cyrexx

If you want great trigger response but not high rate of fire you I would recommend a ZCI High torque motor and a SHS 12:1 gear set. The ZCI is slow but has huge amounts of torque (it will happily pull an M170 spring on a 10:1 gear set)

http://www.airsoftpro.cz/ if you want upgrade parts for snipers and AEG's http://www.crw-airsoft.com/ for Gas guns and gas upgrade parts

"Mostly from UK sites" That answer howyou got that price, I buy everything from abroad as it's a hell of a lot cheaper. I've not look at uk prices in ages as it always seem way over priced.

Not sure how you've got £350 in extra's? I added it all up on got £175, including internal upgrades

Someone originally asking £550 for an A&K M249 http://forums.zeroin.co.uk/showthread.php?258424-A-amp-K-m249-well-upgraded-looks-great when for £210 you can get a brand new one from http://www.taiwangun.com/en/pj249-mkii-black-p-j?from=listing&campaign-id=19

Have you considered looking at using 18650 batteries? They have a higher voltage and a lot more capacity than AAA batteries. Plus they are rechargeable.

It's probably worth pointing out that SHS High torque motors run hot and draw a lot of current.

I got shot in the "Tip" and folded over like a cardboard box, they had to stop the game and I to pretty much had crawl out the arena, I inspected the damage and it was not pretty. I know make sure everything is well protected.

Looks like it's sticking out a bit too much.

AB should not cause the increase in battery temperature, motor braking accomplished by shorting the motor outputs. The only type of braking that uses the battery is Regenerative braking (which actually recharges the battery). If he's using a 7.4v LiPo probably doesn't need an AB mosfet but if he's using an 11.1v then he may need one considering the Lonex A1 is a high speed motor

LiPo batteries get warm under heavy load, you only need to worry when they get hot. If they get hot it means the load it too much for them and they will start to puff out and in some extreme cases set on fire. Also bigger batteries are always better, a nuprol 11.1v 3200mah shouldn't get as warm, plus it will increase trigger response and slight increase to RoF.

Oops. totally did not see it on the list. my bad.

you put "I am looking for useful resources, are there any missing from below?" The ASM forum is the best forum for the technical side of airsoft so it should be on your list.

http://forums.airsoftmechanics.com/

I agree with you that the range of internal and external parts is not as big and varied as M4's, AK's or MP5's. But I wouldn't say it makes it harder to upgrade or you need to be more technically minded. Also the nozzles on all guns are different so I wouldn't call it propriety. I thought both the ICS and G&G hop chambers in the Sig 550 series are supposed to be good?

Your correct, the spring rating effects the FPS, an M90=300 fps, M100=330 fps, M110=360 fps. if you want more to increase yor fps consider an M100 spring. Increasing the spring power does reduce the RoF but only by a small amount.

Getting a high torque motor, 11.1v Lipo and Mosfet is right. Gear set wise you want something like a 13:1 or 12:1 http://www.ebay.co.uk/itm/SHS-13-1-High-Speed-Ultra-Strong-Gear-Set-for-Ver-2-3-AEG-Airsoft-Gearbox-/271844910348?pt=LH_DefaultDomain_3&hash=item3f4b38250c http://www.ebay.co.uk/itm/SHS-12-1-Extreme-High-Speed-Airsoft-AEG-Gear-Set-NEW-DESIGN-CNC-CUTTING-/271844908262?pt=LH_DefaultDomain_3&hash=item3f4b381ce6 Delay clips can be handy if you are having feeding issues when the mag cannot feed BB's into the gun fast enough.

Mainly the comments "You will struggle to get after market parts for Sig 552" & "I wouldnt buy it unless you are quite technically minded because upgrading them isnt as easy as most of the more common guns" I wouldn't say you would struggle to find after market parts, they are still easy to find just not as common and being a V3 gearbox it's the same as a G36 or an AK, which I would say is just about as easy as upgrading a V2 Gearbox.

Not sure why you are saying this as both the G&G and ICS use V3 gearboxes?

Not 100% correct but almost, it depends on the mAh and C rating of the battery being used, e.g. a 2000 mAh 9.6v will produce a better trigger response than say a 800 mAh 15C 7.4 LiPo. Also the voltage range of a 7.4v LiPo goes from 8.4v (fully charged) down to 6v (empty/max lowest safe voltage).

Just spotted this on WGCshop. http://www8.wgcshop.com/wgc2008/main/product_detail1.php?search_From=special&item=HEP-GBB-T21BK&search=special&rs=Coming%20Soon&catid=&cat=&view_choice=a

Lol, Shows that I haven't ordered anything Taiwan gun in long while.

Customs check them some times, I know people that have ordered from www.taiwangun.com without UKARA numbers and not had any issues. If you don't have a UKARA number attached to it they may send a letter to you asking you to provide "a valid defence" for importing, this could proof of membership to a airsoft site or Reenactment Association membership.

You will need to programme the Baofeng for it to work with the channels you want to use. You can programme them manually through the handset, which is surprisingly easy, or you can use the USB cable and use a piece of software called CHIRP. Personally I would recommend you learn how to programme it manually so can make changes out in the field. Baofengs use the Kenwood 2 pin for PTT, which I believe is a 3.5mm and a 2.5mm Hope that helps

http://www.airsoftpro.cz/