Wondering if anyone tried a SSG for their xs60?

[renowntwo]

Was just sitting here thinking about the FD pcp and wonder if anyone has tried this mod to their AR? If so, can you give some details about what supplies you used and details about how it preformed.

[Ribbonstone]

OK...fast skim of the trials of the XS60c (avoiding the dead-ends):


Set #1: test it as it came.

As out the box (1500psi fill):


OK...first off, wanted more shots (kind of set a goal of 20 shots) and something like 20 foot pounds per shot.

Second off, that bugger is lound, so figured out an LDC.

Step #2: keep the LOW tesnion of step #1 and reduce the air flow to the pellet.

Decied to reduce the transfer port size.  Not as easy as it seems, as you have to reduce the barrel tansfer port.



Results: (pre-post transfer port reduction)



STEP #3: reduce the WEIGHT of the striker and increase the spring tension in steps (chronographing at eash step).

Results:



STEP 4: fiddle around a little with spring tesnion/striker weight.  Little adjustments, nothing drastic as step #3 was pretty close to where I wanted to be

Likely you could skip step #2 (port restriction) and spent more time on #3 and #4, and just use the full sized barrel-port, but a little more fiddling around with spring tesnion/striker weight.

Toss in a recrown. Really don't know it needed one, but was looking a little ragged at the muzzle.  Sharp-eyed readers will notice the use a "dead"/ shaped QB valve stem for a lap. (Could of skipped this as well...made it look nicer/not shoot nicer.)



Anyway...where is stands now: (but to be honest, most tests it has a starting or ending shot 3-4FPS lower, which ruings the 4% shot count to 19 shots).




Mention all this not becasue an SSG would be a bad idea (maybe a little more complcated than the Crosman version due to the rifle's design), but what these little 1500psi rifles can do.

[nervoustrigger]

I made one for a .22 cal FD-PCP just a few weeks ago.  Really just trying to tame the beast to get a decent shot count.  It was shooting the Crosman Premiers at 1070fps (36fpe)...for about 4 good shots.  I wanted something more like Ribbonstone's and Bob's 20fpe tunes.

I had fiddled with about 10 different bstaley O-ring and preload configurations and just couldn't get a decent result.  Then I looked at it and realized a basic SSG would be super simple.  All I did was remove the power adjuster screw and replace it with a piece of 3/16" rod threaded on both ends.

A little trial and error with spring preload and the gap and I ended up with 16 shots at 21fpe.  Good enough for a lightweight squirrel rifle.

The parts pictured were from one I made for a 2240 but it's basically the same thing.

[renowntwo]

Thanks for the information guys. Question for Mr. Jason
1. How long is the 3/16 thread bolt you used?
2. what size o-ring did you use?
3.  Is the grind down bolt smaller in diameter than the spring? The reason I ask is because I assume the bolt doesn't move just the spring?
4. Can you define gap setting a little bit more? I kind of understand what it is but just wanted someone else to clear it up for me.
 Mr. Ribbonstone
1. What weight reduction in the hammer did you decide on and how did you achieve the weight reduction?
2. What spring tension was used?  Let's say if I had the AR apart and I was looking at power adjuster how many turns in should I go from no preload?

[nervoustrigger]

1. How long is the 3/16 thread bolt you used?

I didn't keep a record of its length but if you understand the intent of the SSG, it's easy to do a dry fit and figure out the appropriate length.  You want the SSG to stop pushing the hammer just before the hammer contacts the valve stem. 

So here's what to do.  Remove the factory screw that adjusts the hammer spring preload.  Take your 3/16" rod and insert it until it bottoms out in the pocket of the hammer.  You want the rod sticking out the back of the receiver by about 1/2" (+/- 1/16").  Mark that spot and cut the rod to length.  Thread this 1/2" section.  It's 3/16" rod so you can thread it directly to #10-32.

Then thread 1/8" of the other end to accept a nut that will capture the spring.  For this nut, I ground down a regular hex nut to 0.3" round, just small enough to fit into the pocket of the hammer.  Use some threadlocker to keep this nut from coming loose.

2. what size o-ring did you use?

Size -008, a snug fit to the 3/16" rod.

3.  Is the grind down bolt smaller in diameter than the spring? The reason I ask is because I assume the bolt doesn't move just the spring?

Not sure I understand.  There is no bolt, just a piece of 3/16" rod.  However I have seen them made from a socket head cap screw.  Is that what you mean?

In any case, the rod (or bolt) indeed moves.  When you cock the rifle, withdrawing the bolt pulls the hammer back which in turn causes the rod to extend out the back of the receiver.

4. Can you define gap setting a little bit more? I kind of understand what it is but just wanted someone else to clear it up for me.

If the hammer is touching the valve stem, it's the distance between the end of the SSG and the hammer.  In other words, the amount the hammer can rattle back and forth between the SSG and valve stem.

Usually it's a very small amount, maybe 0.03" to 0.1"

[renowntwo]

Thanks again for the information. I think that I'm heading to a hardware store tomorrow after work. I just have to gave this a try.