FX Impact M3 .357, in the search for more umph

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To each their own. Mine shot great with pellets out of the box, but I never wanted it for pellets. I want a hard and accurate hitting slug launcher. I nearly got it there, but I wanted a little more.

I also try to live more by the perspective of I only live once and pay myself first. I don't treat money like it is everything and if I need more for what I want, well, I will just work more and harder. With my profession, I observe people pass away quite often. We never know when our time will come. Could be in some horrific accident or old age with dementia. Might as well enjoy when and if you can.

Separately, with any luck from our current political climate money won't be worth jack anyhow. They just live by the "print more" and "free handouts from the middle class pool of working Americans," but that is another topic.
 
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Definitely understand wanting to make your rifle specifically for what you need. I understand death very well and am grateful to still be here myself. Medically retired military and then went through multiple rounds of chemotherapy treatments so I am more than thankful to be here.
Although money isn’t the reason for complaining, it is better than just throwing it at every new trinket that the fx team presents.
Point being, not being able to get items necessary for our rifles to do what we were told they could do. Thus, either getting new barrels made or waiting for whatever else is needed to get the rifle’s to do what they are supposed to do shouldn’t be the case.
The .35 is the last rifle, for me, which I will spend extra for. Again, like you said, to each is their own. Wish you the best in trying to get the .35 to be what you want it to be. The Rattler is looking like it may be what I am looking for for the power levels it can produce out the box. I’m still going to wait a bit to see how they hold up over time.
 
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Well this evening I decided to disassemble the entire gun and replace all the orings on the valve rod and forward of the plenum. I also swapped in the factory. Valve adjuster spring to test it out. My thought is the valve closing faster could be a good thing, at least when it comes to dwell time and not wasting air. As a plus it may help with hammer bounce too. With a couple dry fires, it looks like the gun can still drop some serious bars with the change. In essence the same as before, which was upwards of 10 bar a shot if wanted. I set it close to 6 to 7 bar a shot with the valve adjuster, which should be somewhere around 900 to 930 fps at 170 bar if yesterdays testing results match up.

I also recieved some slugs from horseshoe mountain casting. 94 grain .357's. Measuring them, they seem to be more like NSA .356's in diameter. Other than that, they appear to be nice slugs and I can't wait to see if my gun likes them.
 
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I finally found the leak!

It took my hard headedness to finally just submerge the gun in the bathtub. Over the past couple of weeks this leak has driven me nuts literally. I have rebuilt the gun including regs more than once. Turns out one of my Sekhmet guages was bleeding air out of one of the connector pins on the display side.

I emailed Sekhmet to see what the resolve will be. In the mean time the old wika gauge is back on the gun.

I may just delete the first reg gauge too since I no longer have it. However, I will need to figure out what type of plug could seal the port.
 
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7Green said:
I finally found the leak!

It took my hard headedness to finally just submerge the gun in the bathtub. Over the past couple of weeks this leak has driven me nuts literally. I have rebuilt the gun including regs more than once. Turns out one of my Sekhmet guages was bleeding air out of one of the connector pins on the display side.

I emailed Sekhmet to see what the resolve will be. In the mean time the old wika gauge is back on the gun.

I may just delete the first reg gauge too since I no longer have it. However, I will need to figure out what type of plug could seal the port.
Click to expand...
It would be a dog tipped grub screw like what’s used to lock your valve down on the rear block, but in 1/8” bsp threads
 
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So today, I finally got my M3 back together after breaking my barrel liner lock a couple weeks ago. I did it when I installed Huma's barrel tensioner system.

The tensioner system definately stiffened the barrel system up some. What I really like is how the rail slides on and lines up the back bone of the rifle.

One thing I didn't like, but was an easy fix, was the carbon fiber sleeve that slides over the barrel liner can be rotated once the barrel was tensioned. I blame this and myself for why I broke my liner lock. To fix it, I put a delrin spacer and an oring in the barrel tensioning piece huma provides with the setup. Now the barrel is tensioned and the sleeve does not rotate.

Another way to solve this would be to epoxy it directly to the barrel, but if you ever wanted to index it with the barrel it would become permanent. I thought about doing this, but haven't made up my mind.

I also changed out the valve adjuster spring for the FX one, instead of the super light Huma version. I left the Huma hammer spring in.

At 185 bar with .357 93 grain NSA's, and a tensioned barrel I am seeing half to 3/4" groups at 50 yards and 912 fps. The valve adjuster is on line 4. Previously and with Huma's lighter spring, I would by in the 960's at this reg pressure, but accuracy would suffer and shot count was aweful. Guessing and estimating, I am around 9 to 12 shots at full fill of 250 bar right now.

I have not messed with more tension, indexing, or anything else. Just installed and shot.

I found a pretty nice scope level on Amazon too. Quick easy install and mounts to the picitanny rail. Appears to be made from Aluminum.

