Impact X Tuning Questions

If it were mine id bump up the reg pressure a bit maybe to 157-158. I got 960s with the 28gr NSAs out of a Boss with a 600mm barrel. But that could be with close to 160 reg pressure and that was definitely wasting air. But no worries my compressor can make more air easily!

Your gauge could be out in either direction. I’d start with the regulator pressure lower at 130 and go up 5 bar at a time. As Nathen said keep going till the speed plateaus past 150bar a little if necessary. If your gauge is out and actual pressure is higher your hammer may not be opening the valve fully 

Michael

Nice!!

Sounds like you'll get the velocity the slugs like.

As far as the oring for the (reg?) adjustment screw? I wouldn't worry about that one. I've adjusted the reg on my Crown A LOT in the first two weeks with zero issues.

The bigger thing to worry about is when you make the adjustment for lower pressure, that you don't do it with air pressure in the system.

For the Crown, the manual says to remove the bottle and then dry fire it with the transfer port on LOW and Hammer Wheel on MIN. Personally I don't like that, as when I first start tuning, I have the hammer wheel adjustment screw maxed out AND I also have an Ernest Rowe hammer tune kit in there. So my MIN might not be light enough. I don't know if the Impact manual says the same thing.

I always depressurize by backing OUT the reg pressure screw a tiny bit until the air is released. Just remember to turn the same screw IN enough so that when you reattach the bottle, your reg pressure will be lower than what you want it to be so you can increase from there.

Unless you meant that you're worried about the oring failing from too much pressure instead of too many adjustments?

That I couldn't tell you as I've not gone past 150 with my Crown.

So I finally got my new 600mm .22 slug liner and barrel kit installed this evening. I think that I have hit an upper limit and need some help.

I have my regulator turned up to 150bar (Huma gauge, not sure how accurate it is and I might put my EDMU on it soon); the adjustment screw is probably a half turn from being completely flush.

The hammer spring screw is maxed out, I adjusted it so that there's zero play when on the max setting.

The valve stop is all the way out.

Shooting 23gr .218 NSA's, the fastest I'm seeing is 892fps (I clocked a 21gr .218 at 914, it actually penetrated through my pellet stop and through some other things that were unexpected).

Is this about the limit for this rifle without (1) 700mm barrel (2) further hardware mods?

Is the rule of thumb for the regulator adjustment screw, not to go to or beyond the flush level with the housing?

At the end of the day, I was banking on getting 920-940 out of this! Looks like it is falling short this far :/

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So many questions! ok lets see if I can help

First of all, my recommendation is get to know the impact first before changing from pellets to slugs (and tuning a lot), that is the safe way to go, but hell who wants safe! jaja

EDMU gauge is not as good as it sound...no to easy to read and there are many failures report. That been said, is the most advanced gauge available right now (in my books at least), wika 315 bar is second best (and little to no failures). (jaja I have both, but my originals ones looks fine so no need to change anything, not that important to me as long as accuracy and chrony give me the magic numbers ) side note: last night I shoot a 5 inches rat @ 45 meters in the head...damn I love my impact! (feeder + red light to see)

Regarding Speed, that is probably the fastest you will get on the impact with stock configuration on a 23gn slug 600mm liner (all in theory because I do not have mine just yet to try it by myself), probably you can up that a bit (donno 910fps?), but not much more. We see a lot of videos on slugs right now but neither of them have a disclaimer saying THIS IS NOT A STOCK IMPACT (Ejemple: 28gn 0.22 cal Slugs @ 950fps ... latest Matt D. video) No way a stock impact will shot that.

Regarding the Regulator, yes, better be safe, BUT and is a big one. Videos found about it are from old regs, maybe new ones change a bit. For example, according to Matt D. videos on impact x, you can actually screw clockwise the regulator without degas on the impact x (only impact x). Been a "Beta Tester" of FX (and specially the impact) he can do much more than us (without throwing money away I mean). Maybe @sniperlabyo aka Ernest Rowe can Chime in?

