PP700 adventure started(Artemis PP700s-a)

[rumbleUU]

thanks Guys, thinking of it, Its better have it regulated anyway, better accuracy and probably more shots per fill...

I will order a 4.5mm pp700s-a, and make it a little carbine with that folding stock
I have 2 allready, this will be the 3:rd one , Yeah I know, why a 3:rd one, well I just love these little pistols, its so fun to take them apart and tune them, and Ive really never had any issuse with the stock regulators, The only thing that bothers me is you dont know what regpressure is at, but I think I know howto check that, even if it takes a few shots to see where it drops... but then again, it is good to shot like 100 shots threw these little pistols to get everything settled anyway... 

[denovich]

Any advice on setting valve spring tension? I had some debris in my valve that required disassembly to remove. I didn't think to take note of how far it was screwed in.

[Rallyshark]

Any advice on setting valve spring tension? I had some debris in my valve that required disassembly to remove. I didn't think to take note of how far it was screwed in.

Go ahead and screw it in pretty far.  That will help keep it sealed when the pressure is low.  The valve spring isn't that finicky about where it is set otherwise, so it is hard to "do it wrong".

[denovich]

Thank you... I was hoping that would be the answer. I currently have it screwed so that top of the valve nut is a little beyond flush with the top of the threaded portion. Valve stem can be pressed about a millimeter past flush with the valve body before it feels like it binds.

[denovich]

"dang" it, the bit of debris left a small dent in the white plastic seating surface of the valve core. The fettling continues.

[denovich]

I chucked the valve core in my drill press and used a small file to rework the seating surface. Problem solved.

[Wayne52]

I chucked the valve core in my drill press and used a small file to rework the seating surface. Problem solved.

A burnishing file REALLY works nice for something like that, just gotta keep the burnishing file as clean as possible to keep it working good, they give a super smooth surface.

[denovich]

I think I need to add a burnishing file to my bag of tricks.

I had a countersink that was approximately the same angle as the valve seat. After the spin on the drill press I used the countersink to make a hole in a piece of good mdf. I then applied a little diamond lapping paste to the hole and then spun the valve core with a drill while pushing it into the counter sunk hole. That left a pretty decent surface finish and a nice polish where the metal stem transitions to the acetyl. More importantly I felt it was unlikely to screw things up any more than they already were (I was getting a bit anxious by this point)

It worked, but not everyone has an array of diamond pastes, and I’m sure there are many easier, less convoluted options so I didn’t mention it. Sometimes it’s better to be lucky than good.

Side note: Diamond paste on MDF is an interesting technique for sharpening and polishing, especially for super hard materials.

[YEMX]

Uh, kind of an odd question to ask, but I'm having a hard time finding the answer:

Between a .177 and .22, is the part pictured below the same?  Is the Oring the same? 



Also, what's the thread spec for that piece pictured?   

[Pelletjunkie]

Any advice on setting valve spring tension? I had some debris in my valve that required disassembly to remove. I didn't think to take note of how far it was screwed in.

Set it 4mm deep.

[denovich]

I got a .22 from Canadian Shooting Supply last week. Only power mod so far (other than fixing the valve body after I got some debris in it) was drilling out the transfer port to 5/32. I didn't touch the hammer spring or the regulator.

I haven't had a chance to get stats on longer strings... I'm learning that my Chrony Beta is very picky about indoor lighting. But I did get a few dozen shots over it with a few different pellets. 

575fps with 18.5gr H&N Barracuda Hunter Extremes
520fps with 21.14gr H&N Barracuda Power Dome (copper plated)
630fps with some RWS Superpoints that must be 15years old (not sure of the weight)

Haven't shot it until it fell off the reg yet, but getting at least 30 shots, with what looks like good consistency shot to shot.

[Rallyshark]

Uh, kind of an odd question to ask, but I'm having a hard time finding the answer:

Between a .177 and .22, is the part pictured below the same?  Is the Oring the same? 



Also, what's the thread spec for that piece pictured?

I could be wrong, but I think they are the same.