I still have more messing around to do. Part of me wonders if with the Huma spring I could use this bar setting or lower to get more shots and accuracy by simply screwing in the valve adjuster more. I know I can see 920 to 930 fps with it at 160 to 165 bar from prior testing. Some where in there is effiency and accuracy, it just takes a lot of trial and error.

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This morning I changed out the FX valve adjuster spring with the Huma spring once again and changed the reg pressure to 160 bar. I then went out and shot it. I noticed a big velocity drop, around 865fps vs the old 930 fps range. I also noticed I felt air by my cheek. Doh! I must have blown the 2.2 x 1 buna 70 oring.

When I got home, I confirmed my suspicions. Half the oring was literally gone.

What I have learned with the Huma valve adjuster spring is that it is so light that if you don't have the valve adjuster screwed in enough and fire the gun, there is a chance the valve may open too far and slice the oring on the exterior of the channel it rides inside as it re-enters the channel. At least that is my theory as I have done it twice now.

After 20 min or so, I fixed the issue and no more blow by. Further, and if my memory serves me right, when the valve adjuster is on line 4 with the Huma spring, max velocity is acheived. Unlike the FX version where I could back out the valve adjuster 2 to 3 turns past line 4.

Either way it is fun to tinker and expensive and frusterating at times. I guess that is why the call it a hobby. Just don't tell the wife how much I have in the gun and my other toys...;)
 
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This afternoon I shot the gun once again. I was only able to get to 925 fps with the 93 nsa at 190 bar. Previously I hit 975 fps at these settings. I scratched my head on this one and thought maybe I imagined it before lol. 160 bar should have yielded 920 to 930 fps like before.

When I got home, I went through the entire gun checking orings and taking measurements. The only contributing factor I can see is the Huma power spring. New it measured 56mm and it now measures 54mm. Stock hammer spring is 52mm.

52mm yielded 860's, 54mm yielded 920's, and 56mm yielded 970's. My hunch is the loss of spring power is causing the velocity loss. Maybe the Huma spring doesn't like full compression.

Looks like I may order another to confirm my suspicions.
 
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I replaced the orings as suggested and no change. The only two things I can recall changing recently is the addition of the K&L reg delete and the Huma barrel tensioning system.

Two things I am wondering are:

The Huma power spring measures 54mm instead of the original 56mm.

&

Does the slower refill time of the 1st reg contribute to a longer valve open dwell time vs. when it is deleted.
 
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Pellets are super easy to tune in. 135 bar to 145 bar is all you should need on the 2nd reg. Aim for pellet speeds of 840 to 890 fps. Accuracy usually falls some where in that range. Most claim around 850 to 860 fps. Your 1st reg at 150 to 160 should be fine. You can fine tune your speeds with the macro wheel, micro dial, and valve adjuster. If your gun came with the power block, you may be able to run an even lower 2nd reg setting to get the desired speeds.
 
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Tuning - FX Impact M3 35 cal power destiny

A little history from my personal experiences thus far. Currently I have fired well over a 1200 rounds between 81 grain JSB's and 93 grain NSA's in the .357. When I first started, the gun came from the factory firing JSB's at around 880 fps and the NSA' were 790 to 800 fps. I began playing...
www.airgunnation.com www.airgunnation.com

Lots of good info in my previous post too. Have a look if you are curious about anything.
 
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7Green said:
Pellets are super easy to tune in. 135 bar to 145 bar is all you should need on the 2nd reg. Aim for pellet speeds of 840 to 890 fps. Accuracy usually falls some where in that range. Most claim around 850 to 860 fps. Your 1st reg at 150 to 160 should be fine. You can fine tune your speeds with the macro wheel, micro dial, and valve adjuster. If your gun came with the power block, you may be able to run an even lower 2nd reg setting to get the desired speeds.
Click to expand...
It’s the power block model, accuracy just hasn’t been too good. The scope rail and backbone were loose when I got it. I cleaned the barrel and have about 250 shots through it. I have never had this much of an issue setting a gun up.
 
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I would double check all screws on the frame of the gun to make sure they are tight. Do NOT use locktite when tightening. There is NO need for it and you could strip the aluminum holes if you do.

Being it is a power block model, you may be able to get away with slightly less pressure on the 2nd reg. The idea is to tune it for efficiency so you don't waste air. I don't see a reason to mess with the 1st reg as you are just shooting pellets.

What type of scope did you put on it? Some lower tier scopes can have issues and may cause you to think it is the gun. I also always torque scope ring bolts per manufacturer specs and use blue locktite. The clamp to the rail I do not use locktite on, but torque to specs.

I had good luck with JSB and FX pellets which I believe are just rebranded JSB's. My barrel is an 800mm barrel.

It may take sone pellets to lead up the barrel and settle it down too. Mine shot well out of the box though. Are you using a chrony to tune it or just shooting it?
 
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