XS60C PCP Repeater project

[johninthecamper]

its possible to increase or decrease the length,keeping the same weight.its also possible to keep the same weight and change the length.weight/length and shape can all be adjusted,by changing two variables, one can stay the same or two can stay the same with one change

[stalwart]

At this length, they fit perfectly in the stock loading tray.... and at this dia, they are snug, but not in a bad way. Have no idea how they fit in a stock chamber, but I'll sure find out asap. Got no legs right now, but they are on order...lol.    All in good time!

[johninthecamper]

fourth variable, dia.
that can be adjusted too

[stalwart]

Guys, I need input on a few things:

Is there any reason the valve's throat can't be offset toward the barrel? I can't see any, but that's no insurance.

My coating oven situation has worked out nicely, I'll be up soon. I'll be able to do seamless coatings on the fixed barrel Bobcats, and fit the 31" tubes/receivers that 25" barrel/40mm tail combos require. I will stock and offer Desert Tan (Mil) and Federal Matte Black, and was wondering what you guys thought of offering a super durable powder coated primer that could be nicely spray bomb camo-ed to taste. Worth stocking?

I've looked into making .22 barrels using liners and sleeves. I'm starting to wonder if there is any real benefit, to many, in spending the money to allow having a pellet + bullet gun. MG barrels aren't cheap, and I have to buy in lots to keep costs down. A 25" straight bullet barrel can be built for about the cost of an MG at 20 - 21". Is anyone drooling for a 60 MG... or should I stow that concept for a while?

[rsterne]

No reason I can see not to offset the throat, other than shrouding of the poppet on one side by the valve/tube ID, but that might not matter.... As you move closer to the exhaust port you need more angle on the port (or the further you have to move the seat back) to be able to "see" through the port/throat combo.... and IMO the better you can see through it the better the airflow....

I personally don't like painting guns, the typical spray-bomb paint is too easil scratched....

I was looking forward to a .22 cal MG barrel as I already have the bullets.... and I think at about 60 FPE it will fill a gap in available PCPs by making a .22 cal bullet shooter available that isn't trying to emulate a .22LR, which is pretty tough (and therefore expensive).... However, I would be unlikely to shoot pellets in it, so a 25" bullet only barrel would also work....

Bob

[stalwart]

We're thinking along the same lines. I'm not sure I would ever shoot pellets in a gun that can do bullets. These already need to be de-tuned to efficiently shoot pellets. An easy and repeatable adjustor would make a lot of sense in a dual projectile gun... and make the concept make more sense as well.

I have been pondering building a true survival rifle someday... maybe that is the best place to put in that kind of infrequently used versatility. We'll mess with it this winter, but I wouldn't be surprised if we are the only ones who end up doing so. 60fpe is a great level, I'd think it would find a lot of uses.

The powder primer will make the spray bomb stronger, but on it's own should keep scratches from being deep enough to cause rust. Touching up the paint (or changing the camo to match the season or conditions) would be easy and quick. I'm a little surprised that there aren't more threads on custom finished 60s... I was fully expecting to see some crazy **** by now. Maybe we need a contest to bring out some creativity? I've asked why GTA doesn't have contests... got crickets. I could put up some decent prizes, if someone got something going in that direction.

[RMM]

We're thinking along the same lines. I'm not sure I would ever shoot pellets in a gun that can do bullets. These already need to be de-tuned to efficiently shoot pellets. An easy and repeatable adjustor would make a lot of sense in a dual projectile gun... and make the concept make more sense as well.

I have been pondering building a true survival rifle someday... maybe that is the best place to put in that kind of infrequently used versatility. We'll mess with it this winter, but I wouldn't be surprised if we are the only ones who end up doing so. 60fpe is a great level, I'd think it would find a lot of uses.

The powder primer will make the spray bomb stronger, but on it's own should keep scratches from being deep enough to cause rust. Touching up the paint (or changing the camo to match the season or conditions) would be easy and quick. I'm a little surprised that there aren't more threads on custom finished 60s... I was fully expecting to see some crazy **** by now. Maybe we need a contest to bring out some creativity? I've asked why GTA doesn't have contests... got crickets. I could put up some decent prizes, if someone got something going in that direction.

I'll be puttin a spray finish (Cerakote or such) on my Bobcats this fall or early winter.  Shelf life of some of these coatings are short and I want fresh product when I spray plus I want to have two rifles ready when I start.

[RHytonen]

The powder primer will make the spray bomb stronger, but on it's own should keep scratches from being deep enough to cause rust. Touching up the paint (or changing the camo to match the season or conditions) would be easy and quick. I'm a little surprised that there aren't more threads on custom finished 60s....

