Well I tested it out and will going back to my previous setup. It appears from my data that peak hammer energy was some where near my old setup. Plus, the gun shot amazing with that tune.
New assembly peaked velocity at 921 to 926fps for JSB's and 850 to 854fps for NSA's.
I also notice the 79 grain NSA's seem to shoot at similar speeds as the 81 grain JSB's.
Well, my gun finally arrived today. Naturally, I spent all day reassembling and resetting it up. Then I pumped a bunch of lead down range. I spent hours and dollars verifying your conclusions. After much frustration, I got a chuckle out of seeing our data line-up.
From FX warranty repair, with a request to shoot NSA 93s at 860 and JSB's at 930, that is how it arrived, with the following settings:
Front Reg-185
Rear Reg-170
4.5 Micro
16 Macro
13.5 on the Valve adjuster, which is way, way past the 4th line.
With these settings the gun was very consistent, but not at all accurate at 50 yards with either projectile. Turning the Macro down to 12 put the JSB's at 880fps, and they became very accurate.
I started adjusting the dials to find accuracy for the 93gr Nielsens. I went as low as 815 fps and as high as 870 fps. Interestingly, a couple of times I went off the second reg, and I noticed a speed increase, as 7Green noted, so I dropped the second reg down to 165 with a slight speed bump. So with the stock .35 hammer set-up and all other internals freshly sorted from FX USA, there's definitely a point at which reg pressure exceeds hammer capability. The gun is also much happier at 165 than how it came back to me at 170, and I will bump down to 160 tomorrow and try that.
I am a tad frustrated that I moved through a whole box of the 93's without finding anything that is remotely close to acceptable accuracy, regardless of how tight the spread is kept. I only have 3 more boxes of the .357 93 gr's. I am beginning to wonder if I will need the .358's as even though I've kept a spread of 3fps through ten shots and a few different speeds, nothing wants to group at 50 yards. Getting a consistent speed and fine tuning the accuracy is what the new Harmonic Tuning system is suppose to be all about. I know barrel whip is a real thing with the 800mm barrel, and given I am getting a super tight fps spread, I believe my issue is finding the right harmonic node or maybe I need the .358s.
I did have two boxes of the 79gr (357s), which are moving at 930-933ish at max, matching my max JSB 81 gr speed, and they actually show more promise than the 93grs in terms of accuracy. Everything I've read and seen online states the 93gr's can have the same or better accuracy as the 81 gr JSB's, but I haven't read much positive about the 79gr Nielsens in the FX 35. Thus far, they have better accuracy than the 93s.
I'll try some more stuff tomorrow. I do have a .30 cal 600mm conversion with a heavy Superior liner and a few different .30 slugs that I want to try on the .35 M3 as well in the near future.
In summary, it seems that the way the gun came back to me was as requested and in line with advertised performance, but the same performance is available with a lower reg pressure of 165 or below. Even with a tight extreme spread, I am not getting anything to group well yet at 50 yards except the JSB's at 880, and it seems no matter how I arrive at that magic speed, regardless of hammer and reg settings or valve adjustment, they just start grouping well.
Time for a drink and some dinner
