August 14, 2014 at 14:11 #3448
I received a question from a PF Friendly, Ryan who ran with us at MSW’s DO Event.
Dennis my goal with my rifle is to make it shoot either just under MSW rifleman fps limits or make it a dmr. With the suppressor I can fit a 510mm barrel. My cylinder, piston, piston head, and nozzle are all stock and don’t have a very good air seal. Should I get a cylinder without a port? And do you have any recommendations for what brand and type of parts to buy? I want something of good quality, but not real expensive. Thanks Dennis.
FEEDBACK – I’m not a expert but do have a fair amount of experience collected from my own experiments, members of the team and other airsofter’s I respect. I think this is more than you asked for and most you may already know … but I hope this helps.
The MSW limits are pretty standard so its a good goal to shoot for. If you don’t have a chrono, I suggest buying one and always chrono with quantity ammo, min weight you should be shooting is 0.25. If you decide to go the DMR route a mechanical lock-out for full auto is required (one that can’t be removed in the field)
Pistols, Shotguns, GBBR, AEGs & LMGs: 1.5 Joules
6mm: 400fps w/0.20g, 366fps w/0.25g
DMR/Sniper Rifles: 2.8 Joules (Minimum engagement distance 100ft)
6mm: 550fps w/0.20g, 490fps w/0.25g
CYLINDER PORT- At 510mm for the barrel, I would NOT use a ported cylinder, above 550mm barrel length calls for a cylinder bore-up, I have never messed with that. There are a lot of forums out there on this subject if you wish to do more research.
AIR LEAKS – Air leaks can be a real bitch to solve, don’t try to overcompensate by using a strong spring, it will only end up breaking things.
Piston head o-ring and cylinder head leak: easy to check, put your finger over the cylinder head nozzle and see if you can push the piston up in the cylinder, if it moves you have a leak. If it leaks, put it in a big bowl of water and push the piston up again. Make sure to have the piston inserted in the cylinder before putting it in the water, you want to trap air in the cylinder. Where the air bubbles come from will help determine if its the piston head o-ring, cylinder head o-ring or both. A single wrap of Teflon tape around the cylinder head helps a lot, make sure none ends up in the cylinder or interferes with the air nozzle. A new piston o-ring is cheap insurance, I buy them in bulk from home depot the o-ring is a size 14 or 014, find them in the plumbing section. I store my new ones stretched over a old cylinder it stretches them out perfectly. Make sure to stretch the o-ring for a few days before installing.
Hopup bucking leak around the barrel: Harder to identify, but if the hopup bucking/barrel slide too easily into the hopup chamber, chances are there is a leak. I cut off about 6mm off the end of the bucking and then give 2-3 wraps of Teflon tape to lock in in place. Make sure not to cover the barrel notches for the hopup chamber c-clip. Also make sure the BB contact patch is centered in the barrel grove after you tape. I then install the hopup chamber and wrap it 3-4 times with more Teflon tape. Yes I love my tape … use the cheap white tape for water pipes, the yellow gas tape is too thick.
Air nozzle leak: If the air nozzle is really worn you can get some air leakage around it and the cylinder head tube. I’d replace the air nozzle, some have a o-ring inside. A little quality gearbox grease also helps seal this slip joint.
Parts – There are lot of different parts out there, I usually stick with Matrix, Modify or AIM, not too expensive. I use the madbull green piston almost exclusively, but honestly they have not been real consistent, they last forever or break right away. AIM also has a full metal tooth piston, I bought two, one failed right away, the other is still humming along (same AEG). Just bought a Modify all metal tooth waiting to try. If your trying to be quite, a full metal tooth piston is not the way to go, but you will need to keep your ROF down or you will strip the piston in no time.
Piston head, I’d do a aluminum ported piston head (many opinion on ported or not), make sure it includes the bearings.
Barrels are interesting, I like the madbull python tight bore 6.03, it’s in most of my AEGs. Its aluminium so it lighter, nice on a already heavy gun. I know others swear on steel barrels, they are not supposed to flex as much. I did try a madbull 6.01 in my SR10, I did not see any improvement in accuracy over the 6.03 but a slight bump in FPS. I also had serious jamming problem when the temp got down below 40, I think the barrel actually shrunk in the cold and tolerances are already tight.
I will say one of my new most favorite parts is the maple leaf bucking and flat nub. It will even fit a KWA hopup chamber, and they are notoriously tight. You can get the bucking and nub from amazon make sure you get the one including the flat nub! I’d say you want a 70 or 75 hardness
You also can’t go wrong with a madbull Blue bucking. If you find a part you really like let us know.
Last bit of advice –
Go to Deans connector .. get rid of tamiya.
Take your time shimming the gearbox
Make sure you wires are all in good shape
Double check your motor connectors. don’t over tighten the motor set screw
My favorite all around gearbox grease and everything AEG grease is “Super Lube” it think you can find it at Harbor Freight … It’s the only grease I use in my AEG.
Hope this helps, others on the team may chime in with their experience.
Shoot me a FB PM if you have any questions or I can send you a forum login if you wish.February 22, 2015 at 15:49 #3799
I heard back from Ryan last month about the status of his project and wanted to share ….
It has taken me a while to do my research and get the most bang for buck.
Stock spring guide.
Prommy 120 spring.
Shs blue metal rack piston.
(Unknown) ported aluminum piston head.
(Unknown) full cylinder (I had to cut a custom noch in the cylinder for it to fit. I think its because my gearbox is for a ebb).
(Unknown) aluminum cylinder head.
(Unknown) aluminum nozzle.
Stock tappet plate.
Stock selector plate.
Stock trigger contacts.
Shs 13:1 gears.
Shs 8mm bearing bushings.
16 awg wiring (not sure I’m totally satisfied with it, but it works).
Evike monster torque-up motor.
G&P 10.8v 2300mah NiMH battery.
Angel custom 510mm 6.01 tbb.
Stock g&g hop up unit.
Maple leaf 75 bucking with flat nub
I also disabled the blowback function (it didn’t work that well anyway).
For those who might ask why there is wire coming out of both sides of the gearbox: Because my battery is so big, there is no room for a fuse or MOSFET in the crane stock. So I have it wired up so I can put the fuse in the front, inside the rails.
Looks pretty great .. I look forward to seeing the results in the near future .. like FPS and ROF.
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