But it is much better. Before, it would leak down completely in 2 or 3 days. I last filled it Christmas Day, haven't had time to shoot is since then. 2400 psi fill, just checked it, it was down to a little under 1000 psi. I think it's possible the rest of the problem is having to reuse orings, I need to order some new ones. The only other possibility, which I didn't think of until it was all back together :-(, is a crack or something in the firing valve. Next time I tear it down, I think I'm going to try and Zyglo the valve body, see if something shows up.
My headache now is valve lock and consistency. I shot a couple of 60 shot chrony strings, one filled to 2200 psi, the second filled to 2500 psi. The first one was a near linear drop in velocity from 866 to 565 fps. Deviation and spread got steadily worse as the velocity dropped. The second string was much more interesting. It started at 838, climbed to 917 by shot 15, then a linear drop again to 781 fps. The really interesting part was that shots 11-20 had a SD of only 4.01 and an ES of only 13.9 fps, 21-30 were 6.84 SD and 20.3 fps spread. All shooting was done using CPH's, apparently it wants to shoot these at over 900 fps. This is with a lighter than stock hammer spring set up for max power. If anyone's that interested, I have chrony spreadsheets and graphs that I can post.
I'm not sure what to do next. The lighter hammer spring is still giving me way more power than I really want, but it's forcing me to walk a really fine line, with valve lock if I step over it. But to get the consistency I want, I have to push that line. And even then, I'm only getting 20 really good shots. Supposedly, the stock spring will let me fill to higher pressure, but it wastes air, especially with a .177. My options at this point seem to be, go back to the stock spring, switch to a lighter pellet, and I've considered trying a lighter valve spring, the stock spring looks like it came out of my Suburban. I'm not crazy about the lighter pellet, I'm only able to shoot at 10 yards right now, but the CPH's are one holers at that range. Tried some CPL's earlier, not nearly as good.
The other thing that bugs me is the hammer. Compared to my Talon, this thing is massive, over 150 grams with the spring guide top hat. For comparison, my Talon's original hammer was only 11 grams, the custom I'm using is about 70, and I have a heavy one at 110 grams. I tried the heavy one in my Talon, but I actually get more power and better consistency from the one I'm using. I'm thinking the same might hold true for the B50, but I'm not sure just how to do it.
Despite all the above, or maybe because of it :-), I'm really enjoying this rifle. My only regret is I don't have as much time as I'd like to spend on it. And one of these days soon, I'm going to have to break down and get me a mini lathe. Just too many things I want to try that require some machining ability. I can see why they have such a loyal following, and I still think it makes a great compliment to my Talon. And I WILL get it ironed out, then it will be time to order a 51 stock for it. Will keep ya'll posted, later.
Dave
