Snipers on 12 grams / on CO2 Discussion

[BLachance75]

RAZRBAKK any suggestions?

I was setting my 2k Sniper for SC. I took off the reg and screwed the bucket straight in, it shot amazing. After the 3rd 12ie, air out the back block and through the feed, completely bleeding the 12 gram in a few shots and can't get to velocity. From what I gather, 12 grams need to go through the reg, so I guess that's just how I'll have to set it up, but was curious what you ended up doing with yours.

I’m guessing you blew out your cup seal.

I will use 12 gr with my S6. I don’t adjust the reg at all. All that I have to do is turn up the velocity a little bit. It shoots about 15-20 fps slower in 12 gr than it does on hpa.

[RAZRBAKK]

RAZRBAKK any suggestions?

I was setting my 2k Sniper for SC. I took off the reg and screwed the bucket straight in, it shot amazing. After the 3rd 12ie, air out the back block and through the feed, completely bleeding the 12 gram in a few shots and can't get to velocity. From what I gather, 12 grams need to go through the reg, so I guess that's just how I'll have to set it up, but was curious what you ended up doing with yours.

Mine has a female Palmers Stabilizer that I screw a 12 gram changer into. The reg is sweet spotted, and that's about it.

Truth be told I need to change some things because my results haven't been fantastic. I'll be doing more experimentation this weekend before it gets too cold.

[Murdoc555]

RAZRBAKK any suggestions?

I was setting my 2k Sniper for SC. I took off the reg and screwed the bucket straight in, it shot amazing. After the 3rd 12ie, air out the back block and through the feed, completely bleeding the 12 gram in a few shots and can't get to velocity. From what I gather, 12 grams need to go through the reg, so I guess that's just how I'll have to set it up, but was curious what you ended up doing with yours.

[Chuck E Ducky]

I think to get 30+ it’s going to have be at a lower velocity. Snipers just aren't that efficient. But I’m interested to see what you come up with.

[RAZRBAKK]

Chuck E Ducky It is, but I am hoping to break 30. Next round of testing is going to be finding the peak for both of these guns. Matching bore, good paint, balancing springs, etc.

[Chuck E Ducky]

Looks usable

[RAZRBAKK]

This is about as unscientific as I could get. Since I have a 2k2 VF body now, I decided to bring all the externals over. Same barrel, reg, 12 gram changer. Did not weigh the 12 gram. The paint doesn't match a sphere, let alone the barrel bore.

1. 264
272
252
283
265
269
279
294
272
262
271
270
264
276
261
268
269
268
286
264
274
240
297
269
25. 252

26. 209

Vent.

25 useable shots. Again.

How interesting. I'm going to play with it on 12ies tomorrow with different paint, and I will report back with real world data.

[Chuck E Ducky]

So many factors come into play when dealing with 12g efficiency. It’s hard to lock down sold numbers. Over the chrono numbers often never result in real world use. However If your not getting your numbers over a chrono they won’t be accurate. Velocity plays a big part in efficiency numbers.

Air Temp
Velocity
How long you wait between shots
Paint to bore match
Paint quality consistency
Firing over the chrono the same exact way each time
Position of the 12g
Even current elevation plays a part


12g is a small pressure vessel and it’s effected by many factors so it’s difficult to find that sweet spot especially in unregulated Sniper body setups. It’s all in the springs they need to be balanced perfectly. It’s a ton of trial and error to get any decent numbers with a Sniper setup.

You want High pressure as high as you can get. That valve needs to slam close as fast as you can get it for efficiency. Bore needs to be tight, bolt needs to fit tight or have an Oring keeping pressure going out the barrel and not up the feedneck. You need consistent hardy paint to do this as the small burst of high pressure and a tight bore is hard on paint. Follow up shots need to be delayed allowing the co2 to fully expand. Longer wait time the colder it gets. Brand 12g makes a difference as well.

I find I get less shots out of the non food grade 12g. Maybe due to the oils weight when getting filled. Or the internals reaction to the 12g oil building up over time. Not sure but I find I get way better consistent performance out of food grade 12g without oil and longer maintenance intervals as the internals stay cleaner longer.


FYI stock CCM sniper will produce 30 shots @280fps with temps around 60-70* if you shoot it slow. That’s at relatively low operating pressure 350ish and regulated. Those numbers are what I consider my bench mark when messing with 12g powered Snipers. If I can get close to 30 shots real world use I’m happy. Anything past that is splitting hairs over the chrono and has no real world use or is just adjusted to a lower velocity to get more shots.

[Cdn_Cuda]

After some quick and dirty testing with 12gs, my Karni and my 2k5 Black Magic seem to get the most shots. Didn’t have time to chrono yet, but Karni was well above all 4 other pumps. It may have been shooting at a lower velocity though. I’ll update with numbers once I can.
the Karni runs a standard sized valve and the BM runs a 11/16 valve.

[RAZRBAKK]

Not against spending more, but I think I should work through my current valves before buying more lol

[Toestr]

The Inception valve is advertised as having low dwell because of the stem oring. From what I understand the cupseal is pretty soft though so I don't know if it would be CO2 friendly. The Shocktech Rat and ANS and AC Parts clones also have orings and I think they should be ok with CO2. Just a thought. I know you're not looking at spending more.

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[RAZRBAKK]

anson Yeah, I am starting with the IVG turned in about half way, reg turned out.

I'm turning it up to increase the velocity, until it starts to drop, and then backing it out. The point at which the velocity starts to drop comes very early in this process, which is why I thought maybe a lighter valve spring would work.

Like I said, I'm going to experiment with springs. I'll probably end up going through all of them at some point. I'm just not sure since I got basically identical results with 3 different spring setups.

[anson]

Also I'm having a hard time understanding how you're sweetspotting the reg? Crank the reg up until velocity drops then back half a turn.

[anson]

Just saying. My Carter's both have very heavy valve springs. This forces the valve to close very quickly reducing the amount of wasted air

[RAZRBAKK]

Have you seen this thread by russc ?

https://www.pbnation.com/showthread....3032401?page=3

He also concludes that pre2k bodies got better efficiency, but also the additional volume of a pressure tester hurt efficiency, so I'm not too sure what to think. I'm not sure that springing will do anything on a regged Sheridan other than change at what pressure it sweetspots.

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Maybe that's where I got the idea that the Pre2k was more efficient. He also tests a 99 and gets 36 shots, citing the venturi bolt as a possible cause for efficiency loss.

He also said:

The mainspring is weak enough where I can cock it by holding it in one hand and making a punching motion.

Which both gave me a chuckle and makes me think I need to rethink my springing.

Has anyone tried lightening hammer to eliminate bounce?

RAZRBAKK I wonder if you use a very stiff valve spring if efficiency would go up. I think a lot of air is wasted through valve dwell. Don't give up on that pre 2k body just yet

I'm definitely not done, just gotta think about it more.

I have tested now with my 2nd heaviest valve spring + medium main, my heaviest valve spring + medium main, and my 2nd lightest valve spring and a medium main spring.

I re-sweetspotted the reg each time to be sure, and no matter what I seemed to be very close to lowering the pressure too much, and the valve leaking after every shot, or the FPS dropping because the pressure is slamming the valve shut.

I'm going to keep messing with it, but I'm out of paint and almost out of 12ies.

Three things I am going to try:

medium valve, lighter main spring
A different co2 compatible reg
The original valve

Hopefully not all at the same time so I can get a conclusive answer.

I will update when I do.