loading for frame mt. vs. slide mt.

I searched previous postings but couldn't find any information going from a slide to a frame mounted ultradot. Is there a standard to use a really low charge and light 10 pound spring or a regular 3.8gr bullseye type load with a heavier spring. Zero 185 LSWCHP is the probable long line bullet.

Unless recoil is a huge issue, it might be better to add two pounds on the spring and shoot the same ammo.  Presuming, of course, the ammo shoots well.

I shoot the same loads in my frame mounted Matchdot II that I shoot with irons.  As Wobbley said above work with the spring if you already have a load you like.  Don

Typically you find a load the gun shoots well and then tune the springs to the load.  So if 3.8 BE worked well with the slide mount you can keep the same load and retune the springs, probably going up a couple of pounds.

One of the reasons some folks like a frame mount is that it gives them the opportunity to shoot superlight loads reliably on the short line.  I've seen people reference loads as low as 3.3 BE and possibly even 3.1 BE.  Whether the individual gun is accurate and reliable with such loads would require testing.  And you might not like the feel of them either; or then again you might.  I have not personally done this with a 45, but I have done the analogous thing with a 9mm.

Look not only at the recoil spring, but the mainspring as well.  If you reduce the MS, you may be surprised at what you can do with your load.

kc.crawford.7 wrote:Look not only at the recoil spring, but the mainspring as well.  If you reduce the MS, you may be surprised at what you can do with your load.

Would you provide some guidance please? 15, 17, 19 and 22 lbs. mainsprings are what I see on Brownells. Is the 22 lbs. 'stock'? Are there pairings you would suggest with recoil springs?

thanks for the inputs. I might try the slow 200gr. that Jon talks about since I have some and the 185gr for the shortline. starting with a 10lb. recoil spring.

I remember someone posting that Mike Curtis used a 19lb. mainspring in his wadcutter pistols.

Robert I always go back to how tight is lock up? If slide comes out of battery fast you will need a heavier recoil spring. Regardless of where the optics are mounted. Trial & error!
Jon

Lots of factors total slide/optic weight for one.  Both guns running same mainspring and have the same firing pin stop radius (s/b large). If you have converted the gun to frame mount then start with 0.2gr less and test from there.  I've been able to go as much as 0.4gr less but with mainspring and recoil spring adjustments too.  

I run 19lb mainsprings, for the recoil spring I start with a spring heavy enough that it won't lock back on the last round. Next I reduce the spring weight until I get lock back on the last round and I finish up by going 1lb lighter.  Seems to work for me.

I have set up several .45's (all frame mounts) with the exact same load using this method and I don't always end up with the same recoil spring weight and I may have to adjust the load for that gun to be accurate.
- Dave

ps I've also dropped a load 0.2gr going from slide to frame mount and have had the groups expanded a bunch.