Please explain revolver timing and other checks

[rajbcpa]

I purchased a few revolvers recently.

A new 686, a M66 (1972), and a M36 (1976)

Anyway, revolvers are completely new to me but I would like to collect a few more over time.

Questions
How is revolver timing checked and can this be done without firing the gun?

Does dry firing hurt DA revolvers? Do you dry fire in both SA and DA modes to test the triggers before buying? Any difference in dry firing tests between revolvers that have and do not have the firing pin on the hammer?

Do you check the clearance between the forcing cone and chambers?

Is there any way to see if the rifling is good?

What else do you check before you buy a revolver?

 

[HarrishMasher]

Excellent questions. I look forward to seeing the responses as well.

 

[yfdcap]

Check out the video on youtube by midwayusa with Larry Potterfield on buying a used Smith. Its should help with your questions.

 

[Muss Muggins]

Check out the video on youtube by midwayusa with Larry Potterfield on buying a used Smith. Its should help with your questions.

Good advice. Each of these questions is worthy of a thread by itself, and there probably are several existing threads that cover the answers thoroughly.

 

[varmint243]

Check and make sure it has S&W stamped on it
check complete

IMO the people on this board get way too worked up over this
One of my favorite 686's would fail every check
Been shooting it that way since I got it 20+ years ago
Just had fastest time at a club fun shoot on speed plates with it this weekend
buy, shoot, enjoy

 

[Waywatcher]

Timing:

Single action: slowly cock the hammer. Watch the cylinder and cylinder stop. The cylinder stop should drop out of the notch before the cylinder tries to rotate. The cylinder should finish rotating and lock at the next notch before the hammer is fully cocked. This would be perfect timing. If one or more chambers don't quite lock up, pull the trigger. If pulling the trigger nudges the cylinder into lock up, this is fine. If the gun can be cocked and the trigger pressed without the gun going to full lockup, the gun needs work.

Double action: slowly and smoothly pull the trigger. Just as before, the cylinder stop should drop before the cylinder attempts to rotate, and the cylinder should reach its next notch and lock up prior to the hammer falling. This is perfect timing. If the gun fully rotates to the next notch at a regular trigger speed the timing is ok.

Barrel to cylinder alignment: pull the trigger and hold it rearward. Shine a flashlight at the firing pin area by the rear of the cylinder. Look down the muzzle. There should be an thin, even dark ring where the cylinder ends and the bore begins. If it's a crescent shape, it's not aligned. The ultimate check for alignment is firing--spitting lead is a sure sign of misalignment.

Dry firing does not hurt centerfire revolvers. That said, it's not a carte blanche to snap away a billion times and expect nothing bad to ever happen. Parts will wear out. No difference in hammer/frame mounted firing pins.

The best way to check the gap between the cylinder and barrel is with feeler gauges. Pushing the cylinder forward for one measurement and rearward for the second measurement. The difference is endshake and should definitely be 0.005" or less and ideally 0.001" to 0.002." Zero endshake is not desirable for reliability reasons.

The rifling is probably fine if the bore has no obvious scrapes, shadows (especially a ring of shadow mid bore). The important place to check is the crown, where the rifling ends at the muzzle. I do it with a qtip: stick the qtip in the middle of the barrel, then push it off to the side, and drag it out of the muzzle. Do this as many times as necessary to check the entire circumference. If any fibers are consistently grabbed at the crown, it is damaged/defective.

 

[Muss Muggins]

Check and make sure it has S&W stamped on it
check complete

IMO the people on this board get way too worked up over this
One of my favorite 686's would fail every check
Been shooting it that way since I got it 20+ years ago
Just had fastest time at a club fun shoot on speed plates with it this weekend
buy, shoot, enjoy

I'll agree that there's a lot of form over function discussed here, but timing and push off are pretty important. I wouldn't shoot a revolver that failed those checks.

 

[Biggfoot44]

A *no tools* test of timing is to use a finger to put some drag on cylnder , and slowly draw hammer to full cock. The bolt stop should drop into the notch before full cock. Droping too soon , or too late are both bad , too late is more dangerous. Repeat each chamber. Repeat test with slow DA pull. Once bolt stop drops , you can stop w/o letting hammer fall.

Visually inspect the ratchet for uneven wear or damage.

Presuming your basic revolver handing skills includes how to safely lower a hammer ( if it hasn't , you need to learn) , use that method to test the SA trigger pull. Repeate each chamber. Absolute lightness is not particularly the goal. You are checking for smoothness and consistancy. It takes more Dexterity and DA skills , but DA pull can also be judges w/o dropping hammer.

*For me* , I am practiced enough to judge b/c gap by eye, at least into darn tight/ about average/ pretty wide . Once again check each chamber , for consistancy.

There's more , but this will give you a start.

 

[0311oldgrunt]

Timing:

Single action: slowly cock the hammer. Watch the cylinder and cylinder stop. The cylinder stop should drop out of the notch before the cylinder tries to rotate. The cylinder should finish rotating and lock at the next notch before the hammer is fully cocked. This would be perfect timing. If one or more chambers don't quite lock up, pull the trigger. If pulling the trigger nudges the cylinder into lock up, this is fine. If the gun can be cocked and the trigger pressed without the gun going to full lockup, the gun needs work.

Double action: slowly and smoothly pull the trigger. Just as before, the cylinder stop should drop before the cylinder attempts to rotate, and the cylinder should reach its next notch and lock up prior to the hammer falling. This is perfect timing. If the gun fully rotates to the next notch at a regular trigger speed the timing is ok.

Barrel to cylinder alignment: pull the trigger and hold it rearward. Shine a flashlight at the firing pin area by the rear of the cylinder. Look down the muzzle. There should be an thin, even dark ring where the cylinder ends and the bore begins. If it's a crescent shape, it's not aligned. The ultimate check for alignment is firing--spitting lead is a sure sign of misalignment.

Dry firing does not hurt centerfire revolvers. That said, it's not a carte blanche to snap away a billion times and expect nothing bad to ever happen. Parts will wear out. No difference in hammer/frame mounted firing pins.

The best way to check the gap between the cylinder and barrel is with feeler gauges. Pushing the cylinder forward for one measurement and rearward for the second measurement. The difference is endshake and should definitely be 0.005" or less and ideally 0.001" to 0.002." Zero endshake is not desirable for reliability reasons.

The rifling is probably fine if the bore has no obvious scrapes, shadows (especially a ring of shadow mid bore). The important place to check is the crown, where the rifling ends at the muzzle. I do it with a qtip: stick the qtip in the middle of the barrel, then push it off to the side, and drag it out of the muzzle. Do this as many times as necessary to check the entire circumference. If any fibers are consistently grabbed at the crown, it is damaged/defective.

Old post but still works for those still buying revolvers. Thanks. P.S. I will be taking a copy of this to the ffl next week.