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Tuning FX Impact M3 35 cal power destiny
- Thread starter 7Green
- Start date
Yes, I do not get the same accuracy with lighter slugs. I have tried .356's in both too. The speed is similar to the JSB pellets. If you scroll through the past 10 pages or so, you will read about everything I have done.
FX must have read this post because they now have a tungsten hammer weight, which is what I spoke about last year. I am glad they are making one finally. In my testing, I got peak velocities around 29.5 to 30.5 grains (total assembly weight). I also made a custom hammer with tungsten bedded in my hammer. I am still using this setup and am waiting for all the new parts to come out before I push for more power. With my custom hammer, I can use the full adjustment, up to #5 on the micro dial too.
FX must have read this post because they now have a tungsten hammer weight, which is what I spoke about last year. I am glad they are making one finally. In my testing, I got peak velocities around 29.5 to 30.5 grains (total assembly weight). I also made a custom hammer with tungsten bedded in my hammer. I am still using this setup and am waiting for all the new parts to come out before I push for more power. With my custom hammer, I can use the full adjustment, up to #5 on the micro dial too.
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On my new M3 Impact .35 I've reached 960 fps with 81 grs FX pellets, thats with the Huma .35 v2 slug power kit, at 190 bar and the hammer spring maxed out
I've ordered plenum and port kit from Vlad and looking forward to push 93 grs NSA at +1000 fps
Vlad pressure test his plenums with 450 bar
I've ordered plenum and port kit from Vlad and looking forward to push 93 grs NSA at +1000 fps
Vlad pressure test his plenums with 450 bar
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I am running the stock 800mm barrel.
960 with pellets is awesome. It tells me I have something positive to look forward to, as I am 20 to 25 fps slower with pellets.
I also have the Huma power kit and 2nd stage reg. I just haven't installed the power kit yet. If the new tensioned slug barrels shows up soon, I would rather install the transfer port piece on that. Currently my gun is so accurate that I have been lazy about tearing it apart again.
960 with pellets is awesome. It tells me I have something positive to look forward to, as I am 20 to 25 fps slower with pellets.
I also have the Huma power kit and 2nd stage reg. I just haven't installed the power kit yet. If the new tensioned slug barrels shows up soon, I would rather install the transfer port piece on that. Currently my gun is so accurate that I have been lazy about tearing it apart again.
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Hey guys,
Is it too late to join this .357 crew of tinkerers? I went through the thread and luckily my conversion from the factory had all the right parts. I might be able to help a bit- I have a spring rate gauge here at home that I used for all my airguns. I haven't tested/document the FX springs yet, but it's definitely helpful to understand the rate differences vs results. Also, I just got my powerblock and huma high flow transfer port & waiting for the tungsten hammer. Admitedly i've already started modifying the powerblock to get some better flow for the .357. The block's transfer port needs to be enlarged a bit for the 357, and I think I can build an adapter for a safe external plenum using a 9ci (145cc) tippman tank. It helps I have a lathe and mill here at home. Let me snap some pictures/ take some measurements and see if I can contribute some. I'm a bit dissappointed there isnt as much in-depth teardown and specs as other airguns, but we'll get there. The more we know the better.
Is it too late to join this .357 crew of tinkerers? I went through the thread and luckily my conversion from the factory had all the right parts. I might be able to help a bit- I have a spring rate gauge here at home that I used for all my airguns. I haven't tested/document the FX springs yet, but it's definitely helpful to understand the rate differences vs results. Also, I just got my powerblock and huma high flow transfer port & waiting for the tungsten hammer. Admitedly i've already started modifying the powerblock to get some better flow for the .357. The block's transfer port needs to be enlarged a bit for the 357, and I think I can build an adapter for a safe external plenum using a 9ci (145cc) tippman tank. It helps I have a lathe and mill here at home. Let me snap some pictures/ take some measurements and see if I can contribute some. I'm a bit dissappointed there isnt as much in-depth teardown and specs as other airguns, but we'll get there. The more we know the better.
