BTW I'm currently exploring 50BMGs and the Gordy bars shore are handy for reaching in! I'd say "reaching in like breeding a cow" cuz I'm a farm kid but I'd prolly offend somebody...
So I won't
Spider in steady fingers question..
- Thread starter skipkh
- Start date
BTW I'm currently exploring 50BMGs and the Gordy bars shore are handy for reaching in! I'd say "reaching in like breeding a cow" cuz I'm a farm kid but I'd prolly offend somebody...
So I won't
I guess I'm unclear on the difference between chambering with a chuck and spider (either outboard or spider in the steady) to dial out runout and to get axial alignment, and the "Gordy" method. I get we are talking about Gordy Gritters but what's so different? I've been hiding under a rock but lI always thought he chambered in the headstock with the spider on the outboard basically like everyone else...
I guess my point was I'm not sure it matters where the spider is. Outboard or in the steady fingers it's still two points of contact for alignment - the chuck and the spider. I mean the barrel is going through dead air in the spindle hole to get to the spider at the end of the spindle, and it's going through dead air across the lathe to get to the spider in the steady. Same difference. At least that was my reasoning, assuming I've still got enough active neurons to reason with LOL!!
I guess my point was I'm not sure it matters where the spider is. Outboard or in the steady fingers it's still two points of contact for alignment - the chuck and the spider. I mean the barrel is going through dead air in the spindle hole to get to the spider at the end of the spindle, and it's going through dead air across the lathe to get to the spider in the steady. Same difference. At least that was my reasoning, assuming I've still got enough active neurons to reason with LOL!!
Gordy doesn't indicate the muzzle. He uses two points in the chamber.
MilGunsmith
Member
I have the drawings for the bearing fitted steady rest design. I got them from Speedy when he was at TSJC. I built one to fit on my lathe that has a .750" spindle hole. I can send them or try posting them here.
MilGunsmith
Member
I see this a little differently..... I don't use "two points in the chamber" but instead I run the section of barrel 1" behind the leade and 2-4" in front of the leade and align it for one reason and one reason only....NOT because I think it's somehow "more accurate" than chambering between centers and NOT to "get the bullet started straight into the bore but because in simple fact many barrels exhibit some sort of curvature and I want to be able to turn that curvature to my advantage, not to fight it.
I start "between centers"
I then run the 4-5" section around the bullet to find WHERE the muzzle points, moving the muzzle off-center.
At this juncture I set the exit point to where I want it and I doubt that whether I now chamber between centers or aligned with my barrel section makes any difference whatsoever, it's just that I want the roller-coaster-ride of the bullet to be close to vertical. I don't like guns jumping sideways. And I've had me some hoppers thru the years!
Also, at this point it's child's play to set back to "between centers" if I want......and it's also then possible to look through the barrel and verify the lope and direction....
Butch Lambert
Active member
So what kind of a curve does the bore wander off to?
They're all different, probably some sort of helix based on visually watching the various lopes...... many are straight to within less than a thou. Some run off center by ten thou in the middle...... I've had 8 lately that I've set between centers and found only a tenth or less of runout on the chamber end. I don't even mess with these. I've only set up 5 50cals and they've been dead straight. Fat, slow-twist 6's are often good, I've had a number of Shilen's, Bartleins and Kriegers with no measurable runout in Varmint tapers. But I've had some pretty loopy 8-twist 30" blanks. I had a CF bbl a while back had a solid KINK on the shank, I've seen this abrupt kinking 3 times. It doesn't seem to affect accuracy as long as I can point it. Worst runout seems to be in off-calibers and definitely smaller contours and fluting are a factor. That said, just last week I turned an 1.700 Lilja down to .835 muzzle @.010 tpi and it developed NO runout, stayed straight as a die. (I'm doing this for a project, a prototype, not for a customer) I will hazard a guess that the kinking occurs from encountering some sort of stiff spot or inclusion in the melt. Maybe somebody opened the door in the middle of a squirt......
The worst I've ever seen was a .270 bbl, fluted #5 contour done between centers by one of the top gunsmith's in America. Bbl was factory contoured and fluted by the best (Feldkamp) poi was 18" low and right of the numbers on a Borden action which I assume to be straight. In assessing this barrel I found muzzle-leade and rear end of chamber to be dead true, 3 points aligned. But now, looking thru the barrel it looked like a jump-rope. Hunting/pack-around gun so the hop wasn't a big deal and it shot OK but was so far out of alignment that I had to hand-lap the Tally rings to center or run out of adjustment in the scope.
I've got BR barrels that run out over 20 thou at the muzzle and shoot smooth like butter. I spun one up on video to show I could dial one in, CHAMBER it, shoot it and years later go back. This one is marked "27thou wobble" and when I put 'er back in 5yrs after the fact and aligned the rear of the chamber and points 2"-4" from the leade it showed .022 and was advanced about 6* fro the old punch-mark for 'top'. I'm running it in a bolt-in Neuvo 10.5lb setup testing trying to get a bolt-in to shoot like a glue-in. It shoots..... I don't have time to run it, but "It Can't Shoot Big" which is one of my short-cut tests.
I get a 'normous giggle from guys who'll run a 4" Lon'Gisland clanking over the lands all day but think a Gordy bar will flex and climb
On a 50BMG I can Gordy, then drill out the chamber, get the reamer going and then RE-check running the Gordy bar in and slipping a long-stem into the chamber alongside the bar, setting the ball 'wayyy up near the front of the chamber......
This 50BMG thing is kinda' fun. Basically I've realized "Life Is Short, Then You Die" so I'm jumping right over a bunch of incremental testing and going right to the top of the food chain. I've recently started filming my "50BMG Challenge" where I set out my newest goals out in front of God and Ever'buddy...... got 5 episodes in the can.
