Question on timing

[scooter123]

I have a new model 620 purchased on April 15. Yesterday I got hit by some fragments 2 times when shooting 357 Magnums (Federal 158 gr JSP) at my local indoor range. Since it is only a 60 foot range it could heve been crap thow back from the bullet trap, however I was hitting COM on the target so the rounds should not have been impacting the trap too far off center. B/C gap on this revolver measures at 0.005 inch and headshake is essentially zero. Examination of the forcing cone shows no indication of any shaved lead or uneven wear to the forcing cone.

Because this is a new purchase, I had their revolver expert take a look at the gun. If the cylinder is held back firmly while cocking the gun, timing on the cylinder is a tiny bit "late". However, if the cylinder is not held back, the timing is 100% perfect. He did not think this was an issue worth sending the gun back to Smith for correction. I am inclined to agree however thought I should ask for a second opinion.

BTW, the timing was checked with the cylinder unloaded and there is some "slop" in the movement of the extracter star, which is NOT pinned for rotation as was done on my model 67. Frankly, I think this was a mistake on Smith's part because relying on the flat machined on the ejector rod to reference rotation allows the star too much movement. I suspect that this movement is the reason why the timing is late when the cylinder is held back.

So, should I be concerned about this or am I worrying over nothing? My thought is that it's probably a non-issue.

 

[john traveler]

From your description and the check the range guy made, timing is probably not an issue. Unburned propellent granules, especially ball powder, sometimes come out the BC gap to strike the shooter or bystanders. To check for NC gap particulates, line a 1'x1' cardboard box with white paper, and fire the revolver through this "tunnel". You can see the bullet shavings or unburned powder bits if present.

 

[OKFC05]

Unburned propellent granules, especially ball powder, sometimes come out the BC gap

And the "booth" in an indoor range tends to put it right back in your face. Common complaint.

 

[robertrwalsh]

John T has probably the best answer. That way you get something that is fairly objective. I am inclined to agree about the timing not being a real issue.

 

[bountyhunter]

Originally posted by scooter123:
I had their revolver expert take a look at the gun. If the cylinder is held back firmly while cocking the gun, timing on the cylinder is a tiny bit "late". However, if the cylinder is not held back, the timing is 100% perfect. He did not think this was an issue worth sending the gun back to Smith for correction. I am inclined to agree however thought I should ask for a second opinion.

The majority of SW guns I have seen are just like this, including many new guns. If the carry up is OK during normal cocking motion or DA pull, it is OK to shoot.

Originally posted by scooter123:

BTW, the timing was checked with the cylinder unloaded and there is some "slop" in the movement of the extracter star, which is NOT pinned for rotation as was done on my model 67. Frankly, I think this was a mistake on Smith's part because relying on the flat machined on the ejector rod to reference rotation allows the star too much movement.

The brass in the cylinders is what locks the star and cylinder together under operation, and you should check carry up with the cylinder full of fired brass.

 

[Fastbolt]

Yep, "carry up" is checked on new style S&W revolvers (non-pinned extractors) with properly sized dummy rounds in the cylinder, since the new style extractor relies on cases to hold it in position so the hand can engage the ratchets.

FWIW, when we were being trained in the armorer class to cut new revolver extractors with the S&W cutting arm & hand tool we were repeatedly reminded to use properly sized dummy rounds in the cylinder so the cutting hand would cut the ratchets to the right length for the cylinder to be loaded and used live ammunition.

Creating excess drag by touching the cylinder (holding it back) was not a recommended method for properly checking carry up.

Double Action carry up is checked by holding the muzzle of the EMPTY revolver with one hand, and using the other hand to hold the grip (frame) with the other hand. The trigger is pulled back slowly (but not Slooooooowwly ). The cylinder stop should enter each cylinder stop notch before the hammer falls.

In Single Action the stop should snap up into each of the stop notches by the time the hammer snaps into single action.

We were also told that sometimes the cylinder stop's snapping up into the stop notch might occur just barely before the hammer fell in DA or reached full cock in single action.

Slowly staging DA trigger strokes while trying to hold a steady sight picture is a common mistake made by some revolver users. A reasonably quick, brisk but smooth continuous trigger stroke, while holding the sight picture/aligned sights and following-through with the sight picture, can help reduce the tendency for the muzzle & sight picture to continually wander (preventing anticipatory flinching is helpful, too

).

Fragments? What kind of fragments? Copper? Lead? Powder?

I used to really dislike shooting Winchester .357 Magnum loads (which used ball powder) through both my issued service revolver and my personal revolvers. It often felt like I was being 'bead blasted'

, and my revolvers were 'in time', too.

It can also be rather amazing what can bounce back at you in the way of fragments sometimes, too.

Anybody else shooting at the same time? I've had the pleasure catching fragments from other folks as they were shooting, as well.

Excellent reason to wear eye protection.

Naturally, I have absolutely no idea what's happening with your particular revolver, since I'm not there.

You could call back and ask to speak to a revolver repair technician ... (not the same thing as a customer service person, although it's not uncommon to talk to one who used to be in production and is knowledgeable) ... to explain your experience and express your concern. They do warranty their products, and sometimes a warranty repair (parts replacement or other corrective action) is needed.

Just my thoughts.

 

[scooter123]

Thanks for the replies, they confirm what I already suspected. BTW, I have been hit by stuff kicked back from the bullet traps, including jacket fragments. However that usually happens when some youngster is in the next lane machine gunning his glock and not coming close to hitting his target well. However the range was nearly empty yesterday and that was not an issue. So, it was a bit surprizing to feel something hit my cheek. Most likely it was debris from the B/C gap as suggested by others. It just reinforces the need to wear shooting glasses, which I do out of habit.

Now, I need to order some meprolight night sights for it. The overhead sight illuminator was out on my lane yesterday and I was basically just point shooting because I could not see the sights at all. The only good news is the 620 points well and the new X frame grips makes shooting full power magnum loads not bad at all.