Crosman 140

[Doc Sharptail]

Like I said, if it has that sleeve inside the valve, pull it out and try it.... you can always put it back if you want.... I've found it increases the velocity over 6 pumps, makes it easier to pump, and reduces the trigger pull weight.... Where is the negative in that?....

Bob

Actually, none, and none

There's no sleeve in the valve, which I should have mentioned last night...

I'm pretty sure I'm losing velocity in 2 places- that ill-fitting poly transfer tube, and either the quad seal, or sear block spring.

I did pump it up to 15 pumps, just once, to see what it would do, and it gave me 620. Pump tension gets really heavy after 6 pumps, and that fifteen pumps is a lot of grunt work. I don't think I'll be doing that often...

I'm hoping the hill pump I have in mind for the QB-D is not as hard to pump as that- I'll be in trouble if it is...

Regards,

Doc Sharptail

[Doc Sharptail]

Went to a small, extremely crowded gun show on Saturday. I picked up a set of the intermounts for the 140, just to see what it would do.



That's a well-travelled 4-12X 40mm Banner.



Group at right shows how the 140 reacts to the jsb 15.9 gr straton points. 5 pumps per shot at 12 M , rested under the fore-arm. 5 Shots. Gun has issues with bbl play at the bbl band/pivot block. Nothing really new, or insurmountable there.

It looks a bit funny with the big modern scope on it. I'll try with either a 3/4" steel tube Weaver B-4, or an older Banner fixed 4X rimfire scope...

It looks like this bbl's a good one, from what I can see of how it wants to put holes together at bottom left and right...

Regards,

Doc Sharptail

[Doc Sharptail]

I did some more with the 140 tonight. I robbed a transfer port out of one of the modern pumpers.



The bottom of the breech needs to be relieved. It holds well, though.

Velocity improved markedly:

3 pumps- 384.2 fps

5 pumps- 478.0 fps

7 pumps-551.0 fps

10 pumps-628.4 fps.

15 pumps- 677.3 fps

I'm pleased with that performance- it's amazing what this old gal will do.

I pinched my hand in the gap between the pump handle and stock again, but didn't lose any wood this time.

Does anyone here have a photo of what an original 140 transfer port looks like? It may help a lot. I can't leave that over-sized port in there for very long- I'm worried about warping the bottom of the breech. There isn't a lot of steel there.... If I can avoid cutting into the bottom of the breech, I'd be a lot happier.

Regards,

Doc Sharptail

[SeanMP]

I've only ever seen one original.

It was similar in size and shape to the current transfer ports in 13xx,22xx but the rib in the center was thin and there was remnants of the usual flat rubber washer top and bottom.

Having said that there is no guarantee that was even "original" ...You know how it goes

I have a couple 140/1400's in for repair but they are at home and I'm on the ship, so it would be a few days before I could have a peek

[Doc Sharptail]

Thanks for the description Sean. It may be difficult coming up with a photo of an original.

I did check a SBK kit breech on it. The rear breech screw hole and transfer port holes line up, but not the front breech screw hole. There's potential there- if I want to do it. That's a decision that's going to require a bit of thought.... For the time being, I had better order in a small handful of the modern transfer ports, and make chips fly with the dremel and drill press

Regards,

Doc Sharptail

[rsterne]

I put a modern style transfer port in a 140.... The only critical issue is drilling the 0.200" ID recess in the barrel for the upper part of the transfer port to the correct depth to apply some compression on the lower seal without lifting the breech up.... Isn't the breech already drilled 1/4" right through?.... I thought it was....

Bob

[Doc Sharptail]

I put a modern style transfer port in a 140.... The only critical issue is drilling the 0.200" ID recess in the barrel for the upper part of the transfer port to the correct depth to apply some compression on the lower seal without lifting the breech up.... Isn't the breech already drilled 1/4" right through?.... I thought it was....

Bob

It's a bit less than 0.25", and quite elliptical :P I should put my 1/4" mill cutter to work on it.

How hard is it seperating bbl and breech on these? There's a hefty burr holding the 2 together on this gun. Hopefully I'll be able to drift them apart without laying too much of a beating on the bbl shank...

Regards,

Doc Sharptail

[rsterne]

I've never had a problem removing the barrel.... snug fit, but just a pull and a twist.... Once it's out, you'll find the port is in the same place as the modern barrels, it just doesn't have the 0.200" counterdrill for the transfer port recess....

Bob

[Doc Sharptail]

I've got it nearly to my liking now. I had to put the bbl into a padded vise to get the breech off. One twist with a drift in the rear screw hole, and it slid off easily. It was nice to be able to see the deep jet black lustre blue that "Power Without Powder" was using in those halcyon days, in the protected area behind the breech opening. The rest of it's plum brown, in comparison...

I couldn't set up in the drill press. There isn't a suitable press vise there for something as small as that 140 breech. I tried laying the breech on top of one of the vise rails for some semblance of level, but couldn't get it. A vise for round stock just got added to my list. I did it all by hand on the top of the work bench. The steel on the breech is very hard- it almost looks like case knit coloring on the bottom of the breech. The bbl steel was kind of hard to work with- porous and crumbly. It wanted to tear under the bit, rather than cut. I had to take it very slow and gentle.

Couldn't come up with a 0.20" drill. Two closest were .196" , and .205" I made do with the .196" The bottom of the breech sits almost flush with the compression tube, and there's no leaks.

I sat down with it to group:



That's 6 of the Daisy 14.3 gr h.p.'s at 12 meters, 6 X on the 4-12 Banner. 5 pumps each shot. I have no explanation for that flier at top- it was shot #4. I certainly didn't yank it.

For a 50 year old bbl, that ain't bad at all. I now have to determine which pellets this gun likes....



That's 17 of the Daisy pellets at 12 meters. I was varying the pumps, and also shooting as fast as I could from a rest under the fore-arm. Lowest number of pumps was 3, and the highest was 10. The only pellet not to make it through both sides of the tin was the 3 pump shot....



Not bad at all, considering how that "tin" metal hardens up once it's been penetrated...

That's good news on the modern bbl hole lining up- filed away for future reference, just in case...

Regards,

Doc Sharptail