Gritter's chambering video

Al is correct in the reasoning for making them 12" long.
I had originally planned to make mine 18" long but after talking to Gordy decided 12 was enough.(Al a measured 12" not what you been telling your wife is 12"):D.
I thought I had taken some pictures of the ones I made but can't find them, I'll ty to take some and post them.
One of the reasons I went with brass rod was the machining concerns you guys have and I had it on hand.
I drilled the end before turning it down then ran a live center on the end and cucked it in close to the chuck to prevent flex. I turned them down to the point the bushing would almost fit on then pollished until they did fit.
I didn't do any measuring as I wanted the bushings to fit as tight as possible without them being "grabby" but turn smoothly and I figured I could get them closer by fitting than measuring.
James
 
I haven't noticed that drill rod was hard to machine. It will work harden though. If I were to build one, I would borrow a screw out of one of my reamers to check size. I would put it in a collet to drill and tap. I would put it in my spin collet and put it on my surface grinder and grind to fit the bushing. I have a toolpost grinder, but don't like to use it if I can get by without it.
Butch
 
Butch Lambert said:
I haven't noticed that drill rod was hard to machine. It will work harden though. If I were to build one, I would borrow a screw out of one of my reamers to check size. I would put it in a collet to drill and tap. I would put it in my spin collet and put it on my surface grinder and grind to fit the bushing. I have a toolpost grinder, but don't like to use it if I can get by without it.
Butch
Click to expand...

"SNAP" is the sound small taps make in tough material (like drill rod)

I have a tool post grinder, so I guess I'll order up some drill rod and go for it.

Brass sounds interesting, any problems with it yielding?

What diameter drill rod, for 22 cal and up?

Ben
 
Using a caliper with resolution to .0002 most readings I get are .0002 smaller than those in the picture. You don't want any slop between the rod and the bushing or more correctly no more clearance than is required for the bushing to rotate on the rod.

indirod.jpg


You'll notice that there is a step in the smaller rod I will probably turn it down to .200 the rest of the way down the rod until there is only about 1" left unturned so the rod isn't trying to flex in to places.
James
 
Bnhpr said:
"SNAP" is the sound small taps make in tough material (like drill rod)

I have a tool post grinder, so I guess I'll order up some drill rod and go for it.

Brass sounds interesting, any problems with it yielding?

What diameter drill rod, for 22 cal and up?

Ben
Click to expand...
Ben I saw your post after I posted mine.
The rod on the left is for 22 cal and 6mm.
The one on the right is for 7mm.
I don't know at what caliber the ID of the bushings change.
No problems with the brass yet.

James
 
I made my first one out of some 303 stainless 0.250" rod that I had laying around (for the 6mm range rod), and the next one for 6.5mm from 0.250" W1 drill rod. If you look here you can see some pictures. Just follow the slideshow in about 5 pics or so.

They are about 16" long to ensure good sensitivity. I machined the bushing surfaces to about 0.0003" over size, then went the rest of the way with a diamond "ez-lap" hone and some 320 grit paper, until the fit was perfect. The 6mm rod was machined down to about 0.232" for the first 8 inches or so. Next time I'll use the appropriate size drill rod and eliminate the diameter reduction step, as you can get it in 1/64" increments, and it machines very nicely.

I tapped the screw hole by holding the tap in the tailstock chuck,and rotating the spindle by hand (carefully), with lots of high-sulphur cutting oil. No drama at all.

Cheers,
 
Drill Rod

Drill Rod, before it is hardenned, is certainly not "tough". In fact, it machines, drills, and taps, rather easilly. But Butch is correct, it will work harden due to the high carbon content.
For this "range rod", anything will do, as long as it will go into the ID of the barrel with enough clearance to do the job. The only thing important is the fit of the bushings ID. The more slack the bushing has over the turned, (or ground), end of the rod, the more induced error there can be in the transfered readings. For instance, if the bushing has .0003 clearance, it is possible to start with that much error that is built into the set-up.........jackie
 
I've got to think this through, BUT................I question this.


