Snipers on 12 grams / on CO2 Discussion

[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.

[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

[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.

[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.

[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]

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

[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.

[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.

[RAZRBAKK]

Murdoc555 I think so, you might have to play with springing a little.

[Murdoc555]

RAZRBAKK If I remember right, the basic start point after this is a hard valve and soft hammer spring? Chuck E Ducky

[Chuck E Ducky]

With non regulated your going to want stiff. Get it shooting as hot as possible (stiff springs) with the IVG in the middle of its adjustment. Then back it down till you hit field speed. If you cant get it to go below 300fps go a lil softer. Regulated just get a good balanced spring combo. CCM work great for me.

[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]

Looks usable

[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]

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.

[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.

[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.

[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.

[Murdoc555]

Cup seals blown even if it holds air when cocked?

[RAZRBAKK]

@Murdoch555 you might just have an imbalance in your springing.

[Ivorygmyst]

[Ivorygmyst]

I’m getting 18 shots out of a 12 g

[RAZRBAKK]

I don't think CP regs get a long with co2 very well.

[Loophole]

Anyone tested 2k+ Bolts?.. I am looking for a new bolt for my scout. Hoping someone has done a bunch of testing

[Chuck E Ducky]

My Scout came with a special small bore bolt built for it. I’m assuming to get some extra efficiency. Even though it’s not very efficient.

[Chuck E Ducky]

Stock Scout bolt made by Ken. I should try a CCM in it see what happens can’t hurt I know I got one laying around somewhere.

[Loophole]

I see! You have one of the run of 9. I have the prior 6 with dropouts. Mine was one of the ealier ones at that.. so it just had a modified pre2k bolt drilled for 2k+. Curious if anyone has done testing with bolts.. i would like to upgrade to something with detent slots so i don't destroy my dual cocker detents!

[Chuck E Ducky]

Yeah I’m almost positive mines the last one. It’s the one Ken made for himself. I got it from him years after they were out of production. I would like to find the one out of 15ish that was built with the regulator built in. I have never seen it posted or shown off. I’m curious how he added regulation. Yours is definitely an early one if not the prototype.

[ChuckLove]

I was able to get about 24 usable shots at Slim's last month with my new Mini Ripper.

[ChuckLove]

Chuck E Ducky 30 is quite impressive. I was pleasantly surprised that I could reach the mid 20's with mine. I'm curious if I could stretch that out with quality paint and a tight bore match.

[Chuck E Ducky]

Yeah key is consistent paint so you can go tight with the bore.

[BLachance75]

My S6 will get 30 shots off a 12 gram most days. On a hot day it is more. It will shoot full velocity for all but the last shot which is usually 200ish FPS then its done.

[Pump&Run]

If I’ve read everything correct as far as ideal body… is it now a 2k+ front chamber, 11/16 valve , and ( after the Chuck’s above brief discussion ) possibly a bolt face with a smaller air passage to help with efficiency ?

[ChuckLove]

I don't believe 11/16 valves help with 12 g efficiency. The valve chamber is larger which if anything will most likely decrease efficiency with CO2.

[Pump&Run]

Ok, I must have mixed up the information from the lineage of this/these studies in regards to valve size outcomes. So then the post 2K and pre 2k body debate centers around the air chamber then and a standard 9/16th valve all around.

[ketzer7]

I would love to know what the secret is to getting 12 grams to work on a Sniper-based gun.

At Slim's I spent a bunch of time messing around trying to get my new T2 from CCM working on 12 grams. I could never get it to shoot with any sort of decent velocity at all. It would seem to start out with the first shot or two being full power, and then it would rapidly taper off to the point it couldn't even launch a ball out of the barrel. And no the 12 gram wasn't empty. If I dumped it, there was plenty of gas left in it. I'm talking it would taper off in like 5-6 shots. Other times, it would never get above like 150 fps no matter how I adjusted the reg pressure or main spring.

The CCM reg the gun came with didn't seem to like CO2 at all. One time it vented off through the bottom, two other times, it essentially stopped flowing entirely. Both times, when I took the reg apart to find out why it had stopped, the reg seat o-ring had been partially sucked down into the poppet nut, almost like the pressure was too high? All I can say is that I had already pre-adjusted the reg at home to output 300 psi on HPA, and didn't adjust it at all when switching it over to 12 gram, but it just seemed to be all over the place.

Thinking maybe the problems were being caused by the reg, I switched the gun over to using a Sidewinder I had laying around. Similarly, I pre-adjusted it to 300 psi output, and then didn't touch it after putting it on 12 gram. Didn't really get any different results. Could never achieve any decent velocity out of the gun. I wouldn't think it would.be a problem, but it almost seemed like the gun was sucking liquid in, but I have no idea.

Maybe I am just a moron and doing something wrong, but I gave up. If someone has some tips to try, I'd be happy to try it again because it was really frustrating knowing that folks were using their Sniper-based guns just fine on 12 grams.

[ChuckLove]

What's the output pressure of the tank regulator that you use with it? I wouldn't think it would cause that big of an issue but if it's a lower pressure output you may run into issues. If your tank reg is set at 800 or slightly above and then you sweet spot your high pressure regulator you may have better results on 12g's.

[ketzer7]

It was probably around 500 psi on the HPA tank output. I have another that is set to 750, so I could try that I guess. I've also wondered if the cheapo bucket changer I'm using could have anything to do with it, but don't know.