FX Smooth Twist Barrel's at FX Factory being made and tested by Himself Freedric Axel

[JeffKr]

I tested the twist rate on a .177 smooth twist barrel yesterday, anyone want to guess what it is?
Dan

How in the heck did nobody respond to this? I've heard it was extremely low - something like 1 rotation in 60 inches. What is it?? I'm assuming empirical tests?

 

[DanB]

1:96", yes empirical test.
Dan

 

[JeffKr]

So the next question is, assuming the newer smooth twist barrels that performed very well (not sure if there's politics involved or if certain heavy weight players didn't show up to displace them) in the recent aoa extreme benchrest competition didn't change that rate of rotation: are we overstabalizing our front-heavy pellets using formulas made for football shaped bullets? Can conventionally rifled barrels benefit from perhaps a far lesser twist rate? And are the conventional barrel manufacturer's even equipped to make a, say, 1 in 32" twist barrel?

 

[JG66]

Not blanks but same barrels used in CZ200. Www.euroshooting.eu. Email: varga@iol.cz (secretary/PA is called Sarka). I was told 130 euro apiece, minimum 2. Several UK guys trying to get blanks I.e. not already machined but havent been able to secure any. I contacted CZ USA and no dice.

Here's a thread that mentions using them in a few builds.

http://www.airrifle.co.za/showthread.php?t=27174&highlight=blank

DoctorBoudreau,

...indeed your info is correct...I got Mirsolav Varga to order me 5 X Cz 200 barrels (not entirely blanks - but good enough to machine) and had them sent to Jon Harris in the UK (he does all my modding & power pimping) - and am in the process of experimenting and fitting several on to spare Fwb P70 barrel holders; one is currently fitted on a power modded Walther LG 400 (12 ft/lb) and initial reports are positive...tough I have yet to get the Walther back and perform actual groupings & tests.

Just FYI, see this from Jon Harris: http://www.airrifle.co.za/showthread.php?t=31051&page=3

Regarding Barrel Twist Rate

"It got the better of me i tried to guage and compare the twist rates in various barrels old and new. Due to the various lengths involved treat my figure for comparison purposes.
No means scientific there could be errors, here goes make of it what you want.
P800 425 long 1 rev 16.77 ratio
CZ 477 long 16.69 ratio
P70FT 625 long 16.9? ratio
LG110 Walther issue 452 long approx 16 ratio
Walther 611 long 1 1/4 ish revs 19.2 ratio Bog standard available in shops
HW100 610 long 1 1/2 revs 18.77 ratio really notchy barrel could have slipped
8002 421 long 16.79 ratio
Vostok 419 long 16.8 ratio
Every barrel has a twist close on 1 rev for the same length. Around 15 years i have had a gut feeling its the way the power is delivered to the pellet but no way of testing or proving. The only other factor could be depth of rifling but doubt it having had a few over the years, they took serious wind. We all know springers take less wind than pneumatics, maybe this is it.

Known rifles with these barrels on take serious wind and a lot more than most.

Think the only way to confirm now is to put one of the above barrels on a P800. Know what i am thinking? No wind!"


Bottom line...Fwb 800 barrels (for the 10m event at low power) are SUPERB & ACCURATE like nothing ...even at the increased power mod of 11.5 ft/lb. And yes, the Fwb800 barrel can be bought for approx Euro239 a piece - unfortunately It comes with the steel sleeve, which would need to be heated to break the glue bonding to reveal the actual barrel.

Fwb agent I use in Europe is: Bogdan Kimla > http://www.pimpmyairgun.com/viewtopic.php?f=82&t=624

 

[JG66]

Regarding : Smooth Twist Barrels on Milbro Matisse (Ben Taylor air rifle) >> http://www.airgunshooting.co.uk/news/video_milbro_visit_1_1113433

From here > http://www.shooting-the-breeze.com/forums/showthread.php?t=14607&highlight=Matisse

"Hi I've tested a few FX Airguns with smoothtwist barrels I couldnt find any difference in accuracy to normal rifled. I've not long tested the FX Biathlon FX Field Target just waiting on a single shot converter. I was very sceptical burin practical testing groups are tight. Both versions I tested were .177 versions."

and

"I'm not a pro shooter in as much as I do not do comp's.
People in my club think I'm strange as I enjoys long distance shooting out to 100 yards.
I had taken of the MTC Genesis today and changed it for my Sightron 10-50 x 60.
Ranged in at 60 yards , and as it was still air I could put five pellets in to a Birchwood Casey shoot and see 1inch dot without to much trouble and was concistantly hitting a three inch shoot and see at just over 97 yards ( back end of our club range ).
Chrono today was reading 11.4 ft/lbs average , with well over 100 rounds per fill .
The twin shuttle took a while to get used to but it works fine for me now .
Found the sound of it ( or lack of it ) when it fires a little strangeas it is so quiet , have used JSB , H&N , and Wierauch pellets through it , not to much of a difference between them , i did have to alter the sight a lot more with the Matise , than I have ever done before with the Ripper or Airstream changing between those manufacturers .
Tank."


I guess the conclusion from the above - the Smooth Twist Barrels arent more, nor less accurate - so no performance gain, at 11.5 Ft/lb. Perhaps at FAC levels, and 0.22 caliber, that would be another story ?

 

[JeffKr]

That seems to be the consensus, but it's just odd to have a comparable level of accuracy with such a low rate of rotation when the pellets leave the barrel unless the rate of rotation simply doesn't need to be as high as is traditionally thought.