Tightbore: Yea or Nay?

[GreyCoyote]

Thanks to nwahs, who's getting my CA M15A4 RIS Carbine shipped in by the third week of December, I should have my first AEG soon. And because I tend to get ahead of myself, I'm thinking upgrades. Now, most of the indoor airsoft arenas near where I live have a strict FPS limit of 350. The M15A4 has a stock FPS of 315-320. Now I don't know the first thing about electric guns, but I do know that I'd like to make the carbine more accurate. One way I've heard of to do this is to get a tightbore tube installed in the barrel. I've got my eye on one that's 6.03mm. This will, I understand, also significantly increase the muzzle velocity of the BB.

So here's my question. Will a tightbore barrel on an AEG firing on full auto cause any complications with the internals? If not, are there any other problems associated with tightbore tubes I should know about?

Also, would a 6.03mm inner diameter tube be likely to increase the speed of my BB past the limit (keeping in mind that it starts at somewhere around 315, and that the gun is a 1:1 scale model of an RIS M4A1)?

The latter question may prove difficult to answer because I don't know the specifications of the stock bore on CA AEGs.

Thanks in advance.

[Crunchmeister]

The tightbore should add anywhere between 10-25 fps. My CA M15A4 rifle shot 360 (after a spring upgrade). With a 6.03mm tightbore, it now shoots 385. My JG HK416 shot 390 with a standard barrel, and 415 with a tightbore.

And it should have no effect on your internals.

[Mist3r.B]

I've never got more than a 10fps increase with my 6.04 Tighbore. So I wouldn't be too worry if I were you.

[m102404]

A tightbore will help with accuracy. It will up your FPS.

How much it will raise your FPS is extremely variable. There's a lot of variables that come into play that affect your final FPS and the consistency of your shots. (without a consistent FPS....a tightbore will loose most if not all value...your shot placement will still be erratic).
1. Quality of BBs
2. Tightness of airseal between the hopup rubber and barrel
3. Fit of hopup rubber/barrel in the hopup unit
4. Quality/consistency of the seal between the nozzle and the hopup rubber

Even just separating the upper and lower of your rifle, reseating the hopup unit/barrel and putting it back together...can change your FPS/consistency. Maybe not by much, but it can.

I know one guy who fudged his FPS with a really loose hopup rubber...just to get it under 350fps.

So...the only way to really know what your rifle shoots...its to chrony it after it's been assembled. I'd also recommend that you put a mag or two through it before you chrony it...AEGs need several shots after upgrades to get everything settled in.

Personally...I'd recommend that you shoot it as is at the fields/ranges/places that you're going to play at. You may very well find that there is no reason to upgrade the accuracy of it (i.e. Defcon is pretty small and only kitty-corner shots will benefit...TTAC3 CQB is usually pretty tight as well).

Also...so far as shot times go...there's very little difference between 330fps and 350fps. 350fps is the MAX limit. It is your responsibility to ensure that you are consistently shooting UNDER that limit...or face being banned from future games, sent home (and being f*cking despised by the other players for being a cheater) and possibly even losing your rifle (that's the house rules at some places). At 330fps...you're at 94% of the MAX limit. Limits are there to help ensure safety.

A complete guess...but if your rifle is consistently shooting a high of 320fps...you're going to be in the 335fps range (that still leaves you a good margin of error).

[BORDENSNIPER]

6.03 will do u good, Im not sure if that gun comes with a ball bearing spring guide, if not get one along with a ball bearing piston head and airseal nozzle.

toatl fps change should be close to 20fps with bspring guide, airseal nozzle, bb piston head, and tightbore.

[SINN]

Nay: I say leave your gun as is if you are playing indoors. It is better to upgrade the player before the gun. Go play and have fun shooting stock before you start with the upgrades.

[Skladfin]

why need a tightbore for indoors?

[m102404]

M100+bearing spring guide+good airseal nozzle+bearing piston head + tightbore= more than 350fps in a good assembly and not suitable for the indoor limits at most places (350fps MAX w/ 0.20g bbs).

I've just downgraded 3 rifles for indoors and they all needed M90 springs (which is "weaker" than a stock CA spring). They're all shooting 335-345fps...and the owners are perfectly happy with that.

2 were M4's (one was shooting just around 355 and the other 360 and change) and the third was an MP5 (which was shooting a high of 370fps with a M100 spring...that was a nice tight assembly).

Chronograph after assembly to be sure.