Disassembling the Crosman 707 Rifle, Part 2

On to the valves...

You can see the o-ring split when I tried to remove it. A good hint that the o-ring has seen better days.

The cir-clip was removed.

The valve guts.

The valve "stem" 700-39. The seal face looked ok, so I decided to try reusing it. There was no obvious way to remove the steel button, so I would likely have had to drill out the back of the stem and press the button out. If I have to, I will, but if it holds gas then no need.

The piercing assembly.

The roll pin was punched out.

The components.

The o-ring also split when removed.

The tool I made to work on the 38T valve fit the slots in the piercing assembly as well!

Once removed I fished out the small o-ring that seals the piercing pin. It too will be replaced.

The sear. Notice the complex cutouts in the stock. There is no trigger safety on this rifle, instead you can lock the bolt when cocked, against firing.

One of the ugliest stocks ever. Why Crosman went with this plank-like look is beyond me.

Disassembling the Crosman 707 Rifle, Part 1

Merry Christmas! What better present to myself than some time in the shop? I decided to take apart and reseal the Crosman 707 rifle I recently acquired. You can download a manual and exploded drawing from the Crosman archive. The 707 is the .177 caliber version of the .22 caliber 700, which should be the same mechanically.

I removed the two screws holding the action to the stock.

The action.

The CO2 piercing assembly was unscrewed, and the rear band clamp slid off.

Now what to remove?

Screw 700-10 was removed.

The bolt knob 700-16 was unscrewed.

The tap loading knob was unscrewed and the tap removed.

It appears someone else had visited the gun previously as the spring bushing 700-18 was a bit chewed up and the detent ball was missing.

The bushing was pulled out with pliers.

Screw 700-31 was removed.

At this point the barrel is free and was pulled out.

A somewhat swiss cheese looking breech.

The "bolt" 700-15 and spring then fall out the front as well.

I pushed the valve assembly out the back leaving an empty tube.

More to come...

Snowy Ramble...

I still haven't found time to work on airguns, due to both work and our crazy weather here in the Northwest. I hope to get back to having fun as soon as the holiday rush is over!

Anyway, for more diversions. Popular Mechanics and Popular Science have put many back issues up on Google Books for free.
Typing in: Crosman Popular Mechanics yields this result.
Clicking on the first link and you get this. with those words you seek highlighted in yellow.
Then (I haven't found a way around this, but there may be something simpler) remove the highlighting by removing "&dq=crosman+popular+mechanics" from the URL which yields this.

There are old ads, articles and all sorts of wonderful stuff to waste your time. I particularly loved finding this...

You can also go to the advanced search page to make sure you only yield results within those magazines...there are all sorts of tricks I'll have to figure out. Anyway, you get the idea.

I also thought this picture was pretty cool (via one of the UK forums)

Saturday Hy-Score

As I said earlier, I'm hammered with work right now, no time for airgun projects...
Here's the Hy-Score air pistol I picked up a few weeks ago at the gun show.

In box, with papers.


At full extension of the cocking stroke.

Pellet port closed.

Pellet port open.

Looking into the grip...

The tube.

The inside of the box lid (these pics can be opened separately and should be higher res...)
The manual and flyer below...






Anyway, I hope this makes up for my lack of postings...
Oh, the pistol is about as accurate as my Webley Hurricane...but fun to shoot.

Derrick's Xisico/BAM B26-2, Part 7

Derrick finishes up with his BAM saga today, thanks again!

In the first installment on the 26-2, I mentioned that the cheek piece was a member of the mile high club. My quick and dirty fix involving a set of high mounts and an .22 dovetail-to-.22 dovetail riser didn't get the scope quite high enough. After a few sessions with a too low scope, I finally bought a Leapers .22 to Weaver adapter. Leapers part number: MNT-PMTOWL This mount coupled with a set of Leapers high profile Weaver-style rings (#RGWM-25H4) put the scope high enough for a good "heads-up" position. Scope used was--you guessed it--a Leapers. It's the 4X32 AO "Bug Buster" (SCP-432AOMDL2). The scope mount is almost 3/4 of an inch higher than normal. If I hadn't corrected for the barrel droop with such a stiff plunger spring, it's unlikely there would have been enough elevation adjustment in the scope to get on target.

Utilizing the built in recoil stop pin in the base, the mount overhangs the rear of the tube by about 1/4". The Picitinny mount comes with a 5mm x 0.80 set screw to act as a recoil stop pin when mounted on a spring piston air rifle. Past experience has proven this type of pin to be prone to failure. Once I finalize the mount location, the mount will be flush cut to the end of the rifle and a larger stop pin (or two) will be added. The rifle, like the HW's, comes with 3 recoil pin stop holes in the top of the receiver. Ideally, airgun manufacturers would redesign their spring guns to include a Picitinny/Weaver base. Use of Weaver-style rings would then eliminate the need for scope stops. Imagine, no more scope ring movement, no more broken stop pins.

The wood was very good on this gun.

I couldn't bring myself to cut down the cheek piece. I know several others have done it before with great success. I think if the gun had been shooting tight groups all along that would have happened. It's hard for me to get psyched up for an involved woodworking project when the gun doesn't shoot for beans. As it stands, I like the upright shooting position. It's just different enough to be very handy for quick off-hand shots. It comes to shoulder quickly and takes no time to find the reticule.
The bad news is that now that it shoots, it becomes really easy to justify additional time and effort. Maybe there's some stock work to be done after all.

Another shot of a lathe turned screw cup.

A few extra pics of the gun. When I was first looking into buying a BAM, there were almost no pics on the net of the gun--aside from the obligatory tiny side shot from the manufacturer. Well, there was another shot of the gun being held by a scantily clad young woman...




Looking back over the posts I wrote, I noticed I never gave the final velocity. The gun was putting out 675 fps with a light .22 cal lead pellet in stock form. With the retrofitted Weihrauch R10 mainspring and spring guide that number jumped to 748 fps. With a heavier field pellet like the Crosman Premier, the number is in the middle 720's.
Want a summation? If Xisco/BAM fixes the too short trigger adjustment spring and gets the QC on the barrel lock-up dialed, this would be a much better gun than most of what GAMO is fielding right now. If they also up the ante with a quality mainspring and a real spring guide, they will almost equal many of the German guns from just a few years ago.