GAP and forcing cone

[Patrick1981]

Hello, I write from Italy.

I have a question to ask. I recently bought a S&W 686 SSR pro series:

I checked with a feeler blades to the gap between cylinder and barrel and I have on the left side 0.015 mm.(0,006 inch) space and on the right side 0.025 mm. (0,010 inch). Easily the surface of the forcing cone is not perfectly symmetrical.

The accuracy seems good anyway..

There may be problems of loss of pressure or something else?

Don't touch nothing or leave all the gap to 0.025 mm?

thanks

[Bill Sahlberg]

Patrick,

Think of the forcing cone as a funnel, it just gets the bullet start into the bbl. The last .0005 is where your accuracy will come from as the bullet is leaving the bbl, rather than entering it. I shoot a S&W 627 with 38 Colt Shorts and "freebore" 3/4" (.750) before the bullet even touches the forcing cone and accuracy is still awesome after 50K+ rounds

Bill Sahlberg

USA

[Patrick1981]

So what is important as the projectile leaves the barrel.

When you say BBL you mean barrel? I've heard of the 38 short Colt used in 8 times.

Despite nearly 2 cm between ball and barrel pressures do not have problems ?

excuse for my english but i use a translater

[Bubber]

So what is important as the projectile leaves the barrel.

When you say BBL you mean barrel? I've heard of the 38 short Colt used in 8 times.

Despite nearly 2 cm between ball and barrel pressures do not have problems ?

excuse for my english but i use a translater

Patrick, if it has accepable accuracy, no worries, shoot and enjoy. .006 is within tolerence. On my 686 homemade 38 super I have to bump the load to get the speed I need but it works and I just shoot it...Not well but I shoot it. Oh yea welcome to the forums. later rdd

Edited November 1, 2010 by Bubber

[John Z Sr]

Welcome to the forum and revo world Patrick, best of luck in your shooting.

[Patrick1981]

Thanks to all the guys for the welcome.

Next Sunday I have the first ICORE race with my new 686 SSR (after four years with 686-5 with six inch barrel).

I will let you know how it went.

A big hello from Italy

[John Z Sr]

Are you shooting the ICORE postalmatch Patrick?

[Wap wap]

Usually bulls eye matches (bianchi cup, ppc) , long range silhoutte , highpressure calibers or bullets with sharp shoulders benefit most from 90 deg. facing, and/or 11 or so deg. forcing cone reaming. Brownells has a good kit for about $80. If you are getting a level of accuracy acceptable with action shooting sports why bother?

[Patrick1981]

Exactly, i shoot the Icore postal match.

From 25 meters (27 iarde) in a single action can hit six out of six plates, so as you say I should not worry at all..

thanks anyway

Out of curiosity what do you call that Brownells kit?

[Wap wap]

Revolver chamfering tools-- mainly tools that came about by a pistol smith by the name of Ron Powers, during the high pt. of IMHSA, and when the Ransom Pistol rest was invented.

[Patrick1981]

thanks a lot for info

anyway I hope I never need it.

[Patrick1981]

Icore postal match is made.

I enjoyed it even if I could do better.

I made an unforgivable error of procedure that I added 10 seconds !

Shoot one more in a target and less on the another. Obviously the shots were limited.

The next will be better

Edited November 9, 2010 by Patrick1981