[Pelletjunkie]

Uh, kind of an odd question to ask, but I'm having a hard time finding the answer:

Between a .177 and .22, is the part pictured below the same?  Is the Oring the same? 



Also, what's the thread spec for that piece pictured?

8mmX1.0

[Pelletjunkie]

It’s the same thread pitch on both ends of the barrel. I used 8mmX1.0 when I was building all the different length barrels for mine.

[YEMX]

Okay cool- Many thanks!!  I might not copy the thread- I may just make a slip on collar, and "glue" it in place with some loctite in the receiver.  I'm going to be doing a caliber conversion, and the barrel will be thicker than a PP700 barrel, and I don't want to reduce the OD of the entire barrel.  I'm not running a shroud. 

Here's a crazy thought, has anyone thought to (or has) increase the bore size through the receiver so the barrel can be thicker?  Or is there just not enough room?

[Pelletjunkie]

Okay cool- Many thanks!!  I might not copy the thread- I may just make a slip on collar, and "glue" it in place with some loctite in the receiver.  I'm going to be doing a caliber conversion, and the barrel will be thicker than a PP700 barrel, and I don't want to reduce the OD of the entire barrel.  I'm not running a shroud. 

Here's a crazy thought, has anyone thought to (or has) increase the bore size through the receiver so the barrel can be thicker?  Or is there just not enough room?

I have tried a few different approaches with barrels. Mainly out of laziness. Who wants to thread both ends of every barrel when you are building and testing a bunch of them. But just like firearms, its hard to beat a barrel that's threaded into the receiver. On top of that is the tension nut. I tried to eliminate it but my barrels shot better under tension. I had one combo that I built a round shroud that functioned for it but no tension nut. Just an air stripper. It was accurate. Good enough for most guys. When I scrapped the round shroud, threaded the barrel and put it under tension, the accuracy was crazy. If you have read this whole thread, you know I made my gun shorter. It is so accurate with Crow Magnums of all pellets that I don't think I have ever missed a starling out to and including 60yrds.

[Pelletjunkie]

All of the LW barrels I tried on my PP700 were larger diameter. I just turn down the part that slides into the receiver and leave the rest full size. I think .357" but don't quote me. There is a process to get the threading and the lip of the barrel when it returns to full diameter to jive. I like to thread my barrel in and when the lip hits the receiver, everything is perfectly flush on the loading end. This makes the threaded bushing less critical and you have one ridged setup. I was going to make my gun a .25 just for a winter killing time project but I planned on building a bigger ID barrel bushing threaded 10mmX1.0 and the same on the tension nut. There would not be enough barrel material to thread it 8mm with a big .25cal hole. That why some guys have ripped the end of their barrels off when tightening the tension nut in the .22 models. Things are getting thin.

[YEMX]

Pelletjunkie- I had a massive brain-fart...  As I was reading your posts, I remembered that the tensioning nut (tensioning anchor?) has flats- and that I should drill a hole and tap for a grub screw to secure the nut in the receiver...  getting old isn't fun.  I'm kind of embarrassed actually... 

Because I didn't think about that old mod (drill and tap for the grub screw) I was fixated on how to install the barrel, since there's no way to tighten the nut when it's in the receiver...    Anyhoo, problem solved!  Thank you!

[rumbleUU]

Ok, my PP700S-A 4.5mm is on its way, just checking if I missed something on my "to do list" ?
(Im keeping the stock regulator, It is working fine in my other PP700, So Im expecting this one to be good to....)

* Fix trigger, polish all parts
* Grubscrew(M3) to hold the breach in place
* Put a 15.5x1.5 o-ring if it is leaking where the black tube meets the silverpart
* check the inlet and crown of the barrel (As i always do), fix if not good
* If getting  breach blow when shooting, fix so the barrel comes out a tiny bit (make a shim)

Did I miss something?

And is there a way to get better flow somewhere? maybe gaining some efficiency, (Im thinking from the reg to the barrel inlet)

[Rocker1]

8mmx.1 is the thread, you can screw the barrel in far enough and use a HW breech seal, You do need to put a grub screw in the breech, Read back on some of Scotts (motorhead) older posts .  David