Tuning Another Maverick question

Check the two M4 x 8 grub screws on the cocking block that locks on to the cocking rod. It’s what your cocking linkage is connected to. If those are working their way loose it will cause your pellet probe transfer port to misalign with the barrels transfer port and give you wise spreads like that out of the blue.
If you are going to check the screws and reset it, see if the rod will rotate. It should be screwed in snugly.
 
I think that is part #38 on the schematic. I put Loctite on both grub screws but will check again!
Most everyone I’ve chatted with thru text or pms that own the maverick and wildcat platforms, I’ve suggested to them to get away from the grub screws and just use a socket head screw for these two screws. If you can easily source Torx head that would be the best, as you can really cinch down tight against that rod with no fear of your Allen wrench rounding off the allen socket. I use M4 x 6 stainless Torx screws for that cock block, along with lock tight on the fasteners threads.

The problem wiyh the M4 grub screws is when you try over tightening those you risk rounding off the Allen socket, and if you do, you’re pretty much screwed as now you’re having to not only order a new cock block, you’ll have to disassemble a good portion of the gun to install the new one.

But hey! You still have the get the old cock block off of the rod! See where I’m going with this? Even if those screws never were the cause of your velocity spreads, change those grub screws out!
 
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Ok, I have gone up to 150 on first and 120 on 2nd. Shooting inside on chronograph cuz it’s cold here! 15.89 FX pellets.
In 30 or so shots, it seems the “stray” shot has gone…so far! Shooting in the mid 880’s. Will do more extensive shooting tomorrow at indoor range. Cross your fingers and thanks for the suggestions and help! Will letcha know what happens!!
 
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Ok, I have gone up to 150 on first and 120 on 2nd. Shooting inside on chronograph cuz it’s cold here! 15.89 FX pellets.
In 30 or so shots, it seems the “stray” shot has gone…so far! Shooting in the mid 880’s. Will do more extensive shooting tomorrow at indoor range. Cross your fingers and thanks for the suggestions and help! Will letcha know what happens!!
What's your hammer wheel set at? FPS seems a bit low for that 2nd reg pressure.
 
I put the hammer wheel on 4 but had to turn the IHS to about 9 turns (to the left) to get it in the 880 range. Now I gotta get to the sweet spot.......
I'd turn the spring back, then shoot strings of 5 shots at each hammer wheel setting, going up until you don't get a speed increase, or very little speed increase anymore. I was getting a good increase on mine up until 6, then at 7 it only went up a few FPS so back to 6. Then I adjusted the IHS back and forth to get tight spread. For comparison on my .25 cal VP my 2nd reg is at 112, hammer wheel is at 6, IHS is turned out 1/2 of turn. I'm shooting 34 grain JSB's at 907. My spread over 30 shots is 7 fps, SD is 2.94. Shoots better than I can with a high shot count.

If you're happy with your tune that's what counts but I think you can be more efficient with your air and get to the same spot. Prior to starting over I was getting 880 with 2nd reg at 122. The other benefit is my shot is noticeably quieter now.
 
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I'd turn the spring back, then shoot strings of 5 shots at each hammer wheel setting, going up until you don't get a speed increase, or very little speed increase anymore. I was getting a good increase on mine up until 6, then at 7 it only went up a few FPS so back to 6. Then I adjusted the IHS back and forth to get tight spread. For comparison on my .25 cal VP my 2nd reg is at 112, hammer wheel is at 6, IHS is turned out 1/2 of turn. I'm shooting 34 grain JSB's at 907. My spread over 30 shots is 7 fps, SD is 2.94. Shoots better than I can with a high shot count.

If you're happy with your tune that's what counts but I think you can be more efficient with your air and get to the same spot. Prior to starting over I was getting 880 with 2nd reg at 122. The other benefit is my shot is noticeably quieter now.
Great idea! I’ll do it at the range tomorrow! I really appreciate your comments! Thanks…..I want to save as much air as I can for higher shot count.
 