Regarding mods, I have an Idea (haven´t make it real yet, but I might be soon). I have 0.22 - 600mm 0.25 700mm and 0.30, with the 25 - 700 mm I am able to shoot 25gn pellets @ 950 fps or so, and the only difference besides the 100 longer is the pellet probe transfer port and the brass transfer port (and of course the tuning and the reg pressure). So I thing that just making bigger on 0.22 cal the TP Holes, you can get improve speeds. That is easy to do (But need to be sure, specially living in a place that is not as easy as you guys living in USA to get the spares), recently Ernest publish a great video on barrel on a Bob´s thread 

Finally I ask a few months ago something similar to Ernest, need mayor mods to do that including:

1. Double TP on barrel and probe
2. Large VS bore to 6.35mm
3. Larger delrin seat to 7.85mm
4. 125g hammer/spring guide 
5. Milled valve housing 
6. 40cc plenum tube

With that mods you can achieve on 0.22

500mm barrel 890Fps 25g
600mm barrel 985Fps 25g 
700mm barrel 1045fps 25g & 33g 935fps

I ve been studying the topic a bit as you can see (buy HEY! those are Ernest ideas not mine)

Stock Xs should be shoot fine 19gn (donno about accuracy on those since is 0.217 and no 0.218) and 21gn, 23 is just in the limit (considering 950 fps). That is why 0.25 cal liner slugs + 0.25 cal RatSniper slug (light weight) sound shootable on stock impact, but been reading bad comments about RatSS service (not delivering), bummer! (This researching on the web only, NSA on 0.25 are heavy right now) sadly 0.25 liners for slug are not ready yet for us mortals...jaja

I Have a Question for you guys: What has been the max regulator pressure you have push? (On impacts, impact x or Crowns)

PS: I edit a lot, sorry for that, but remember English is not my main language so sometimes I re read what I post...and I have to edit in order to express myself a little better.

I enjoy all Matt’s videos and have learnt a lot from him. I heard him say the new Impacts an be ajusted down while under pressure also but as far as I’m aware the new Impacts don’t have the new AMP regulator. Until they do I definitely wouldn’t try to ajust the reg pressure down while under pressure. 

I enjoy all Matt’s videos and have learnt a lot from him. I heard him say the new Impacts an be ajusted down while under pressure also but as far as I’m aware the new Impacts don’t have the new AMP regulator. Until they do I definitely wouldn’t try to ajust the reg pressure down while under pressure.

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Me too, and he is very responsive (at least to me, he always answer my Q) But definitely is a different regulator on the impact x, than the old versions...jaja I haven't try it either considering that degassing is too easy. But just in case I have an extra Regulator at hand that Fx give to me (Ernest) a few months ago (That is the thing with Fx and Ernest...they are great!)

Good to read! 23gn slug is in the limit, probably with 700mm barrel you will be in the 45ish fpe

Can not wait for the power kit!

Looking forward to your early reports!!

Good to read! 23gn slug is in the limit, probably with 700mm barrel you will be in the 45ish fpe

Can not wait for the power kit!

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Scan the thread titled "Impact Shooting Slugs", the only mod that I'm aware of that Roelf had was a 2MM spacer in his hammer spring. He said that was sent to him by FX to test 28mm slugs out of a 700mm barrel. 

Probably more to the story, my gun isn't anywhere near close to what he reported.

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Naa don't think is the only one mod, 28mm slugs? you mean grain?

I think I have it tuned as efficiently as I can get it for these 23gr slugs now. Tonight I decided to test with the .217's, and they seem to come out hotter than the .218's. Weird, but I'll take any gains I can get until I put turbos on it.

At just under 150bar on the reg they are clocking in at 920fps on an average when it's maxed out (936 was the fastest I've seen under 150bar). 

I turned down the power wheel to 4, lost around 10fps, and I worked the valve control until it sits around just under the third line. This gives me 42FPE roughly, then I tweaked the valve knob until it sounded efficient if that makes sense.

Snowing like no tomorrow outside. Hoping I'm able to get out to one of my long range target shooting spots tomorrow and Sunday to see how it groups.

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Imagine 28gn slugs, No way you can achieve 950 fps on a stock impact, Still waiting for my liner but I have the 25gn pellet (monsters redesigned) and no way I can shoot it at 950 fps in my stock impact

Just saw the topic

https://www.airgunnation.com/topic/impact-shooting-slugs/

Ahh but it was a 26gn slug no 28gn, 700mm barrel (not available), and that spacer, now it make more sense ... that spacer should be very easy to make