of it pretty easily.

Another thing and a long shot is your side plate may be too tightly fit. Aluminum does expand radically (compared to steel) when it heats up. It could be causing it to squeeze the hammer or trigger after shooting awhile but it would be a serious amount of heat that would cause that, so I highly doubt this is your lockup problem as you'd likely not be wanting to shoot a gun that's hot. Some guns have shims inside to set the clearances properly. It will require a gunsmith to properly fit it if it turns out to be the culprit which I think unlikely. I think it really odd that when you get home the problem is gone until you get into your next range session when it reappears.

[Doc_Glock]

I think the problem was fouling from the crap ammo. I shot 50 of my dad’s old Nyclad 125 grains today after cleaning it out well last night and had zero issues. Pretty light recoiling ammo too. Hope it wasn’t some sort of collector’s item since it had to be 40 years old.

I shot it up fast to heat the gun up. It all went bang. No trigger issues. No keyholes, but POI was way lower than the 158 grain at 6 yards which hit to sights pretty much.

I will just avoid that PPU ammo or clean it after every 50 or so since I still have 600 rounds of it. Need to grab some
Chore Boys. Thanks for the tips. I think I could learn to love the J Frame, but who knew so many little things could go wrong with them (stuff y’all listed above).



Any tips on cheapish FMJ Range ammo that will hit to sights?

[blues]

I use American Eagle 130 gr. Primarily because I carry 130 gr +P Winchester Ranger (Bonded) RA38B