How low can I or should I go

currently using 4.0 gr of BE and a 190 gr swc cast bullet. Slide mounted 9000 sc and 11 lb recoil spring in a pretty stock RO.  shoots pretty well but being the tinkering type I’d like to try some 160’s and maybe a lighter load for the short line.  With BE or even wst, how low can I go with a 190 or even a 160 and not hurt my gun with too light a spring?  I see some going as low as 10lb springs and I’m sure is fine but for some reason I feel that’s too low..be advised I have no clue why I think this.  My mainspring is 19 lb.  I see some using 3.5-3.8 BE but not sure that would function a slide mount d 9000sc.

Any advice would be greatly appreciated..your load data with the 9000sc on a slide.  I know not all wad guns are created equal but it will give me a good starting place.  Winter is coming and I’ll have the indoor range to play around with load data etc.

Gentleman, I thank you in advance.

Joe

160 GR use 4.3 GR BE
Match your spring. 10-12#

james r chapman wrote:160 GR use 4.3 GR BE
Match your spring. 10-12#

Thanks buddy...how about 190’s. So, going to 10lb spring is ok?

Put the 10# pound in with the 190's and drop till cycling gets spotty then raise .1-.2 grains. Should get you around 3.6-3.7 BE. Depends on the bearing surface and diameter of the 190. I've seen big differences between a Magnus #801 and a H&G 68 185, same grain bullet but huge difference in powder charge for the same result.

zanemoseley wrote:Put the 10# pound in with the 190's and drop till cycling gets spotty then raise .1-.2 grains. Should get you around 3.6-3.7 BE. Depends on the bearing surface and diameter of the 190. I've seen big differences between a Magnus #801 and a H&G 68 185, same grain bullet but huge difference in powder charge for the same result.

Awesome info. Thanks buddy
I know with the 11 lb and the 4.0 be I swear I can feel that slide push back and forth .like I can feel it cycle

I went through this excercise but with a different powder (vectan ba10, it was really cheap). It gets REALLY dirty at low charge weights. Only three lbs to go before I can get back to WST, or Titegroup, or bullseye... I was down to 2.5gr BA10 with an 11 lb spring and a vortex strikefire, a sight similar in weight to the 9000. Looked like I was shooting black powder. On the indoor range, had a hard time seeing the target for the fourth and fifth shot of time fire. Last round laid in the ejection port...

I went back to 3.2, still pretty dirty, but pretty comfy to shoot.

My old 25 yd load was 3.8 gr. HS-700X behind the 185 gr. LSWCHP and Rem 2 1/2 primer. Extreemely consistent velocity over 2 dwecades at an avearge 0f ca 710 fps with a single digit SD. Very accurate and comfy load to shoot. Our local club and league matches are shot at 50 ft and 25 yds.