PDI 140% in stock TM G36C?

[Aaidin]

So, I got a new spring, metal bushings and my TK twist tightbore installed. However the spring I got was a PDI 140% which the shop said would put it up to about 330, turns out it's firing 380. Is that supposed to happen? I don't blame the shop, I blame myself for not doing my research better before buying the spring, but right now I don't even want to use the gun the barrel is ineffective and I don't think firing 380 with absolutely no upgrades but bushings is very smart.

I'm looking for a new spring that will settle in at 320-330 fps. Recommendations?

[medhatboy]

Check with the spring chart, the 140 at 380fps is just about right. If your looking for 320-330 try a PDI 120, and try to stay with PDI, I put a Prometheos MS 120 in my gun, the place that I bought to from said that it would do about the 360-370 area, it shoots at almost 440fps.

http://www.airsoftcanada.com/SpringChart.html

[damage]

Prometheus M100

[Aaidin]

I'm thinking an M100 or M90 spring with a Guarder Ball Bearing Spring Guide, should put it in about the fps range I'd like and reduce stress on my mechbox, etc...Basically my goal is to get the most bang for my buck as far as upgrades vs. durability.

[malachite]

i dont know about charts and such but i know that when my friend put a new spring in his gun at first it was shooting really hard.. we figured that was because it was new and wasnt warn in yet..

he had shot me in the leg right after he upgraded it and caused me to bleed we did the same thing a couple days later after firing it a bunch.. (but on a full batery now) and it just left a welt..

so ya.. i think it might just be begining tensile strength in the unused spring

[swatt13]

hold on its more simple than that. that metal pice that goes inside your piston (what holds your stock spring on place) and what the stock piston head screws too acts as a spacer or shim, which inturn adds to the overall fps. if you didnt take that out thats your problem.

if you did, then the fact you have a tb, 140, good hopup adjustment all add to the overall fps. you could have recieved a mismarked spring.

380 on "stock" mechbox is just fine. if you still had the nylon bushings youd still be ok. as it stands now your gun will run fine for atleast 1-2 seasons (depending on use and abuse). all i reccomend to members is to put metal bushings a 140% (nothing more) and and upgraded piston on a 9.6v and thats all. only reason i reccomend the piston is a stock piston will wear down withing a year and youll end up opening the mechbox again to replace that. take care of it the first time. anything over 140% or a higher voltage warrants gears, and definatly a piston. but as it stands now your gun is fine.

[Aaidin]

Thanks Swatt13, nice to know. But with the TK Twist Barrel I still need it to drop down to 330. I'll Chrono it again in a week after some more testing and see what needs to be done. Thanks.

[swatt13]

y ai was thinking about that at work today, i didnt realize you said a twist barrel, i was thinking just regular tb barrel. ya unfortunatly youll have some stress with that high an fps and a twist, i would reccommend dropping the barrel. but before you get too excited, try it out and see how bad it wings the rounds off target, it might not be too bad. in my opinion tho, id keep the spring setup and drop the barrel.

[milehigh]

I wouldnt worry too much about mech box stress. Most of the people that I play with use 170% springs and bushings alone, and have had no problems, even after using the guns for years. The only issue was a cracked Version 2 mech box from a local gun abuser.