Butch Lambert
Active member
Have you seen the preview of the Grizzly chambering video on 6mmBR.com? Check it out and explain to me how he is indicating the bore.
Butch
Butch
Gritter's chambering video
- Thread starter Butch Lambert
- Start date
M
mike in co
Guest
well butch.....
hmmmmm
he is using the spyder to move the opposite end of the bbl.....(everything pivoting on the chuck jaws)
i think his method is to align a section of the bore to be straight at the reamer side.......my guess is that he assumes that if this section of bore is in line with the reamer....the chamber is inline with the bore......
just one more method......if his guns shoot i guess it works...
mike in co...
hmmmmm
he is using the spyder to move the opposite end of the bbl.....(everything pivoting on the chuck jaws)
i think his method is to align a section of the bore to be straight at the reamer side.......my guess is that he assumes that if this section of bore is in line with the reamer....the chamber is inline with the bore......
just one more method......if his guns shoot i guess it works...
mike in co...
I spoke with a very well known reamer manufacturer about the rod Mr. Gritters is using. He said they use to make them but, due to their length run out was a problem. As far as the rod goes for indicating, the double lock up method, bushing & taper, was still the best method as far as he was concerned. Mr. Gritters inidcating rod appeared to be about 18" or so and he was using the tail stock to hold/insert it in the bore 2" or more at a time. I guess you cant argue with his success, just one more way to do it.
Here’s the YouTube video.
http://www.youtube.com/watch?v=aII2tbavKnM
I don’t have the DVD, what cartridge is he chambering and how much muzzle runout there was after the setup?
It looks like a good setup of you’re going to ream the entire chamber and not going to pre-bore.
Interesting video none the less.
http://www.youtube.com/watch?v=aII2tbavKnM
I don’t have the DVD, what cartridge is he chambering and how much muzzle runout there was after the setup?
It looks like the long stem indicator, wobbly muzzle, indicate the throat and slightly beyond as a cylinder method discussed several times in this forum. But he’s using a piloted rod on top of the lands (and indicating off the rod at a mid point) instead of pre boring and using a long indicator stem reading the grooves.
It looks like a good setup of you’re going to ream the entire chamber and not going to pre-bore.
I don’t believe he’s assuming anything Mike, if the setup is for a 6ppc he’s indicating ½” past the chamber.
Rod runout wouldn't be a factor because the rod isn’t turning, only the pilot. Unless the rod is bent so much that it contacts the bore instead of the bushing, or cocks the bushing itself causing rod flex when the barrel is rotated.
Interesting video none the less.
S
Shiraz Balolia
Guest
Watch the whole 90 minute video.
What you see on 6mmBR is a miniscule part of the chambering video, a teaser if you will. To understand exactly what he is doing and why he is doing it you should watch the whole 90 minute video.
Gordy builds extremely accurate benchrest rifles and has built world record holding guns.
What you see on 6mmBR is a miniscule part of the chambering video, a teaser if you will. To understand exactly what he is doing and why he is doing it you should watch the whole 90 minute video.
Gordy builds extremely accurate benchrest rifles and has built world record holding guns.
dennisinaz
New member
I have watched to whole DVD and what he is saying makes sense. He just calls it a range rod and doesn't talk too much about it. I suppose he isn't giving everything away.
He basically lines up the first2 2"-3" of the bore and doesn't worry about the muzzle end. In fact, on the barrel he chambered, you could see the muzzle run out in the spider- maybe .005-.006 or so. This is just to make a point of the bore not being PERFECTLY straight.
He basically lines up the first2 2"-3" of the bore and doesn't worry about the muzzle end. In fact, on the barrel he chambered, you could see the muzzle run out in the spider- maybe .005-.006 or so. This is just to make a point of the bore not being PERFECTLY straight.
Dusty Stevens
Hollow Point Dispenser
I'd like to see that video
http://www.grizzly.com/products/DVD-Chambering-A-Championship-Match-Barrel/H8396
or if you mean the video clip look at post#4.
James
What Gordy is using is a 12” piece of drill rod machined to hold a reamer bushing with minimal clearance. As someone else stated the rod is held in the tailstock so rod run out isn’t an issue.
I chambered my last barrel using Gordy’s method and setup was surprisingly simple and quick.
But whenever you chamber a barrel you have to make a compromise somewhere along the way because of the curved bore.
You may remember an earlier thread discussing bore curve where I tried to point out that the bore isn’t a perfect arc but has a curve to it, more like a helix. That is the one thing that I don’t know how to properly address with any setup. Anyway after chambering and threading the barrel and indexing it I flipped it around and indicated the muzzle to cut the crown using the same method to indicate as the chamber and found as I expected would be the case the muzzle actually pointed a little off to the right instead of straight up because the helical curve in the bore. But regardless, with what little testing I have done with the barrel I believe it will shoot well enough(been too damn cold to do much testing). I also know that Gordy makes some extremely accurate rifles so his method must be sound. Gordy’s method does do an excellent job of making sure that the first rifling that the bullet hits is dead true with the bullets travel and has the cartridge and bullet dead centered and in line with the beginning of the bore.
As has been said many times on this forum there are many ways to chamber an accurate rifle you just need to find what method you are most comfortable with.
The next barrel I do will be chambered with Gordy’s method also.
James
I chambered my last barrel using Gordy’s method and setup was surprisingly simple and quick.
But whenever you chamber a barrel you have to make a compromise somewhere along the way because of the curved bore.
You may remember an earlier thread discussing bore curve where I tried to point out that the bore isn’t a perfect arc but has a curve to it, more like a helix. That is the one thing that I don’t know how to properly address with any setup. Anyway after chambering and threading the barrel and indexing it I flipped it around and indicated the muzzle to cut the crown using the same method to indicate as the chamber and found as I expected would be the case the muzzle actually pointed a little off to the right instead of straight up because the helical curve in the bore. But regardless, with what little testing I have done with the barrel I believe it will shoot well enough(been too damn cold to do much testing). I also know that Gordy makes some extremely accurate rifles so his method must be sound. Gordy’s method does do an excellent job of making sure that the first rifling that the bullet hits is dead true with the bullets travel and has the cartridge and bullet dead centered and in line with the beginning of the bore.
As has been said many times on this forum there are many ways to chamber an accurate rifle you just need to find what method you are most comfortable with.
The next barrel I do will be chambered with Gordy’s method also.
James
M
mike in co
Guest
ok...what some others do( from what i have read) is to cut a chamber inline to a point where the throat is expected to be. what i believe gordy is trying to do is make a chamber that is "pointing" along the bore meeting at the throat. this assumes the the curve/spiral is continuous and smooth. that was the assumption i was talking about. his chamber is not necessarily parrallel to the bbl...as others have pointed out the was visible run out on the muzzle....and as was just said when the muzzle is crowned the same way, the face is not perpenticular to the od....but is to the last of the bore.
just one more way ro skin a cat....
mike in co
just one more way ro skin a cat....
mike in co
P
pduryee
Guest
Guess I missed something in the video and need to watch it a few more times. I was under the impression that he got the chamber end close first by adjusting the spider then switched to the four jaw to dial it in. Then he adjusted the muzzle true by adjusting the spider and the chamber end by the four jaw....switching back and forth until both were running true. Speaking as a novice at this stuff and teaching myself machine work I can say that I learned a lot from the video and am very satisfied with the 4003 lathe.
JerrySharrett
Senile Member
I'll admit the Gritters method is ingenious but when you get done chambering, turning the tenon and shoulder that butts up against your action, where is the muzzle pointing?? Is it pointing up or down or left or right???
IIRC, a post in a different thread said he indicates the barrel so the muzzle runout is on the vertical plane, high side up.
Jerry, you obviously haven't seen the vid. Gordy clocks his barrels so that the bend is up, right wrong or indifferent this is where he SETS it, no guesswork.
Regarding all of the other posts picking on Gordie's methods.........none of you really seem to get it, even the "very well known reamer mfgr" is all wet on this one.
If ANY of you can actually EXPLAIN a better way, not just "9 ways to flay a cat" but explain your reasoning, then feel free but this Gordy Bashing is just stupid!
He did a great job on the video and showed me several K.I.S.S. simple improvements over my several ways..........the use of the range rod is simply inspired.
al
Regarding all of the other posts picking on Gordie's methods.........none of you really seem to get it, even the "very well known reamer mfgr" is all wet on this one.
If ANY of you can actually EXPLAIN a better way, not just "9 ways to flay a cat" but explain your reasoning, then feel free but this Gordy Bashing is just stupid!
He did a great job on the video and showed me several K.I.S.S. simple improvements over my several ways..........the use of the range rod is simply inspired.
al
Jerry
JJ is correct.
Mark the location that the muzzle is pointing up then fit the action so that it will be pointing up when assembled then chamber the barrel.
I don't want to take anything away from Gordy but after I had chambered a total of 4 barrels I pondered on how to do a better job of indicating a barrel (not that I had problems I just wasn't comfortable with it) and came up with the same idea that Gordy uses. I doubt that I would have ever tried it though, had I not known someone else was doing it this way with success. So there have got to be others doing it this way too but you just don't hear about it, or anyway I haven't(didn't know Gordy was doing it this way until I got the video).
The issues that I had with trying it were:
1)How accurate can it be indicated using secondary measurements off the indicator rod.
2)Dealing with the helical curve with the bore, which is an issue no matter how you indicate the barrel.
Gordy doesn't only set the barrel up using the indicator rod, he also uses a Mitutoyo indicator with a long stylus that he reaches into the bore to recheck the runout.
With the Mitutoyo and long stylus, after rough drilling he is able to reach way in and check the runout of the bore where the throat will be before boreing and reaming the chamber.
I do not have a test indicator with long stylus like Gordy yet, maybe in the future.
I hope what I posted makes sense.
James
JJ is correct.
