Autocockers, 12 Grams, Regulators, etc

[Lt. head-shot]

I know there were several topics on this "pre-hack", but I am working on a stock class pump cocker now, and would like to get some info. This is mostly going to be a fun project build so I am not looking to make it an insane 40+ shot gun, but I would be happy with 30. Might also run a 3.5 ounce off the front end.

Any thoughts or experiences are appreciated.

1 - I have sourced a 2K RF cocker body, and am planning on running a 12 gram changer /co2 tank right into the vert ASA.
2 - I know that 99 bodies are better, but what is the general process for devolumizing a 2K body?
3 - Palmers makes a "high pressure" autococker valve, is it needed and does it make a big difference?
4 - Palmers also makes a 12gram Cart Regulator, is this a better option?

[russc]

The only way you're gonna get into the 40s is with a regulator...you could probably do 30s unregged, but it'll shoot down at the end. I'd just use the cart regulator and be done with it.

[NONOBLITUS]

Russo said it and I agree. I would also throw on a lever changer stock and your in business

[Lt. head-shot]

Well, Cart Regulator ordered, went for the 12gram specific one and killed 2 birds with one stone. Also bought a lapco angled asa with a gauge so hopefully I'll be able to tune a bit more easily. Any recommendations on starting pressure?

[Jordan]

Most 2ks with stock valving run 350-400 psi. I'd start at 325ish and go from there, you will need to sweetspot the input pressure so I'd recommend using bulk air to do so, it's very frustrating to use 12grams when setting up a reg pressure. Once it's set, though, you really don't have to touch it, regardless of what propellant you use.

RussC is right, though... you won't see 40+ shots without a reg, you're on the right path to uber-efficiency. I had a pre2K Sniper 3 setup that got close to 40 shots on a 12gram, probably could have snuck a few more out of it with a bigger valve chamber/lower operating pressure.

[Lt. head-shot]

Ok, I will start there and work up. Sadly I bought the all in one 12 gram Cart, so I might have to make a dummy 12 gram for testing. And like I said I am not looking to be crazy, 40+ is probably out of reach. I'll be genuinely happy with 30-35 good shots. The regulator also has the added bit of allowing me to possibly use 12 grams in the cold, which is one of the big reasons I don't currently use them as much.

I'm going to start with the stock springs that come with the gun, so we'll see how that goes for sweetspotting. I do have an inception spring kit that I may try to work with later.

[scottieb]

I had a pre2K Sniper 3 setup that got close to 40 shots on a 12gram, probably could have snuck a few more out of it with a bigger valve chamber/lower operating pressure.

Is that the one that went to MAR? Then to me?

[Jordan]

Yes... I think so.

[scottieb]

Good to know Jordan. I had always thought it was a mini cocker with the pump kit added.

[Lt. head-shot]

Just a little update. This is what I ended up building. 2K body, 12gram PPS Cart regulator (with new external adjustment), Stiffest Valve spring I could find. 250PSI on the reg. With literally no tuning I was getting 33ish shots out of it. 681 tightbore 16inch barrel, running 682-684 paint at 280 FPS. So taking what has been said on here and elsewhere, running a reg is the BEST way to go. I've ended up parting this build out since I got a GREAT deal on a phantom, but it was super fun to shoot while it lasted. If anyone need the 12 gram regulator for a build, hit me up.

[Murdoc555]

How did this compare to the CCI bucket changer in regards to how well it connected and screwed out? Some of the other buckets like mastersconi take way too many revolutions, compared to the phantoms 2 - 2.5 turns.

[Lt. head-shot]

Murdoc555 I can't say I remember it being too bad, but I think it was close to the CCI one. For bad changers I've always just glued a penny in the bottom of the changer which helps take up space on the threads.

[Murdoc555]

Cool, thanks for the tip. I have a sniper I’m wanted to convert to SC as well, and will probably just but this Cart that you have. Thanks for the write up, I’d over even heard of it.

[Alexndl]

Pm sent on 12g reg
need one for a build

[Magmoormaster]

That ano is nuts!! Or is it a dip?

I'm curious how volume plays into this. I've previously understood that running hP with a pre-97 body was the best way to go for efficiency. With a LP setup (250PSI is crazy low btw!!), I wonder if 2k+ volume is the ideal or if you'd want the smaller volume and run a slightly higher pressure.

[Lt. head-shot]

Its a hydro-dip. First attempt at it, came out ok. Don't know about volume vs pressure, didn't fudge with it too much. Just put it together and click clack boop.

[russc]

At this point I'm convinced there's a ton of cross-talk between different tuning strategies and platforms. With Nelson valved guns, I think devolumizing causes the gun to shoot a saturated liquid/vapor mixture, which then expands in the barrel. If you run a hard valve spring, you can precisely meter how much of that mixture is escaping, so you can get great efficiency. That logic was then applied to 2k snipers, and folks started devolumizing them to 99 spec. I always found unregged Sheridan/Snipers to be pretty bad performers, so I'd be interested to see before and after data on devolumizing.

In my mind, the ideal valve chamber size on a regulated gun would be just big enough to provide backpressure on the valve to prevent venting or burping, while getting you to your target velocity.

[Chuck E Ducky]

I average 30 shots at 280fps above 60* with a completely stock CCM. All I do is screw in an ICD leverchanger in the ASA and use a small bore barrel. Only issue I have been having is with the CCM fittings. I plan on switching it out with a hard line like a phantom uses, or braided line to make it seal all the time.

[$L!mBo]

steel braided with those blocky 90°s would look great. i found some red annoed ones a while back, ill see if i can dig em out

[Chuck E Ducky]

Thanks Slimbo I’m going to check those out.

[RAZRBAKK]

I'm actually really happy this topic has come up again. It was an interesting discussion, and I'm in the process of putting together a SC sniper.

So, the consensus is pre-2k body, at least one regulator. Sweet spot it, and you're pretty much good to go? How do I sweet spot again?

[Jonnydread]

Put the IVG a turn or two in, crank the reg up (testing the FPS intermittently) until the FPS drops rather than increases, turn it back 1/4 turn and set velocity.

[Fantom919]

I'm running two regs on a 2k sniper which works well. 34 shots in 63* weather. Very consistent and having 2 regs gives more surface area for the gas to warm up like an old expansion chamber. Even after shooting quickly, the reg going into the ASA remains relatively the same temperature.

I've tried this set up with a pre 2k body and i think there is maybe not enough volume if you're pushing lower pressure. Most pre 2k pump kit shafts are solid and don't allow for extra volume like the 2k kits do (ccm or inception for example). I've found I've had to increase the input pressure to hit 280 velocity on the pre 2k body.

With the 2k pump kits, the added volume seems to help and also gives more surface area for the gas to warm up assuming its not too cold outside. I imagine I lose efficiency due to all the added volume from the pump kit and extra reg but I'm okay with the number, especially since I can shoot fast and not have shoot down due to pressure drop.