Butt Plate For the Crosman 180

This is a boring post, but the work had to be done...

Derrick sent me this butt plate. He has no idea what it's off of.

It had bosses on the underside.

Using my relatively inaccurate method of finding the centerline.

Existing holes plugged and the hole locations marked.

I drilled for the bosses with what turned out to be a very dull Forstner bit. Need to buy a good set of these at some point.

I decided to use #10-24 machine screws. Coarse pitch machine screws work fine in wood, especially dense hardwood.

I marked up the plate with a silver Sharpie and scribed the outline. I nibbled off most of the waste with the bandsaw.

Coarse sanding done. The plate was made of some sort of hellish smelling phenolic. I had to wear a dust mask and basically wanted to burn my clothes afterwards. The dust was that nasty.


I finished up with wet/dry silicon carbide which kept the dust under control. It isn't perfect but it continues the lines pretty well. I would have put more time into it but the material didn't make it fun.

The good stuff comes next...

A new Crosman 22XX--Bolt and Gas Tube End Cap

Onward upward or something to that effect.

A piece of 0.250" tool steel a bit longer than a Crosman .22 cal bolt.

Faced the ends.

Turned down to create an extended nose.

Shaped a ball-end with a file.

Cut the angle.

Mounted the bolt in a small machinist vise and secured it to the drill press table. Spotted then through drilled with a #29 bit--the tapping size for #8-32. Not shown: Tapped using the drill chuck for alignment.

Back to the Taig to add a rare earth magnet to the rear of the bolt. Same procedures as previously covered here. Once you have a bolt-hold open, you can't own a Crosman without. Loading is that much easier.

With the bolt completed, I moved on to the gas tube end cap. A small piece of 0.750" diameter steel rod was faced.

Didn't have much length of rod to hold on to, so I switched to the steel 4-jaw chuck. Cut the step to fit into the rear of the gas tube.

Cut right to the shoulder leaving a nice clean corner.

Spotted, the drilled successively larger to 5/16"--the diameter of the hammer spring. Didn't drill completely through--a bit more than halfway. Not shown: Used an end mill to produce a flat bottomed hole.

Then spotted again and through drilled with a #3 drill bit.

Followed by a 1/4-28 plug tap.

Finished with a tap wrench as the tap began slipping in the Jacobs chuck.

Thinned the head of the cap and added a taper.



Needs a couple #8-32 threaded holes.

Mounted the gas tube in a padded vise and centered on the hole using a drill bit as a hole size gauge. I forgot to write the size down. The bit just fits through the hole. This centered and aligned the work to the bit.

Put the cap into place and secured it with a bar clamp. Then spotted the hole.

And drilled through with a #29 bit.



Followed with a #8-32 plug tap.

Couldn't get enough leverage turning the chuck by hand so I removed the vise and switched to a tap wrench--leaving the tap started in the work.

More coming.

Blogiversarry

Well it's been two years since we started the blog, with my post on fixing the Predom rear sight. I had initially planned to only post once a week or so but Derrick and I have written a post every two days on average. We hope you've found a odd tidbit or two of useful information. We'll keep messing with perfectly good airguns for no good reason until we work our way through the entire Blue Book of Airguns or our wives leave us.

If you're new to the blog you can see the index of all posts to get an idea what we've covered thus far. I recently added a Google search bar and a list of post labels in the sidebar.

We're always looking for beater airguns to work on, and any and all donations are useful to our project. We don't have sponsors (although we wish we did) and we don't work on airguns for a living (good thing!) so what you see is entirely from our meagre hobby budgets.

Here's a picture of a Benjamin Rocket 77 so you don't get bored.

More posts to come shortly!

A New Crosman 22XX--Breech Cap and Cocking Pin

Still (slowly) working away at all the bits and pieces to finish this 2250 pistol.

Needed an end cap for the steel breech. Not sure how exactly I ended up with a Crosman steel breech missing all the assorted bits and pieces...Anyway, I began with a short length of 0.500" diameter drill rod.

Turned the end down to about a quarter inch to fit into the end of the breech.

A Crosman breech plug served as a model.

It's too long because I needed something to hold in the chuck.

Cut the excess off.

Just free-handed the end. If you move the carriage and the crosslide simultaneously, you can cut concave or convex shapes if you're careful. Or you can trash the part in fractions of a second--it's all part of the learning curve. Things worked out fine this time around.

Just needs the clearance hole for the rear breech bolt.

Used the breech itself as the jig. Clamped the breech in a small machinist's vise and bolted it to the drill press table. Aligned through the hole without the plug in place, then installed and through drilled.

Another view.

Blued with Birchwood Casey Perma Blue paste. It's almost a dead-ringer for the Crosman part.

The hammer (striker!) needs a cocking pin. Again, a Crosman part is shown as a reference. A piece of 0.250" O-1 tool steel should do nicely.

Faced off each end and duplicated the part.

Halfway home. Matched the lengths of the ends to the stock component.

The new hammer, breech cap and cocking pin.

Still need a bolt, bolt handle and an end cap for the gas tube, then I think I can slap this thing together. Finally settled on .22 cal. Had to make a caliber decision before turning the bolt. Finding a spare .22 cal barrel from a previous project gun in the parts box sealed the deal.

More to come.

Getting that Beater Crosman 600 Working, Part 2

Well the feed problem needed sorting.

I pulled the cam rod out of the other 600, the new ring wouldn't slide all the way. Again a corner clearance issue. Just wanted to check. Obviously all it needs is the corners relieved in the helix. Better too tight than too loose in my book. But I'm not using this rod in this 600, because it's in the other one...

So I found some 3/16" square and radiused the edges to fit the new ring.

Cut to length and the corners radiused to fit the new ring along the length of it.

I chucked up a 3/16" dowel pin in the 4 jaw and got it true. This saves time when chucking square stock.

Truing up square stock in a 4 jaw is difficult. You have to wiggle the chuck to find the minimum reading at each jaw before adjusting. A little time consuming.

The round section turned on the rod.

I put the good cam rod in the mill vise and set the stop. I lined up a ball endmill with the divot.

Milling a round pocket for the feed arm set screw.

I put the rod in a vise and twisted it with the adjustable wrench held right where the helix ends. Very easy. I was a bit nervous doing this by eye rather than taking 100 measurements, etc. But I doubt the tolerances are that extreme. It has a little bit of play. If I were to do it again I'd make the rod out of stock slightly larger than 3/16" maybe .190" I'd probably also spot for the setscrew divot by holding the feed arm in alignment with the magazine.

The gas leak was no doubt due to the extremely wide valve seat.

I ground up a skinny little toolbit and fed it in carefully to trim the outside diameter of the seat.

The ring is thinner so more force holding it shut.

The last thing I did was polish the lead of the feed arm. I used a cratex bullet and got it smooth.

So...it works! I doesn't go full auto and doesn't leak. It feeds fine with 8 pellets in the mag but with 10 sometimes it jams and sometimes it doesn't. I think that it's due to the overall slop (the feed arm was really scarred up) where the pellets go into the feed arm, leading them to cock. If the magazine spring had slightly less force it would probably be more reliable. I'll see how it performs over time.
Now this is not a pistol I have a lot of confidence in. The wear on the sear parts means I'll always have to keep an eye on it. It also makes me less likely to buy a 600 without being able to check those parts before purchase as both of the 600's had issues with those parts (broken link on the other one).