Monday, February 15, 2010

Getting One Crosman 600 Back Together

So I put one of the Crosman 600 pistols back together. I scavenged the piercing cap and link from the other pistol. So I need to get replacements for both...also due to a slight amount of over zealous arbor press action I managed to bend the shank of one of the valve stems - it's repairable but below is the 2nd reseal I did...Anyway the pistol really does go back together easily in reverse of disassembly.

The shank stands proud of the end of the valve assembly.

Set up on the arbor press.

That gets it started.

I used a pin punch, but a short dowel pin is better - it was just on the edge of almost bending the long punch.

Pressed apart.

I bored out a lot of the old hard seal.

Which freed it up enough to be removed.

Same technique and tool as on the S&W 79.


There's the seal.

Pressing the assembly back together. I used that aluminum spacer so I could press past the end of the brass body. It is easy to press so far the seal deforms, so I had to lightly press, check, press, check...

I replaced the valve o-ring with a 113 Viton ring.

I reused the old transfer port seal (I also reused the internal o-ring in the hammer, it was surprisingly pliable). I slid it in from the front as I didn't want to get hung up on the hole in the back of the casting.

Then I slid the tube back further out the end to get the hammer in and then the ring.

All assembled but it had some issues. I noticed the slide was really loose in the frame channel.

Way too much play.

So I gently tapped the rails against the slide. Chipped the paint a bit...It looks worse than it is.

I had some serious cycling problems so flipped the ring around. It was facing backwards as shown, so I flipped it so the square was to the front. I don't think it matters though?

While I had it apart again I refaced the valve seat with a cratex rod as I could hear a tiny leak and saw a small ding in the valve face. Worked like a charm.

Holding the rear sight detent ball in with some grease.

No leaks but still having cycling problems...must be the barrel. Should have set clearance between the barrel and shuttle to .003"...

You have to rotate the barrel so the setscrew doesn't pick up the old burr and force it out of alignment.

A .003" gage does the trick for setting clearance.

With that the pistol performs flawlessly. I've fired about 140+ rounds through it so far.
I get about 35 shots per cartridge in our current temperatures of 50 degrees F. Velocity goes from a high of about 345 for the first shot to a low of 291 after 35 shots. The manual says "340 fps @ 70 deg." so that's clearly in the ballpark.

Now to figure out what I need to get the other one running (that'll be a while). I also need to think about disassembling this one again, fixing the trigger guard and repainting.


derrick38 said...

Nick, I'm copying and pasting this question from FrankB.
"My Crosman 600 failed to work on the very day I received a Mac-1 14" barrel w/three-baffle brake !This really sucks...holding gas,fire it and the valve doesn't open at all. Any idea what could cause that?"

Bryan Hamblin said...


Thanks again for a great series. I used your expertise and parts from JGA to get my old 600 up and working again. Well almost. The cam has burrs and chips out of it. I have one on order. at least it is sealing now.

Any more thoughts regarding making a cam ring for your second gun? If so you might consider making several. This part seems to be very difficult to find.

Nick Carter said...

Rick at Precision Pellet has rings made for him, quite reasonably (less than it would cost me to make them)
Rick Willnecker
Precision Pellet
37 Stoney Lane
New Park, PA 17352
717-382-4065 Fax
web site

I'm going to order one, although I may still try and make one/fix the bad one.

Nick Carter said...


If the valve doesn't open? Something blocking the hammer? Is the cocking slide pushed into the forward position? Other than that I can't imagine what - maybe a broken trigger component?

Yama Holic said...

Thanks for a great write-up on the Crosman 600! After using this to rebuild my 600 I've decided to sell a 99% complete 600 with plenty of good, usable parts - check out eBay item number: 281527519790