View Full Version : Shadow gamers, converge here, let's chat

03-28-2021, 08:18 PM
This really is applicable for all hammer fired pistolas. It is a technical thread but probably not interesting for a general consumption to post elsewhere.

I was futzing around with my Dos Shadows today. My traditional setup is 11 lbs for mainspring and recoil spring. I installed a 15 lbs mainspring on my match gun. Couldn't find a 9 lbs recoil spring so I put in 8 lbs. I was trying to explain the reasoning to GJM but he called in alchemy or something like that.

Hammer spring provides a resistance to the slide moving back, so in theory 15 lbs spring should bleed off 30% of slide's energy (or momentum, or velocity; probably all of them but I no love physics). Lighter recoil spring is to assure that slide cycles fully and, as a benefit, offers less forward dip on return to battery. My expectations were a flatter shooting gun. The observations were:

- Predictably, worse DA pull. At about 22 yards, first shot about .20 slower, maybe less, for the same 3A/2C at IPSC target, range for both guns 1.3x-16x.

- I would have to reinstall the old mainspring to be sure, but I think that SA pull got lighter.

- Subjectively, the dot with heavier mainspring appeared to stay flatter. I was doing about .25 splits at 22-23 yards (@GJM, I misspoke, 18s were at 15 yards), and the dot didn't seem to leave turtle target. I did get some dipping but I think it was me because this was in the middle of 194 pf 1911 practice.

- However, the hits were pretty much the same with regular setup and heavy mainspring.

I blew through almost 150 rounds playing with this and am still not certain. May play more with it. Anybody done this before?

04-12-2021, 12:49 PM
I don't have the ammo to do a ton of live fire outside of matches other than some basic yes it still works. I switched my 11.5MS for a 13MS to more reliably ignite my stash of small rifle primers. My DA went from sub 6# to 8 1/2# which was unfortunate, the SA went from around 2 1/4# to 1 1/2#:cool: Also have the CGW reach reduction kit and everything is lightly polished.

I use a 10# recoil spring with a shok buff. The limited shooting I did I was more interested in function and did not specifically pay attention to the recoil impulse, but nothing jumped out to me as amazing or abnormal.

04-12-2021, 11:39 PM
the SA went from around 2 1/4# to 1 1/2#

Thanks for confirming that this happens with heavier hammer spring.

I'll be going back to Shadows and Carry Optics for May and June. For now I'll keep 15 lbs mainspring in one of mine. Mostly curious about effect on slide and sight tracking than trigger pull.