Increase in FPS?

[Jbone 11 11]

I have an M4 that was put together by my local shop and have been using it for months without any complaints from other players about my FPS being too high (I live in Italy right now and they have a 1 Joule/328FPS rule).

I have just installed a Prometheus 6.03 inner barrel and a systema rubber and all of a sudden, Im getting guys telling my I need to clock my M4 because it might be shooting too hard?

Now its my understanding that changing the inner barrel would not cause an increase in FPS. Also, I was using heavier BB's at the time (.25's instead of .20's) and had mentioned this, but these guys insist I need to clock it and then change my spring if need be?!

Is it possible that my barrel change made the difference, and people are feeling it?

Tx
J

[Evans]

Yes.

[Nova316]

It wouldnt make a big difference I think a tightbore only gives 10-15fps
But what could of changed is that you had a bad hopup rubber and the new one + new inner has created a much better airseal, thus increasing your FPS quite a bit higher then you use to be shooting

[pusangani]

the tighter the barrel, the less air to escape arround the bb, thus more pressure behind the bb, the more power you get

Originally Posted by Nova316

It wouldnt make a big difference I think a tightbore only gives 10-15fps
But what could of changed is that you had a bad hopup rubber and the new one + new inner has created a much better airseal, thus increasing your FPS quite a bit higher then you use to be shooting

that's also possible, but he said he had the gun put together by a shop, so assuming that that they did a decent job in the first place..

[Styrak]

Originally Posted by Jbone 11 11

Now its my understanding that changing the inner barrel would not cause an increase in FPS. Also, I was using heavier BB's at the time (.25's instead of .20's) and had mentioned this, but these guys insist I need to clock it and then change my spring if need be?!

Since you have a 1 joule rule, it doesn't matter what weight of BB you're shooting, you have to be 1 joule or under. With 0.20's that's the 328fps, but with 0.25's it about 300fps.

Also yes, a tightbore can increase FPS as well.

[m102404]

Tightbores will increase FPS a bit. Barrel length also affects it, depending on your setup. I had a nice setup where I'd use a M4 length barrel to get 385fps and if I swapped to a CQB barrel it'd be 345fps (outdoor and indoor limits here are 400 and 350 respectively).

This may open up a big can of worms...but a hit at any given range with a heavier BB is "felt" more than with a lighter BB. The muzzle energy is the same...but the retained energy is more greater with heavier BBs.

Chrony your rifle to be sure. Chrony with the standard weight of BBs (0.20? for you?). Be prepared to chrony on demand. One night we were getting hammered by one dude. His shots seemed to really, really hurt. Someone asked him to chrony and he shot right up there, but below maximum. The difference between a 300fps hit with a 0.20 and a 349fps hit with a 0.20 is definitely noticeable. If you're playing with guys that are honest, level headed and respectful...a night of shooting with 300fps is a lot of fun.

In CQB (5-40ft)...there's no practical effective range difference between light and heavier bbs. There may be some accuracy difference, but at those ranges it's not very consequential for hitting a guy. There's hardly any "shot time to target" difference (the time it takes the bb to get from your rifle to the target).

At longer ranges...sure, heavier BBs are definitely advantageous over lighter BBs.

[AngelusNex]

Both hopup and tighbores can increase FPS (those are what I always suggest upgrading before springs if you want more power) will. Once I got +50 FPS when I threw a longer tighbore in my hk416, so depending what brand you get you could get 20-25 extra FPS while remaining at the same length. And another proof for the rubber, Crunch threw a guarder clear in his 380 fps hk416 and ended up getting 410(IIRC, could've been 430)

The good news however, is you can now put a weaker spring in your M4, increaseing ROF and the lifespan of the mechbox.

[Jbone 11 11]

Good to know!... Again, thanks for the info everyone. That definitely helps clear the air a bit. Based on what I've just read, Im pretty sure the heavier BB's had a bit more to do with the complaints (I actually hit a guy in the face, unintentionally, that game). It looked nasty and Im sure its what lead to speculation.

That being said, I guess I gotta chrono my rifle now. Again, thanks a lot for the info!
; )