Newbie here.
Looking for tuning info on new M3 I have coming,
What weight pellets do you use?
Slugs? Tuning?
Looking for tuning info on new M3 I have coming,
What weight pellets do you use?
Slugs? Tuning?
Tuning .35 FX Impact M3 Tuning
- Thread starter Geico
- Start date
I've had the .35/800mm MK3 Impact for a couple months now. I've tuned it from scratch several times. I'm no airgun expert but here's my experience so far.
First off the 800mm barrel is a mixed blessing. It allows decent speeds with reasonable reg pressure but I think harmonics and hold are significant factors in taming the accuracy due to the amount of time the pellet spends traveling down the long barrel.
Before you go hanging a Donnyfl Emperor on it know that added weight on the end of the barrel changes the point of impact. a lot. Like 10-12 inches low at 80yds. I swapped the Emperor for a Ronin but didn't really do any more testing of POI change. It's kinda loud but not ear damaging with the stock moderator, which is way lighter than both the Donnyfls. Anyway, to continue...
In my initial tuning sessions I was going for speeds in the high 800s to over 900 if possible, which it is, but... With first reg cranked to 165+ bar, second reg at 140 or so, and the hammer settings close to maxed out I got 870-890 or so. This is with JSB and FX 81gr pellets. Yay!, right? Nuh uh.
Holy smokes at those settings the thing kicks like a mule, for an airgun, making it ridiculously hold sensitive and hard (for me anyway) to shoot consistantly. I was having trouble keeping 6in groups at 65yds. Now, how much of that was barrel harmonics and how much just me I have no idea. I'm no competition shooter but I'm not that bad.
Sooo, after having no luck taming the beast at those settings I started over, one more time. This time I went back to first reg factory setting of 150bar. I set the hammer controls in the middle, which I believe is with both circled settings lined up. Macro wheel on 8, micro thumbwheel on 3. Front valve open all the way, which on mine is roughly 2 full turns out from the fourth line.
Just for ha ha's I set the second reg down to 110 bar and started shooting. As expected the speed was in the low 600s. But, I noticed that when increasing the Macro wheel a step at a time the speed would stop increasing at like 12 or so. Hmmm, ok, increase second reg 5bar to 115. Now the speed would increase up to 14 on the wheel but no increase going to 16. Ah ha, increase second reg another 5bar to 120. Now the speed increased every step of the wheel up to 16. At macro 16 with the front valve wide open I got 865fps. I closed the valve limiter a bit at a time till macro 16 was down to 850fps.
That's where I'm at right now. First reg 150bar, second reg 120bar, hammer settings in the middle lined up on the circles. All hammer changes are done by increasing/decreasing macro wheel. At macro wheel 6 speed is 765fps, macro 8 780fps, macro 10 800fps, and so on up to 16 at 850fps. The kick and jump is way down and I'm managing 1.5in and better groups at 65yds on macro 10. There are definitely speeds it likes and doesn't like.
Sorry for the dissertation but that's a couple thousand pellets worth of experimentation.
First off the 800mm barrel is a mixed blessing. It allows decent speeds with reasonable reg pressure but I think harmonics and hold are significant factors in taming the accuracy due to the amount of time the pellet spends traveling down the long barrel.
Before you go hanging a Donnyfl Emperor on it know that added weight on the end of the barrel changes the point of impact. a lot. Like 10-12 inches low at 80yds. I swapped the Emperor for a Ronin but didn't really do any more testing of POI change. It's kinda loud but not ear damaging with the stock moderator, which is way lighter than both the Donnyfls. Anyway, to continue...
In my initial tuning sessions I was going for speeds in the high 800s to over 900 if possible, which it is, but... With first reg cranked to 165+ bar, second reg at 140 or so, and the hammer settings close to maxed out I got 870-890 or so. This is with JSB and FX 81gr pellets. Yay!, right? Nuh uh.
Holy smokes at those settings the thing kicks like a mule, for an airgun, making it ridiculously hold sensitive and hard (for me anyway) to shoot consistantly. I was having trouble keeping 6in groups at 65yds. Now, how much of that was barrel harmonics and how much just me I have no idea. I'm no competition shooter but I'm not that bad.
Sooo, after having no luck taming the beast at those settings I started over, one more time. This time I went back to first reg factory setting of 150bar. I set the hammer controls in the middle, which I believe is with both circled settings lined up. Macro wheel on 8, micro thumbwheel on 3. Front valve open all the way, which on mine is roughly 2 full turns out from the fourth line.
Just for ha ha's I set the second reg down to 110 bar and started shooting. As expected the speed was in the low 600s. But, I noticed that when increasing the Macro wheel a step at a time the speed would stop increasing at like 12 or so. Hmmm, ok, increase second reg 5bar to 115. Now the speed would increase up to 14 on the wheel but no increase going to 16. Ah ha, increase second reg another 5bar to 120. Now the speed increased every step of the wheel up to 16. At macro 16 with the front valve wide open I got 865fps. I closed the valve limiter a bit at a time till macro 16 was down to 850fps.
That's where I'm at right now. First reg 150bar, second reg 120bar, hammer settings in the middle lined up on the circles. All hammer changes are done by increasing/decreasing macro wheel. At macro wheel 6 speed is 765fps, macro 8 780fps, macro 10 800fps, and so on up to 16 at 850fps. The kick and jump is way down and I'm managing 1.5in and better groups at 65yds on macro 10. There are definitely speeds it likes and doesn't like.
