Tuning FX Impact Mk2/M3 - slower first shot - no reg creep - quasi-scientific analysis

[PcpMachinist]

PcpMachinist=Accu-Shot orings.
So I wonder whether it is appropriate for him to post in the user section to put his o-rings in a positive light.

A lot of interesting information was shared here about the problem, the custom part from Mubhaur, the official updated part by FX, and the positive experiences people have with it.

It must be said that PcpMachinist/Accu-shot has a very interesting video about pellet or slug seating, but when it comes to selling the plenum o-rings, this video, by someone who knows what he's talking about, shows it in all honesty:

sorry bud your wrong no affiliation with accu shot o rings nice assumption
like judging people eh,, another one someone who knows what there talking about lol Karen....
guys were right about this site don't bother mods were all set with this site good luck Karens...

example :: I agree I have found a lot of trolls on AGN lately seems everyone has a problem with venders or other members. I try and be friends with everyone because I love AGN and most members are great help and friendly guys!! but I find am getting fed up with the trash talking and a lot of new Karin's on hear now.

 

[CrashKT]

sorry bud your wrong no affiliation with accu shot o rings nice assumption
like judging people eh,, another one someone who knows what there talking about lol Karen....
guys were right about this site don't bother mods were all set with this site good luck Karens...

example :: I agree I have found a lot of trolls on AGN lately seems everyone has a problem with venders or other members. I try and be friends with everyone because I love AGN and most members are great help and friendly guys!! but I find am getting fed up with the trash talking and a lot of new Karin's on hear now.

@Michael I think this guy needs a break.

 

[av8torgc]

Yesterday, I installed the new plenum end piece without the plastic bushing, but with the supporting o-ring (5.5x1.5 NBR70) so that the new o-ring (2.9x1.78 PUR90) stays in place during installation.

Today, I checked and saw that everything had remained under pressure whitout a leak, so I decided to test it.
The first shot was 3 fps slower than the last one yesterday.

Yesterday, after reassembling it, I didn't adjust it very precise and there was a 10 fps spread, so I can't even say if it still had an effect after 24 hours.

It now really seems that drilling the conical seat flat was the solution.
Why it took so long or why they had to drill it out so far is something I'll never know.

It's also clear that the bushing only serves to keep the o-ring more or less in place during assembly.
Anyway, fortunately, it works just as well without the bushing and with the supporting o-ring.

Apollo,

I ordered one of the new plenum end pieces (it is still in shipping), and was wondering if you had any tips on removing that plastic bushing (to make the replacement of the O-ring easier when/if it ever needs to be replaced). Thanks!

 

[Vetmx]

We solved this almost three years ago. Some of us have been living happily ever after. Why is it still being debated and why are guys getting angry. We are not defending our wives here. It’s just a toy.

If the Mubhaur part, peek disc, new plenum from FX or any other concoction that lets the oring rest on a flat surface is not working for you, it’s your tune. But don’t confuse that with you have a bad tune. If where you have your hammer and valve set yields excellent and consistent results but you still have a slow shot or a few, I’d say just live with it. You might never find what you have again when you use more aggressive settings to overcome some slight stiction that always exists under extreme pressures.

 

[Apollo]

Apollo,

I ordered one of the new plenum end pieces (it is still in shipping), and was wondering if you had any tips on removing that plastic bushing (to make the replacement of the O-ring easier when/if it ever needs to be replaced). Thanks!

I hope FX supplies the part without the bushing and o-ring pre-installed so that you can recover and reuse the supporting o-ring.
If it is pre-installed, I would leave it as it is and only remove the bushing when you want to replace the o-ring.

The bushing is 6 mm high, of which 4 mm has a diameter of 7.9 mm and 2 mm has a diameter of 8.10 mm.
Since it only fits on a 2 mm ring, I hope that it will still be fairly easy to remove.

You could also use the bushing instead of the supporting o-ring, but then I would sand it down a little to reduce the diameter.
After all, it should not be too tight or very secure; just enough to more or less hold the o-ring in place is sufficient.