Xisico 60C tuning

[superchikn]

I have a 60C in 22 I bought from Mike a couple years ago and I really like this thing. 
I know Mike says the Xisicos are not bench guns and I accept that but I really like mine.
Mike tuned it to shoot just under 700 fps with FTTs.
Most often it would shoot a nickel to a quarter at 30 yds with occasional dimes.
Last week I noticed some air blowing out seemingly at the breech.  I also know that my hammer was oily form over oiling the bolt and oiling the hammer when I first got it.
So I tore it all down yesterday. Cleaned everything and burnished bolt bore and hammer bore with powdered tungsten.I replaced the oring(s) on the probe, barrel, and one on the valve. The valve oring was damaged removing the valve.
I put it all back together, leaks are sealed, shooting 730-740fps with the 14.66 FTTs head size 5.54. This was tethered to a CO2 bottle outside where it was nearly 90 degrees.

 After reassembly with the exception of an occasional flyer, or more likely I pulled the shot, 5-10 shots were all under a nickel and most under a dime.  shot 4 groups like that.  That is the best I have ever been able to do with it.  Hope I can do it again tonight.

The questions are:

• Inside the receiver there looks to be powdercoat overspray in the hammer bore and the bolt bore.  Do you guys hone this out or leave it?
• I believe my hammer strike is too great as I am getting vapor out of the LDC, the spring adjuster is all the way out.  I am thinking take a coil or so off the spring.  Any thoughts?

Thank you

[nervoustrigger]

It’s hard to gauge whether it’s wasting CO2 based on the presence of vapor.  A small amount, especially when it is hot and humid outside, isn’t unusual even if it’s tuned efficiently.   Better to check velocity over the chronograph and keep backing out the hammer spring preload until you just begin to see the velocity fall by 5% or so.  Then if you can’t get to that point with the preload adjuster all the way out, shortening the spring or try a weaker one.
 
Regarding the powdercoat overspray, I didn’t bother to remove it.  I did smooth it down to eliminate the texture, but I did not attempt to remove it all because I didn’t want to remove any of the aluminum.  The bolt in particular was already a sloppy fit.  I just polished the bolt and hammer to make them slide easily.   

[Blowpipe Sam]

I have just purchased an XS60c recently and I am very interested in seeing how this thread develops.  Mine is very accurate out of the box and it is improving as the trigger breaks in.  Mike tuned this gun for small game hunting and claims 680fps with 14.3 gr fodder.

[superchikn]

It’s hard to gauge whether it’s wasting CO2 based on the presence of vapor.  A small amount, especially when it is hot and humid outside, isn’t unusual even if it’s tuned efficiently.   Better to check velocity over the chronograph and keep backing out the hammer spring preload until you just begin to see the velocity fall by 5% or so.  Then if you can’t get to that point with the preload adjuster all the way out, shortening the spring or try a weaker one.
 
Regarding the powdercoat overspray, I didn’t bother to remove it.  I did smooth it down to eliminate the texture, but I did not attempt to remove it all because I didn’t want to remove any of the aluminum.  The bolt in particular was already a sloppy fit.  I just polished the bolt and hammer to make them slide easily.   

Thank You Jason,
Understood on the vapor cloud.  It may just be a feeling that the hammer strike is a little heavy, but the screw is backed all of the way out so to test I would need to cut or replace the spring and run the screw in a bit.

[Wayne52]

That XS60C looks to be about the best co2 out there for power.

[superchikn]

That XS60C looks to be about the best co2 out there for power.

I have not paid much attention to other CO2 rifle level power levels but I guess that was about 17.5 fpe yesterday in the very high eighties.

[Blowpipe Sam]

That XS60C looks to be about the best co2 out there for power.

I've been doing research for the last three months before buying mine.  Based on all the reviews I read and videos I watched the XS60 is the easiest to mod for more power initially.  The adjustable hammer force seems to be the key there.  The QB78 seems to have the advantage if you want to do more serious mods.  I have heard claims of over 20fpe for a well tuned QB78
 

[nervoustrigger]

Yeah, 20fpe on a QB78 is feasible with the porting opened up.  The first QB78 I tuned produced 20fpe on 850 psi air so it would have been in the same ballpark on CO2 on a warm day.  That was with simple porting (75% of caliber) so there was still room to squeeze out some more energy, but that would not be my preference for anything running on 12gr cartridges.  Better suited for a tanker. 

[Hoosier Daddy]

Ray,
 You may want to check with Mike M. on this before taking my word for it.... BUT.
 I am 98% sure in my past discussions with him one my XS60-C that the power adjuster works opposite of others. You turn it out to increase, and in to decrease.
 With you having yours all the way out you at at max power. There should be a thread here on GTA where we cleared up that misconception.
  I remember a photo as well.
Let me see what I can dig up.

[superchikn]

That XS60C looks to be about the best co2 out there for power.

