FX Impact M3 Tuning Advice (inconsistency)

Jump to latest Follow Reply
F

Floridaman2005

Member
Oct 11, 2024
58
38
So I have my Impact shooting pretty decent groups after tuning but most of my shot charts look like this. I am shooting 18.1g FX ammo at 120/85 bar and usually shoot between 880-900 fps.

I did notice my regs creep a little and that’s why the first shot is low, but why the buildup like that. Should I have more pressure at the rear reg so it has a stronger contact with the valve adjuster? I can’t figure out why my strings are like this. Anything I can fix?


IMG_9915.png


IMG_9914.png
 
Here ya go:

FX - FX impact M4 velocity “warm up”

I’m wondering if someone can shed some light on this question. I’ve recently got an FX Impact M4 .22 700mm with slug power kit installed, heavy liner, carbon sleeve etc. If the rifle has been resting (but is room temperature) I notice it takes a good 10-15 shots for the velocity to get to...
www.airgunnation.com www.airgunnation.com
 
Upvote 0
Floridaman2005 said:
It’s a 500mm
Click to expand...
I was going to say low, I think he's having to open the valve too long to get the velocity. For Giggles I'd go up another 10 bar or so and start reducing his hammer/dwell. I'd also increase #1 to 140 faster refill. We don't see hit shot timing and with low pressure that'll play havoc with speeds...JMHO
 
  • Like
Reactions: 1handwill.gc
Upvote 0
Floridaman2005 said:
So I have my Impact shooting pretty decent groups after tuning but most of my shot charts look like this. I am shooting 18.1g FX ammo at 120/85 bar and usually shoot between 880-900 fps.

I did notice my regs creep a little and that’s why the first shot is low, but why the buildup like that. Should I have more pressure at the rear reg so it has a stronger contact with the valve adjuster? I can’t figure out why my strings are like this. Anything I can fix?


View attachment 514956

View attachment 514957
Click to expand...
I can accept that 20+ FPS spread for a regulated airgun which cost s$300.
For an airgun that cost $2000+ not so much.

A $2000+ airgun better be almost perfect.
As in I can shoot it without tuning it.
 
Upvote 0
nobody1 said:
I can accept that 20+ FPS spread for a regulated airgun which cost s$300.
For an airgun that cost $2000+ not so much.

A $2000+ airgun better be almost perfect.
As in I can shoot it without tuning it.
Click to expand...
Well I’ve shot most groups with spreads around 5. This was after letting the gun sit for a few days and the first 20 shots of the day on it. The low first shots were due to a little reg creep but it took a little while before it leveled off. It’s definitely not tuned to perfection as this is my first PCP and first tune attempt. That’s why I came here for advice.
 
Last edited:
Upvote 0
Floridaman2005 said:
Well I’ve shot most groups with spreads around 5. This was after letting the gun sit for a few days and the first 20 shots of the day on it. The low first shots were due to a little reg creep but it took a little while before it leveled off. It’s definitely not tuned to perfection as this is my first PCP and first tune attempt. That’s why I came here for advice.
Click to expand...
It takes one shot with every other gun on the planet to clear what happens when your reg creeps a little. What you are experiencing is not your fault.
 
Upvote 0
Vetmx said:
It takes one shot with every other gun on the planet to clear what happens when your reg creeps a little. What you are experiencing is not your fault.
Click to expand...
It’s really not worth making a big deal over that the first 2 shots of the day come out 10-15 too slow. A dry fire before shooting would essentially eliminate the issue. And it really has never affected accuracy. It really doesn’t both me at all and there are multiple fixes out there from polishing the piston to buying a new Huma reg. If I was worried about $ I would have bought a cheap rifle. If I need to modify my regs to be more precise or pay for an “upgraded” part, so be it. I’m happy to learn the inner workings of the rifle and spend some time getting things ironed out. Love everything about the rifle. Hard to complain about 1/2 shots being off. I’ll never be in a situation where I can’t dry fire a shot before loading a magazine.
 
  • Like
Reactions: 1handwill.gc and Justaguy
Upvote 0
You’re absolutely right it’ll probably work itself out, but I still think you’re using too high pressure. Maybe you need to play with the hammer a little more will you get about 30 ft./s faster than you want and then start lowering the rec pressure about 5 pounds at a time Until you get to 900 ft./s then start playing a little bit with the bow return adjustment until you get both consistency and even better accuracy but the reason no hurry you’ll get it exactly what you want by the time you’re done I have no doubt and you’ll get used to the gun as well so in my book, it’s a win-win situation
 
Upvote 0
1handwill.gc said:
You’re absolutely right it’ll probably work itself out, but I still think you’re using too high pressure. Maybe you need to play with the hammer a little more will you get about 30 ft./s faster than you want and then start lowering the rec pressure about 5 pounds at a time Until you get to 900 ft./s then start playing a little bit with the bow return adjustment until you get both consistency and even better accuracy but the reason no hurry you’ll get it exactly what you want by the time you’re done I have no doubt and you’ll get used to the gun as well so in my book, it’s a win-win situation
Click to expand...
Agree with the reg pressure speculation. But I'd start with a lower pressure and slowly raise it until you get your sweet spot.
Raising the pressure as you tune is soooo much easier than lowering it when tuning.
 
Upvote 0
dens228 said:
Agree with the reg pressure speculation. But I'd start with a lower pressure and slowly raise it until you get your sweet spot.
Raising the pressure as you tune is soooo much easier than lowering it when tuning.
Click to expand...
I definitely started on the low side from what I understand about the compact barrel. I looked up a lot of tunes and stumbled upon a video of someone on here, his name slips my mind, but it was all about impact m3 compact .22 tuning and I copied his first 18.1g tune. And I got very similar results someone suggested turning UP my first reg to 140 for better refresh rate and increase my 2nd. I’ve adjusted both but haven’t had a chance to test the results. Also curious to see how the pellet port will affect things. I have used slug port since day 1 because that’s how it was when I bought it but when I took it apart to clean it I swapped to pellet port to see if that is better since I’m shooting pellets. I’m happy to try different things and see what works.
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu