jackie schmidt
New member
Jerry
I am too lazy to change the chuck...........jackie
I am too lazy to change the chuck...........jackie
Mike Bryant
Active member
It doesn't take much gripping force for doing barrel work. I used a 4 jaw for years, but I like the adjust true chucks better. As per just about everything on doing barrel work, a lot of it is personal preference. However, I recently bought an adjust true backing plate to fit my lathe and the plan is to tap it for 4 brass tipped set screws as per Dave Tooley's post on another thread mainly so I can work on shorter barrels through a long headstock and be able to adjust both ends of the barrel. I built one awhile back with 6 set screws, but it was very difficult to get adjusted correctly. Too many screws seemed to work against each other making it harder to center the barrel.
On the adjust true chucks, I leave the front screws that hold the chuck against the backing plate tight. The adjust tru set screws don't seem to have a problem with moving the chuck to where ever you want it set within the range of motion allowed by the backing plate to chuck fit. Every once in awhile you'll get a barrel especially if the bore isn't the straightest in the world that will not indicate in to crown when the barrel is cut off pretty short. These barrels can get outside the limited adjustment range of the adjust true type chuck. Then a 4 jaw chuck or set screw collar would be the way to go.
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Dennis Sorensen
Guest
I am posting this just to show Alinwa that I do indicate muzzles in for crowning on customers rifles...even if I think is does not make any difference in accuracy. 
I always finish them with a piloted 60 degree chamfer reamer, it leaves such a perfect finish.
This is a 6.5 x 55 hunting rifle with a new Gaillard barrel.
I always finish them with a piloted 60 degree chamfer reamer, it leaves such a perfect finish.This is a 6.5 x 55 hunting rifle with a new Gaillard barrel.
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nemo999
Guest
Dennis, what did you use to wrap around the barrel? Some kind of tape?
I've also considered getting a piloted crown reamer to reduce setup time.
I have a 3 jaw Yuasa 8" that has 3 screws to loosen the backplate and only 3 adjusting screws at 60° instead of 4 like the Buck Chuck. I've been able to dial that in to .0001 no problem although a little bit trickier than the four 90° opposing screws. I find the Yuasa a very well made chuck and has a better fit and finish than the Bison.
http://img90.imageshack.us/gal.php?g=img5338.jpg
My Bison 6" Adjust Tru has 3 screws to loosen backplate and has the 4 screw adjuster setup at 60° and 120° like Don has illustrated. I have no problem whatsoever zeroing that Bison dead on in a minute on a barrel. It works.
Of course the 4 jaw chucks have maximum gripping power, but I've found that unnecessary for barrel work and much easier/faster to use the Adjust Tru type 3 Jaws with shims.
I did have a 6 Jaw 6" older Buck Chuck with the four 90° opposing screws and liked it very much, except for loosening and tightening 6 backplate screws, but then the chuck got badly sprung and became scrap. I got a deal at Enco for the Bison for under $500 delivered last year to replace it. I like that chuck and it now gets used the most.
I've also considered getting a piloted crown reamer to reduce setup time.
I have a 3 jaw Yuasa 8" that has 3 screws to loosen the backplate and only 3 adjusting screws at 60° instead of 4 like the Buck Chuck. I've been able to dial that in to .0001 no problem although a little bit trickier than the four 90° opposing screws. I find the Yuasa a very well made chuck and has a better fit and finish than the Bison.
http://img90.imageshack.us/gal.php?g=img5338.jpg
My Bison 6" Adjust Tru has 3 screws to loosen backplate and has the 4 screw adjuster setup at 60° and 120° like Don has illustrated. I have no problem whatsoever zeroing that Bison dead on in a minute on a barrel. It works.
Of course the 4 jaw chucks have maximum gripping power, but I've found that unnecessary for barrel work and much easier/faster to use the Adjust Tru type 3 Jaws with shims.
I did have a 6 Jaw 6" older Buck Chuck with the four 90° opposing screws and liked it very much, except for loosening and tightening 6 backplate screws, but then the chuck got badly sprung and became scrap. I got a deal at Enco for the Bison for under $500 delivered last year to replace it. I like that chuck and it now gets used the most.
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Dennis Sorensen
Guest
Just 3 wraps of 3M masking tape and the jaws lightly adjusted... the other end is dialed in too. The tape works fine for light crowning and prevents marking the barrel. The barrel being tapered only contacts the inside end of the jaws, not much in front of the chuck.
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blagg
Guest
I've got something to add since we are talking about crowns. I shot in the Hunter Benchrest discipline for a few years and have not had much time in the last ten years or so. It is general practice to cut the 11 degree crown. The main reason of many was when cut very fine at high speed with coolant and light cuts slightly above center will produce a mirror finish! Cutting above center will leave very little if any burr. Also when after firing each round or match, the crown before cleaning of course, could be inspected by looking at the black whiskers or powder trails leaving the bore. When a noticeable difference is seen at one of the lands or grooves, whatever way you want to look at it, upon close inspection you could tell it was time to recrown! It is not uncommon to recrown a couple of times a season. This was taught to me by Larry Cribbs who builds some of the best Hunter rifles shot at a match! I beleive in his theory because it works, period. I crown almost all barrels this way unless they are ultra light hunting barrels.
As a side note the barrel has to be indicated just as true as the chamber end while crowning for a 11 degree. At least thats how I do it. Thats my 2 cents worth.
As a side note the barrel has to be indicated just as true as the chamber end while crowning for a 11 degree. At least thats how I do it. Thats my 2 cents worth.