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Not at all too late, better late than never 
My plan is to get around 1000 fps with 93 grs NSA with good accuracy
This is for racoon dug hunt, and the requirements in DK is 175 joule at 100m (129 fpe at 109 yd)
My plan is to get around 1000 fps with 93 grs NSA with good accuracy
This is for racoon dug hunt, and the requirements in DK is 175 joule at 100m (129 fpe at 109 yd)
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Hey sorry, got caught up with other projects.
Yes- I opened up the powerblock transfer port to something that should flow much better with the Huma V2 transfer port. I haven't put my M3 back together because I was highly dissappointed with the teflon tape factory solution to making the barrel housing fit the liner. No wonder this thing is floppy. I picked up a 12x15mm CF tube that im going to tap for the transfer port (IIRC its m12x1.0 thread) and JB weld (epoxy) the CF tube straight to the liner. How I plan to assemble it, the entire thing will end up as a solid unit and I wont be able to remove the transfer port. Not completely horrible, as i don't intend on using FX liners beyond this one. I took some pictures of the powerblock when i bored it out, and can snap some pictures of the CF tube, paintball tanks, and other parts. Let me find those and I'll post them up.
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FX Impact M3 .357, in the search for more umph
https://www.airgunnation.com/threads/fx-impact-m3-35-cal-power-destiny.1071873/ Many of you recall my mission last summer. Well the mission continues. I left off shooting NSA 93 grain slugs in a very accurate 860 to 865fps range out of the standard superior stx barrel. I have taken small...
www.airgunnation.com Before you do it, check out my new thread. I did some mods and got near 200fpe out of the gun. Just in case you were looking for more.
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Does the 12 x 15mm fit through the blocks on the gun? The tube over the liner is just under 14mm.
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Very nice! This gives me hope. I have the Huma HP reg in there too, but when i was around 170bar it blew an o-ring which started all this for me.
To answer your question regarding the CF tube- No. The bore on the blocks is slightly over 14mm, with the o-rings filling the gap. I'm going to bore my blocks to 15mm, which was as big as i felt I could safely make them without making the blocks too weak.
Attached are pictures i took of the M3 block as I was cutting it up. I lost my sheet with exact dimensions of the powerblock transfer port before i drilled it out, but i want to say it was around .28". I used the biggest drill i had that wouldnt touch the locknut theads which was about .321", IIRC. As you can see, i didnt polish the bore yet in these pictures.
Power block on left- notice the bigger lock nut size so you have the ability to drill that transfer port slightly bigger.
Bored powerblock on left
Stock Block
Bored powerblock
Stock M3 transfer port on stock block
Stock M3 transfer port on powerblock below. Yes, it may not look like much of a difference- I thought that too. If the original powerblock bore was .28" and new bore is .321", it's only .02" bigger on each side. However...
Surface area of .28" is 0.062 sqin
Surface area of .321" is 0.081 sqin
You gain 0.19 sqin of surface area, which is 30.6% more area for flow.
Huma V2 on bored power block (I need to mill the locating pin slot slightly so i can shift it backwards a hair, as you start to see the edge of the O-ring. I'll test it first to see if it holds before bothering with it.
Huma V2 view on the bored powerblock from the barrel side. Now you can see the restriction is the transfer port itself. Should flow a lot nicer.
And just my quick setup to bore it on my smaller mill
To answer your question regarding the CF tube- No. The bore on the blocks is slightly over 14mm, with the o-rings filling the gap. I'm going to bore my blocks to 15mm, which was as big as i felt I could safely make them without making the blocks too weak.
Attached are pictures i took of the M3 block as I was cutting it up. I lost my sheet with exact dimensions of the powerblock transfer port before i drilled it out, but i want to say it was around .28". I used the biggest drill i had that wouldnt touch the locknut theads which was about .321", IIRC. As you can see, i didnt polish the bore yet in these pictures.
Power block on left- notice the bigger lock nut size so you have the ability to drill that transfer port slightly bigger.
Bored powerblock on left
Stock Block
Bored powerblock
Stock M3 transfer port on stock block
Stock M3 transfer port on powerblock below. Yes, it may not look like much of a difference- I thought that too. If the original powerblock bore was .28" and new bore is .321", it's only .02" bigger on each side. However...
