Best fittings QF on a fast flow, anyone done it ?

[angrybear]

Ok, I just bought a pre-owned but unused best fittings QF, thinking to fit it on my FAC fast flow.
Looking at the BF valve pin the port is very small compared to the FF porting, mines a 5 hole from memory, but it's got me thinking,

If I use a rapid bottle adapter with no valve pin so it's straight through, coupled with the BF brass extender will that act a bit like a pre-chamber/plenum to counter act the smaller valve port,
or will the restricted air flow from the bottle reduce the muzzle energy ?

Has anyone already had a play with this set-up to let me know how it went ?

[jackrooz]

look for maxtich in the sales section under sold seems like he has done something like that

[Squinty]

Possible that it may change the power curve.
Few years back I fitted one of Bob's QFs to my R7.
Was running 35fpe with one of Bb's valves, first shots were supersonic.
When I'd wound it back and topped up the power curve was 5 bar lower.

[KevG]

if its the one with the brass extension they send your bottle way to forward for my liking.and as all ready said can change the power curve on an unreged gun.
kevG

[angrybear]

look for maxtich in the sales section under sold seems like he has done something like that

That's the one I've just bought  , it was to see if anyone had actually done a comparison, but it looks like  I'll be having a play myself .

[Squinty]

I'm guessing that the inlet side of the QF has smaller or fewer holes than the FAC/export bottle holder.
Probably more suited to sub-12 - their bottle valves can be restrictive on some FACs.

Maxtich has removed the photos , the stainless adapter is universal 1/4bsp?
I'd drill 2-3-4 2>2.5 mm holes around the adapter push-pin.... thats if there's room on the back to feed through .

I've seen a few FACs for sale with them fitted, I always wonder whether simply as a non wood butchering QF-guage or an attempt to increase volume (doesn't appear to be much ie fastflow on a fastflow)

[angrybear]

I'm guessing that the inlet side of the QF has smaller or fewer holes than the FAC/export bottle holder.
Probably more suited to sub-12 - their bottle valves can be restrictive on some FACs.

Maxtich has removed the photos , the stainless adapter is universal 1/4bsp?
I'd drill 2-3-4 2>2.5 mm holes around the adapter push-pin.... thats if there's room on the back to feed through .

I've seen a few FACs for sale with them fitted, I always wonder whether simply as a non wood butchering QF-guage or an attempt to increase volume (doesn't appear to be much ie fastflow on a fastflow)

The stainless is a std theoben type bottle adaptor but with no thread to take a reg core, just drilled 9mm & fitted with a std bottle pin which is redundant with the QF in place.

The QF itself, could screw direct to the bottle adaptor or there are 2 brass 'extenders' 1x40mm & 1x55mm, designed to move the QF forward to avoid drilling the stock, but if used they're going to increase the chamber volume by around 3ml or 5ml respectively.
The QF doesn't use a screw in bottle pin, so would be drilling the fitting itself which I don't really fancy.

[Squinty]

gotcha, the QF/ guage block is  1/4bsp >1/4bsp. and the brass parts are just hollow extensions.
5mm-ish? exit but only a small single Inlet.
The fixed pin is a bugger but at least you can still retain the valve and remove the bottle.

I wouldn't think that taking the standard push pin disc out is going to create the same unrestricted flow that Bob's fixed/valveless QF can.
Bit of a long route for the air to take through different i/ds 👍 👎
Hopefully the volume will make up for the flow rate./demand.
Looking forward to seeing your results.

[maxtich]

I've done none of the mods to this kit despite Jackrooze has mentioned..god knows where he got that from!

It's been in my box of spares for a while..I wasn't going to use it hence the sale!

[angrybear]

Well now wasn't that an interesting afternoon 

All tests were a 10 shot string starting with the bottle charged to 200bar pellets FX (JSB) .25cal, 25.4gn straight from the tin.

Test 1- original set-up, bottle in to Theoben fast flow adaptor ; hi 891fps, low 858fps, ave 876fps.

Test 2- 9mm straight through theoben bottle adaptor, Best Fittings V QF, bottle ; hi 899fps, low 881fps, ave 890fps.

Test 3- 9mm bottle adaptor, 40mm BF extension, BF Quick fill, bottle ; hi 902fps, low 884fps, ave 893fps.

I ran out of time to test the 55mm BF extension, but even the 40mm felt bad enough I'll never use it.

So the quick fill does NOT restrict the muzzle energy, in fact using a straight through bottle adaptor, rather than a fast flow, it actually raises it a fraction.
imo, any benefit from the extension, isn't worth the change of balance & handling.

Most likely I will fit the QF & straight through adaptor, & just trim the stock to fit.

[jackrooz]

I've done none of the mods to this kit despite Jackrooze has mentioned..god knows where he got that from!

It's been in my box of spares for a while..I wasn't going to use it hence the sale!

never made qoute of any mods you had done and hope I haven't upset you

I did make mention of you doing something similar never quoted anything you had or hadn't done

was trying to be helpful

[maxtich]

Ok fair enough.