Snipers on 12 grams / on CO2 Discussion

[RAZRBAKK]

Really enjoyed this thread on the old MCB, so I'm trying to compress some of the information into a new thread for further discussion.

https://web.archive.org/web/20110319...iscussion.html

Sweetspotting:

Ignore gauge pressures altogether. Every gun has a different sweetspot. The only tool you need is a chronograph, a fistful of paint and about 5 minutes. Bring your pressure all the way down, so that the balls are just lobbing out. You want it high enough so that it doesn't vent after a shot. Turn the IVG (rear adjuster) out most of the way, maybe one or two turns in.

Now, once you are at a low pressure and your IVG is backed out almost all the way, start turning your regulator pressure up, just like 1/4 to 1/8 turn at a time, chronoing after every change. Try to get the gun shooting as hot as possible, without touching the IVG. That means if you can get the gun shooting 350 fps, all the better.

Don't stop turning the pressure up until the FPS stops going up. If your FPS starts going down, turn your pressure back a bit. You want it to shoot as hot as possible.

Now, once you hit that peak pressure, that's your sweetspot. You should never touch your regulator at all, not even to chrono after you set the sweetspot. It's the perfect pressure for your gun and anything lower or higher will not shoot as good for you, particularly with 12 grams. If you need to turn the gun up or down at this point, use the IVG. If you can't turn it down enough, you need to either clip the spring or get a softer mainspring. Again, do not turn the pressure down no matter how easy it would be compared to swapping springs. If you want the best efficiency and consistency you want your gun at this peak pressure.

Remember, gauges are unnecessary except for bragging to your friends that "my gun is shooting XXX psi!!!" When someone says
turn your gun to 350 psi," they may be offering advice to get your gun working, however that's sure as hell not the way you should tune your gun. Getting your gun to shoot, and getting it to shoot as best it can are two different things.

excelent post russc

paintballnerd there is a second version of the sweetspotting technic,this is not to confuse you just to let you know you may encounter it, essentially you start with your IVG turned in half way into the body,find optimal reg pressure as russ instructed then back the IVG out to optimal velocity we picked this version up from an old palmers tech,we have found that both versions work well so its not a matter of one over the other.

if your starting with a maddman spring kit, wich is the most common and available kit at this point,our go to springs to get started with are a blue valve/green main,and experiment from there,keep in mind also when tuning for efficiency with springing the feel of the gun will change somtimes you will have to make a compramise between feel and performance.

to reiterate what russ said,sitting down with the gun and a bag of the best paint you can get in the best conditions possible and taking your time is the way to get the most out of your gun,make small adjustments and be patient gauges are unnescasary

its easyer and i feel more accurate, to tune from a bench mounted set up,use a red chrono, support the gun so the barrel sits in the same spot for each shot over the chrono,red chronos dont like bright sun somtimes so try and keep shaded

get the best paint you can find,pour some out, keep your bare hands off of it and sperate any mishapen dented or dimpled balls that you can see

get the best paint to bore match you can aswell, this all sounds tedious,dont be to anal about it just takes a few extra minutes to reduce headaches

and make nice even complete pump strokes for each shot


good luck

Tests in chronological order:

First of all, I have a set of shots I'd like to share.


These were made with a stock 2k4 WGP gun, black magic reg, .684 Un1tec barrel, line SI lever changer in bottomline config, stock aluminum open face bolt. All shots were made without holding the pump, rubber band used as return spring. Shot interval was about 5-10 seconds as I only had two paintballs, so every shot I walked over and picked the ball back up after shooting it into a hanging bathrobe.

1. *forgot to chrono(
227 (adjusted)
296
300
304
289
291
296
297
10. 309
295
295
295
293
291
293
294
296
290
20. 294
302
291
292
294
296
299
298
295
296
30. 294
298
298
303
296
300
302
303
302
*lost ball*
291
40. 289
324
340 (WTF! Gun loses sweetspot, starts to shoot hot)
43. 291
233 - vented after shot

As you can see, not only does it get insane efficiency to rival the best Nelson setups out there, but the FPS curve is essentially flat until you get to the last 3-4 shots. I don't believe this gun was properly sweet spotted as you can see when the regged pressure dipped at the end the gun went all the way up to 340 fps. 43 shots in total, all of them in the top range of allowable velocities.

