Metadyne Thumper/Phoenix Redux

[Timefreak17]

Update: phoenix

So on a observation between my thumper and phoenix, I thought the barrel to breech was too tight for the spring to seat the barrel properly. Leaving a gap that air escapes behind the ball, and forces the barrel forward. The thumper has an oring seal that works very well for this. So took a little sand paper to the back of the barrel ball catch, and a little to the edge of the breech that the barrel ball catch slides over.

After some tweaking I found the phoenix was shooting 384, with the barrel being held in place. And 220 just letting the barrel go do it's thing.

So more adjustment on the velocity adjustment screw, I was getting 280's withe the barrel held back into the breech.

And getting anywhere from 240 to 274 letting the barrel do it's thing.

I believe that a stiffer rear barrel spring will give a more consistent shot fps. This would hold the barrel into the breech with more pressure. Thus allowing more air down the barrel before the barrel gets pushed forward enough to let air escape via the rear breech and nut area.

Also I trimmed the detents to points that worked well still.

Can not tell you break to shot ratio as I was using re-usable rounds.

My next move is stronger spring in the rear.

Thank you for your time, hope this helps some.
Any questions or ideas post I'm up.

[XEMON]

I made a custom gasket for mine, I need to do more testing and will eventually machine the breach to hold it in place.
A stiffer spring return will need a spring guide so it doesn't reflect to the side and get damaged.

[Timefreak17]

Custom gasket between the barrel slide and breech? I'm assuming attached to the breech non-moving side.
That is a pretty good move, to help the sealing issue... 🤔.

I haven't had a kink issue (lol) with my return spring yet, but I will heed your advice on a spring guide.

[XEMON]

Yes, the gasket on the fixed side so when the slide comes back is seats against it. I will need to machine a few things to make sure it has the proper clearance and stay in place.
I also bored the barrel holder/slider so the freak insert comes all the way back and the ball sits inside the control bore. It helps tremendously with breaks.

Making a spring guide is gonna be a bit more complicated than on a Sheridan for example, I want it fixed on the body and go all the way through the rear slide to support the spring the entire length. It all needs to be drilled perfectly aligned to not bind.

[capitalpaintball]

I know this is not going to go down well, Considering all the problems everyone has had but... i shot it today at stockclass and it performed great. No breaks, chrono'ed 275. Absolutely no issues.
I bought the phoenix on ebay this week. Its number 0035. It came from Idaho (same as metadyne) i took it apart and lubed it(it was dry inside) it seems the guns has had a few factory fixes, the feed is bored out so tubes fit fine, and the barrel looks re-cut.
there are definitely things i would have done differently if i was designing it.i was getting 18 shots to a 12gram,slightly worse then the Thumpers 20. And the feed could have been longer, like 12 balls. I miss the vert asa but a icd 12gram stock works great and you can hold the front of the frame and use the thumb paddles.

[RuleOfSines]

Did you take any pictures of it apart by chance? I’m interested to see what unannounced fixes they have put in place.

[capitalpaintball]

Not any from the piston and reg. Area. Is the detent block always raw?

[Timefreak17]

They really just killed the rear feed tube and left it un-anodized...ok. I feel that's a quick fix and a sharp edge for balls to hit while loading.

The detent block is a raw finish, but probably clear coat anodized.

[RuleOfSines]

I was wondering if there was enough metal on the feed to bore it out like that without making it too fragile.