60fps difference from a tight bore?

[Vex]

So i've rebuilt my gearbox and the hop unit im using is giving me 270 If I switch to my other hop unit which has a madbull 6.03 tight bore 285mm I get 328.

I dont believe that im getting that much fps increase from just using a tight bore, the madbull is about 10mm longer than the other both units are the same and are fine. I will try swapping the units and the barrels over to see what happens then but I can't get my head round it.

[Sidewinderforge]

Re: 60fps difference from a tight bore?

One setup gives better airseal probably.

[Dechande]

Re: 60fps difference from a tight bore?

If a hop unit fits into the gearbox aperture where the nozzle comes out, it can give a good jump in fps due to the airseal. Guarder hops with the o-ring at the back have given me good results when compared to stock hop units when used with G&P gearboxes. A tightbore will usually give a 5-20ish fps boost due to more air pressure behind the bb as there is less room for air to escape around the bb before it leaves the barrel.

[jonglow]

Re: 60fps difference from a tight bore?

The madbull tightbore will normaly give 10-15% fps increase alone with it conected to a hop which has a better air seal it will increase the fps even more,do you know the make of the hop units your using? And is the fps constant within 2-4 fps
A python inner barrel and ultimate hop unit by madbul I've found are a great combo for reliable consistent fps.

[Vex]

Re: 60fps difference from a tight bore?

Yeah its a consistant fps, must be a leak with the one, will confirm later when I switch them over, i have 2 madbull ultimates and i think they are awful paired with a python you can literally spin the barrel around when its clamped into the unit because its so loose.

[jonglow]

Re: 60fps difference from a tight bore?

Haven't tried to "spin" mine around must admit,I've put the barrel and hop in two of my aeg's with no down sides just positive results my we katana is putting out 350-352 all the time on .20bbs since putting the combo madbul in :-)

[Vex]

Re: 60fps difference from a tight bore?

It's not so bad paired with any other barrel its because the pythons aren't as chunky as standard barrels.

[Vex]

Re: 60fps difference from a tight bore?

After trying both hops & barrels in my other m4 i get 340 with the tight bore and 325 with the standard so it must be an air leak with that one combination. I'll just swap them so I have 328 and 325 in both. Need another chimera now, the trigger pull on the one without is horrible and weird.