"For instance, if the bushing has .0003 clearance, it is possible to start with that much error that is built into the set-up."



I don't know that that's really true Jackie, a small amount of pre-load will ensure that whether you've got .0003 or .003 you'll get a good reading. Even on a reamer pilot this holds true as one flute is sure to be doing SOME more cutting than the others, the end of the reamer doesn't just flop around inside the bushing....


al
 
alinwa said:
I've got to think this through, BUT................I question this.


"For instance, if the bushing has .0003 clearance, it is possible to start with that much error that is built into the set-up."



I don't know that that's really true Jackie, a small amount of pre-load will ensure that whether you've got .0003 or .003 you'll get a good reading. Even on a reamer pilot this holds true as one flute is sure to be doing SOME more cutting than the others, the end of the reamer doesn't just flop around inside the bushing....


al
Click to expand...

Al,

To preload it, you run it of your rest? From your tailstock, it will be kinda centered, i.e., not preloaded, or possible preloaded up or down, maybe not in the axis your indicator is lying?

So, this begs the question, shouly it be run off the tailstock or carriage?
 
All's I'm saying is that you HAVE to give it SOME preload simply because you can't avoid it.........just like a reamer it WILL hold to one side or the other. In the case of a reamer this simply means that the reamed hole will be "1/2 of the play out" or in the case of Jackie's example, if you used a reamer pilot with .0003 of clearance then the reamed hole will be at minimum .00015 oversized :)


In the case of the range rod I can't see ANY induced play............after all the long-reach indicator isn't contained at all. You just load it against one side and go.


al
 
Spott3r said:
It was really neat to meet Shiraz and see Gordy showing the G0509 with a real barrel in progress.

The G0670 was very neat. As was the G0667X

http://www.grizzly.com/products/9-x-48-High-Precision-Variable-Speed-Vertical-Mill/G0667X

http://www.grizzly.com/products/16-X-40-Electronic-Variable-Speed-Lathe/G0670

Going back Tuesday am for the class for the Gunsmithing School.
Click to expand...

The VFD drives are sweet to operate. I bought a Clausing Metosa variable speed last year for work, and it really saves time.

I'm not familiar with the Yaskawa drives, but I have worked with many other drives extensively, and will say that they are becoming very reliable these days.
 
Got home from the show in Vegas just a few minutes after midnight this morning - left Vegas just after 7am CST, then drove in snow from about 90mi. west of Flagstaff to about 20mi. west of Albuquerque. I have to tell you guys, the long drive (2144mi.) was worth it. Lots of neat guns, optics, & other shooting gear to look at for sure, but one of the highlights for me was to meet Shiraz & Gordy and get a close look at those Grizzly lathes.

Gordy spent probably 15min. answering my questions about both the lathe & his methods - I've met a lot of good people over the past 30+yrs. in the shooting game, and there's no doubt in my mind that Gordy's one of the good guys. Shiraz was also very cordial - my biggest regret after getting a good look at the machines at the show is that he didn't have this selection of models available a few years ago when I was looking for a good lathe & mill.

I'm gonna pop myself a big bowl of popcorn and settle in to watch the chambering DVD.
 
I got home from the SHOT show a few hours ago- only a 3 1/2 hour drive for me. Every time I went by the Grizzly booth it was swamped. I got to look at stuff for about 5 minutes and talked to Shiraz about the difference between the Taiwan and Chinese models.

Dave Kiff makes two different range rods- one for unchambered barrels and one for chambered barrels. They are $38 plus $8 per bushing. That is cheap enough not to fool with making one myself.

I wish I had gotten the opportunity to talk to Gordy more about the range rod use but it just didn't happen.

Both the G0509G and the bigger "looking" but apparently same size, 670 looked like nice machines and certainly up to the task at hand.

Too bad this thread had to turn into such a pissing match...
 
Dennis
If Dave is only making 2 indicator rods then he must have dicided not to make the ones that Gordy is using because Gordy's indicator rod is different than either Daves range rod or indicator rod.