Actually what I think it needs desperately is a durable functional coating for INSIDE the receiver's bolt and valve tubes.
I'm looking for a way to fill those longitudinal production 'scratches' - grooves, really- that I found when trying to smooth those channels. And the galling in the bolt channel was even worse.

I hope my temporary measures (like adding side screws to the valve and its "backing plug,'' if that's what you call it) won't be a problem when I want the Bobcat/Slick and "through tube" mods.

What size tube do you put on (or in) there? I have a stick or two of 7/8-.065 4130. Do you replace the bottom half of the receiver and set the cut-away top half on it like a saddle, (best for a new, durable cocking slot, IMO, and the ID of the 7/8 is the familiar .745"...)- or do you sleeve it with something smaller?

What can I spray in that bolt channel in the meantime? (I have rattlecan DuPont "Teflon Silicone Lubricant" to try for temporary.)

To cut the "A%^&*-r" QB fill plug's TWO o-ring slots out for the Crosman 113's, it looks like I'll have to get out the "hillbilly lathe" (LARGE two-handed 1/2" drill, and even more huge 3/4" chuck...
need to find a 1/2"-20 bolt for a mandrel...)

[stalwart]

Rod, given that the plans you have to back up the valve won't use the same screws as my set up (and there's the difference in position), and the through tube (7/8 DOM... same as your shorter one) will negate most of your work... I'd suggest we start with a fresh receiver (I'm stocked).

If you manage to imbed silicone or Teflon into your receiver (and you will), there is no way later coatings will stick. Anyone who is contemplating eventual powder coatings should stick to lubes that can be flushed fully out of the metal's surface.

With my design, the striker and pin both ride in steel... and both are Teflon coated. With the bolt channel heavily Teflon coated (both slick and smaller  ) you'll be happy with it. I love the feel of mine.

I say keep going with what you're doing, and learn what you can in the process. When the time comes for a 3K or 4.5... we'll start from scratch.

[RHytonen]

Rod, given that the plans you have to back up the valve won't use the same screws as my set up (and there's the difference in position), and the through tube (7/8 DOM... same as your shorter one) will negate most of your work... I'd suggest we start with a fresh receiver (I'm stocked).

If you manage to imbed silicone or Teflon into your receiver (and you will), there is no way later coatings will stick. Anyone who is contemplating eventual powder coatings should stick to lubes that can be flushed fully out of the metal's surface.

With my design, the striker and pin both ride in steel... and both are Teflon coated. With the bolt channel heavily Teflon coated (both slick and smaller  ) you'll be happy with it. I love the feel of mine.

I say keep going with what you're doing, and learn what you can in the process. When the time comes for a 3K or 4.5... we'll start from scratch.

LOL definitely "learning" -most of it bad, some tragic, - and glad you mentioned receivers,
I was about to try another (probably just as futile) attempt to get parts from Mike.
I'm seriously considering a raw oob parts G1 if he'll do it on the next round.
For our project I could contribute a fresh (paint-stripped) receiver AND 4' of 7/8" .65w 4130...

I find myself wondering how people who add side screws, to support the valve, avoid leaks.
An exhaust port o-ring seems to me the only way.
And there won't be an empty thread's depth in there to seal the screws, with the cap heads fitted into both valve and receiver (poorly, BTW-hand tools only-- more "learning.") [hmmm...black expoxy putty left over from bedding the P17... socket caps will be somewhat sunk into the receiver anyway...]

In retrospect it would have been FAR better to put the side screws in the "plug" ;( 
(Making a new one anyway, this one's ~Plastic~ YUCK. Hammer strikes feel SO cheap...
and it's zero backup for the valve in a pressure "surprise," unless someone wants to get into those inserts the one stock screw uses.)

I'm still waiting for the back ordered HP fittings... now the gun won't be ready before Thursday (surgery,)  which means a six week delay.
I think I have some CO2 carts for the T4,but they won't last six weeks (recovery).

The pain/sleepdep/painkillers-addled brain is starting to design lever options...
I always loved the W'73...thin billet levers up the sides could do it (even though exposed.)
If I could only steal the room for one pin through a nonpressurized part of the receiver
- and no more single-sided bolt activation.

Hey, how's that exposed power adjuster access coming? Abandoned?

[stalwart]

The adjuster is figured out... it'll happen. Eventually.

Time is short around here, for now. Lots of non AG related stuff going on right now, I'm looking forward to this winter, when I'll have more time to enjoy focusing on R&D for these.

[RHytonen]

I think I have a way to salvage this receiver (but still need to get at least one parts gun to have a fresh receiver for Eric to do Bobcat/Slick/Through Sleeve, maybe bullet barrel, mods.)

