I've played a few games now and have had a couple double feeds due to paint so small it was rolling through my .679 insert. For the same reason I have had one ball get in the insert far enough with the slide back to still allow another ball to get half in the breech. I was pumping normally but could feel something catch and looked down to see what was going on. Still no pinches though! If you pump it fast, the ramp on the snub just kicks that ball back up into the feed tube in one piece. In the heat of battle I've been pumping it back and letting go of the slide while the return spring slaps the slide home. I'm not sure if that's a bad thing or not, and I try to baby it when I can, but this thing is built solid. Here is the ramp on the snub for those who haven't seen it.
I picked up a Thunder Pig spring set and a Ranger power tube and cup seal from Bacci to mess around with tuning.
My goal is consistency, not trying to squeeze 50 shots out of a 12g, but that'd be cool too. I didn't have a ton of time today but figured I'd start with a new hammer spring and see what happened.
Temp outside was 50 degrees. I started with the stock hammer and valve springs, with the TPC in 3 full turns. First shot was 276 with the next 9 around 271-259. Shot the rest of that 12g and then swapped to a red (heavy) hammer spring. First shot was at 291 (sizzle!) and the next 9 were at 288-269. I was waiting about 15 seconds between shots. There was a much more noticeable kick and cloud of gas at the muzzle on these 10 shots and the efficiency was lower, which was to be expected.
I noticed that the red spring was a little longer than the stock CCI spring. My Dux has the longer slot where you can cock it without it being aired up. Pumping it hard can cause the valve to open, venting gas. I noticed after adding the red spring that I couldn't get the valve to do that. I pumped it pretty hard, but didn't Hercules the thing. Some more testing is needed here...
Anything above 225 is usable I think but if I can stay above 250 for 30 shots, I think I'll be very happy. I didn't record more than the first 10 shots because I'm using crossman 12gs and crappy field paint so I didn't think the numbers would be truly accurate. I'm going to pick up some Nelson Anarchy and a batch of Lovely Coconuts's to run some official tests with the spring configs and the different powertubes. I read CJ got great results from the ranger tube.
One other thing I noticed recently is that there appears to be a strip of tape or something like it on the inside of the slide where it contacts the frame. I assume it's to make it slide better and reduce wear. Do the original reduxes have this?