I've been doing research for the last three months before buying mine.  Based on all the reviews I read and videos I watched the XS60 is the easiest to mod for more power initially.  The adjustable hammer force seems to be the key there.  The QB78 seems to have the advantage if you want to do more serious mods.  I have heard claims of over 20fpe for a well tuned QB78

Carter,
I had Mike Mellick set mine up for 675 to 700 fps so I could still use the two 12gr carts when away from the bench.  he worked on the valve and also opened up the radial barrel ports, among the other items he takes care of when you buy one of his 60Cs.
I still get a pretty good shot count with the 2- 12s, I don't remember what that count is off hand but I can shoot it and see.
I also have the HSA backed off all of the way and can see how much more I can get out of it.  Heavier pellets would help of course and AA 16gr domes shoot almost as well out of mine.

[Hoosier Daddy]

Compliments of our own rsterne




Now if I can find that thread...

[superchikn]

Ray,
 You may want to check with Mike M. on this before taking my word for it.... BUT.
 I am 98% sure in my past discussions with him one my XS60-C that the power adjuster works opposite of others. You turn it out to increase, and in to decrease.
 With you having yours all the way out you at at max power. There should be a thread here on GTA where we cleared up that misconception.
  I remember a photo as well.
Let me see what I can dig up.

Hey Scott,

 I believe I remember that discussion and may have been part of it, or it was which way to turn the regulator adjuster on the Nova Liberties.
At any rate I believe (and I may be mistaken) I had asked Mike about this two years ago and I believe he told me CCW to back it off.  The threads are not reversed and the head of that screw is against its bracket giving the spring the least amount of preload possible.
I will check it tonight when I get home anyway.  I am going to drop it out of the stock to see what gains are to be found by adding preload to the the HS.

[Ribbonstone]

Did make me take it out of the stock and take a look....don't see a problem with a 1-maybe 2 coil shortening of the striker spring.  Better to try little cahnges....you can't put too much back on.

At that speed/energy,you likely are using a good bit of co2 per shot. Trace of vapor would be expected.... more visible on humid days.

Overspray doesn't seem to be a problem.....plenty old enough/well used that it would have shown gouging.

Mike must have adjusted that one....fast for a co2 rifle,so you will use a good bit of co2 per shot.  Tank makes sense for playing/prtactice/testing.

[superchikn]

Did make me take it out of the stock and take a look....don't see a problem with a 1-maybe 2 coil shortening of the striker spring.  Better to try little cahnges....you can't put too much back on.

At that speed/energy,you likely are using a good bit of co2 per shot. Trace of vapor would be expected.... more visible on humid days.

Overspray doesn't seem to be a problem.....plenty old enough/well used that it would have shown gouging.

Mike must have adjusted that one....fast for a co2 rifle,so you will use a good bit of co2 per shot.  Tank makes sense for playing/prtactice/testing.

To add to things, before I tore it down yesterday I shot over the long green box for about 680-690 fps.tank was probably in the mid 70s.
After I put it all back together ant tank was in the mid to high 80s 740 -734 fps.  No direct sun at any point. 

Minor leaks are gone, hammer (not polished) is clean and dry and with tungsten disulfide burnished in.
I don't recall seeing it ever shoot that fast before but have not chronoed it that often.

[moorepower]

I would find another spring so if you want to go back you can. Fun little guns

[superchikn]

I would find another spring so if you want to go back you can. Fun little guns

Was thinking the same.

[Blowpipe Sam]

I've had mine since last Thursday and I 've got about 250 shots through it now.  The trigger is much smoother though the annoying chirping sound of the spring is still there.  The gun came drenched in yak grease and it has just stopped geysering oil with every shot. I cleaned the bore and mopped the worst of the oil off before shooting but I haven't done anything else to it.  The bolt was very stiff at first but has now smoothed out nicely promising good things to come as the gun continues to break in.  My crummy cell phone app chrono was giving readings as high as 3000 fps for 14.3gr CPDUM leading me to believe that this is the same app that Crosman and Gamo use to test their guns velocity.   Given the trajectory and the satisfying smack the pellet makes at the far end I believe Mike's claim of 680 fps with 14.3gr pellets.  The trigger pull is still a little too long and kind of gritty but very light with a nice clean break.  The gun is plenty powerful and it is more accurate than I am at 30 yards.  In the 90+ degree conditions that prevail here right now it is getting 40 good money shots from two 12g cartridges.   So why the heck would I want to modify it?  I don't want to but I want to know as much about this gun as possible.

[nervoustrigger]

That’s a good yield, almost 300fpe per cartridge.

[Wayne52]

The thing that appeals to me about both XS60C and the QB78 are the fact you can leave them charged for extended periods of time like the old Crosmans, it's a method that's proven itself over time.

[superchikn]

Got home tonight and set up straight from the garage, CO2 was in the 70s.  High 680s.  So the 735 -740 speeds were the high temps.  Here is the kicker,  accuracy was not nearly as good as the faster speeds.  Not sure how to solve that one.
Did not get to play beyond that but will over the next few days.