Surface area of .28" is 0.062 sqin
Surface area of .321" is 0.081 sqin
You gain 0.19 sqin of surface area, which is 30.6% more area for flow.
Huma V2 on bored power block (I need to mill the locating pin slot slightly so i can shift it backwards a hair, as you start to see the edge of the O-ring. I'll test it first to see if it holds before bothering with it.
Huma V2 view on the bored powerblock from the barrel side. Now you can see the restriction is the transfer port itself. Should flow a lot nicer.
And just my quick setup to bore it on my smaller mill
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Have you done anything to handle the restriction on the new piece that connect the plenum to the block? Reason I ask is I don't know how big that opening could go without messing with the sealing by the valve rod.
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I'm not sure what you're saying (I'm looking at my plenum/valve/block now. Are you saying the Valve body itself? The opening after the valve that feeds into the transfer port can also be opened and blended a little, but I havent measured it yet. The next thing i want to measure/ stick my borescope into is the two valve bodies and measure the valve seat itself. With the 357, i would argue thats the biggest restriction we have.
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Yes, I was trying to think of the name for it off hand. The hole in that piece is the last restriction point on the whole assembly. I'll be interested to see your results. I would imagine it will take less pressure to reach similar velocities with the same mods I did.
I wish I had a lathe because I would get a lothar barrel and mill it down to fit through the blocks. Plus it could be milled to fit or be the transfer port. Maybe some day haha
I wish I had a lathe because I would get a lothar barrel and mill it down to fit through the blocks. Plus it could be milled to fit or be the transfer port. Maybe some day haha
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Here's the CF sleeve I have. 12x15mm but ill have to bore the blocks slightly.
The sleeve itself will be tapped with the m13x0.5 so it threads right onto the transfer port
Its a close, but loose enough fit on the liner that i'll coat the liner with JB weld epoxy, slide the liner on, and thread it onto the transfer port. to make sure its centered perfectly, you taper the muzzle end of the CF tube, and use a thin o-ring to shove in the end to space it equally. To get the 1/2"-20 thread on the muzzle end, I'll machine a piece out of steel on the lathe, that will press-fit directly to the end of the liner. Ultimately I have another 30mm CF tube to use as a shroud that will work to both stiffen the barrel itself and be part of an over-barrel moderator. To help wtih the stiffening there needs to be a few "supports" throughout the shroud to touch the cf/liner combo and hold it steady.
Oops, i just saw your reply- I have a LW barrel to do exactly what you said, but i wanted to try this version first. Unfortuantely LW told me they would only do an 800mm length if i bought at least 10. All they sell is 700mm in the .357, and 600mm in the .25 (my favorite all around caliber)
Heres an example of the .357 liner, my .25 marauder, and a .25 LW. Visually you can simply see how much stiffer the LW will be.
The sleeve itself will be tapped with the m13x0.5 so it threads right onto the transfer port
Its a close, but loose enough fit on the liner that i'll coat the liner with JB weld epoxy, slide the liner on, and thread it onto the transfer port. to make sure its centered perfectly, you taper the muzzle end of the CF tube, and use a thin o-ring to shove in the end to space it equally. To get the 1/2"-20 thread on the muzzle end, I'll machine a piece out of steel on the lathe, that will press-fit directly to the end of the liner. Ultimately I have another 30mm CF tube to use as a shroud that will work to both stiffen the barrel itself and be part of an over-barrel moderator. To help wtih the stiffening there needs to be a few "supports" throughout the shroud to touch the cf/liner combo and hold it steady.
Oops, i just saw your reply- I have a LW barrel to do exactly what you said, but i wanted to try this version first. Unfortuantely LW told me they would only do an 800mm length if i bought at least 10. All they sell is 700mm in the .357, and 600mm in the .25 (my favorite all around caliber)
Heres an example of the .357 liner, my .25 marauder, and a .25 LW. Visually you can simply see how much stiffer the LW will be.
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Agree, and some air relief holes in the spacers to transfer the air thoughout the shroud. Vented bushing basically
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