Mark the location that the muzzle is pointing up then fit the action so that it will be pointing up when assembled then chamber the barrel.
I don't want to take anything away from Gordy but after I had chambered a total of 4 barrels I pondered on how to do a better job of indicating a barrel (not that I had problems I just wasn't comfortable with it) and came up with the same idea that Gordy uses. I doubt that I would have ever tried it though, had I not known someone else was doing it this way with success. So there have got to be others doing it this way too but you just don't hear about it, or anyway I haven't(didn't know Gordy was doing it this way until I got the video).
The issues that I had with trying it were:
1)How accurate can it be indicated using secondary measurements off the indicator rod.
2)Dealing with the helical curve with the bore, which is an issue no matter how you indicate the barrel.
Gordy doesn't only set the barrel up using the indicator rod, he also uses a Mitutoyo indicator with a long stylus that he reaches into the bore to recheck the runout.
With the Mitutoyo and long stylus, after rough drilling he is able to reach way in and check the runout of the bore where the throat will be before boreing and reaming the chamber.
I do not have a test indicator with long stylus like Gordy yet, maybe in the future
.I hope what I posted makes sense.
James
dennisinaz
New member
One thing that is evident throughout the DVD is that he is fanatically meticulous at each stage that everything is running right- he leaves nothing to chance. If it out a little, he fixes it before going on. He even bore scopes the progress as he engages the rifling with the reamer...
All in all, a very thoughful process.
All in all, a very thoughful process.
S
Spott3r
Guest
The Lathe Gordy is using...
..in the Video/DVD is the G0509G Professional Gunsmith Lathe.
http://www.grizzlyimports.com/products/16-x-40-3-Phase-Gunsmith-Metal-Lathe/G0509G
Just to be clear..
Dealing with the helical curve... it really doesn't matter what the bore does with this method. The method indicates possibly the best procedure to align the action and esp. the chamber with the intial bore concentricity. So when the Bullet leaves the chamber it is aligned directly/exactly with the bore direction.
OK...I'll stop there because I don't want to....bore you!!!
It is a 7mm barrel blank.
Really though, get the Video it is well worth it.
..in the Video/DVD is the G0509G Professional Gunsmith Lathe.
http://www.grizzlyimports.com/products/16-x-40-3-Phase-Gunsmith-Metal-Lathe/G0509G
Just to be clear..
Dealing with the helical curve... it really doesn't matter what the bore does with this method. The method indicates possibly the best procedure to align the action and esp. the chamber with the intial bore concentricity. So when the Bullet leaves the chamber it is aligned directly/exactly with the bore direction.
OK...I'll stop there because I don't want to....bore you!!!
It is a 7mm barrel blank.
Really though, get the Video it is well worth it.
Last edited by a moderator:
JerrySharrett
Senile Member
Chisolm, JJ and Al
No, I don't need to see the video, just tell me via the written word.
Chisolm, don't waste your funds on the Mitutoyo. It's not a bad indicator but it sure is not the best. As Bruce Thom says, "cry once".
I have been threading round stuff on a lathe since 1955 with conventional half-nut and digital CNC lathes. If one of you can explain how you are going to "clock" a spot on a barrel so it finishes at the same place every time, in a glued in action that belongs to someone miles away, I'll gladly listen.Jerry
JJ is correct.
Mark the location that the muzzle is pointing up then fit the action so that it will be pointing up when assembled then chamber the barrel.
With the Mitutoyo and long stylus, after rough drilling he is able to reach way in and check the runout of the bore where the throat will be before boreing and reaming the chamber.
I do not have a test indicator with long stylus like Gordy yet, maybe in the future
I hope what I posted makes sense.
James
No, I don't need to see the video, just tell me via the written word.
Chisolm, don't waste your funds on the Mitutoyo. It's not a bad indicator but it sure is not the best. As Bruce Thom says, "cry once".
P
pduryee
Guest
If you had the entire gun at some point and threaded a barrel using the method described. Could you then machine a reference gage that would stay in your shop along with the other gun specs? Seems like if you matched a new barrel to the clock position on the gage it should fit the action also.
Just a thought.
JerrySharrett
Senile Member
Yes, IF. But your proposed IF doesn't come about very much except in building and barreling a gun the first time.
Much of this discussion is making a complicated solution to a non existent problem. A crooked barrel bore is normally not radial or circular. It is normally a compound curve. The important consideration is that the bullet centerline axis point straight into the bore at the freebore/leade area. It is also important that the exit point of that bullet be in linear alignment with the action/stock assembly.
If the entry point of the bullets cylindrical portion in the chamber neck is concentric with the bore at that point all is well and the bullet can get underway without problems of jacket distortion or in-bore skewing.
If the bullets exit point from the bore is not in perfect alignment in the horizontial (left-right) plane with the stock/action the gun will not track correctly.
I'm in no way trying to criticize Mr. Gritters quality of work or his results. I'm sure has a satisfied customer base. It's just with my background of machining and engineering I find it disturbing if the bore exit point doesn't point in the same direction as the bullets entry point.