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?