What's the maximum range I should be getting?
 

I have a TM M4 firing at around anywhere from 350FPS-390FPS with mods in the gearbox.

And I don't know, it seems that I'm lacking range somewhat, especially to its paintball counterparts.

What range should I be getting considering that I'm shooting straight and not in an angle?

Thanks

Should be getting around 150ft easy with 0.25g BBs or heavier. You assume those mods are making your gun shoot that fps, or you chronied it. Could be the upgrade job wasn't done right, or you used too many aftermarket parts of different makers and there is some mismatching going on which is causing things like airleaks and such, dropping your fps and your range accordingly. I've seen it happen lots of times so it's possible.

Ya I am having the same problem, my stock M4 shoots as far or father than my upgraded SR that I have set for range. Im getting a new hopup, bucking, and nozzel for it, have to see if it all helps.

I see..

what causes air leak?

And how should I go about fixing it?

Could be the hop up rubber wasn't installed correctly. Could be your nozzle doesn't match up with the hop up unit properly. Literally anything in the air section, from the spring to the barrel and in between could be causing the problem. Two weeks ago I was working on an ICS AK47 that had low fps (300fps with 110 spring) and found that the clip that locks the barrel and hop up rubber together had snapped at some point, and that caused the barrel to shift forward when firing, causing a really bad airleak.

hop up rubber cracked and the piston head not making a seal with the cylidner b/c of too much grease making the oring stick.

Too much grease actually makes a better seal between the piston and cylinder. Apocolypse has a CA M249 that was shooting like 380fps, so he greased the shit outta the piston and the fps got boosted up to about 420fps and stayed there for quite a while. Mind yo he had to use about 10-15 patches to clear the grease out of his barrel before he got his accuracy back.

I see... I'll take a look.

What are obvious signs of air leak on the parts?

sorry, I've got a lot of questions

try getting your gun chronoed first, that would help alot more

The best way to check for leakage, IMHO, is to strip the gun down to the mechbox and remove the compression system. Take out the hopup unit, cylinder, piston, cylinder head, and nozzle.

Hold the cylinder (with cylinder head in place) in one hand and put your index finger (on the same hand you're holding the cylinder with) over the nozzle end of the cylinder head. Then try and insert the piston. If you airseal is perfect, the piston will slide into the cylinder a cm or two and then stop - air pressure will stop it from going in any more. If it slides all the way in fairly easily, something is leaking air, so check the piston head o-ring and the cylinder head o-rings to make sure they aren't nicked, and try soaking them overnight in silicone oil (this will cause them to swell slightly, making a better seal). Yu may need to replace the o-ring completely. Also check to see that the piston head itself isn't nicked/chipped/out of round.

Also take apart your hopup and check to see that the rubber is correctly installed and not torn.

http://www.uncompany.com/images/ca-m...lastic_big.jpg

One thing I just thought of, see the C shaped clip in the above pic? That holds the barrel and hop up unit together. If your C clip is cracked or not in good shape, when you shoot the barrel will move forward away from the nozzle and would cause airleaking as well, pretty bad leaking actually.

Here is my airleak fix. Although I did not really have a airleak issue I just "upgraded" the hop up to prevent leaks.

In this picture a Systema one piece metal hop up with Laylax Strike chamber for M16/M4. You see three O-rings. Hop up to barrel, hop up to gearbox and lower hop up to magazine. I also wrapped the hop up to barrel with teflon.

Another "upgrade" I did was the cylinder head wrapped with teflon so the cylinder head is "tight" on the cylinder. The last area that I "upgraded" was the piston head O-ring. Replaced the stock Systema with an oversized one.

I gained 7fps with this mod.

Bought the O-rings from Crap tire. To let you guys know.

http://img442.imageshack.us/img442/5486/dsc08171uy1.jpg

theres ALOT of components that affect range on a weapon. Pretty well any part that touches the air to get the BB out of the barrel has an affect on range and grouping (including spring guide, piston and spring). My friend's VSR-10 was shooting 470fps and he only got 2/3 the range of my G3 which was shooting a mere 365fps. tightbore barrel and hopup rubber make a big difference on range.