"3 Things;
-#1- 1/4moa with available 750gr + bullets (no light cheater bullets"
-#2- packable rifle under 20lb, hopefully nearer 15lb and
-#3- recoil less than a Walmart 30-06
I've just the last couple days bolted together an aluminum screen door assy which makes the 15lb part...... this week is testing on the recoil sled (My primers came in), then if it ever stops raining out to the outside bench to shoot for effect. (CAN'T shoot these out the window!)
I 'think' one of the three bbls I'm working with is one'a Woody Woodall's Walthers cuz she squeals like a PIGGY and work-hardens like austenitic 300-series hardware stock. But I turned 'er down and and she stayed wikkid straight!
Butch Lambert
Active member
They're all different, probably some sort of helix based on visually watching the various lopes...... many are straight to within less than a thou. Some run off center by ten thou in the middle...... I've had 8 lately that I've set between centers and found only a tenth or less of runout on the chamber end. I don't even mess with these. I've only set up 5 50cals and they've been dead straight. Fat, slow-twist 6's are often good, I've had a number of Shilen's, Bartleins and Kriegers with no measurable runout in Varmint tapers. But I've had some pretty loopy 8-twist 30" blanks. I had a CF bbl a while back had a solid KINK on the shank, I've seen this abrupt kinking 3 times. It doesn't seem to affect accuracy as long as I can point it. Worst runout seems to be in off-calibers and definitely smaller contours and fluting are a factor. That said, just last week I turned an 1.700 Lilja down to .835 muzzle @.010 tpi and it developed NO runout, stayed straight as a die. (I'm doing this for a project, a prototype, not for a customer) I will hazard a guess that the kinking occurs from encountering some sort of stiff spot or inclusion in the melt. Maybe somebody opened the door in the middle of a squirt......
The worst I've ever seen was a .270 bbl, fluted #5 contour done between centers by one of the top gunsmith's in America. Bbl was factory contoured and fluted by the best (Feldkamp) poi was 18" low and right of the numbers on a Borden action which I assume to be straight. In assessing this barrel I found muzzle-leade and rear end of chamber to be dead true, 3 points aligned. But now, looking thru the barrel it looked like a jump-rope. Hunting/pack-around gun so the hop wasn't a big deal and it shot OK but was so far out of alignment that I had to hand-lap the Tally rings to center or run out of adjustment in the scope.
I've got BR barrels that run out over 20 thou at the muzzle and shoot smooth like butter. I spun one up on video to show I could dial one in, CHAMBER it, shoot it and years later go back. This one is marked "27thou wobble" and when I put 'er back in 5yrs after the fact and aligned the rear of the chamber and points 2"-4" from the leade it showed .022 and was advanced about 6* fro the old punch-mark for 'top'. I'm running it in a bolt-in Neuvo 10.5lb setup testing trying to get a bolt-in to shoot like a glue-in. It shoots..... I don't have time to run it, but "It Can't Shoot Big" which is one of my short-cut tests.
I get a 'normous giggle from guys who'll run a 4" Lon'Gisland clanking over the lands all day but think a Gordy bar will flex and climb
On a 50BMG I can Gordy, then drill out the chamber, get the reamer going and then RE-check running the Gordy bar in and slipping a long-stem into the chamber alongside the bar, setting the ball 'wayyy up near the front of the chamber......
This 50BMG thing is kinda' fun. Basically I've realized "Life Is Short, Then You Die" so I'm jumping right over a bunch of incremental testing and going right to the top of the food chain. I've recently started filming my "50BMG Challenge" where I set out my newest goals out in front of God and Ever'buddy...... got 5 episodes in the can.
"3 Things;
-#1- 1/4moa with available 750gr + bullets (no light cheater bullets"
-#2- packable rifle under 20lb, hopefully nearer 15lb and
-#3- recoil less than a Walmart 30-06
I've just the last couple days bolted together an aluminum screen door assy which makes the 15lb part...... this week is testing on the recoil sled (My primers came in), then if it ever stops raining out to the outside bench to shoot for effect. (CAN'T shoot these out the window!)
I 'think' one of the three bbls I'm working with is one'a Woody Woodall's Walthers cuz she squeals like a PIGGY and work-hardens like austenitic 300-series hardware stock. But I turned 'er down and and she stayed wikkid straight!
"OLE Woody, I'm glad that he is gone. Jackie Schmidt thinks and I concur that it is a PH type stainless. Got to use a lot of speed and feed.
yes
Get 'er hooked in an eating and KEEP 'ER THERE!! I blew up a parting tool, shoulda' just stuck er in the bandsaw but I was in a hurry.
But chambering with a hand-held reamer holder was a whole 'nuther level! I chambered with a leather welding glove on my driving hand 'fore I'd dare peck so deep. I re-chambered..... recut the existing Noreen chamber by chasing out the threads, truing and running in about an inch with my reamer. Tried to chatter, squealed, but I gentled 'er down and got a glassy smooth job, tight.
The first time I used Jackie method of creating three points that are now running true. There was no longer a need to to then have to clock the muzzle at 12:00 or 6:00 o'clock. As it remains running true with the other two points that were also established. I also personally feel that it also eliminates an un-desirable or just possibly another uneeded variable for me to have to now deal with / clocking the muzzle.
Another important point that Jackie pointed out is the need to go back in there and to check your work to see if it was actually done correctly. When I went back to check my own work all three points were still running dead true with each other.
Another important point that Jackie pointed out is the need to go back in there and to check your work to see if it was actually done correctly. When I went back to check my own work all three points were still running dead true with each other.