TM MP7 poor performance

[Pollynator_bravo2]

Afternoon,

Ive been looking at my mates TM MP7 aeg. He brought a couple of new mags hi cap ones and they seem to reduce the performance of the gun to 100fps. The only modification he’s done to it is to adapt it from the odd tm battery adapter configuration which I think was a 7.2v battery over to a tamiya lipo 7.4v. 
 

if it’s the mags I’m not sure I can solve that one. 
anyone else had a similar issue?

[Tackle]

Could they be slightly misaligned with the feed nozzle to the hop ?, not enough to stop them feeding but just enough to move the hop a fraction,  causing a loss of air seal ?

[Pollynator_bravo2]

On 16/02/2025 at 15:47, Tackle said:

Could they be slightly misaligned with the feed nozzle to the hop ?, not enough to stop them feeding but just enough to move the hop a fraction,  causing a loss of air seal ?

How would I check that? There is very very little play when they are in so it must be a design fault I’m guessing

[Tackle]

Only way would be to precisely measure them, compare the new mags to the old ones, ideally with a decent vernier caliper.

[BigStew]

Quick question are they Tokyo Marui branded mags?

[Pollynator_bravo2]

No I believe they are amorak 

[Nick G]

Does the fps go back up when an original TM mag is used ? If so , there's your issue, the aftermarket mags.

[Pollynator_bravo2]

On 18/04/2025 at 13:04, Nick G said:

Does the fps go back up when an original TM mag is used ? If so , there's your issue, the aftermarket mags.

Yes mate. I thought that was the case DEFCON don’t accept it but hey ho