Pneuma...think I settled on my settings.

[Ribbonstone]

Even thought this gun will do what you want...Pneuma...and on sale for $260 (AOA) to $299 (PA)..am NOT going to recommend it in .177.   


(BTW: bought this one used/cheaper)

Being ugly is just a bonus.

Do think its a wonderful inexpensive buy in .22 or .25, but just too powerful in .177 with too short a shot count.  Been working on it for weeks, strangling off the gas flow, in order to get the shot count up and the velocity down.

Had to spend a good bit of time and effort closing off valve ports (it has 6 ports around the valve) and making smaller transfer ports to the barrel.  Had to make a tool in order to adjust spring tension.  There is no stroke adjustment.  Barrel is threaded for a standard size add-on LDC (even though I went with a ˝ shroud...there are threads under there).  BUT, understand...one of the reasons I bought this gun was because I LIKE doing those things (shop time is like therapy for me).

Just dialing down the spring tension does make PCPs shoot slower...but it also makes them shoot at lower pressure, and the shot count is still sucky. Really need other adjustmnets to balance the gun out to run at high pressure, at a selected speed, with a good shot count.

 To get to 60 good shots (under 20fps variation), ended up at 13.5 foot pounds. I could fiddle around with making another couple of transfer ports, maybe tweek the striker tension a bit, and perhaps do a few other things to get the energy up at the cost of some shot count. Those things an Mrod owner could to by turning a few screws... I'd spend hours at a lathe making the parts to do the same thing.

Short range:


Longer range:


60 shot “sweet spot” on a breezy day (today):

[ralphtonka]

I'm new here, easy adjustment of hammer spring.

much more consistant velocity


Darren

[Ribbonstone]

From what i understand, the easier adjustment is only on the repeater version...although they do adjust the same things.  Single shot just needs a long allen key.

[rsterne]

The hole in the tube that lines up with the hole in the hammer is in a different position on the single shot and the repeater.... One needs to be cocked to adjust, the other not.... One needs a longer allen key.... I think the pump action is different again.... All the guns, however, adjust in the same way.... you unscrew the adjuster (ie CCW) to compress the hammer spring and increase the power.... The gun I worked on (side lever / bolt action repeater) was locktitied and very difficult to break loose.... Once loose, it would not hold adjustment and required disassembly and loctite to hold again....

Bob

[Stefan]

Darren, i like the solution on picture 3, closing the holes on air cylinder? can you describe how you did it? maybe some dimensions and material?

[rsterne]

He used JB Weld.... I drilled and tapped the one I did for 6-32 SHSSs.... His is prettier!!!

Bob

[Ribbonstone]

Found mine to be kind of in between sized.  Without drilling, are a little large for a 4-40 tap/screw (but will cut shallow threads) and a tiny bit tight for 5-40 tap/screws (will cut full depth threads, but be casreful not to snap a tap).  Could drill and tap them to 6-32/

Went ahead and just tapped the existing holes 4-40, made set screws (cutting off 4-40 screws ans slotting the head),  In my case, the air tube lined up with the transfer port between two ports..so left them both open (but both tapped in case I want to plug one).  Covered the 4 tapped/pluged holes with expoxy putty to keep the air from running around the recess before finding the transfer port to the barrel.

[ralphtonka]

Hi Guys,

Bob is right, epoxy!
I took a drill bit close to valve id, a couple wraps of painters tape (to size), stuffed into valve inlet then took two part epoxy putty, filled holes and groove, let set up, cleaned up excess, has stood up to 3000+ shots, made a rva
http://s678.photobucket.com/albums/vv142/ralphtonka/?action=view&current=IMG00372-20110822-2030.jpg
requires tapping trigger assembly,
http://s678.photobucket.com/albums/vv142/ralphtonka/?action=view&current=IMG00369-20110822-2020.jpg
a little at44 pump pup, stock almost ready for final coat, electricaly fired, runs on 2 "aa" batteries and uses a spyder paintball solenoid. 26 1/2" long to stay "legal"

[rsterne]

In my case, the air tube lined up with the transfer port between two ports

The brass block that the air reservoir screws into is located in the outer tube with a screw on the bottom.... If you slack off the screw slightly, you will find that it isn't very tight in the hole, so the block can slide fore and aft slightly.... Since the shoulder on the valve on the air reservoir tightens against the end of the air tube, if you slide the block back and forth, you will change the relationship between the threads and the end of the tube.... You don't need to move it very far to change the rotation by 1/12th of a turn so that one of the holes lines up perfectly straight up in line with the transfer port.... The one I had only required about 1/24th of a turn to line up, and the transfer port was still so close to the center of the hole in the top of the tube you couldn't tell.... Retighten the screw in the block and it will stay in place providing you don't REEF on the air tube but just tighten it finger tight....

Bob

[Ribbonstone]

Thanks...hadn't considered that. 
Will look into that next time I have the urge to fiddle with it...not displeased with the shot count or the energy right now...but know I'll get to wondering "what if" sooner or later.

[slow]

Ralph,

that's one cool mod right there!
Well done.

[ralphtonka]

Thanks slow,

It originaly was gonna sit behind the seat of the work truck as a grouser. I got to figurin it would be nice if it were a little more compact.

Darren