Crosman Powermatic 500 Disassembly, Part 3

On I go…

The barrel and magazine just popped out. I’m not sure whether that’s a good or a bad thing. The barrels seems to have been bulged to be a press fit in the valve assembly.

Did I mention it was rusty?

The roll pin that holds the front sight and barrel plug thingy in.

I punched out the pin.

And gently tapped the piece out using a chopstick as a drift. Bamboo chopsticks are wonderful tools.
It was difficult to slide the barrel out – The shroud was dented so I had to massage it with some pliers.

This die cast part is formed around the barrel. It allows the sight to be screwed in as well as helping align things.

There’s a notch for the magazine to pass through.

No seriously, it’s rusty.

I removed the piercing pin retaining nut.

All the piercing parts. Looks like another Crosman 38 style assembly.

The leftmost washer was stepped on the underside.

The valve stem is rusty…

The seal is completely gone.

The BB shuttle?I’m guessing this is actuated by that flat piece in the left side of the action.

The shuttle.

That plastic piece covers the magnet (presumably for BB feeding).

You can see bits of steel fuzz on it.
So now I have to clean the damn thing and see if I can even get it to cycle, much less work. Not particularly optimistic given my failures of late. But we’ll see.

Crosman Powermatic 500 Disassembly, Part 2

On I go…

I removed the CO2 clamp & screw.

One screw on the other receiver half.

Notice how corroded the screw is…

This freed up the valve assembly. One spring was unhooked.

The valve assembly with barrel and magazine attached.

It’s important to take pictures of how spring hooks are oriented.

Everything is rusty.

The trigger group.

It’s somewhat interesting and different.

This piece pivots on that pin.

Let’s take more pictures. It will help.

You know it hasn’t been shot when it has cobwebs.

The grease has dried out completely.

I punched out the one, longer, pin.

Interesting spacers.

I tried to remove the shorter pin but it seems swaged – best to leave it. I can clean around it.
More to come…

Crosman Powermatic 500 Disassembly, Part 1

Having hit a velocity wall with the V-350 I decided that a slight change of pace was in order. So I dug a Crosman Powermatic 500 out of my pile of airguns.
Not a bad looking rifle, with the same lines as most other Crosman air rifles of the era.

It has an inline BB magazine above the barrel.

There’s a bit of corrosion.

Power Matic 500

More corrosion. This isn’t inspiring confidence.

This is where the CO2 cartridge goes, The plastic plate which hides it is missing.

As is one forestock screw.

Time to begin by removing the buttstock.

The stock is really heavy. I believe that this is a Croswood stock.

Removing the one remaining forearm screw.

The knurled CO2 nut needs to come off.

I clamped the nut in the vise to get the punch started on the roll pin and then removed it so I could rotate it 90 degrees to fully tap it out.

Notice that the forearm isn’t lightweight like a plastic part – it only has enough material removed for the parts to fit in.

The “barrel” band holds the shoud to the stock.

I removed three screws.

And carefully separated the halves. Nothing shot across the room, which is always a good thing.

As you can see the innards are corroded and full of cobwebs.

I took a bunch of views to make reassembly easier.

Notice that the safety is missing.

Another view…

Not really that complex although I’m unsure how the mechanism works.
More to come…

Tech Force TF79 / AR2078A Upgrades--Part 9

Some quick notes about what's coming in the semi-near future: I've got one of Frank B's Feinwerkbau 124Ds to overhaul with some Maccari parts--and I may use that as an excuse to take a break from the Tech Force. Also, I have a lost post from August of 2009 that I started to write, then shelved, on a stock modification for a BAM B26-2. I liked the concept, but I wasn't happy with my sketches or the first prototype. (We call them prototypes when it all goes wrong) Anyway, I've got a better(?) way this time around, so that's back towards the top of the project que. Right now, I'm checking back in with our slowest airgun project to date: The TF79. With the holes drilled for the adjustable cheek piece, it was necessary to add two more additional holes in the side. I'll make threaded aluminum inserts for these holes that will house screws to lock the cheek piece in position. Yeah, there was layout to find the locations for the holes. The 1/2" holes allow for easy insert manufacture from a piece of stock aluminum rod.

Many chemical strippers have a shelf life and my old can of Strypeeze was apparently done. It barely softened the finish.

Got a can of Dad's Easy Spray and it did the trick on the heavy Tech Force finish. I'm guessing that it was an acrylic. Whatever it was, it was excruciatingly difficult to remove. Sanding it all off was out of the question due to it's thickness as it instantly loaded the sandpaper.

Some thin stain left behind. That was straightforward to sand out. Sanding drums, the Dremel tool and a lot of time reshaped and blended the adjustable cheek piece into the body of the stock.

Here it is, sitting at 100 grit. Needs to go to about 220 or so to be somewhat respectable. There's a few tiny areas that still need the factory stain sanded off. Probably another two hours of work before it's ready for some color.

Happily surprised to find zero wood filler. From all the airgun article I've read over the years, I was led to believe that massive amounts of wood putty was mandatory for China made rifle stocks. Maybe in the past, maybe on some, but not here. The only filler present is the small amounts of epoxy that I added when fitting the slot for the accessory rail. I'm tempted to make a slightly flared maple grip cap to get some extra length on the short (for me) grip. Since it's taken this long already, I'll probably do it. Assuming that the dark areas are mineral streaks. I've no idea what kind of wood this is. Hope it stains well. Let me rephrase that. I hope it stains well the first time, as I have no desire to sand it out and start anew. More soon.