GP100 cyl gap questions

[gunzo]

Bought a new Match Champion yesterday, took it home, looked it over, shot it some & then gave it a really close inspection.
I was overall very pleased with one exception... A thirteen thousanths(.013") cylinder gap. I honestly think that is way too much, what do you all think?
I checked about a dozen other revolvers & the biggest gap I found was .008" & I never was crazy about that, preferring .006" or less.

I plan to call Ruger tomorrow with hopes that a person will tell me what their acceptable tolerance is. You think that can happen? Or will they simply tell me to send it to them?

Thanks

 

[rugerguy]

I agree, it used to be the industry standard was .004 to .012" and that has narrowed down and many of us prefer .004-.006" anything closer tends to get fouled with "target" loads or using soft lead...bottom line is how does it shoot?? any splatter or blow by?? easy enough to check, just take a piece of slim cardboard, and roll it over ( arch it) covering the gun from left to right, and shoot through the arch, and you will find out quickly what's going on, BEFORE the guy standing next to you , in the adjoining stall says ANYTHING........ :roll:
yes, see what Ruger tells you...................

 

[brushunter]

That sounds excessive ... .013 is a large gap. If it were mine I believe I'd be callin. Both of my Blackhawk revolvers ( a SBH Hunter and a Blackhawk 45C ) have gaps of .0085 . I kinda thought that was excessive ... but they are both excellant shooters with virtually no leading and no spatter from the gap. My Redhawk is .006 ...as is the GP -100 , I'd think that is a more desirable tolerance. Good luck

regards , brushunter

 

[woodsy]

If you need any more "ammo" to go up to Ruger CS, my 6" blued GP has .004" BC gap, and my 4" SS SP .357 has .004" BC gap. That's right out of the box, and still holding strong after several thousand rounds (each gun) of mixed .38 spl and .357 mag. In other words, it won't get much worse right away, and it will get worse some time down the (long) road.

 

[cityslicker]

my 5inch gp100 is .006,and my 3inch sp101 is .005.

 

[gunzo]

The more I think about it & read everyones comments, .013" is simply too much. I was mainly concerned about velocity loss. Hadn't considered safety issues due to spatter, or accelerated wear & problems down the road. Yep, I'll be callin' customer service tomorrow.

 

[Boomer]

I just now measured my new MC purchased last Friday (not yet fired). I hadn't measured cyl gap before, so googled to ensure I was doing it correctly. A .006 shim passes through with slight drag at the forcing cone but .007 does not. BTW, serial #: 176-815xx

(Edited after rechecking measurements by cycling all cylinder chambers)

 

[Chuck 100 yd]

.006 = GOOD .013 = BAD!! IMHO

 

[gunzo]

I just now measured my new MC purchased last Friday (not yet fired). I hadn't measured cyl gap before, so googled to ensure I was doing it correctly. A .006 shim passes through with slight drag at the forcing cone but .007 does not. BTW, serial #: 176-815xx

(Edited after rechecking measurements by cycling all cylinder chambers)

Thats interesting..... My s/n is 176-8159X

Gunzo

 

[jimbo1096]

One of the first things I noticed when I put mine on the bench was the tight B/C gap. You can't see daylight through it and a .002 feeler gauge is very tight. It has exceptional accuracy. Mine is 176-8242X.
Wished I could show pics but not with this firewall.

 

[Carry_Up]

.015" - if true - is exceptionally large. The barrel has to be set back or replaced.

One of the first things I noticed when I put mine on the bench was the tight B/C gap. You can't see daylight through it and a .002 feeler gauge is very tight. It has exceptional accuracy.

One of the things we find out about revolvers is that there is a minimum as well as a maximum for most things. If your GP really has .002" b/c gap, you will get to fire at most 10 rounds before the cylinder locks up against the barrel. The lockup happens because the cylinder expands as it warms up. A simple touch up with a facing cutter will solve it. Accuracy is not dependent upon a small b/c gap. Throat diameter vs bullet diameter, forcing cone dimensions, chamber-to-barrel alignment and the crown are the things that determine accuracy. Using the facing cutter will improve your accuracy because the rear barrel face will be perpendicular to the chambers (or looking at it another way - parallel to the cylinder face).

carry_up

 

[Carry_Up]

BTW the cylinder must be held to the rear for measurement of b/c gap. Measure from the right side. Use the blade that fits with a slight drag....slight!

 

[gunzo]

Ruger & I don't seem to on the same page on this issue at this time. They want accuracy results, which I will provide.
I'll be back.

 

[Boomer]

Been watching for an update on Ruger's response. I don't get it - either your 1754 is within dimensional spec - or not. Why would they expect (bench rest) target results to determine if substandard? If poor target results are from a lousy shooter (no inference intended), does that mean Ruger will replace it? Seems totally illogical unless factory manufacturing cyl gap tolerance is broader than they choose to publish. If you bought from a LGS with gunsmith on staff, maybe having a verified measurement sent to Ruger on your behalf would be helpful.

 

[Carry_Up]

You will never get the factory to give you their internal dimensional specs. As stated, the b/c gap does not affect accuracy. As the gap opens up, velocity will decrease somewhat because more gas is vented out the sides. So the gun may be very accurate even though the b/c gap is larger than it should be. So accuracy is not the issue. Just request that the barrel be set back or replaced to reduce the b/c gap to the usual .004"-.008" range.

carry_up