Keep in mind, this is an unmodified mid-pressure stock WGP gun with a 12gram changer in the bottomline duckbill.

So, there's a few things that are worth discussing here.

1. Regged low-med pressure 12 gram guns can get a flatter pressure curve, while getting just about as many shots.

2. "dead space" is less significant, if not inconsequential in a regged setup versus an unregged setup where all expansion is avoided.

3. The sweet spot on Snipers have potential for abuse. This is why I tell people who want to run unregged CO2 or HPA into their Snipers to get a pre-2k valve. Say you start at 280 fps, with the unregged pressure slamming your valve shut. Once your pressure starts dropping you will begin to have insanely high velocity as the gun is reaching its sweet spot the lower you go.

4. Why don't more stock class setups incorporate regulators, as a flat pressure curve is more desirable than a dipping pressure curve, given that you aren't losing many shots, if any.

I don't think the pre-reg expansion actually matters at all. It might even help stop liquid from going past the reg. I have the bottomline, macro, now a pressure gauge after the reg too and I'm at shot #38 in this new test and I'm at 288 fps.

[edit] turns out shot 38 was the last one. I'll post the list in a sec but the reg tester did hurt efficiency a bit.


did another test. This time I have a reg tester on the gun post-reg, it appears to have slightly hurt the efficiency, so devolumizing may still be a good idea...to a point. You want enough to seal your valve and allow for good consistency, but too much can still hurt. I still think it's the post-reg volume that will end up mattering the most.

I re-sweet spotted the reg, you can tell the difference now that it doesn't shoot up at the end. Turned mainspring out abuot 3 turns, 240 was the post-sweetspotting pressure, not sure what it was before.

1. 293
242 <- second ball, grungy and old
281
290
280
292
286
281
252 <--second ball, I stop using it after this shot
10. 284
283
279
289
293
290
290
290
285
287
20. 300
295
294
295
299
296
291
299
294
296
30. 297
292
297
295
295
295
292
288
38. 240
vents, last shot.

Soo...who's going to build the first low pressure regulated KP-2 with a turned down cocker valve?

Here's a test on my pre2k sniper:

AA Unireg
14" .685 un1tec
stock valve, sweetspotted at 500 psi
SI lever changer on XSV duckbill
Carter venturi bolt

1. 290
288
287
286
290
290
287
289
287
10. 290
295
292
289
295
284
287
?
286
285
20. 290
291
290
296
284
284
289
286
271
293
30. 284
30. 292
292
283
288
283
36. 263
227 - vents after shot

Again, a two shot drop in an otherwise flat FPS curve. The 2k+ got better efficiency, but I am running a venturi in this gun which may make a difference. Pressure is also about 250 psi higher and the springing is much harder.

After reading this I had to test my own sniper to see how it matched up against others. I also took the time to see what a little devolumization did for efficiency.

The first test occured at dusk with my regular setup. It was an 02 right feed with stock valve running red valve spring and green main. It is being fed with a BL Torpedo that I had sweet spotted a while back, but I think it could use some improvement. The bolt was a delrin open face bolt with orings removed. Barrel was a J&J Edge kit with .685 back (only one ball rolled out during both tests. I was using a Copperhead 12g. Paint was some 2 month old Xball from Dick's but it was rotated and dimple free. Size did vary, though.

The first test was at 80* under my carport. Both the gun and 12g were kept inside at 71* till testing started. The changer was on the bottom line with a Tippmann asa and 5" of macro. 5-10 sec between each shot to record the fps.

1. 269
276
--
275
266
266
271
259
260
270
11. 256
279
264
268
262
268
264
--
269
261
21. 268
266
258
278
280
280
265
28. 253
209
-- (dumps air)

28 good shots before dropoff. Not bad compared to most guns, but it's still low compared to the others posted.
This led me to see what pre and post reg expansion does for efficiency. The next morning I removed the bottomline and used my Vert air adapter from my phantom to attach the changer vertically to the reg. I also took up .1 cu/in from the total .4 cu/in of space in the chamber using some cylinder bearings. I also put a similar bearing after the reg in the asa threads. The test was similar with 84* outside temp and gun/12g being 71* from inside.

