comparing loads between frame and slide mount optics?

I've read here that having a frame mount allows one to go lower on powder charge due to moving less mass on the slide.  I've also read "greased rocks" and comments about softer 25 yd line loads being less tiring.

Has any one tested approx. how much lower one can load a frame mount for the same reliable operation?  For the 25 yd line, I am wondering on other's posted loads (those which are clearly identified as slide mount) if I can downgrade them for the 25 yd line.

As a test, I have loaded some lower loads of N310 behind a 185 gr Magnus 801 for tomorrow (3.65, 3.60, 3.55 and 3.50) to test functioning with a 10# recoil spring.

I know that for the 50yd line the recipes are about accuracy and I would not anticipate changing those powder loads without impacting accuracy (with usual caveat of different pistols performing differently with the same loaded ammo).

Thanks

How do you reliably throw powder to the hundredths decimal place?  Are you using a prometheus or an auto-trickler and an fx-120i?


-- Scott

In warmer weather I run 3.4 gr BE with 200 lswc for the shortline on slide mounted scope. Jerry Keefer’s last build for his lady shooter was running 3.0 BE but I can’t remember which bullet; 180 or 200
Had a 1:12 twist barrel on frame mount.
Jon

swehrman wrote:How do you reliably throw powder to the hundredths decimal place?  Are you using a prometheus or an auto-trickler and an fx-120i?


-- Scott

Scott,  

It is just like area aiming     

I set the RCBS micrometer to give me ten throws which together weigh ten-times the weight I want (scale measures to ten's place) and then the AVERAGE throw is to the 100's place.

Actually something like this would allow to weight charges with 0.02 of a grain accuracy.
https://www.amazon.com/My-Weigh-SCGEMPRO300-0-001g-Scale/dp/B01A5GEB94/ref=sr_1_8?ie=UTF8&qid=1550391583&sr=8-8&keywords=gem+pro+250

And I use very simple, albeit somewhat time consuming, method to achieve such accuracy with my XL650s.  I set powder measure to drop slightly higher charge than desired first.  Then after case is primed on station 2 I take it out, put on the scale (Gem Pro 250) and zero scale out.  Then drop charge, remove charged case on station three and put it on scale again - it will show actual charge weight.  Then I just spill out excess charge by tilting and rotating case between thumb and point fingers.  After doing this for a few dozen cases you develop cadence, so it would not be that complicated.  This method also will allow you to true up your press, and determine actual delta with particular powder without calculator.  That is how I know that my presses hold +/-0.06 gr. with Bulls Eye.

AP