Post by deputy865 on Feb 17, 2012 22:21:01 GMT -5
Well, as the title states, this is my first sniper rifle build. I knew it seemed to good to be true when everything went together so easily for me.
First things first.. Parts list:
JG BAR 10
Stock Hopup Assembly
King Arms Bucking
Stock Cylinder
PDI Spring Guide
PDI ''SPR'' 300% Spring
Laylax High Pressure Piston S/Silent Shaft (Wasn't thrilled about mixing brands but I had no choice and needed a 90 degree piston)
PDI Tapered Cylinder Head
Noobies M-Trigger
EdGi 435mm x 6.01mm TBB
Madbull .40g BB's
I have Teflon taped around the bucking and the threads of the cylinder head for added insurance.. So much for that.
First time around trying to shoot it, nothing happened. BB's were loading but were getting stuck. The problem was the hop up arm was pressing too much on the bucking itself. So I shaved the nub. ((I plan on doing the TDC mod soon)). When I received the gun, the hop up arm nub had been broken off and was glued back on by previous owner. It obviously stuck out much further then stock, so I shaved it down..
After shaving it and re-installing, I racked the gun back and shot it. To my amazement, a BB flew out.. But at the compression of a fart.. So I tore everything down, redid the Teflon tape around the bucking and cylinder head, as well as shaved the hop up arm nub a little more... I have yet to test it.
Air has to be escaping somewhere and I can't seem to figure it out. The PDI cylinder head definitely fits snug into the bucking so that portion is getting a good seal. I am sure of this because if I unscrew the outer barrel, the cylinder head likes to come with it unless I pull the assembly back a bit.
Any ideas for me to try? I should of seen this coming.. It all seemed far to easy then just buying nice parts and installing them.
EDIT: After trying it out for the second time, it seems I got a little bit better compression. Lubed the gun up as well. I also held my finger over the cylinder head and fired the rifle. The piston seemed to hit the cylinder head just as it would if my finger wasn't in the way... So would that mean I'm loosing compression at the piston? There aren't any O-rings around it, just plastic pieces. The piston doesn't really fit THAT snug inside the the cylinder either.. It has some play, but not a lot. Probably enough to let air out though. So how would I go about fixing that?
EDIT II: I'd also like to add that the gun is super loud... Also, I tried a compression test with the spring out of the cylinder, putting my thumb over the cylinder head and pushing the piston into the the head. It freely goes in and out, there is no vacuum at all. I also read that the airbrakes on these pistons suck power from guns, so I removed the airbrake and put the grub screw in. I also put the O-ring around the massive canyon in the piston. I even filled the canyon with Teflon tape. No change in compression.. What the hell is going on!!?! I'm trying all kinds of stuff...
Shane
First things first.. Parts list:
JG BAR 10
Stock Hopup Assembly
King Arms Bucking
Stock Cylinder
PDI Spring Guide
PDI ''SPR'' 300% Spring
Laylax High Pressure Piston S/Silent Shaft (Wasn't thrilled about mixing brands but I had no choice and needed a 90 degree piston)
PDI Tapered Cylinder Head
Noobies M-Trigger
EdGi 435mm x 6.01mm TBB
Madbull .40g BB's
I have Teflon taped around the bucking and the threads of the cylinder head for added insurance.. So much for that.
First time around trying to shoot it, nothing happened. BB's were loading but were getting stuck. The problem was the hop up arm was pressing too much on the bucking itself. So I shaved the nub. ((I plan on doing the TDC mod soon)). When I received the gun, the hop up arm nub had been broken off and was glued back on by previous owner. It obviously stuck out much further then stock, so I shaved it down..
After shaving it and re-installing, I racked the gun back and shot it. To my amazement, a BB flew out.. But at the compression of a fart.. So I tore everything down, redid the Teflon tape around the bucking and cylinder head, as well as shaved the hop up arm nub a little more... I have yet to test it.
Air has to be escaping somewhere and I can't seem to figure it out. The PDI cylinder head definitely fits snug into the bucking so that portion is getting a good seal. I am sure of this because if I unscrew the outer barrel, the cylinder head likes to come with it unless I pull the assembly back a bit.
Any ideas for me to try? I should of seen this coming.. It all seemed far to easy then just buying nice parts and installing them.
EDIT: After trying it out for the second time, it seems I got a little bit better compression. Lubed the gun up as well. I also held my finger over the cylinder head and fired the rifle. The piston seemed to hit the cylinder head just as it would if my finger wasn't in the way... So would that mean I'm loosing compression at the piston? There aren't any O-rings around it, just plastic pieces. The piston doesn't really fit THAT snug inside the the cylinder either.. It has some play, but not a lot. Probably enough to let air out though. So how would I go about fixing that?
EDIT II: I'd also like to add that the gun is super loud... Also, I tried a compression test with the spring out of the cylinder, putting my thumb over the cylinder head and pushing the piston into the the head. It freely goes in and out, there is no vacuum at all. I also read that the airbrakes on these pistons suck power from guns, so I removed the airbrake and put the grub screw in. I also put the O-ring around the massive canyon in the piston. I even filled the canyon with Teflon tape. No change in compression.. What the hell is going on!!?! I'm trying all kinds of stuff...
Shane