Revolver Cylinder Chamfer Question

[Geeko]

I am trying to figure out what going on with the SW 625 revolver to chamfer using the chamfer tool and pilots from Brownells.  Brownells website says to use the 45-1 version for the SW 25 & 625.  Both Steel & Brass pilots are the 45-1 ver.

 

The replacement cylinder was from a repair job S&W did 6 months ago prior to founding out the pilots did not fit the orig cyl S&W sent back, but the pilots fit with the replacement cyl.  My friend has a new 625-8 to which the pilots did not fit as well and S&W told him its to SAMMI spec and sent it back to him unmodified.

 

What are we missing?

[pyrrhic3gun]

What are the minor/major diameters of the pilots?   Please show us pics of the two pilots. 

[Geeko]

These are Pilots from Brownells on their website, per their info, the 45-1 for the SW 625.  Mind you, they fit just right on the replacement cyl with no mod to anything.

Edited April 29, 2020 by Geeko

[pyrrhic3gun]

Well, I just used gage pins on my 625 and the minor diameter (cylinder throat) of the pilot has to be less than .453" and the major diameter (chamber) has to be .477" or less to drop all the way into my gun's chamber.  S&W is known to produce guns with undersize chambers, so it's really no surprise that the pilot doesn't drop all the way in.  You can have a gunsmith run  a chamber reamer and an appropriate size throater into the cylinder or have the pilot turned to the correct diameter to work with your gun.  Using gage pins will tell you the diameters you need.  

[Geeko]

Thx for your reply.  The typical home gunsmith or maybe, call me a garage gunsmith, having done some/limited research, buy tools from Brownells to which a lot of people mention then generally are able to gunsmith with no problem.  I do understand about gage pins, however, can be very $$ for many others to start.  I thought of pin gages as well, but thought I would be able get by with some basic tools to start.

 

As it can be seen in the original post pic, the replacement cylinder from S&W was just fine with the Brownells chamfer pilots and I was easily able to chamfer the chambers.  Being so, why would the original factory cylinder have such problem as well as my friend's new 625-8.

 

What I am asking is - what have people done to overcome the 625-8 cyl issue.  It appears from other research that this issue has been going on for some time, 2010 the earliest I have seen, yet I have not seen a solution how people have overcome this with simple basic tools like those I have mentioned before and in the pic of tools purchased from Brownells.

 

Tools are the Throat reamer for the 45 cyl, throat reamer pilots, the chamber finish reamer for the 45, the 2 45-1 chamfer tool pilots

 

Edited April 29, 2020 by Geeko

[MikeBurgess]

when 625s were the gun in USPSA it was a known issue to have tight chambers on some guns, from what I remember many people had the cylinder chambers and throats reamed to the spec they wanted.  basically to use the chamfer cutter you have you can either make one of your pilots smaller to cit the cylinder or make the cylinder chambers and or throats larger to fit the pilots. 

 

when it comes to cutting chamfers for loading you can also do it free hand with a non piloted cutter, I have done several with a 1/2" countersinc from home depot, I know the piloted cutter would make it pretty and even but they load and function just fine, and that always been my main goal.

[Geeko]

Thx for your reply Mike.  I have participated in USPSA, ICORE, IDPA for yrs as well.  Great fun.

 

However, what have people done with tools as advertised per web forums, websites to fix the chamfer pilot issue.  Would using the 45GAP chamber reamer work enough to open up the chamber near the throat,  given the chamber SAMMI dimensions that near the throat area, the chamber diameter is less than the beginning opening?

 

**  SAMMI chamber for the 45 tappers from breech face 0.4812 through to 0.4796 and ends at the throat at 0.4740  with chamber depth 0.898 - 0.920, if I read the SAMMI diagram right.

 

It appears S&W cuts the chambers tight near the throat, almost too tight for the Brownells pilots.

 

I just thought it was interesting that the cylinder S&W replaced worked just fine with the chamfer pilots, yet the original as well as other people have had this problem for some time.

 

I do not have access to gage pins, a milling machine, nor tools shop.  Just a basic garage gunsmith trying to figure things out with limit resources.  My hands are just not as steady as they use to be without the pilot.

 

 

 

SAMMI_45ACP_Chamber.pdf

Edited April 29, 2020 by Geeko