Gordy or Dave Kiff, if you see this could you comment on the availability of the "Gordy's indicator rod".

James
 
Dennis,
I don't see this as a pissing match at all. Several opinions came out in this thread. I was able to call Gordy and visit for about 30 min. It was a great conversation.
Butch
 
Shot Show

The Shot Show was great, last time I was there was in Houton Texas 1983! Took my 17 year old son and one of his friends, drove from Phoenix. Spent about a hour over two days at the Grizzly booth #1973. I got to meet Shiraz, a real gentleman, and watch Gordy at work while he was visiting with everyone. I found both Shiraz and Gordy to be laid back and very easy to talk with. Well worth the trip to Las Vegas. My son and his friend found the show to be overwhelming, as did I. Now to sell one of my lathes so I can fit the new 16 x 40 into the shop. Doc Marsh
 
Range rods

Just got back from the SHOT show and it went just great out there. I met a great bunch of people and amazingly I didn't even screw any barrels up while chambering surrounded by a crowd:) I really have to say the Grizzly lathes performed beyond what I even thought they would do. I chambered on one for the first time last summer when we made the DVD, and now did three more chambers at the SHOT show - all of them came out perfect!!. It took a little while to start getting the feel of the machine, but oh man did it do a great job- every one came out flawless, even with all the distractions.

Those of you who were there saw that all three barrels I chambered ended up with absolutely no runout whatsoever in the chambers front to rear (the .0001" indicator didn't even wiggle when turning the barrel), even with quite varying amounts of curvature between the three barrels the throats were all perfect, and the runout in the bores ahead of the chambers stayed less than .0001" for at least 2-3" ahead of the chambers before the curvature slowly started to become measurable.

I had a lot of questions on range rods, and I see some of the same questions here after I got back so I thought I'd clarify how I do it. I made three sizes of rods for the main chambers I do: #1 for 22 and 6mm: make from 13/64" drill rod, turn the end down to about .189" and then grind it or spin it down to where the reamer bushings will just barely go on and turn freely. #2 for 25, 6.5, 270 and 7mm: use 15/64" drill rod and turn end down to about .220" and fit bushing same way. #3 rod for 30 cal, 338 and larger: use 17/64" rod and turn end to about .252" and fit bushings. The ends will drill and tap easily. Dave Kiff at Pacific Precision is making them now so those of you who don't want to make them can buy them and the bushings all from Dave.

I hold the range rod in the tailstock chuck as little as possible - only about 1/16" or so to allow the range rod to freely pivot back and forth as the bore moves. I've had better luck doing it this way than holding the rod more firmly in the chuck.

I did have an extra large bore and consequently a very loose fitting bushing one time and no tighter bushing, so for that particular job I bent the range rod slightly and held it firmly in the chuck so it would hold tighter against one side of the bore and I could get a pretty good reading on it, but it works way better to get a good fitting bushing and let it freely move.

One other thing to keep in mind is what Alinwa posted earlier - it's having more of the shaft outside the barrel to give more accurate readings (the pivot point is farther away from the indicator), so the longer the rod the closer your indicator readings will be to the actual bore movement you are measuring. I think 12" is minimum size and works really well, but it sure wouldn't hurt to go even longer yet.

After seeing how many questions guys had, even after seeing the Grizzly DVD, it really seemed to help quite a few guys understand so much better what was going on when they could see it in person and ask a lot of questions as the process went on. The DVD shows all the basics, but there are so many details that aren't on the DVD that I explained to people at the show in person, and it really seemed to help.

I do several classes a year now on long range shooting and after seeing the interest at the SHOT show, I think I will start offering classes in chambering, crowning and bore slugging/evaluation to interested people at my shop. I can do this about any time since I chamber barrels year-round. I have rifle ranges from 100 to 1000 yards right outside the door at my shop that you can also shoot on if you want, and my wife has started a bed & breakfast at our home for hunters and shooters if you need a place to stay (my shop is attached to my home and she's a great cook). Just let me know if anyone is interested.

Thanks!
Gordy Gritters
 
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