Crosman MK2 Modifications -- Part 2

I was going to rebarrel this Crosman MK2 to either .20 or .22 cal, but since someone already took the time to machine a really nice .177 cal loading bolt, I sourced a 24" Crosman 1760 barrel instead.













The stock MK2 barrel is just shy of 8" OAL. 

Cut the new barrel off somewhere around 10.3" long.  Assuming  that the final length will be pretty close to 10" after threading, facing and crowning.

Measured the major diameter of the thread--the barrel needs 3/8"-24 threads at each end.

Chucked the new barrel in the Taig and turned the end down to 0.369"  Cut a slight taper at the very end to make the threading die easier to start.

With a die holder mounted to the tailstock, I started the thread. 

Eventually, the barrel slipped in the chuck, so it was transferred to rubberized jaws in a bench vise and the thread was finished.

Back in the Taig to face then cut a 0.370" shoulder behind the thread.   This will be the breech end of the barrel.  I'll be working breech to muzzle.

 














A little bit of measuring gave the location for the CO2 transfer hole in the breech-end of the barrel.  Clamped the barrel in a v-block (this proved to be a mistake) and lined up to drill the hole.

Spotted.

Drilled with a #28.   Removed the barrel and immediately realized I had no way to line up this hole with the transfer port in the gun.  The original barrel features a dimple for the barrel setscrew opposite from the CO2 hole.  The dimple allows indication by alignment with the threaded hole in the gun's receiver before installing the setscrew. 

Mounted the barrel in a 5C collet and a square collet block.  Took a couple minutes to orient the hole so it faced straight up and was centered under the mill spindle.   Positioned a work stop against the collet block.  Flipped the collet block over and butted against the work stop.  Drilled a shallow hole with a spotting drill.

Began the cut for the pellet leade with a small tapered burr.




















Knew it wasn't going to be deep enough, so I started looking around for something to use.  Remembered I had a set of tapered pin reamers that are likely a few decades older than I am.

The #2 was a likely looking candidate.  Slow speed and lots of cutting oil. Lot of test fitting followed by several small pieces of emery cloth backed with a small brass rod to complete the polishing.

Another test fit.

 Bolt rotates closed. 

Not shown.  Threaded the muzzle end of things.

 Faced.

Recessed, crowned and polished to 500 grit.



















After pondering the various sizes of metal stock in the basement and weighing the pros and cons of steel vs. aluminum,  I finally settled on a 7/8" DOM steel tube to sleeve up the barrel. 

Out in the garage, the tube was chucked in the Shopmaster lathe and the end was turned down to 0.755" OD.  This will slip fit into the breech of the receiver.

Cut the tube 7.125" from the step at the shoulder to the muzzle.

Test fit.  So far, so good.  In the next couple days, I'll make a nut for the muzzle.  It will tension the barrel as well as secure the 7/8" barrel sleeve.  Then I'll need to make a plug to act as a base for the hammer spring and fit (or make) a new front sight.

Please check back soon.

Crosman MK2 Modifications -- Part 1

(Barely) Started a new project today.  Don't have much to show for it yet and (as usual) I don't have a firm plan yet as to how it's exactly going to go.














This is a Crosman MK2 .177 caliber CO2 pistol.  Got it several years ago from highly esteemed airgunner "Wacky Wayne". 

I've got a MK1 (same gun, but .22 caliber) also, but this MK2 won the toss for further modification largely because the bolt has already been replaced.  And since it's not a stock gun anymore, it's easier to justify additional work.


















Wayne sent the gun with no explanation as to the exceptionally machined loading bolt.  It's made from stainless steel and the knurling is so sharp and precise, it's obviously cut and not forged.

I think the plan is to fit a longer barrel, and replace the tapered barrel cover with something that looks more "bull barrel-esque".  Got started by removing the barrel nut at the front of the shroud.   I used a Shimano bicycle tool normally used to hold chainring nuts.  I suppose it could correctly be termed a "peg spanner". 

Notching a steel bar would also work.














 
With the nut removed, the shroud slides off the barrel.  The lower lug on the bottom of the shroud acts as a base for the hammer spring.  Most of the bull barrel replacements I've seen start by cutting the shroud off just in front of the ring.  Saves the hassle of making (and attaching) a new lower lug.





















The stock MK 1 and 2 barrels aren't very substantial.  3/8" diameter. 

Removed the setscrew.  The setscrew pushes the barrel downward to seal against the transfer port.

Unscrewed the rear knurled barrel nut.

And the barrel slides out.  As you can see, this is a "tensioned" barrel arrangement.  The barrel is threaded at each end with the shroud in between. 

More soon.

Beeman R1 Laser MK2

About two months ago, I walked into Precision Airgun and Chuck handed me this really heavy rifle case.  Then he gave me that Cheshire cat grin.  I pretty much just hand over my wallet at that point.  I wonder if he takes direct payroll deposit?










It's a Beeman embroidered Boyt soft case.

Opened it up and it was holding a mint condition Beeman R1 Laser MKII.




 






















It's a .20 caliber.  The scope is a Leopold 3-9 with the EFR.   It's held in a Beeman Dampa-Mount base.

The Laser stock appears to be a maple laminate.  It was released about the same time as the  Feinwerkbau 600/601 series match guns and the stock material and construction are the same.  The grip and the forearm are stippled.


















An old receipt was still in the case for the gun.  It came from Airgun Express.  The rifle was originally sold on November 11, 1998.  Also from the receipt, I see that a box of Crosman Premiers in .20 cal has almost exactly doubled in price since then.

Outside of the old Beeman catalogs, the information and pictures of this model are pretty scarce.  I've no idea how rare they are, but I'd never seen one in the flesh before. 

 Here's a better shot of the stippling.

The MKII has a higher comb than the original R1 Laser.  The earlier version also has a rosewood grip cap. 

I've put several dozen shots through the gun. It's a bit buzzy.  I think after all these years, it's probably in need of some fresh lube.  Try to get it over the chronograph before taking a look inside.





















This is the only thing I'm not in love with.  The original Beeman muzzle brake, while it works fine, doesn't have any appeal to my eye.  Probably replace it with something more svelte--like a Beeman Crow Magnum brake.

More soon.