1. 239
246
248
237
249
245
263
236
242
237
11. 252
255
239
248
245
239
261
244
240
246
21. 261
244
249
245
246
239
247
255
249
247
31. 249
247
239
243
35. 247
207
167(vents)

7 extra shots. This could very well be a combination of a larger fill in the 12g, the 21 fps lower average shot(267v246), and lower pre/post reg expansion. Not bad considering how little work was required to get that. More time needs to be put in to work out how much each individual change affects the total. The 20th I'll be playing some games, so I'll see how my shot count goes. If I have some extra 12g and paint left, I'll keep testing.

Finally took the time to run this test on my mQ gun ...
mQ2 sniper, '03 halfblocked full-size body, jcurt bolt, WWA pump kit, Pi regulator, Universal T-board @ 4ms dwell, no capacitor. Kaner 14" .682 back. Rat attack dropout QC screwed into bottomline.
Chronod to ~280 fps on a somewhat questionable tank before performing tests. One shot every 3-5 seconds.

Pull #1, using 9.6v NiMH battery
1. 291.4
280.3
275.7
280
277.5
281.7
276.5
279.0
272.7
10. 277.5
279.3
280.9
278.6
274.2
278.0
0 <--- blank
273.6
277.5
276.5
20. 279.7
280.8
277.2
267
274.4
275.9
276.2
274.4
271.5
272.8
30. 273.6
275.0
274.7
273.9
277.2
271.6
275.1
278.7
282.0
291.6 <- Low pressure hot shots
40. 291.3
255.0 <- Drop off point
130.7 <- Last shot, ball doesn't leave barrel after this.

40 shots, maybe 41 if you count the 255 shot.
standard deviation including first high shot and low pressure hot shots: 5.13
standard deviation between those: 3.27

Pull #2, 9v li-ion battery (required pressure raise a bit)
1. 264.6 <- Eh?
275
281
276
273.7
271.8
279.5
279.2
280.6
10. 285.1
278.2
276.6
279.9
279.2
281.3
277.6
274.9
277.8
277.5
20. 282.4
281.1
286.2
279.1
284.9
279.4
284
281.6
279.7
284.5
30. 282.5
272.4
268.6
273.9
270.8
273.2
281.4
280.7
266.5
271.9
40. 285.2 <- Low pressure hot shot?
287.6 <- Low pressure hot shot?
42. 301.7 <- Low pressure hot shot
182 <- Last shot as above

42 shots, 41 if you consider the 301 compromised
standard deviation including first low shot and low pressure hot shots: 6.41
standard deviation between: 4.73-4.96

Couple low shots blew the curve, I'm gonna blame the paint

But yeah .. about 40 shots for me on crosman 12 grams. Sweet.

Relevant Discussion

I just want to add one thing - regged 12g setups are for summer play only. Outside temperature drops below 20 deg.C and whole sweetspotting goes bye-bye, plus dropoffs and frozen regs. Unregged-old valve setup wins here.

Not necessarily. The valve sweetspot isn't going to change just because of temp changes, but dropoff and frozen regs are definitely a factor. I don't think an unregged setup wins, though...

Consider that the 2k+ gun I first tested sweetspotted at 240 psi. That means the co2 does not necessarily have to reach its normal pressure of 850 psi. As long as it's somewhere above that 240 psi mark, it'll keep working. I guess it depends on how much pre-reg expansion you have, but let's just assume that the volume before the regulator drops the "fill %" by half, or doubles the volume in the cartridge.



At freezing point, CO2 will be at 500 psi according to these graphs, until it hits 15% fill. It remains to be seen how much liquid would be shot through the reg and wasted, but you can see that the gun would still function better than your average 12g gun.

This also applies in the summer where many guns are vapor locked. A 50% fill in the pre-reg volume at 100 degrees F still gives you around 1200 psi. Most guns lock up, but with good fittings the regged setup should work perfectly.

