My M3 is underperforming…

Like Rappert said, if you’re going to be shooting peewee slugs, use your stock hammer. Your gun will be way more tunable. I’ve said it a ton of times but there are a lot of things guys keep buying that their guns just don’t need. But that’s what makes the Impact industries wheels go round and round.
 
What happens is that the super heavy strike immediate opens the valve fully and then crashes back off the frame, allowing the valve to shut an instant later, releasing little air. Sooner, rather than later, that much hammer with so little reg pressure will damage the valve. As other said, Tungsten is only needed to open a valve that has a wall of 170+bar air keeping it closed. With a long barrel and such light slugs you should be running a pussy cat tune. With stock hammer (still way more than enough for your goal!), I’d go for 130 reg, open the valve knob fully and set the macro at its highest (then forget about it). Chrony shots starting from 2.0 on the micro. Click micro up 2 at a time till you reach your desired speed +10fps. Then incrementally close the valve knob (clockwise) until you lose that extra 10fps. That ensures that the valve is providing a short burst of air). Now, lots of folks are confused about this: The macro simply jogs the micro 5 clicks at a time. Play with it and watch the micro! Its utility is to find “presets” to use for different ammo at desired speeds. It allows the use of one tune to shoot different projectiles. You find their desired speed via trial and error and note the macro settings for each ammo (like macro 16 for your slugs and macro 5 for hades at 890fps). A bit like using channel presets on an old car radio. You can simply slip between slugs and hades by turning the macro, then go back to slugs, etc. The catch is that your primary tune (which is associated with the necessary reg pressure) should always be developed for your heaviest projectile. You can’t use this method to macro click to heavier/faster (more power; because that might require more reg pressure). That why I recommended tuning for the slug on the highest macro setting.
When you say "I'd go for 130 reg" are you talking about the second reg?
 
So I’ve noticed that my M3 is underperforming compared to a friends M3 at the range. I’m at 121 bar and pushing 24.8 .218 NSAs at 1002 FPS but my hammer spring is at 4.8ish.


My friend for comparison is pushing 27 grain .217 NSAs at 990 and only at 110 bar.

What’s weirder is that I have the power block and tungsten hammer and he has neither.

What’s goin on here?
One thing we all must remember is that the air pressure gages on these guns are very inaccurate. I just bought an M3 and while the dealer was setting it up, it shot amazingly fast at 110 bar. Well, this gun developed a leak right away, so we pulled another off the rack and set it up the same way to get the same velocity. This one had reg pressure of 125. If you are getting 1002 fps with 24.8 NSAs, you are doing very well. Leave it alone.
 
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One thing we all must remember is that the air pressure gages on these guns are very inaccurate. I just bought an M3 and while the dealer was setting it up, it shot amazingly fast at 110 bar. Well, this gun developed a leak right away, so we pulled another off the rack and set it up the same way to get the same velocity. This one had reg pressure of 125. If you are getting 1002 fps with 24.8 NSAs, you are doing very well. Leave it alone.
Right! Just ignore what a raft of other experienced tuners have said and destroy the valve..
 
Breaking it down, you’re hitting the valve too hard. Do that for long, and you’ll be putting a new valve in. If you think that’s the best setting for accuracy, go ahead, leave it like that and replace valves every now and then.
Otherwise, listen to what guys are telling you and tone it back. With slugs you need a snappier shot cycle. Lower your hammer and turn in your valve spring, you’ll watch your groups tighten up as that valve dwell starts to shorten.
 
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I didn’t say be stupid. For a given pressure, one gage may be 10 or 15 bar different than the next. A 10 percent tolerance should be expected with these imprecise instruments.
I think the gauge thing is a good idea, but when he chronied his shots, and half the numbers on the power wheel give you the same speed, it’s obvious the hammer is too much for the reg pressure.
 
new to all this. dont have an fx,,, yet. after reading this thread im wondering if anyone is offering a class on airgunning? (in english) j/k but i really dont know what most of this is all about.
having said that...........
i will point out first that we are not comparing apples/apples. horrible start.
#2 nobody has even questioned the ammo....???? is your friend using silicone or treating his ammo in any way?
#3 are these tests side by side? if not, are they indoor? outdoor? if outdoor,, what was the temp? humidity? bar pressure?

side by side, exact ammo, apples/apples. then come back and let us know.