I know there's a bunch of skeptics out there about choking barrels and how to do it and blah blah blah. Well, I pulled the dreaded Quest from the safe today and made up a set of choke blocks to squeeze the last inch of my barrel. I pumped them in my 12 ton press and rotated the barrel 90 degrees per squeeze and figured that I hadn't done anything but fart in a whirlwind. To my surprise, the last inch of my bore took considerably more effort to push the pellet through. I tried it with 5 pellets and all of them were harder to push than before I 'choked' it. The groups were the proof that the choke did something to improve the rifle. Finally, I think the Quest is a fair shooter instead of the P.O.S. that it was last night when I put it away.

Great post - there's been lots of speculation about this, especially negative speculation from those who have never tried it. It's good to see some results.

very nice Ralph.
nice looking group.

excellent work..and you sure gathered the lead up.

Can someone provide groove dimensions to form a choke like this? I mean to say if I want to choke a 16mm OD barrel down to desired choked size then do I have to make both the grooves equally downsized or only one of the groove has to be downsized? I am also curious if this operation leaves any pinching marks on barrel OD?

Very Nice work !

Sweet... Could this be done in a vise (instead of a press)? My brain is hard at work designing/testing the poor mans version... How much less should the diameter of the block "hole" be than the barrel?

I've done the same thing using a nicro press tool useing a inch lbs tork wrench to control the pressuer so I get it the same when I turn the tool 90 deg. a nicro press tool is also used for fencing and wire rope as well as boats. howie PS you will feel slight indentations on the barrel where you choked it on the outside, also you could also slug the barrel inside to see the amy of choke you have put in your barrel.

Haven't tried this yet, but why couldn't a muzzle brake type cylinder be shrink/press fit on the barrel to squeeze it down? This should result in uniform diameter reduction and minimal out-of-roundness.

That can be done and has many times by Fix.

nice set of choke blocks.... its the same method most tuners that offer rechoking a barrel use BTW :)

I wish I had a mill so I could experiment with a few things but I always though a set of knurlers with smooth and polished wheels would be usefull for chucking a barrel into a lathe and turning it and tightening the wheels down to add choke... but for barrels/actions that cant be chucked up this is a great way of doing it..... also the press fit or even a band that gets tightend around the end of the muzzle will work as well

Do you think a 9/16 or 5/8 collar clamp would work for this as well?
http://www.grainger.com/Grainger/RULAND-MANUFACTURING-Shaft-Collar-2ADB2

Could you get a 5/8 id and protect the bbl with some leather and crank it down then do the same at another 90°.

I would think that you need to be sure and tighten the screws at the same rate, if they will handle the strain and actually choke the barrel.

Excellent job!

Do you think a 9/16 or 5/8 collar clamp would work for this as well?
http://www.grainger.com/Grainger/RULAND-MANUFACTURING-Shaft-Collar-2ADB2

Could you get a 5/8 id and protect the bbl with some leather and crank it down then do the same at another 90°.

The collar clamps should work OK. It seems you should get clamps as close to the barrel diameter as possible so after the last screw turn there isn't any bulging into the gap between the two halves. It probably would be wise to do intermediate squeezes between the 90 degree points to be sure it ends up perfectly round.

So then since the BBL is 5/8, then we could get a 5/8 collar and then add a shim of some sort inside the collar to create the tension needed to create the choke? Just cut a strip off an aluminum can insert and tighten the screws. They also make a one screw model but I don't think it would work as well.

Sounds like a good approach to me. And I agree on the one screw model. A single screw is never any fun. :D:lol::D:lol::D:lol:

Do you think a 9/16 or 5/8 collar clamp would work for this as well?
http://www.grainger.com/Grainger/RULAND-MANUFACTURING-Shaft-Collar-2ADB2

Could you get a 5/8 id and protect the bbl with some leather and crank it down then do the same at another 90°.

Not a bloody hope in hell...How thin is this barrel..
then put leather between to take up the compression..

yer best bet if yer want to go down this road is a
tapper lock sleeve for a K berring...
(Any berring with the number ending in K has a tappered bore)

http://www.airgunone.com/forums/showthread.php?p=19646#post19646

http://www.airgunone.com/forums/showthread.php?p=12371#post12371

Somewhere I saw a video made by either Paul (Fix) or Pete using a lathe and 3 rollers to choke a barrel....

i dont believe you'll ever get a hand die tough enough to crimp a barrel.
but...a health die in a 10 ton press should crimp it up some.
i would rotate the barrel 22.5 degrees and give it hell eight times.can always hand work the bore if it sizes down to much...its custom work.:rockon: