Question about JG M4A1 upgrading.

[ryan1796]

I'll get a second hand JG M4A1 in few days later. And I have a question about upgrading a gun. If I'm right, JG M4A1 shoots 370ish FPS. But I have to set my velocity no highier than 320 FPS in order to play indoor game during winter. And I've never done to upgrade a gun.
So my questions are,

1. Should I buy an additional spring to lower my verlocity? (If so, which spring do you recommand? brand,name...)

2. Which part should I upgrade first? (I not sure if JG M4 is good enough not to upgrade but if I need to upgrade some parts, what will that be? )

3. I'm going to put a silencer and use a longer barrel than original barrel, whci berrel will be good for me? (below web link is my silencer) http://redwolfairsoft.com/redwolf/ai...l?prodID=25927

4. Which battery should I use between 8.4v and 9.6v? also I'm going to use STAR MOD crane stock, so the battery should fit to the stock.


I'm not going to fully upgrade my m4 at once, I'm going to take the time.
So please recommand me which part I should change or upgrade first.
Thank you!

[Mitchell12]

The only thing you REALLY need to do is put a weaker spring in it. But I'd probably swap in a tightbore and a new hop-up rubber just for good measure.

[yuhaoyang]

it's indoors, not necessary.
Buy a M90, or ms90sp, or s90+, whatever suits your fancy.