Dsg Random FPS Drop

[Bishop]

16:1 VFC/SHS 8 tooth DSG, Gate Titan, ASG 22k/22TPA, M170(cut 2 coils), 2200mAh 50C lipo. 

I have 360FPS with .25bbs pretty consistently. Problem is, randomly, FPS will drop to 250. I will do it one or two times, then go back to 360FPS. 

When it drops FPS you can actually hear it. Kind of like when a gas gun light strikes, that is what it sounds like. So I'm sure its not a air seal issue. First time I have built a DSG, so I have no clue. It feeds great at 35RPS. Had a M160 SHS spring and was around 40RPS but the FPS was acting crazy. Wrong type of spring, I think. Was going to order a Guarder SP150. Not sure If that would be better or If I should use a spacer with m120/130 or not. Also going to switch to a Tienly GT-30000. Any help would be great thanks.

 

[Adolf Hamster]

are you uk based? because i have a nagging feeling 360fps on .25's is gonna raise some eyebrows at chrono......

 

[Speedbird_666]

16:1 VFC/SHS 8 tooth DSG, Gate Titan, ASG 22k/22TPA, M170(cut 2 coils), 2200mAh 50C lipo. 

I have 360FPS with .25bbs pretty consistently. Problem is, randomly, FPS will drop to 250. I will do it one or two times, then go back to 360FPS. 

When it drops FPS you can actually hear it. Kind of like when a gas gun light strikes, that is what it sounds like. So I'm sure its not a air seal issue. First time I have built a DSG, so I have no clue. It feeds great at 35RPS. Had a M160 SHS spring and was around 40RPS but the FPS was acting crazy. Wrong type of spring, I think. Was going to order a Guarder SP150. Not sure If that would be better or If I should use a spacer with m120/130 or not. Also going to switch to a Tienly GT-30000. Any help would be great thanks.

Don't rule out an air seal issue. I had a gun do something similar - turned out that there was way too much grease around the piston head/cylinder and the ports to expand the o-ring would randomly block and the o-ring itself was sticking inside the piston head. I was getting 80-100fps drops in 1 in 10 shots. Noise signature changed too.

Sometimes it's the simple things. Worth cleaning out all the lube in the piston/cylinder and testing the piston head with just the lightest smear of grease.

 

[Bishop]

Private games, and plinking. Really, just bored wanting to learn. I have built 20 SSG guns, no problems. Venturing into DSG world. 

 

[Cr0-Magnon]

Regardless, it's still over The UK legal limit of 1.3J for a full-auto capable airsoft gun.