Crosman 2240/2250 mods - I'm a bit late to the SSG party..

[Shed tuner]

I just did a Stopping Spring Guide for my 2250 and wow, completely takes out a load of hammer bounce; the fart noise has gone, and it now sounds more like a PCP.

Due to our UK power laws, I didn't want something poking out the back, so I went clean through the front of the hammer instead

Basically, drilled a 5mm hole clean though the centre of the hammer, then counterbored from the nose about 9mm, and 4mm deep, for the nut at the end of the spring-loaded bolt to sit in. I turned down the head of the 60mm long bolt so it sits easily in the recess for the spring in the end cap. Used bog std hammer spring, although it now has a bolt-head-thickness more preload now. Fine tuned the bolt length so it sits just about 1mm off the valve stem. The nut is a nylock, but I will probably use some strong threadlocker.

SO how it now works... cock the gun, and the hammer slides back, compressing the spring in the usual way, but the bolt and the nut at the end are now producing about 15mm (whatever the stroke is), through the front face of the piston..
Fire the gun and the hammer shoots forwards, collecting the spring guide (which is free to slide forwards out of the endcap) and the end of the bolt is hammered onto the valve stem. When the valve rebounds, the SSG principle now comes into play, as the preload in the spring loaded bolt is a good geal higher than stock - and of course there's the lack of direct contact between hammer and stem.

There a little inefficiency here, in as much as the hammer is slowed when it collects the guide bolt, but power with a 14" barrel is unchanged at just under 9 fpe. I guess the extra bolt-head-thickness preload compensates.

But it shoots so much sharper, less noisy, and I've got at least a dozen more shots - still counting. So it works. Best of all, nothing externally visible. I haven't seen one done like this, but I'm sure there are - it's too obvious for someone not to have tried it already, but it's defo the way to go for the UK with our laws.

I'll do a piccy sometime. Or another you tube vid. might even wear clothes this time.

Rgds - JB

[rmwesley]

Pictures would really be appreciated, cheers

[--ped--]

look on the GTA forum every possible way of the SSG is shown in this thread
https://www.gatewaytoairguns.org/GTA...;topicseen#new

[eyebull]

This sounds like a very interesting way to go about it and I'd love to see some pics and/or a fully-clothed video

I did go on about this in another thread but it's easy to make it non externally adjustable even if it protrudes from the back, but I do like your idea of having it all contained within the gun (one of my 2250s has it all contained within the stock adapter but this is cheating a bit).
Really if this was part of the manufacturing process it would probably add pennies to the cost of the gun, but with so much benefit.

I do recommend trying a few different combinations of clear space, spring strength and preload. I also recommend applying the principle of tallying 'total foot poundage' as a way of gauging overall efficiency - i.e if you got 10 shots at 3 FPE each, you will have gotten a total of 30 FPE out of the cartridge. Calculated this way it's somewhat easier to find the sweet spot.

[TonyL]

Sounds great, JB.

Will have a better look in tomorrow, though, when my head's not hurting so much.

You bringing it to The Bash?

[Shed tuner]

look on the GTA forum every possible way of the SSG is shown in this thread
https://www.gatewaytoairguns.org/GTA...;topicseen#new

yeah, couldn't find one employing this internal layout, but thats where i got the basic info / starting point

[--ped--]

look on the ssg for discovery thread it sounds similar to the one I made ages back not sure but I think I gave it to my mate
https://www.gatewaytoairguns.org/GTA...opic=104863.20

[Shed tuner]

look on the ssg for discovery thread it sounds similar to the one I made ages back not sure but I think I gave it to my mate
https://www.gatewaytoairguns.org/GTA...opic=104863.20

yes, agreed, frojm the description it does sounds like the same layout. I did guess that i wouldn't have been the first - it's too obvious - just not seen any pics. ALso the UK power laws make internal layour far more attractive.

Costs nothing, takes no time, and works. Crosman should ship 'em like this.

*edit pic from that thread - yes exactly the same - not seen it done on a 22xx, but it's all the same *
http://i1190.photobucket.com/albums/...psxvhphjnw.jpg

[eyebull]

Forgot to ask, how difficult was it to drill into the hammer? Would it be feasible to tap a thread into it do you think?

[Shed tuner]

Forgot to ask, how difficult was it to drill into the hammer? Would it be feasible to tap a thread into it do you think?

there may have been a little case hardening, as it was slightly slow going to get it started, then easy / soft. Crosman aren't known for using the best quality materials, especially in their modern stuff

[--ped--]

they are case hardened and it varies on depth of hardening
what I do is use a carbide burr to get through the hard outer (both front and inside spring recess) then drill through it tapping I recommend using the burr to counter sink both sides once drilled as you'll have less chance of snapping/chipping your tap
if drilling the hammer for a threaded cocking pin I use the bench grinder to make a flat then drill and tap but again be careful when you get to the spring recess as that will be still hardened
I find it easier to make a new hammer from scratch in stainless or use the front of a std one with a light weight rear
I prefer light hammer with stiffer hammer spring as an anti bounce method coupled with an adjustable striker and a few o rings to act as a buffer

[Shed tuner]

yeah, the hammer is so simple, it really is just as easy to make one up...

[arnie2b]

Bob Sterne also writes for hardairmagazine.
https://hardairmagazine.com/ham-colu...e-and-the-ssg/
Good idea to do it from the front though John.

[Andrewjames]

any oppotunity to use the stock hammer spring and make an ssg is a great thing..

i think we all can agree that springs are very easy to come by except for the one you need..

[Shed tuner]

finally did a few pics..