1389 backpacker rebuild

[BerkshireHunter]

This was a parts gun I bought used years ago to scavenge bits and the brass valve. Still have most of the key components so it would be a shame to leave this nice peace of Crosman history in the dust bin. I think I’ll try to order the parts I need and put it back together. It’s a little rough with a bit of surface rust but I’ve brushed most of it off with a brass brush.

Anyone know how much a grip frame costs from Crosman? 

[lefteyeshot]

Did the1389 come with a metal breach?

[BerkshireHunter]

Did the1389 come with a metal breach?

Yeah, it’s from the nineties. I think it’s just a Zamak pot metal but the build quality is nice and it has dovetails.

[stroo]

B.H. I have in my notes 2300A035 as costing $11.65, that is most likely from late last year or earlier this year so that price should be close.  That frame is basically a 2240 (13XX) pistol frame with a tapped hole in the trigger guard for a trigger stop screw.
Good luck and please keep us updated on your project.

[BerkshireHunter]

Update: I’ve had a frustrating time with my parts orders. First, part 0241 (Pellgun oil) is no longer available as an unfinished part, no big deal. But I’m still waiting on a valve face and a grip frame. At first they sent me one that was unfinished, the grip wasn’t tapped and threaded to accept the 3 side plate screws. I called them and told them to check for that but they just promptly sent me another unfinished  frame. So I had to call back a 3rd time and argue because they think I’m lying. As if Crosman only makes perfect products...

Well, hopefully it all comes together eventually.

[BerkshireHunter]

Update: I’ve had a frustrating time with my parts orders. First, part 0241 (Pellgun oil) is no longer available as an unfinished part, no big deal. But I’m still waiting on a valve face and a grip frame. At first they sent me one that was unfinished, the grip wasn’t tapped and threaded to accept the 3 side plate screws. I called them and told them to check for that but they just promptly sent me another unfinished  frame. So I had to call back a 3rd time and argue because they think I’m lying. As if Crosman only makes perfect products...

Well, hopefully it all comes together eventually.

Okay, customer service called me back. Apparently they don’t pre thread those screw holes, I’m told they use self tapping screws to drill the metal grip. Well, guess I’ll try the self tapping screws with my tiny little hex key...     Still waiting on the valve part though

[stroo]

Update: I’ve had a frustrating time with my parts orders. First, part 0241 (Pellgun oil) is no longer available as an unfinished part, no big deal. But I’m still waiting on a valve face and a grip frame. At first they sent me one that was unfinished, the grip wasn’t tapped and threaded to accept the 3 side plate screws. I called them and told them to check for that but they just promptly sent me another unfinished  frame. So I had to call back a 3rd time and argue because they think I’m lying. As if Crosman only makes perfect products...

Well, hopefully it all comes together eventually.

Okay, customer service called me back. Apparently they don’t pre thread those screw holes, I’m told they use self tapping screws to drill the metal grip. Well, guess I’ll try the self tapping screws with my tiny little hex key...     Still waiting on the valve part though

This is true, the frames I have received the last couple years have not been tapped.  I use stainless hex head screws so I have been tapping them myself, the frame material is quite soft.  Have patience, this will be a cool build.   

ETA:  What valve part are you waiting for?

[BerkshireHunter]

Well, it only took about a month and a half but I just got the valve piece I needed from Crosman. Should be a fun project this weekend to put it all back together.

[BerkshireHunter]

After all that wait, it was the wrong valve piece. Turns out the M417/760 valve lacks the screw hole... I don’t blame the customer service person, this is Crosmans fault for not adequately updating the parts diagrams on the website. (There’s still no Legacy 1000 or 362 diagrams and the new 1322 diagram is garbage.)

Anyways, I just decided to use the old valve setup I had lying around even if it’s fractionally less efficient than the new ones. It assembled pretty well and I took some test shots. It seemed weak so I tried shooting a plastic juice bottle and it bounced off. I’m not sure if it’s losing air at the transfer port seal or the weird breech loader mechanism but it did fail the tissue test.

All in all, I think Crosman was right to go with the bolt probe/ O-ring design, it seems much more durable, effective, and easier to load. Still a cool piece of the Crosman history and I hope they bring back the drifter/ backpacker with the old style pumping arm, it works just as well as the classic 1399 shoulder stock. The pump handle is perfection. 

I added two tiny drops of Pellgun oil to the plastic cylinder that holds the pellets, not sure the material of that insert but maybe it had dried out a little? Will test again later.

[Tack Driver 10]

Those are nice little guns not as powerful as the later 13xx guns.
Some swap the stock breech for the modern steel or plastic breech/barrel.
I have a few of them, one converted to shoot airsoft BBs.
Works great for sweeping the deer out of the garden.

Here's a diagram for the 362 valve components.

[Warburrito]

What kind of stock is that?  Very cool.  Just picked up a 1389 this week that's missing the loading gate, but I'm hoping to resolve that with some 3D printing magic.  I'm gonna try to squeeze some O-rings in there while I'm at it... Why not?  Other than that it just needed some bolts and grub screws tightened up and I still need to remove a little surface rust.  Pretty excited about this one.  The forearm is even better than what I had expected and the green color is nice.  Its nice enough I probably won't camo it like I do so many other things I own.  I don't stop at gun camoing either, I just camoed my daughter's bike frame in purple, silver, and desert sand.

[Tack Driver 10]

What kind of stock is that?  Very cool.  Just picked up a 1389 this week that's missing the loading gate, but I'm hoping to resolve that with some 3D printing magic.  I'm gonna try to squeeze some O-rings in there while I'm at it... Why not?  Other than that it just needed some bolts and grub screws tightened up and I still need to remove a little surface rust.  Pretty excited about this one.  The forearm is even better than what I had expected and the green color is nice.  Its nice enough I probably won't camo it like I do so many other things I own.  I don't stop at gun camoing either, I just camoed my daughter's bike frame in purple, silver, and desert sand.

The stock is shop made, part of my E-book, "Crosman Lego Guns Stock Making for Dummies".

https://www.gatewaytoairguns.org/GTA/index.php?topic=146554.0

[BerkshireHunter]

I pulled out this project again, I was pretty sure the weak power was the fit at the transfer port. I wasn’t sure if I had all the right parts since I dissembled it a decade ago. At first I put the brass cap under the rubber gasket (like the rudimentary diagram) and it was around 375 FPS at 10 pumps. Today I took it apart and switched the brass fitting on top of the gasket and it’s still only shooting a weak 375 FPS. I feel like with the longer barrel it should be doing at least 500 FPS ?? (and that would be slow too.)

IDK 

[Hack21]

I am also rebuilding one and plan to replace the square section seal and brass top-hat feature with refrigerator tubing.  Are you certain that the swing out loading tray isn't leaking?  The breech fit gets adjusted by loosening the barrel set screws and sliding the barrel further into the breech so that it creates a tighter fit when the tray is closed. Lastly, I found that the passages inside of the breech were tapered during the die-cast production and there should be some easy velocity gain by drilling them out slightly.  Stock velocity should be 500 - 550 fps with light lead pellets at 10 pumps.  I did some light porting, stuffed the valve, lowered the preload on the the inlet check valve, and bought an adjustable piston for mine.  My hope is 500 fps with light pellets at 6-7 pumps.  Good luck.