Taming the 10mm 1911 slide speed:
The flat-bottomed-firing-pin-stop/stiffer-mainspring strategy for delaying the initial slide movement in 10mm 1911's didn't seem to have a noticeable effect when I tried it (even though it certainly sounds like it should help), and I hated the heavier trigger that the stiffer mainspring produced. I've been thinking about other possible ways to delay initial slide motion that might work. One way (that I've never heard anyone talk about) would (I think) be to use a less-stiff recoil spring that is compressed more in the in-battery position of the slide than the currently produced recoil springs are. I.e., the recoil spring would start out (early in the slide movement) offering more resistance to the slide motion, but would increase in resistance more slowly as the slide moved farther and farther back, ending with less resistance near the slide lockback position than current recoil springs. The speed of the slide near the lockback position is roughly determined by the area under the resistance-vs-compression curve of the recoil spring (starting from the compression in battery, and ending at the compression at the rear of slide movement). It is desirable, I think, that the speed near the rear slide position be fairly small. And, in addition, I think, with such a different type of spring, that the initial delay in slide motion would cause more of the initial recoil to be absorbed by the shooter, leaving less of the recoil showing up as slide velocity. If so, the area under the resistance-vs-compression curve could actually be a little less than the area under the curve for existing recoil springs, and still achieve slow slide movement near the rear position of the slide.
So what I would like to find is a recoil spring that sticks roughly twice as far out of my 1911, before the the recoil plug has been inserted, as it does with my current springs, but which has slightly less resistance at the rear slide position than my existing springs do. If the spring weight designation given by manufacturers represents the resistance at the rear position of the slide (as I've been told), then what I would like to find is a recoil spring rated at perhaps 18 or 16 lbs, but whose "resting length" (after initial break-in and shortening has occurred) is significantly longer than existing recoil springs.
Anyone ever heard of such a recoil spring?
I have not. And, the general consensus of those who really know the 1911 is that the strength of the recoil spring will have little or no effect on initial slide movement or unlock.
http://forum.m1911.org/showthread.php?521-Spring-Things-part-2&highlight=recoil+spring+unlock
As seen here, the prescribed course of action, and the one that has been tested scientifically and proven to slow both unlock and total slide velocity, is the flat bottom firing pin stop which you didn't care for.
At this point, I would be glad to hear you have some previously undiscovered panacea to this ill, but I fear you may we wasting time in pursuit of a unicorn.
More reading on the subject.
http://forum.m1911.org/showthread.php?1950-Recoil-Function&highlight=recoil+spring+unlock
and a very long thread that is probably very worthwhile to read:
http://forum.m1911.org/showthread.php?50640-Locked-Breech-and-Slide-Delay&highlight=recoil+spring+unlock
Sprinco and DPM systems.
Neither of those systems is going to have an impact on unlock in a 1911.
Quote from: sqlbullet on December 30 2013 11:11:45 AM MST
http://forum.m1911.org/showthread.php?521-Spring-Things-part-2&highlight=recoil+spring+unlock
Thanks for that link. It basically reflects my views on the subject. I strongly believed in the logic behind the flat-bottomed-firing-pin-stop/stiff-mainspring strategy, and I was more surprised than anyone when it didn't seem to have any effect in my gun ... I still don't understand WHY it didn't seem to help.
I'll also take a look ASAP at the other two links you supplied ... thanks.
Quote from: Intercooler on December 30 2013 11:20:26 AM MST
Sprinco and DPM systems.
I DID order the Sprinco guide-rod assembly ... probably will arrive today, and I hope to test it at the range this Saturday. I got it in hopes that, by using a weaker recoil spring with it, I can slow down the slide during chambering a bit, and hopefully improve my chambering reliability. But I would also like to slow down my slide during ejection a bit, and a weaker recoil spring will actually make that slightly worse. That's why I'm trying to think about ways of slowing the slide down in both directions. I think the spring I described, perhaps in combination with Sprinco's guide-rod-assembly, might do that. I also think that going back to my preferred relaxed grip might also help, by diverting some of the recoil into initial recoil soaked up by ME (before the slide moves relative to the frame), and away from the slide velocity (in both directions) ... another experiment that's waiting for me. A third possibility (to solve the "springs work both ways" problem) might be to use some kind of a dashpot in a guide-rod assembly ... a dashpot doesn't store energy like a spring does ... rather, it resists motion in one direction (with resistance proportional to speed), and offers little resistance in the opposite direction ... that's what shock-absorbers are, in car suspensions. Dashpots dissipate energy (converting kinetic energy into heat), rather than storing it for later release, and that's why they don't "work both ways" like springs do ... might get pretty hot, though, with a lot of rapid fire.
Quote from: sqlbullet on December 30 2013 11:46:39 AM MST
Neither of those systems is going to have an impact on unlock in a 1911.
You're right.
They won't, but will help with what you are try to do.