Page 1 of 10 123 ... LastLast
Results 1 to 15 of 146

Thread: Gritter's chambering video

  1. #1
    Join Date
    Feb 2003
    Location
    Poetry, Tex.
    Posts
    6,500

    Gritter's chambering video

    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

  2. #2
    Join Date
    Feb 2003
    Location
    aurora, co
    Posts
    3,609
    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...

  3. #3
    Join Date
    Mar 2006
    Location
    Louisiana
    Posts
    430
    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.

  4. #4
    Join Date
    Dec 2006
    Location
    western Iowa
    Posts
    242
    Hereís the YouTube video.
    http://www.youtube.com/watch?v=aII2tbavKnM

    I donít have the DVD, what cartridge is he chambering and how much muzzle runout there was after the setup?

    Quote Originally Posted by Butch Lambert View Post
    Check it out and explain to me how he is indicating the bore.
    Butch
    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 heís 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 youíre going to ream the entire chamber and not going to pre-bore.

    Quote Originally Posted by mike in co View Post
    .......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......
    I donít believe heís assuming anything Mike, if the setup is for a 6ppc heís indicating ĹĒ past the chamber.

    Quote Originally Posted by wnroscoe View Post
    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.
    Rod runout wouldn't be a factor because the rod isnít 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.

  5. #5
    Join Date
    Sep 2005
    Location
    WA State
    Posts
    77

    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.

  6. #6
    Join Date
    Jun 2007
    Location
    AZ
    Posts
    192
    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.

  7. #7
    Join Date
    Oct 2003
    Location
    Malvern, Arkansas
    Posts
    2,763
    I'd like to see that video

  8. #8
    Join Date
    Feb 2004
    Location
    Nebraska
    Posts
    585
    Quote Originally Posted by Dusty Stevens View Post
    I'd like to see that video
    http://www.grizzly.com/products/DVD-...h-Barrel/H8396
    or if you mean the video clip look at post#4.
    James

  9. #9
    Join Date
    Feb 2004
    Location
    Nebraska
    Posts
    585
    What Gordy is using is a 12Ē 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 isnít an issue.
    I chambered my last barrel using Gordyís 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 isnít a perfect arc but has a curve to it, more like a helix. That is the one thing that I donít 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. Gordyís 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 Gordyís method also.
    James

  10. #10
    Join Date
    Feb 2003
    Location
    aurora, co
    Posts
    3,609
    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

  11. #11
    Join Date
    Jan 2004
    Posts
    23
    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.

  12. #12
    Join Date
    Feb 2003
    Location
    Tennessee
    Posts
    6,472
    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???

  13. #13
    Join Date
    Dec 2006
    Location
    western Iowa
    Posts
    242
    Quote Originally Posted by JerrySharrett View Post
    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.

  14. #14
    Join Date
    Dec 2003
    Location
    washington.........STATE that is.
    Posts
    10,714
    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

  15. #15
    Join Date
    Feb 2004
    Location
    Nebraska
    Posts
    585
    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

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •