9 Ball Inner Barrel Reduces FPS

[Nicayu]

Hi All

Just got a chrono and thought I'd check out my TM 5.1 Hi Capa and my Gold Match.

The Gold Match (AM Limcat slide and 140% recoil spring are the only upgrades) was at about 285 -289 fps.

The normal 5.1 Hi Capa (nine ball 6.00mm/112.5mm tight bore inner barrel,Maple Leaf DIAMOND / MONSTER Hop Bucking 60deg,  metal outer barrel, AM Aqua slide, Standard recoil spring, cowcow piston seal) was at about 260fps.

Not happy with the above I went back to stock inner barrel and bucking with little improvement, 

Then I swapped the standard bucking for the maple leaf which up'd the fps to 270, 

Then I swapped the standard inner barrel for the nine ball one, and I get a decrease in fps to about 265.

I'm puzzled by the decrease.....

I wanted to push towards 300fps. 

Any ideas anyone??

View attachment 59919

 

[Adolf Hamster]

what are you using this gun for?

because a hicapa with a decent hop and ammo can reach out pretty damn far, to the point you don't really need the extra energy as you're gonna struggle to shoot well enough to make use of it.

 

[Steveocee]

@Nicayu OP is slightly confusing as you have rambled about 2 different Hi Capa's?

A 6.00 should push you into the >310 territory if you have a decent seal etc. My advice would be to go back over and re-do everything, make sure the seals are good, PTFE bucking to barrel to make double sure if not. Also, check your gas! Make sure the can is not too cold and that your testing is done consistently.

FWIW my GM with a 6.02, ML Decepticon 70deg is touching 305 but that's with 9Ball mag routers, CCT BBU, TM piston head and Enhanced loading nozzle.

Been toying with going for a 6.00 myself but can't help but feel a PDI in 6.01 would be a better choice due to bore quality.

 

[Nicayu]

I'm using for aipsc and general target practice.  Max distance 30m.

I really just expected the fps to increase as all the tutorials indicate.

BTW. I saw a video in which standard TM 5.1 hit targets at 50m, pretty impressive, I don't need shoot that kind of distance. 

Take a look. 

Apologies. I only spoke of the Gold Match to compare the two.

I'm mainly talking (rambling on) about the standard type 5.1 hi capa..

I will run some further checks as you suggest. 

Many thanks

 

[Cr0-Magnon]

A 6.00mm barrel is super-tight, to the point where it's really restrictive on which ammo you can use. The BB's are dropping after 30M? As people have already pointed out, that's less than you should get from a stock Hi-Capa.

 

[Nicayu]

A 6.00mm barrel is super-tight, to the point where it's really restrictive on which ammo you can use. The BB's are dropping after 30M? As people have already pointed out, that's less than you should get from a stock Hi-Capa.

Super tight?? was wondering about this but the bb doesn't look restricted freely falls through.

I have always used .025g bb.

I don't have access to a range beyond 30m but, range isn't a necessarily a problem, it's the fact that the 6.0mm inner barrel didn't have any effect.

 

[Adolf Hamster]

Super tight?? was wondering about this but the bb doesn't look restricted freely falls through.

I have always used .025g bb.

I don't have access to a range beyond 30m but, range isn't a necessarily a problem, it's the fact that the 6.0mm inner barrel didn't have any effect.

the weight isn't the problem, it's the quality/size of the bb's.

tbh if you're just target shooting then i wouldn't worry too much about the raw fps.

the only reference i can think of is mine runs a pdi 6.01 and seems to spit out 1j no matter what weight you put in it.

 

[Nicayu]

Right. I've rechecked everything, change back to the tight bore, put some Abbeys Silcone Oil here and there. 

Just got a 295 fps dropping to about 288 after a few shots.

Not 100% what it was.

A bit happier at that.

Thanks for the input.

the weight isn't the problem, it's the quality/size of the bb's.

tbh if you're just target shooting then i wouldn't worry too much about the raw fps.

the only reference i can think of is mine runs a pdi 6.01 and seems to spit out 1j no matter what weight you put in it.

I always use ASG Devil Blaster BB 0.25g, maybe I should experiment.

I'll look into the PDI 6.01.

many thanks

 

[Wo1f]

You’ll get more accuracy at 20m+ with heavier BB’s I would have thought. 

 

[Steveocee]

May have already done this but fully purge your mag and then refill it.

If your first couple shots are ok then a large drop off it could be has related.

Good luck finding a PDI barrel at the moment. I've been searching for over 2 months, even X-Fire the PDI distributor and not sending out at the moment. Nowhere in EU has them for certain.

 

[heroshark]

Try it with the original piston cup. You want to use really nice ammo on a 6.00mm.