Sorry for the dissertation but that's a couple thousand pellets worth of experimentation.
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Oh and just for the record I tried H+N Grizzly 82gr slugs. They were, and still are, a disaster. Even now at these low settings I can't even keep them on paper at 65yds. And I mean really bad. They go zinging off all over the place. At 20yds I'm lucky to keep them on a 12in target. One of the reasons I went to the Donnyfl moderator is because a Grizzly slug clipped the air stripper of my stock moderator and dinged it bad enough that I didn't want to use it.
Don't want to sound like I'm badmouthing H+N slugs, it's just that my gun really doesn't like the 357 Grizzlys. I even resized a bunch down to 356 but no difference. Your mileage may differ.
Don't want to sound like I'm badmouthing H+N slugs, it's just that my gun really doesn't like the 357 Grizzlys. I even resized a bunch down to 356 but no difference. Your mileage may differ.
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As far as the slugs go, how about using plain .35 cal? The extra diameter that a .357 slug has is a lot of drag?
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Well one of the reasons I tried the Grizzly slugs first was they were closest in weight to JSB and FX pellets, only 1gr heavier. They weren't much, if any, slower. For now I'm concentrating on getting pellets to perform. I will surely go back to experimenting with slugs at some point. 356-357 is the common diameter for guns called 35 cal and I believe that's what FX specifies for use in this gun. The main problem I see with using slugs in this gun is most 35 cal slugs weigh 95gr and up, up a lot. I have a feeling that getting decent speed out of heavy hunting slugs will involve going back up to ridiculous reg pressures and hammer settings. I am 'almost' resigned to considering this model Impact strictly a 'pelletgun'.
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Another reason I'm actually enjoying shooting pellets at these lower speeds and pressures is I'm getting great shot count per fill. I installed a 700cc carbon bottle on it and I'm easily getting 60+ shots per fill. I'd guess with the stock 580cc bottle the count would be at least 45+.
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Currently have the M3 in .35 with 800mm and 600mm barrel configurations. I have the first reg set at 190bar and the second is at 135. With valve opened and power wheel on 16 getting 920fps (800mm). This with the JSB pellets and will stay with pellets until FX comes out with the appropriate liner for slugs. I have the wheel turned down to 9 to get 875fps and groups are great from 35 to 100 yards.
I typically only use the 35 to 75 yard targets because in that range is my true hunting zone. I really haven’t played with the 600mm barrel as of yet but will when the weather gets better. I am also running the 700cc 300 bar bottle but with a harmonic wedge which stabilizes, well enough for me, barrel whip or bounce from shooting. I am using the DonnyFL Emperor but also have the Ronin moderator. For me, again subjective, the Emperor is more quiet than the Ronin. Both will add additional weight as well as cause POI changes when installed.
Have fun and enjoy your rifle once you receive it. Some have had success with slugs, I was not one of those folks and is why I am just waiting until FX finally releases one but it is going on over a year and the standard answer is always soon…
I typically only use the 35 to 75 yard targets because in that range is my true hunting zone. I really haven’t played with the 600mm barrel as of yet but will when the weather gets better. I am also running the 700cc 300 bar bottle but with a harmonic wedge which stabilizes, well enough for me, barrel whip or bounce from shooting. I am using the DonnyFL Emperor but also have the Ronin moderator. For me, again subjective, the Emperor is more quiet than the Ronin. Both will add additional weight as well as cause POI changes when installed.
Have fun and enjoy your rifle once you receive it. Some have had success with slugs, I was not one of those folks and is why I am just waiting until FX finally releases one but it is going on over a year and the standard answer is always soon…
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I'm a hunter also so this is great info! 20-100 yards would be my range hunting hogs at night with a thermal scope. I am using a Ravin crossbow, but it takes too long to reload. Im looking forward being able to the some lead on them.
Why two barrels in .35? What's the difference in performance?
As you can imagine I'm pretty pumped.
I just talked to a Adam, Airgun Depot who said the same thing you just did about slugs. The FX M3 .35 is built for pellets only until they get a slug barrel built and tested. Not saying people can't or shouldn't shoot slug in the FX .35, just saying there are better days ahead.
Thank you to all who post! Keep your settings and comments coming!
Why two barrels in .35? What's the difference in performance?
As you can imagine I'm pretty pumped.
I just talked to a Adam, Airgun Depot who said the same thing you just did about slugs. The FX M3 .35 is built for pellets only until they get a slug barrel built and tested. Not saying people can't or shouldn't shoot slug in the FX .35, just saying there are better days ahead.
Thank you to all who post! Keep your settings and comments coming!
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Two barrel configurations was based on type of hunting. If spot and stock I would prefer the 600mm just due to size and walking with a shorter barrel. If I’m in a blind then the 800mm all day and night. There is a power difference as well due to the 800mm having more runway so the pellets travel faster and need less air to move them.
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Heh, well that didn't last long. I did another iteration of tuning. Ended up at first reg 150, second reg 130, valve two turns from 4th line (measures 12.8mm) and I bumped the thumbwheel micro setting up to 3.5 with macro on 8. This gives me a better top end at 870fps. It also gives a wider useful range on the macro wheel starting low 700s at 1 and incremental increases to 870fps at 16.
So that's it till I can put this tune on paper. Way too windy today.
So that's it till I can put this tune on paper. Way too windy today.
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