Conversion

magnum9987 · Sat May 10, 2008 1:07 pm

I want to turn my Crosman Pumpmaster 760 into an airsoft gun. How?
I know the bore of the barrel must be adjusted but i dont know where to go from their. I don't want to open my gun in fear of permanently damaging it.

bluerussetboy · Sat May 10, 2008 2:20 pm

Is your 760 a .177 cal pellet gun? That translates into 4.5mm cal. Airsoft BBs are 6mm. A whole 1.5 mm larger. You would have to bore you barrel to the larger caliber(this would permanently damage it) unless they sold an airsoft barrel for it. You could probably replace the barrel with a piece of brakeline and keep your old barrel. Is there any lugs attached to the barrel, that could cause problems with the function of the pump.

judgment_arms · Sat May 10, 2008 2:57 pm

In order for that to work you need to:
Replace the barrel
Build a new magazine
And ream out the breach block

After that you’re looking at 650-800fps at muzzle, nobody in there right mind would want to play against that.

If you ask me, it’s a fool’s errand; you’d be better off buying a professional grade airsoft gun.

DYI · Sat May 10, 2008 3:52 pm

Unless they don't know it's doing 800 fps at the muzzle

Yeah, trying to bore out the barrel would be a really, really bad idea. McMaster-Carr sells some .243" ID seamless stainless steel tube that would make a great airsoft barrel, and it's only $30 for 3 feet of the stuff.

magnum9987 · Sat May 10, 2008 6:07 pm

Could it be done if I could find the blueprints?
As of fps, I'm sure if the strength of the pump where reduced, the gun would have, um, manageable, fps rating.

frankrede · Sat May 10, 2008 8:46 pm

magnum9987 wrote:Could it be done if I could find the blueprints?
As of fps, I'm sure if the strength of the pump where reduced, the gun would have, um, manageable, fps rating.

Perhaps the fps could be dropped with some type of air flow restriction.
I know that nerf guns are limited to shooting at piss poor speeds by restricting the flow.

judgment_arms · Sat May 10, 2008 8:58 pm

You could just only put one-three pumps in it, but then nothing but honor stops you from going full steam and… you know, I’ve never heard of a velocity cap on airsoft games…

Blueprints, blueprints for what?

magnum9987 · Sun May 11, 2008 6:51 pm

the crosman pumpmaster 760 searched both the website and advanced search on google, and couldn't find them.

judgment_arms · Mon May 12, 2008 8:11 am

Here, look it up.
Crosman Rifle Manuals

magnum9987 · Mon May 12, 2008 1:45 pm

these will do. How should i approach to change the barrel first?