Cocker Question

Mstrtal · 12-07-2006, 06:16 PM

What is the shortest length that the bottum tube in a cocker has to be? I mean the absolute smallest possible combinatoin of internals. I am not asking about the front pnuematics. Simply what is the limit on how small you can cut a body and still cram in the required internals and have them work?

kidneythief · 12-07-2006, 07:08 PM

That would depend on input pressure and springing. You could theoretically put a shorter and heavier spring in and take down the lower tube alot. Your problem is the IVG and velocity. If you were able to slap an MQ valve in you could cut it down to the valve(unrealistic). I would say that it is perfectly feasable to take about 1/2" off without running into any big problems. Take your cocker and crono it to where you want it...next check to see where the IVG is sitting. Then try some different inpout pressures and spring combos to see if you can still achieve your desired velocity while forwarding the IVG in further.

-Jake

Cunha · 12-07-2006, 07:50 PM

Keep in mind that you are still limited to how large your loader is..for instance if your using an evolution 2 anyways your gun may as well be 6 inches off the back..even with a revvy, much shorter than the normal configuration gets to be pointless.

Theres alot that can be done though, just for the sake of doing it.

Mstrtal · 12-07-2006, 08:12 PM

So length wise how short do ya guys think it could be chopped? 6 inchs 5 inchs 4 inches? The smaller the better!

Walker · 12-07-2006, 08:39 PM

MQ valve? Or mechanical?

With an MQ valve you can reduce the length since you don't need as much space for hammer travel, and then you can turtle it and not need a back block.

The smallest I've had is 5-3/4", not including the front block. That barely leaves you room to bolt a frame to, and no room for a separate beavertail mount. That's a mini with a p-block.

Walker

Tom222 · 12-07-2006, 09:27 PM

An old teamate cut one down to the size of the grip frame. It too, was a mini with a p-block. It worked very well, but was sometimes touchy if you had to adjust the velocity much.

Mstrtal · 12-07-2006, 11:29 PM

Ok so obveously Merlin extrusoins take a diffrent sorta lower internals any one have alink to the deminsoins of these so I can start designing my silly little project?

sniperfan · 12-08-2006, 12:34 PM

Back in 1994 I did some drawings, and if you wanted to get really short, you could move the valve itself foreward in the receiver, drill a new transfer port "rimfire style" like a PGP uses (i.e.-no port in the bolt at all).

The problem with the stock 'cocker platform for shortening the front of the receiver is the positioning of the trigger guard screws, which is not insurmounbtable, but pretty soon youre better off starting with a blank sheet of paper than using a cocker.

My thoughts at the time were to 1) make an adaptor plate that bolted to the bottom of the receiver, then the trigger guard, to make up for the differences. 2) Rimfire the exhaust valve, and move the cocking lug to the rear of the bolt 3) take the pneumatics as far back as practical 4) Shorten and P-block the rear of the receiver 1" and use the rear grip frame screw to retain the IVG, and eliminate the IVG screw, which I did on a Micro-Sniper I did, and it worked well.

If youre designing your own gun with cocker based geometry, the skys pretty much the limit. Once the receiver becomes that short you can probably make your receiver on a basic mill/drill setup.

12-07-2006, 07:08 PM	#2 (permalink)
kidneythief Lord humungus the Mod Join Date: Mar 2006 Location: Home Finally!!!	That would depend on input pressure and springing. You could theoretically put a shorter and heavier spring in and take down the lower tube alot. Your problem is the IVG and velocity. If you were able to slap an MQ valve in you could cut it down to the valve(unrealistic). I would say that it is perfectly feasable to take about 1/2" off without running into any big problems. Take your cocker and crono it to where you want it...next check to see where the IVG is sitting. Then try some different inpout pressures and spring combos to see if you can still achieve your desired velocity while forwarding the IVG in further. -Jake __________________ "I wish simply to be a decent person, yet I will always fear the retards" -Brian Hindt(geech) MCB Moderator Kidney Machine

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12-07-2006, 07:50 PM	#3 (permalink)
Cunha MCB Member Join Date: Apr 2006 Location: Monterey, CA	Keep in mind that you are still limited to how large your loader is..for instance if your using an evolution 2 anyways your gun may as well be 6 inches off the back..even with a revvy, much shorter than the normal configuration gets to be pointless. Theres alot that can be done though, just for the sake of doing it.

12-07-2006, 08:39 PM	#5 (permalink)
Walker MCB Member Join Date: Apr 2006 Location: Spokane, WA	MQ valve? Or mechanical? With an MQ valve you can reduce the length since you don't need as much space for hammer travel, and then you can turtle it and not need a back block. The smallest I've had is 5-3/4", not including the front block. That barely leaves you room to bolt a frame to, and no room for a separate beavertail mount. That's a mini with a p-block. Walker

12-07-2006, 09:27 PM	#6 (permalink)
Tom222 Active Member Join Date: Apr 2006	An old teamate cut one down to the size of the grip frame. It too, was a mini with a p-block. It worked very well, but was sometimes touchy if you had to adjust the velocity much.

12-08-2006, 12:34 PM	#8 (permalink)
sniperfan Rec Poster Join Date: Jul 2006 Location: Bay Area of CA	Back in 1994 I did some drawings, and if you wanted to get really short, you could move the valve itself foreward in the receiver, drill a new transfer port "rimfire style" like a PGP uses (i.e.-no port in the bolt at all). The problem with the stock 'cocker platform for shortening the front of the receiver is the positioning of the trigger guard screws, which is not insurmounbtable, but pretty soon youre better off starting with a blank sheet of paper than using a cocker. My thoughts at the time were to 1) make an adaptor plate that bolted to the bottom of the receiver, then the trigger guard, to make up for the differences. 2) Rimfire the exhaust valve, and move the cocking lug to the rear of the bolt 3) take the pneumatics as far back as practical 4) Shorten and P-block the rear of the receiver 1" and use the rear grip frame screw to retain the IVG, and eliminate the IVG screw, which I did on a Micro-Sniper I did, and it worked well. If youre designing your own gun with cocker based geometry, the skys pretty much the limit. Once the receiver becomes that short you can probably make your receiver on a basic mill/drill setup.