slide velocity question

[roysha]

For Christmas I received a BarSto 9mm conversion barrel for my 40 S&W SIG P226. I got it fit and test fired yesterday. I didn't have a 15lb. 9mm spring so I tested with the 20lb. 40 S&W spring. I fired 60 rounds and it ran great. The cases all landed in a circle about 2 feet in diameter.

My question is: using the 20 lb. spring am I generating unnecessary stress on the frame by having the forward velocity of the slide perhaps too great, therefore hammering the frame going forward? I think, since it runs fine as is, I'm OK but I really don't want to booger up the gun if something as simple as a spring will keep that from happening. I do have a 9mm spring on order so switching out will be no big thing but if I don't have to, it's just one less part to have in the kit.

[GARD72977]

There is no difference in the slide velocity between you 40 and your 9. If the 9mm will function you should be fine. You may find you have more malfunctions with too much spring pressure.

[Springfield]

I personally think run the stiffest spring that will work, as the frame battering from the recoil is going to be worse than any from that of a spring.

[country gent]

Depending on its age and use age you 20 lb spring from the gun may not be 20 lbs any more due to flexing and compression. It may be a little lighter than what it was new. It may be fine as long as you have the cushion from it stripping the cartridge from the mag there to slow it down and cushion it. Letting the slide slam on an empty chamber may be an issue. It is on 1911 s. The magazine springs also play a big part of the slides velocity. a fresh mag spring gives more drag slowing the slide more than a weak spring

[GARD72977]

OP says Sig 226

[1006]

Both the 40 and the 9 slides come to a full stop before they start moving forward. So, provided they both moved fully aft after each firing, the forward velocity of the slide is the same with the 20# spring regardless of the caliber fired or for that matter even if you racked it to the rear stop by hand and left it go.

[roysha]

You are, of course correct. In retrospect it really was a dumb question. That's what happens when I get to thinking. I was mixing some bits of information I had gleaned from a 460 Rowland conversation with the fact that the factory spring for the 9mm P226 was lighter than the 40 S&W spring and arrived at a faulty conclusion.

I am going with the fact that since it functions really well with the 40 S&W spring that all is well. I will try the 9mm spring when I get it but that will be just to see if there is any difference. It may be, as one of the above posts suggests, the the 40 S&W spring is so tired that I have, in actuality, a 9mm spring. Oh well, someone here has to show their ignorance so I guess it just as well be me.:sad: