This weekend at a local gunshow I was fortunate to pickup a 610-2 and a 657-3, both with 6.5 inch barrels and unfluted cylinders. Also had original boxes and paperwork.
My question is about the 610. The paperwork did not have anything particular to a model 610, just a booklet about revolvers in general. The seller told me that the gun would shoot 10mm without moon clips (that were included) but to use the clips if I were to shoot the 40s&w rounds. I am wondering if that is a true statement, as sellers will usually tell you anything in order to buy their guns. The cylinder does have counterbores which look as if they were made for the 10mm cartridge.
I can get some pictures up tomorrow if anyone is interested.

What you are seeing is the cylinder throat

Most revolvers that use moon clips will fire with the case mouth resting against that cylinder throat.

I always use moon clips, but I have had my chambers opened up so that my 610s will not shoot 10MM Magnum, 10MM Auto or 40S&W. Besides it is a pain to push cartridges out with a pencil.
Moonclips ensure proper extraction of all 6 rounds.

I usually sit watching TV the night before I hit the range and load up 10 - 20 moon clips. The night after the range I sit with ajar on the floor and de-moon with a little tool I made from copper tubing and a bicycle grip. Makes life easy

You are correct in assuming the shoulder in the chamber is there for headspacing purposes and the case mouth of some rounds may actually reach that shoulder. However, since SAAMI sets the specs for cartridge dimensions, the shoulder is placed at maximum case length depth for a given caliber. My experience has been that any factory ammo or brass, when new, is usually considerably less than this dimension - meaning that, in reality, headspacing on that shoulder, by the case mouth, seldom actually occurs.

What does happen is that variances in chamber roundness, smoothness, cleanliness and other variables, will hold some cartridges firmly enough that a firing pin strike will ignite the primers. Others are driven forward in the chamber, which results in a light primer strike and a failure to ignite.

Just as some rounds are held tightly enough for ignition and others are driven forward, some cases may drop out of the cylinder from gravity, while others may be "pluckable" and yet others will have to be poked out using a rod.

You should consider moon clips essential for any revolver that is chambered for a rimless or semi-rimmed round. The other alternative is using the rimmed version of that round, if one exists. In the case of a revolver that can fire a shorter round than that actually chambered for, i.e. a .40 S&W in your 10 mm 610, or a .45 GAP in a 25/325/625 while some may ignite because of the variables listed above, your frequency of misfires will be much greater. Besides, as colt saa says - it's a PITA poking out the empties - use clips and the proper tools to charge and empty them.

Adios,

Pizza Bob

__________________
NRA Benefactor Member

OK, here are some pictures. One shows the paperwork that came with it. There are only three pieces of paper, and I am wondering if there was supposed to be an operator's manual that would have been specific to the 610. Does anyone know?

Attached Images

	Mod 610 A.jpg (87.9 KB, 42 views)
	Mod 610 B.jpg (78.4 KB, 38 views)
	Mod 610 C.jpg (111.3 KB, 50 views)
	Mod 610 D.jpg (92.3 KB, 38 views)

Smith and Wesson manuals are generic, not model specific

BTW, that revolver was manufactured on May 6th of 1998

I have a 610 also. Yes, the ridge in the chamber is for using 10mm cartridges without the moon clips. However, you will have to punch them out with a rod as the extractor star will not contact the rimless cartridge. Just use the moon clips, it's much easier. The moon clips will also let you shoot 40 S&W ammo which is shorter than the 10mm.
Extra moon clips are normally available through places like Midway USA.

Thank you for the information on the manufacture date, saa.