Ok, so what? To achieve best overall CO2 efficiency AND consistency, we want:

-2K +/- body/valve ?
-A reg
-more volume before reg? or after?
-Valve spring? (light/medium/hard)
-Main spring? (light/medium/hard)

I have recently acquired an older style body, and a newer style body, and I want to have both a nice SC cocker, and an C/A bulk fed one. I would love to tune the 12g one for ultimate 12g usage, but after reading this thread, everything I thought I knew about SC cockers is blown away.

-A

paintballnerd, there's no comparison. The regulated LP 12 gram setup simply blows unregged out of the water. Of course, you can't have a simple setup like a changer in the vert adapter. If you want a clean setup you might want to lean towards unregged.


As for regging 12ies, just sweetspot your gun and go from there. Right now there isn't a whole lot of information out there on LP Sniper 12 gram setups besides what's in this thread.

I believe you want the lowest sweetspot possible, which depends entirely on your valve and possibly your springs. Having an open face bolt and good valve won't hurt, although we haven't tested a Tornado/Rat valve yet. The lower the pressure, the lower you can shoot into the cartridge and the bigger the difference is between pre and post reg, which should encourage quick regulation. That doesn't mean you should drop your operating pressure for no reason - you want to be running at the highest velocity you can get out of your inline regulator. All other velocity adjustment should be done via mainspring. This will give you the best consistency even when you are shooting quickly.

If you are going to run the gun off of the sweetspot, you need to run it below the ideal pressure. If you run it above the ideal pressure you will get significant shootup. I don't recommend running at anything other than the sweetspot, though.

I got the best efficiency out of an open face bolt, stock 2k+ cocker valve, light (stock) springs.

As for volume, I think you need a certain amount after the regulator but if you can have too much. I dropped a few shots when I added a big pressure tester post-reg. I think the 2k+ gun body has a good amount of room to work with, keep it stock, and avoid putting any big adapters/fittings/testers between the reg and the body.

Pre-regulator volume. I'm not sure how much is needed, but I know you want to have enough to keep liquid from being sucked through the regulator. Remember, I got my original 45+ shot count with a bottomline with about 5 inches of macro hose.

Springs. Just throw heavy valve/light main in the gun, sweetspot and see where you stand. If you need to change, do it. You should pretty much just be following the same guide you'd take to set a low pressure Sniper or Cocker up.

^^^^^

In short: sweet spotting is finding the idea operating pressure (by adjusting the reg) for a given valve/hammer spring combination.

The Sweet spot is the point where velocity drops if the pressure is both increased or decreased.

[russc]

Years later, I think my main takeaways at this point are:

1. Regulated Snipers run better than any Nelson I've tried - regged or unregged.
2. Unregged Snipers are like driving a carbureted car. It's simpler, but it can take some tinkering and you're sacrificing performance for style points.
3. Nelson-valved guns generally run pretty well unregged, and while a regulator gives you more predictable shot drop-off, you won't see a major increase in total shot count.
4. I try and stuff a regulator into anything I use with 12 grams these days. The pros/cons are one-sided unless you are trying to stay slim or simple.

[RAZRBAKK]

Appreciate you putting this whole thing together originally. I'm piecing together an SC setup built around this idea. Excited to test in the Spring.

[grd]

hi russc

[Chuck E Ducky]

Thanks for putting this all back together in one easy to process post. That thread was like 20+ pages long if I remember correctly.

[Impactfour]

This may be an off topic question, but I'm in the process of making a pump action Spyder. I've got my hands on a spring kit so I have some flexibility, but would the tuning process be similar to hit ideal efficiency?

[russc]

Yep, basically the same valve design.

[Spider!]

2. Unregged Snipers are like driving a carbureted car. It's simpler, but it can take some tinkering and you're sacrificing performance for style points.

😪 Sad but true. It's ok to drive a Model T on occasion, especially when you get a group together. The groups tend to look similar too. 😋

[fouge]

Regged sniper will work better... ok. But, pre2k or post2k body for a build?

