S&W firing styles

[Stot]

Hi Guys,

I did some testing with my S&W 686 6" today.

I was interested in what exactly the effect of fast fire would have on the power and shot count.

First test was with a new CO2 Capsule, 7.19gn RWS CO2 Target pellets and around 10-15 seconds between shots.

> RESULT GRAPH <

Quite a nice string of useable shots from 10-45 just above 400fps before the power starts to drop off. Got 68 shots out of one CO2 before a pellet wouldnt leave the gun.

Next I put a new CO2 in and shot a string with ~2 seconds between shots.

> RESULT GRAPH <

As expected the power tails off fairly quickly as the gun cools but I was surprised it did find a level ~350fps that it sat at for a fair few shots. I did actually get more shots out of it this way. The chrono didnt catch them all though which is why the graph stops at 68. Shot nearly 8 full mags before it stopped firing!

It was an interesting test.

Cheers
Stot

[Phil G]

Great posting

Stot

, I know many of us have wondered the effect of CO2's performance.

We sure appreciate your efforts.

Good luck, Phil

[Jim McArthur]

Stot, these are the kinds of practical tests we should be doing. Conventional wisdom has always held that power/velocity drop off quicker in rapid fire, but now you have documentation verifying same: yet with a twist!

Personally, I like to scrap my CO2 cylinders after about 40-45 shots. I feel that accuracy starts becoming compromised after that (gut reaction, no data to prove it), and I fear having a pellet jam the pistol.

Jim

[cookie]

Great post Stot, like Jim i only shoot 5 mags then change the Co2, so looks like i've been doing the right thing. As already said thanks for your time and effort.

atvb

Jason

[Stot]

Got to admit ive been put off CO2 due to the fluctuations in power/temp which is why I did the test. I dont need it to be most powerful but I like consistant. Ill run it again in a few months when the temps drop, see what I get.

Cheers
Stot

[derekm]

Great post Stot, like Jim i only shoot 5 mags then change the Co2, so looks like i've been doing the right thing. As already said thanks for your time and effort.

atvb

Jason

Agreed; 5 mags of useful shots, then it's making a noise and wasting lead.

[MikeB]

Interesting. I've always gone 7 mags on a powerlet, but then I am talking about the 8 shot mags rather than the 10 shot S&W, which is 56; maybe I need to wind that back one mag?

[derekm]

Interesting. I've always gone 7 mags on a powerlet, but then I am talking about the 8 shot mags rather than the 10 shot S&W, which is 56; maybe I need to wind that back one mag?

The Umarex "automatics" are much more economical on gas than their S & Ws. My RWS/Umarex C225 did around 80 shots IIRC.

[Jim McArthur]

The Umarex "automatics" are much more economical on gas than their S & Ws. My RWS/Umarex C225 did around 80 shots IIRC.

I wonder why?

Jim

[Target Bunny]

Not certain about the reason for more shots per bulb. A possible explanation is that on all the revolvers I have seen the mechanism which turns the cylinder also pushes it forward to the end of the barrel and leaves a gap between the rear of the cylinder and the CO2 outlet. I have often wondered if there was a way of fitting a teflon washer to the rear of the cylinder to give a power increase.

Target Bunny.

[Stot]

ive put engineering tape between my breach and magazine on the 686 and it gains me maybe 40fps tops. Im looking to fit an o-ring instead, just trying to figure out a 'nice' way to do it.

I think the other Umarex CO2 guns run a bit lower power than the S&W and the magazine runs tighter tollerances, It can because its smaller. This makes it more efficient and is likley using less gas. This would account for the more shots per bulb in my head.

Cheers
Stot