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

[heavy-impact]

Yeah, another reason why I like the nsa slug probe. It has a heavy hex bolt behind the probe.

But it's all hanging on that little weak rod. The probe, the block and the heavy hex bolt behind it will exit to the rear once the rod fails. Take a good look at that rod and it's attachment. At that power level it's not a matter of if but when. A chain is only as strong as it's weakest link.

 

[7Green]

The one screw and small pin that holds the probe is my biggest worry on that rod assembly. More specifically, the screw loosening or shearing off. The actual rod isn't my concern. The probe also only enters about a 1/4 of an inch of the chamber too.

 

[7Green]

Admittedly, if the connection points could be welded or one solid piece, it would be a stronger, better design.

The sealing point, as in the oring only contacts the very front of the nsa probe slightly too. You can see my grease line here.

 

[7Green]

I wonder what the actual sheer strength the 3mm rod is, since the force is linear. I also wonder what it is made out of...titanium, steel, aluminum etc....

We are also not dealing with firearm pressures, considerably lower. 60k psi vs less than 3k psi after the regulators. 180 bar is 2600 psi roughly. You also need to account for the loss of pressure, or more appropriately, the division of pressure, as it is easier for the pressure to force the round out than in reverse and force the probe out.

Most probably aren't aware of this, but with a semi-auto handgun, you can physically hold the slide closed to keep it in battery and fire one round. The small amount of back pressure used to normally cycle the action won't hurt you and you will barely notice it because it is easier for the pressure to exit the path of the bullet than the action. However, you will have to cycle the slide to shoot again.

I am not saying the design can not be better. We all know it can. I just think there is a little too much worry there. Just my opinion, and we all know what opinion are like...lol
I do partially agree though and I hope FX starts to address some of our concerns.

Personally I am very interested in the Western Rattler .357. 15 shots at 270 fpe, along with the ability to shoot heavy slugs sounds sweet. Semi-auto is an added bonus. I am just waiting a couple generations to see what issues there are; i.e. : if they resolve them (warranty issues), how accurate they are, and if the business succeeds.

 

[7Green]

I would also be curious if anyone has heard of or experienced rod failure with there guns.

If so, please post up.

 

[7Green]

Well this morning, I went ahead and put new o-rings in the first reg and restacked the bellville washers. I then set it at around 190 bar and reset my huma reg to about 165 bar. I'll need to mess with the macro dial to see where accuracy and speed start to like eachother. From what I have read, some where between my old 860's and 890 fps is a common sweet spot.

I have also wondered/contemplated trying to build a carbon fiber tensioner and shroud. The barrel diameter is close to 14mm and it appears 14mm id x 20mm od can be purchased for rather cheap. Part of me wonders if the barrel whip plays more of an issue with accuracy as the speeds increase.

If anyone has any experience or designs in the let me know as this is new to me. I do like the look the carbon fiber has on others guns I have seen online.

 

[7Green]

Update.

It appears with the huma power spring the hammer weight needs to be no more than 28mm long to allow for full compression of the spring. A 3.5mm head will land you on the number 5 of the microdial. Below is a picture with a 3mm head x 28mm length. Total assembly weight is 32.2 grams or about a gram less than before, but with more adjustment of the gun.

 

[drumie]

If you want to get rid of the teflon tape around the barrel, get this tape https://www.amazon.com/gp/product/B00XH9Y7FU/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1.
It is very thin and works to wrap the 357 barrel and give it a snug fit in the tube. I tried scotch tape and it was too thick. This stuff is .002 thick.

 

[7Green]

Good to know. I was ironically trying to take my shroud and liner apart today too. However, the dang thing seems to have permanently attach itself to the liner. I need a vice to get it apart, so for now I left it be. I am curious if the bc shroud/barrel tensioner sleeve will fit over a 12 x 14mm carbon tube. If so, I will replace the factory metal liner with that and tap epoxy the transfer port in it and tap the opposing end for the shroud attachment.

 

[Removed]

Just so everyone is aware, Huma claims their hammer spring is about 10% stronger than the factory spring.

Huma claims lots of things that simply aren't true.

 

[7Green]

Well with it, a custom tungsten hammer weight (assembly weight of 33 grams approx...), and huma extra high pressure 2nd reg, I gained 110 plus fps over my original setup. My original setup was a custom brass hammer/tungsten insert assembly (30.5 gram approx.), with factory tranfer port, and factory spring.

 

[7Green]

I previously launched 93nsa slugs at 860 to 865 fps and now can launch to nearly 970 fps and possibly more. I say possibly more because I stopped at 180 bar on the 2nd reg last time I checked. I am waiting for my k&l 1st reg delete bottle adapter to show up before I will know more.

 

[7Green]

Also, the huma spring is 56mm long vs the 52mm one the factory provides. I haven't measured the valve adjuster spring huma provides, but it is easier to compress than the factory one.

 

[drumie]

The Huma Barrel stiffener kit for the 357 works great at removing the flex from the barrel. https://www.huma-air.com/Extended-S...r-And-Tensioner-Kit-For-FX-Impact-by-Huma-Air
I got 2 of them for my Impacts. Only issue is they don't take the flex out of the space between the barrel and the sleeve.

​

 

[7Green]

Cfs916 helped me out with one, but I have to get my dang shroud off to get the tensioner to work. It siezed itself to the liner somehow.

 

[7Green]

He also makes custom tungsten hammer weights that he sells on ebay, so no need to wait for fx on something so simple to get. A 3.5mm head by 28mm length will yield adjustability number 5 on the micro dial when used with huma's 56 mm spring. A 3mm head x 28mm length will provide about 5.25 adjustability on the micro dial.

Here is the tensioner and a delrin spacer by the shroud.

 

[drumie]

I made that spacer with carbon fiber tube. It helped a little but no were near as much as what the Huma kit does.

 

[7Green]

Oh ok.

 

[drumie]

With just the carbon spacer, you could tell it helped, but if you pushed on the end of the barrel you could move it maybe a 1/2 inch or so. With the Huma one you can barely move it at all.

 

[7Green]

If only if someone would make a set of c clamps, like how scope rings attach, to attach the block to the tensioner and the shroud to the tensioner. This would hold whatever tension the gun is set at too. The barrel lock with the clamp is similar to the idea, but is only on one side and doesn't lock the shroud down to the tensioner.