[Lt. head-shot]

Based on this line - "2. "dead space" is less significant, if not inconsequential in a regged setup versus an unregged setup where all expansion is avoided." - Either body should be fine. More space in a 2k, but with that being less significant, I would say go 2k for more options/parts

[Socalpumpballer]

2k+ bodies. Pre 2k got less shots

[RAZRBAKK]

The original thread inspired a build in my head years ago. Back then I bought a pre2k body/backblock/vasa/etc. because I was sure that other users said they had better efficiency than the 2k+, but that doesn't seem to be the case lol.

Either way, this summer I played true stock class for the first time in many years, and I decided it was time to go ahead with the build.

Starting point:



I have been sitting on a few parts that were perfect for the project, namely a clear acrylic Phantom feed block/cap, a doc Tanto barrel, and a female stabilizer that I decided to take off of my pirate since it wasn't really doing much.

I bought a bunch of AC parts to complete it from a user on here, and I picked up the remaining bits + a Slice kit from autocockerparts.com.



I sent the body to my good friend BLITUS for modification, since he's done similar mods for me on my Automag, and probably something else, I can't remember.





So it was time to throw it all together.





Unfortunately the VASA I got must be a 2k+ as it doesn't actually fit this body, so the search begins for one of those.

Once I have that I'll probably take it out with a 9ci a couple times this winter, but other than that I'm just waiting for Spring so I can sweetspot the reg and really put it through it's paces.

Things I want to change:

-The ASA adapter(I don't know what it's called) is pretty beat up, so I would like to get another one of those.
-The clear feed cap took a nasty fall and the acrylic is pretty brittle so it shattered and is currently held together with epoxy. It works, but I'm going to order a black phantom feed tube/cap and keep the clear block.
-My tanto barrel has taken a beating and is pretty scratched up. I'm not sure if I like it with a longer or shorter barrel, so I'll be messing around with that in the spring as well.
-QD on the steel braid because removing the stabilizer is a pain without one.
-I'm going to try and take one of the slices out of the kit to keep the pump handle nice and short.

[RAZRBAKK]

Latest update:



I was given a VASA to replace the incorrect one I had, and this barrel looks nice on there.

I tried to shorten the screw holding the feedtube on, and ended up ruining it lol.

I also can't figure out what is going on with the pump stroke. I put some orings from Autocockerparts.com on the bolt and the thing really sticks in their now. Unfortunately I threw the only o-rings out, so I can't compare them.

Any suggestions from the sniper enthusiasts on smoothing the pump stroke?

[XEMON]

why not put the macroline fittign directly into the body?
Saves you the vasa on there

[RAZRBAKK]

XEMON thats a little outside my comfort zone.

[XEMON]

I can guide you if youd like, all you need is a hand drill and a tap and drill for 1/8npt.
I did that to my cocker build and it looks nice and small.

[RAZRBAKK]

This project has been slowly coming together for me, and here is the latest update.

The palmers stabilizer had an oring turn to literal goo. I have no idea how it was even sealing, but it was. I did my best to clean it out, rebuilt it, and this week went through sweetspotting and testing.

You're results may vary always seems to apply to me. I've been having a hell of a time eliminating a leak down the barrel. I have tried 3 different valves with 3 different cup seas, and it's intermittent. Today I received some ID springs to try out. I ran the test 3 times after sweet spotting with the rebuilt reg and new springs.

Crosman 12g with 2nd heaviest valve spring and medium hammer spring:

1. 274
2. Chrono error
3. 265
4. 276
5. 262
6. 283
7. 287
8. Error
9. 272
10. 274
11. Error
12. 272
13. Error
14. 270
15. 263
16. 261
17. 267
18. 270
19. 269
20. 285
21. 278
22. 281
23. 293
---- Barrel leak starts
24. 218
25. 100

Not great. I switched to a Leland.

Leland
1. 254
2. 273
3. 237
4. Error
5. 253
6. 261
7. 234
8. 278
9. 237
10. 271
11. 235
12. 270
13. 279
14. 244
15. 258
16. 230
17. 259
18. 242
19. 262
20. 248
21. 275
22. 285
23. 259
24. 273
25. 242
----barrel leak
26. 197
27. 51

So I went back inside, switched it to the heavier valve spring(maybe this is the wrong idea? just trying to deal with my chronic cupseal leak). Re-sweet spotted, and threw in a crosman.

