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Fps Problems With My Ak - Upgrades?


Sturm

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http://www.airsoftgi.com/product_info.php?products_id=7316

Last time I got it chrono'd it shot around 260-280, which is a problem considering it's supposed to shoot around 400 based on all the online chrono's I've seen.

What could be the problem? Bad spring? Piston compression?

It's an EBB, so I can see the piston being worn. I'll take any recommendations for barrels/hopups/buckings/springs/gearbox/gears/pistons, literally anything. I was thinking about a better barrel + PBS-1 Suppressor.

Edited by ProPainTank
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check and make sure that the hopup is seated to the gearbox  tight I have seen bad FPS drop from a hopup not seated all the way .

if that doesn't help try a Little silicon oil in the cylinder  use 100%  silicon make sure it is petroleum distillate free and that its acetone free or use a airsoft oil not something from lowes.

the oil has to be plastic and rubber safe

a few drops of oil will make a better air seal  for a few shots and will show if the O ring needs replaced.

years ago I put a TBB in a gun that had a bad airseal  gun was with TBB shooting 380  at a game I chronoed and I was suddenly shooting 435..

like I said check air seal first  start with the stuff that you don't have to take the gun apart then work inward,  if you don't have a chrono I'm pretty sure there's someone in indy that will let you use theirs

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Are you using .20 bbs?

 

Yes, one event even required that I use their bbs for chrono, so I'm positive of the weight. All of my other guns chrono where they should.

 

 

check and make sure that the hopup is seated to the gearbox  tight I have seen bad FPS drop from a hopup not seated all the way .

 

if that doesn't help try a Little silicon oil in the cylinder  use 100%  silicon make sure it is petroleum distillate free and that its acetone free or use a airsoft oil not something from lowes.

 

the oil has to be plastic and rubber safe

 

a few drops of oil will make a better air seal  for a few shots and will show if the O ring needs replaced.

 

years ago I put a TBB in a gun that had a bad airseal  gun was with TBB shooting 380  at a game I chronoed and I was suddenly shooting 435..

 

like I said check air seal first  start with the stuff that you don't have to take the gun apart then work inward,  if you don't have a chrono I'm pretty sure there's someone in indy that will let you use theirs

 

Ouch, I know my motor was loose a while back, Pot metal around screws causing motor to shake itself loose. Wouldn't be horribly surprised to find a loose gearbox.

For the Cylinder, 20w or 50w? Got both on hand. I would imagine 50 for sealing.

Edited by ProPainTank
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Motor has nothing to do with FPS, fyi.

 

I hope that your 20/50w question is about SILICON oil and not standard motor oil. I'd run with the 20W if it is silicon oil and go light. You don't need a ton.

Also if you are competent enough to open the gearbox, you may want to see if the seal around the cylinder head has failed as this would cause some issues as well as the piston o-ring itself.

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Motor has nothing to do with FPS, fyi.

 

I hope that your 20/50w question is about SILICON oil and not standard motor oil. I'd run with the 20W if it is silicon oil and go light. You don't need a ton.

 

Also if you are competent enough to open the gearbox, you may want to see if the seal around the cylinder head has failed as this would cause some issues as well as the piston o-ring itself.

I am aware that the motor does not affect FPS, I was simply mentioning that I have had previous wear and tear issues. My brain fails to explain things late at night, my bad.

It is indeed pure Silicon oil made for RC shocks; I was under the impression that higher weight was used as an air seal, as it doesn't flow as well as 20w.

I'll take your advice though. I will admit, this is the second time I've touched a gearbox. I can field-strip both of my snipers and understand every part, but I have very little experience with AEGs/gearboxes.

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Unable to mess with the internals yet, I've discovered you can push the grip forward and move the entire gearbox though. Not sure that's good.

On a side note, My orange tip is installed via glued threads on the removable front sight; which is quite unusual. Most AKs have the threads on the actual barrel itself, and the front sight is simply a front sight.

I'm buying a PBS-1 and wood grip/stock set with drum to convert this into something RPKish; No luck with Rubbing Alcohol or Lighter fluid. What's the best method to get rid of the glue?

It's actually a quite decent orange tip flashhider, I'd rather not destroy it.

 

**EDIT**

Boiling water for 30 seconds did wonders!

I was stupid and gripped the thing on the birdcage instead of the base, deformed the orange tip a bit.

Regardless, I'm very happy that I didn't destroy the orange tip or the threads. I wouldn't feel comfortable getting pulled over on the way to an event without the orange tip installed.

Edited by ProPainTank
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