Question on my fps???

[Salvo66US]

Hey Guys,
 I put in a CA 6.04 Tightbore and 120 spring in my CA AR15A4 rifle, found out it was above 400fps( like 410-415 ) and so I went and replaced the 120 with an 110 and kept the tightbore, so I'm rechecking the chrono and I can't get that thing above 299.8fps! I didn't think a 110 would make that much of a difference!!! Am I missing something here? I'm kinda wondering if there is a leak somewhere? I don't hear any odd noises and all... I did not lube the nozzle when I put the tightbore on, should I have? Any help would be appreciated, I was going to use it this weekend at Sasco but I can take my Scout M14 instead... Thanks for your input!  Salvo

[Vince]

Did you get lube on the hopup? Excessive wetness can lower FPS.

Did you put the spring back on the top of the hopup?

You're about 70 FPS too low for what you should be at.

[Salvo66US]

Hey Vince! If I did get grease into the hop up, I have since put probably, maybe 1500ish rounds thru it before I rechecked it on the chrono, and am thinking that any grease would have gotten worked thru the gun by now? Maybe??? I'll run a rod and patch thru it...I thought I made sure to double check everything, even used brand new hop kits and bucking and checked the bucking with a light to make sure it was seated...I did use a "little" grease on the hop sleeve to facilitate sliding the bore and sleeve back into the hop, cleaned off the excess...I can take it back apart tommorrow and recheck everything, I thought it seemed like too much of a loss of fps.  Thanks! I'll post my findings...

[-MAD- SARGE]

Let me see if I have it striaght.  You had the tightbore and 120 installed shooting over 400.  Then you put in a 110 and never touched the barrel and hop up unit as a whole correct?  Meaning you just removed the barrel and hop up as one unit when you installed the 110?  

If that is true, it wouldn't seem to be a hop up issue since it work the first time and you didn't touch it.  What else might you have done when you took the gearbox apart?

[Vince]

Well, you take the bucking out of the hopup to install a new barrel.

Did you check to make sure you have the spring installed on the hopup?

Did you damage the nozzle somehow?

[Salvo66US]

OK....!  Well, I took the rifle apart and inspected everything! Everything looked great, so I got to looking at the amount of play between the hop and the nozzle, seemed alittle excessive, so I put a layer of electrical tape on... not so good...didn't help, so I took that crap off and I decided to try some white lithium on the nozzle, THAT worked like a CHARM!!!! I'm now right at 368-370!!!!! Perfect and you can hear the rifle function much more solidly than before! Yahoo! Thanks for your input guys and see you on the field!