Crosman
1. 274
2. 262
3. 259
4. 270
5. 251
6. 254
7. 262
8. 271
9. 252
10. 263
11. 267
13. 275
14. 257
15. 272
16. error
17. 269
18. 267
19. 271
20. 275
21. 268
22. 261
23. 282
24. 279
25. error
26. 245
---- barrel leak
27. 185
28. 132

So getting around 25 usable shots. Definitely hoping for more than that.

Back to the drawing board. If anyone has any suggestions, I am open to hearing them. I'm not very knowledgeable on cockers/snipers, so maybe I'm going about the springs the wrong way.

Or maybe it's just because I decided to use a pre2k body? I may end up sourcing a 2k+ and starting over.

[Cdn_Cuda]

I think I have some sort of 12 gram feed (should say air adaptor). I can try to throw. It on one of my 2k snipers and see how it performs, if that’s helpful.

[RAZRBAKK]

Well, the feed isn't the important part. If you feel like slapping a 12g changer on and giving it a shot I would be interested to see what you get.

[Cdn_Cuda]

Sorry, meant air adaptor.

[RAZRBAKK]

Gotcha. Yeah man, I'm interested to see how it turns out for you.

[RAZRBAKK]

Ended up swapping the valve spring for a much lighter one(2nd lightest in the Inception kit), and put the most medium main spring in. Re-sweet spotted the reg, and set the velocity to around 270(Most shots between 260 and 280).

Shots 1 - 25 were all strong.

Shot #26 read 244 and the gun started venting. Next shot was 133, and when I popped the 12 gram it was 99% empty.

At this point I think the Pre-2k body may be a significant factor in the efficiency of the gun. It's shooting near perfect. Pretty quiet, no fart/vent/anything when firing, so it's well balanced.

One other thing is that the optimal sweetspot is about a 1/8th turn away from the gun venting when not cocked, so it's quite tough to get it perfect.

I'm out of paint at the house and have used about forty 12 grams in testing, so I think I'm gonna put this on the backburner until I source a 2k+ body (please don't PM me yours, I can't afford it right now).

[Cdn_Cuda]

Hopefully I can get my testing done in advance and it should give you a better idea of how a 2k cocker handles 12gs. I’ve never used them on a cocker.

[anson]

Thoughts on why a 2k+ is more efficient than a pre 2k on 12grams?
is it because 2k+ run at lower pressure?

[RAZRBAKK]

Volume, I think. I remember in the old thread it had been noted that pre2k were less efficient, but I don't remember it being so substantial. I have 2 other valves to try, so I might give those a go in the coming weeks.

[Jordan]

Springing and matched components can really affect everything, too... my pre2k Sniper 3 got close to 40 shots on a Crosman 12gram, sweetspotted around 550psi. Used an old valve and bolt with small passageways and stiff ish springing.

[RAZRBAKK]

I also am interested in trying a different reg. It feels like the sweetspot of the reg is RIGHT at the edge of the pressure needed to keep the valve closed.

[Toestr]

Ended up swapping the valve spring for a much lighter one(2nd lightest in the Inception kit), and put the most medium main spring in. Re-sweet spotted the reg, and set the velocity to around 270(Most shots between 260 and 280).

Shots 1 - 25 were all strong.

Shot #26 read 244 and the gun started venting. Next shot was 133, and when I popped the 12 gram it was 99% empty.

At this point I think the Pre-2k body may be a significant factor in the efficiency of the gun. It's shooting near perfect. Pretty quiet, no fart/vent/anything when firing, so it's well balanced.

One other thing is that the optimal sweetspot is about a 1/8th turn away from the gun venting when not cocked, so it's quite tough to get it perfect.

I'm out of paint at the house and have used about forty 12 grams in testing, so I think I'm gonna put this on the backburner until I source a 2k+ body (please don't PM me yours, I can't afford it right now).

Oops sorry.

Sent from my Pixel 4a using Tapatalk

[Toestr]

Have you seen this thread by russc ?

https://www.pbnation.com/showthread.php?t=3032401#/topics/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.

Sent from my Pixel 4a using Tapatalk

[anson]

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