Testing Spring FPS?

[simon]

I've got allot of spring laying around and dont know the FPS of them. My A&K Minimi has a quick spring change but the spring in it is flat on both ends, can I put the springs with the extra 'L' shaped bit on one end into it to test there FPS? I dont want to take one of my other gearboxes apart 12 times then put the rifle back together to test them. Any help please.

[seansamurai1]

Re: Testing Spring FPS?

the springs with the L shape at the end are very reminisant of TM stock springs, so if they are then anywhere between 260 and 285 would be seen more than likely. Where did you get them, or have they come from other guns you have owned?
Im not sure other manufacturers have the L shape on their stock springs, I know the chinese ones dont in my experiance and I do know TMs do.

[simon]

Re: Testing Spring FPS?

Bought a job lot of springs months ago from this forum and have just bought some more. Can I clip the 'L' end off and use them? Do TM gearboxes need the spring with the 'L' shape? One of the guns I want to upgrade is a TM M4.

[seansamurai1]

Re: Testing Spring FPS?

The L part fits into the piston if I remember correctly, so a TM standard piston you could, not sure about an after market piston though, to be honest you will more than likely loose a hell of a lot of FPS fitting these springs in, as they are stock springs, dependant on what gun they were in originally you will be lucky to achieve 285FPS, it could go as low as 250/260 though, its hard to tell. Also you wont get an accurate reading from your 249 box if you want to fit into for example an M4 afterwards, as differant gearboxes are effected slightly differantly, my version 1 (old famas) had a 110 in and only achieved about 317FPS whereas my LR300 (V2 box) had a 105 spring and was hitting the sharp end of 370FPS, with a M90 its now at a sensible 341FPS.

[neverseemecoming]

Re: Testing Spring FPS?

ive got a jg hk416 and ive just changed the spring inside it. but the piston head has a big block on the back that the l shape fits into. but ive fitted a 1 joule and the fps still dropped from he standard one firing at 385+. i think it varies as to the spring that has it. cus i could cus the l part off of this one and still have it firing at 350 in a normal length gearbox