You should be able to push 25.39gr to 950 without mods. I was able to push 21.9gr AEA pellets to 970fps out of my compact M3 with just the rear reg with the reg at 134b, you can go as high as 165b safely.
So I maxed out the hammer (small adjuster to right below 5) VA all the way out and set 150 on the reg I was getting 965 fps on 25.39 grain pellets. As per the 95% tune recipe, 5% of 965 was 48 fps. So I lowered the hammer tension until I hit 48fps less than 965 (917fps). Then screwed in the VA until I lost 10 fps. So at 150 reg pressure I can get 905 fps on 25.39gr pellets. This is the correct way right? I was hoping for faster speeds. I wonder if i could push 21 grain slugs faster?
The key to power and pellet speed is barrel length! If you wanted max power the compact is not the way to go. It's your limiting factor in your set up!
That's one way to tune it, but there's different ways to skin a cat.
. I would back the reg off a bit and slowly work up to 150 making sure the velocity increases all the way to 150 bar. Then there is no reason to decrease whatever % you are talking about. It’s fine to leave it right on the peak of the knee and use the valve adjuster to slightly cut velocity for best efficiency. There you will be running much faster than low 900’s. I read to back off 5% of the max velocity at that given reg setting to be in "harmony". If I don't do that I think I could push those jsb redesigns 25.39gr at 950 at a 140 bar reg. What's the max you would push a redesign 25.39gr too? I only shoot out to 60 yards. No further.Lots of variables to consider. I have no idea if stock the m4 had enough spring/hammer to completely conquer 150 bar reg
What Trucker is saying is that at 150bar, your max hammer might be unable to reach the plateau speed, such that what you think is 95% is really 85%. Then you have a wonky tune that is really susceptible to creep. Therefore, you start at say 130bar and make sure that you’re hitting a plateau at less than max hammer.
I can shoot a .22 25.39gr pellet out of my M3 compact at 900fps at 138b. It was a solid tune air wise but probably not the best speed wise for that pellet. And yes you will get more speed out of a 21 or 22gr slug at your exact setting. You will need to test .217 and .218 and a lot of hammer settings and a lot of valve settings to find whats the best. Or you could get lucky quick. Just depends on your standards.
If you wanted to shoot a MRD and easily be able to test all speeds that might make that pellet happy and still have a happy gun, you should have went with a 600mm barrel. It will do it in it’s sleep.
FPE is not key with a limp airgun, accuracy is. FPE will be what it is when you find accuracy.
Supersonic, which is not ideal. My buddies compact maverick will do it easily on a higher pressure tune. The monsters are happy to go fast for their weight since they don't have as much contact with the liner as a slug would. The monster hades are super cool for hunting too. I can say that if you leave some overhead on the tune, like you run the power wheel at 8 for monsters, you have plenty of room to shoot 28 and lighter slugs. With the pellet liner.
This was the case in practice on my shooting buddies 500mm maverick. He took the reg pressures a bit too high(unbeknownst to me) and it was just sending them supersonic.
Yeah these platforms are vey capable even in short configurations. I've seen some guys run 300mm barrels and still push 18gr pellets at 900fps, but that's requiring a good amount of reg.