Here's the plan:
Since I already have holes in the receiver to counterbore the heads into the (spare QB) valve, I can cut straight line grooves lengthwise across the top of the valve, one next to each side of the port, running from front O-ring(s) to the rear one(s.)

They sell linear O-ring  material by the inch(ft.?) intended to be glued together for odd or impromptu emergency O-rings.

Then I just put a length of that into each of the two straight line grooves. That would essentially be a sealed port, @least more so than the stock arrangement, also eliminating a (not very...) possible slow; or (more probable) brief 'firing time' leak around the stock valve mounting screw, and of course, the two unacceptable ones I've created by drilling the receiver for the Allen screw heads. Much easier to retain when installing the valve than a round ring at the port, which I could never have retained through its insertion.

I just wish I had a mill, or there was a local machinist who could quickly and cheaply run those two 5/16" long grooves for me. It'll take a fine hand on the angle grinder or Dremel cutoff wheel... (maybe time for a $20 HF 2"-3" electric die grinder?)

Rod

[stalwart]

It's a unique idea. I'll be interested in seeing what happens.

Every single Gen1 I have handled has those grooves (to varying depths). As the receivers are extruded, and the lines are always full length, I'm convinced they are caused by the dies. Even the Gen2 have some traces of them. I sort receivers by these grooves... the bad ones get set aside for through tubes. That takes care of them.

I have considered boring one slightly to see if that would do it, but, I'm probably going to need all the receivers I can get, to upgrade.

Keep us informed?

[RMM]

Didn't rsterne have problem with a slow lead from these grooves and fixed it in some way???   

[stalwart]

Yup. I think the thread is in Mike's V gate.

[RHytonen]

It's a unique idea. I'll be interested in seeing what happens.

Every single Gen1 I have handled has those grooves (to varying depths). As the receivers are extruded, and the lines are always full length, I'm convinced they are caused by the dies. Even the Gens 2 have some traces of them. I sort receivers by these grooves... the bad ones get set aside for through tubes. That takes care of them.

I have considered boring one slightly to see if that would do it, but, I'm probably going to need all the receivers I can get, to upgrade.

Keep us informed?

Will do. Funding on Sept03 - and working on a few other ideas, like visually steampunk-powering(actually electric and pulleys/gears) the FD pump -a health NECESSITY after my first back surgery last week.
-and lever cocking, possibly eventual Winchester '73 (or Daisy)style (ditto "necessity..."- surgery recovery, docs say "push, never pull...")
If(when) I do, it will of course have to be a double, two sided external linkage- no more trying to pull a galling bolt with a handle on only one side!

I STILL can't believe some enterprising semipro machinist(or amateur with a lathe, or even just someone with credit who wants to finance one quick; and a 1/8"npt tap) won't run off HPA fill plugs,
for regulated bottle-feeding the 60C/FDPCP, with two O-ring grooves (to bypass the tube threads!)

It would just need a collar ridge (and OD to the end, like the stock FD plug) on it so they can use their stock FD fill plug screw cap...no check valve needed for a regulated tank. No troublesome threading.
It'd sell like hotcakes at $45-48... It could ("shall?") have two npt holes, and be long enough for one axial(ie on the end) & one radial(on the side)... LOTS of flexibility there for the user. MUCH cheaper solution than a reversing block.

If I had an ounce of credit I'd already have done it.
And I'd buy one or two yesterday, if someone else just would.

Another nice product would be REALLY long ASA/Regulator extensions.. 4-12"
-to get the tank's weight back nearer the trigger, esp. with LONG barrels/tubes.
(Mine will eventually be four FEET)
CP's $20/inch doesn't cut it for those lengths. 

Rod - now age 69.

[RHytonen]

Didn't rsterne have problem with a slow lead from these grooves and fixed it in some way???

One poster said they used coats of nail polish...

I'm eventually going through tube, but will experiment on this receiver with paints, DIY Al powder-filled CA glues, or epoxy.

Rod

[RMM]

Didn't rsterne have problem with a slow lead from these grooves and fixed it in some way???

One poster said they used coats of nail polish...

I'm eventually going through tube, but will experiment on this receiver with paints, DIY Al powder-filled CA glues, or epoxy.

Rod

My preferences in epoxies are Devcon and JB Weld for such fixes.

[RHytonen]

Didn't rsterne have problem with a slow lead from these grooves and fixed it in some way???

One poster said they used coats of nail polish...

I'm eventually going through tube, but will experiment on this receiver with paints, DIY Al powder-filled CA glues, or epoxy.

Rod

My preferences in epoxies are Devcon and JB Weld for such fixes.

I'm guessing it will have to "flow" a little more than that..
Viscosity will be everything.

[avator]

I feel pretty lucky, of the 3 I bought, 2 hold all their air indefinitely. The other holds for days then drops very slowly.