Great idea! I’ll do it at the range tomorrow! I really appreciate your comments! Thanks…..I want to save as much air as I can for higher shot count.
You could probably lower the 2nd reg by at least 10 bar, probably more. I'd probably start the process at 105 on yours. If you start at 105 and at hammer wheel 7 it's not fast enough raise the pressure a few bar and start over. I also probably would start the wheel at 4 and go up.
 
You could probably lower the 2nd reg by at least 10 bar, probably more. I'd probably start the process at 105 on yours. If you start at 105 and at hammer wheel 7 it's not fast enough raise the pressure a few bar and start over. I also probably would start the wheel at 4 and go up.
So, originally I was getting 880s with 1st at 105 and second at 75. PW at 7 IHS at 3 from left. Just had some very weird spreads. That’s where I started upping the reg pressures.
 
So, originally I was getting 880s with 1st at 105 and second at 75. PW at 7 IHS at 3 from left. Just had some very weird spreads. That’s where I started upping the reg pressures.
I'm thinking that's too much hammer for 75 bar, causing the spread. I'd start at 80 or 85 bar and wheel at 4 and work up the pressure maybe 5 bar at a time.
When you get close to the 880 goal see what increasing the hammer does. If you can get your 880 at 4 or 5 I'm thinking any need to tighten the spread can be done with the IHS. I stayed away from FX because I love to tinker and knew this would happen to me. LOL Now I love messing with them.
 
So, originally I was getting 880s with 1st at 105 and second at 75. PW at 7 IHS at 3 from left. Just had some very weird spreads. That’s where I started upping the reg pressures.
Do you have the 177/22 cal hammer weight or the 25cal hammer weight installed? Your numbers remind me of the 25cal hammer weight but wasn't for sure.
 
It was just 1 or 2 shots in a string that caused the spread. Sure wasn’t getting std deviations of 2 or 3, but6-8. Suddenly got a very low (-30fps) or v high + 25) in a string.
Someone else advised it was cuz of pressures being too low for the Amp regs to work efficiently so I started fiddling with it…. Going up.
The pressure being too low for the regs is something I can't comment on because I have no idea if that's true or not. You have it on the pellet port right?
 
I’m not sure. I think it’s the smaller though.11 g is smaller, right?
If your gun was originally a .177cal or 22cal then you have the 7 g version. 11g is 25 cal and 13 g come with the slug power kit. Sorry, I just edited it.
I weighed all may hammer weights. The factory versions for 10.4 grams for the 177/22 cal. 11.5 g for the 25 and 13.2 for the slug power kit version. I also have 2 brass versions from Huma Air that weigh 13.2 and 14.5. Tungsten hammer weight is 26.4 grams.
 
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The pressure being too low for the regs is something I can't comment on because I have no idea if that's true or not. You have it on the pellet port right?
Nope. The larger port. I have the older FX version with 2 ports, the larger port has no “bar” in the middle (like the Huma or 2nd gen FX ports).
 
If your gun was originally a .177cal or 22cal then you have the 7 g version. 11g is 25 cal and 13 g come with the slug power kit. Sorry, I just edited it.
I weighed all may hammer weights. The factory versions for 10.4 grams for the 177/22 cal. 11.5 g for the 25 and 13.2 for the slug power kit version. I also have 2 brass versions from Huma Air that weigh 13.2 and 14.5. Tungsten hammer weight is 26.4 grams.
I hadn’t thought of that. I will check hammer weight. I should have figured this cuz of the physics of delivering the hammer to the valves. F=mv!
Thanks, again!
 
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Just be aware quite a few earlier .22 Mavericks shipped with 6g hammer weights with hollow center instead of 7g, mine included. Since have replaced it with 11.1g .25 hammer weight which is a peach!
This is why I come here! Had no idea of this! So you use the 11 .1 g on a .22? For slugs and pellets? Thanks for the help and info!!
 
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