? chucking up a barrel ?

Butch Lambert said:
Jerry,
If you indicate the flute on your reamer and move your compound so the indicator shows "0" then your boring bar will bore the exact angle that the reamer cuts.
Butch
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But Butch, I don't want my bored chamber body tapered, I want it cylindrical so the reamer body will only contact in one spot as it and the leade/freebore/neck start cutting.

Besides I'd be too lazy to do that much compound cranking....considering arthritic thumbs and all.
 
I taper bore it, to where the reamer goes in about 1/2 way, I then use the reamer, by hand, to finally establish the chamber.........jackie
 
jackie schmidt said:
I taper bore it, to where the reamer goes in about 1/2 way, I then use the reamer, by hand, to finally establish the chamber.........jackie
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I may be doing it wrong, but it looks like the best way to get the reamer started coaxial with the lathe bearings and a good guide for the reamer.
I know we are really splitting hairs, but doing only my own I have all the time in the World.
Butch
 
I did the math on a muzzle that was .020" out of the lathe centerline on a 22" barrel and that much would just move the bullet about 3 1/4" at 100 yards. A longer barrel would be less than that. I've seen barrels indicated in at both ends to .0002" that would be farther out than that from where the previous barrel was hitting. To be fair to Gordy's method of chambering, I called Pacific today and ordered the #1, 2 and 3 Grizzly rods. I'll give his method of indicating in a barrel a try and see how the results compare to the way I've been chambering barrels for years. We'll see.

Mike
 
jackie schmidt said:
I taper bore it, to where the reamer goes in about 1/2 way, I then use the reamer, by hand, to finally establish the chamber.........jackie
Click to expand...

It sounds like you are doing a lot of hand work to finish out the chamber, but I bet it actually it isn't that much. About how much time does it take to finish the chamber by hand with it taper bored that way. A few minutes?
 
Mike Bryant said:
I did the math on a muzzle that was .020" out of the lathe centerline on a 22" barrel and that much would just move the bullet about 3 1/4" at 100 yards. A longer barrel would be less than that. I've seen barrels indicated in at both ends to .0002" that would be farther out than that from where the previous barrel was hitting. To be fair to Gordy's method of chambering, I called Pacific today and ordered the #1, 2 and 3 Grizzly rods. I'll give his method of indicating in a barrel a try and see how the results compare to the way I've been chambering barrels for years. We'll see.

Mike
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Outstanding. I'll be interested to hear how it works for you.

Fitch
 
.100" out will get about 13.8 inches of displacement at 100 yards using the formula (.100")*3600"/26"= amount of displacement in inches.
 
Mike Bryant said:
.100" out will get about 13.8 inches of displacement at 100 yards using the formula (.100")*3600"/26"= amount of displacement in inches.
Click to expand...

That's why it's so important to index the barrel so the bore is pointing up when using Gordy's method. I've had barrels running more than 0.1 out at the muzzle when the chamber was aligned. Pointing one with that much runout up is sort of like getting a built in 13 MOA scope base.

Fitch
 
Mike Bryant said:
.100" out will get about 13.8 inches of displacement at 100 yards using the formula (.100")*3600"/26"= amount of displacement in inches.
Click to expand...

That's not all that bad is it? Calculates at 600 yards to just slightly over 41.6". Lets see, a 600 yard benchrest target is 21" x 21", oops:eek::eek:
 
Are we talking about the amount the bore is off center at the muzzle or, the angle of the last few inches of the bore, which it seems would dictate the bullets path.
Sorry for my non machinist wording.

Aloha, Les
 
Mike, I had a couple of friends over one night, and I did Barrel as fast as I could. From the time I walked up to the Lathe, to the final polish was about 1.5 hours.

Of course, that is a 6PPC Barrel, which I can darned near do blindfolded. And I usually take quite a bit longer, especially if someone is there, because any body that knows me will understand that I spend half the time talking.;):D

As for the reaming, all I use the reamer for is the final finish and shape of the chamber. All of the metal is removed with first the drill, then the boring bar........jackie
 
Jackie, I was asking about the actual amount of time it takes to ream the chamber by hand once you go in with the reamer to finish up the reaming by hand after it's taper bored. I've opened up chambers by hand to a slightly larger body diameter from what it was originally reamed which is basically what you are doing when you taper bore the chamber and finish the chamber by reaming it by hand instead of under power. About a minute or less was all it took. Took more time to get the chips out than it did to do the actual opening up of the chamber.

When you set your compound up to taper bore, do you set the compound up for so many thousandths per inch of travel when you run the compound in and out? That's about the only way I could see to get the compound set to the angle it needs to be.
 
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From a "machinist" standpoint, the only indicating that matters would be at say, 0 the breach face, and pick a number 3,4,5,6,7,8" into the barrel.

What you would be looking for is the longest portion of the barrel, that you can determine is "straight", I'd say a couple of inches past the throat would be plenty. That is what the chamber must align with. Forget the muzzle

You cannot change what the bullet goes through after it enters the rifling, but you have to get it started straight, even if that means it's gonna jog 6" later.....that's out of your control.

The muzzle end only needs supported so it does not flop around and flex the breech section out of alignment.

You cannot lie to that bullet by pointing it at the muzzle, your wasting your time. It's going to travel down the path that's there, not where you wish it to be.

I think most would be better off if they would convince themselves that they are only chambering a 6-8" barrel.
 
TRA said:
From a "machinist" standpoint, the only indicating that matters would be at say, 0 the breach face, and pick a number 3,4,5,6,7,8" into the barrel.

What you would be looking for is the longest portion of the barrel, that you can determine is "straight", I'd say a couple of inches past the throat would be plenty. That is what the chamber must align with. Forget the muzzle

You cannot change what the bullet goes through after it enters the rifling, but you have to get it started straight, even if that means it's gonna jog 6" later.....that's out of your control.

The muzzle end only needs supported so it does not flop around and flex the breech section out of alignment.

You cannot lie to that bullet by pointing it at the muzzle, your wasting your time. It's going to travel down the path that's there, not where you wish it to be.

I think most would be better off if they would convince themselves that they are only chambering a 6-8" barrel.
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+1

Fitch
 
Mike, ascertain the actual taper in a given distance that your reamer cuts, and simply set your compound to where it reads 1/2 that amount. You can then place a mark on the compound for future reference. Since 99 percent of what I do is a BR case or a PPC case, I have one mark that I always go back to.

If I taper bore the hole to where the reamer goes in about 1/2 way, that means there is about .005 of stock left in the hole. That is quite a bit. The reamer, by vision, actually cuts quite a bit of material.

I actually run the reamer in a tad past the "scratch line", because since I establish the chamber first, I can do all of the criticle dimensions such as the shoulder off of the headspace gage in the chamber. To me, it is much simpler to remove .001 from the shoulder than it is to run the reamer in exactly .001 when setting the "headspace".......jackie
 
TRA,
When you indicate both ends and then use your Gordy rod, how much does it move the 1st couple inches?
Butch
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Depends on how straight the barrel is, how straight the bore is, how long the barrel is,,, then it may not move at all because it, by some stroke of luck just happened to measure the same,,,,even though the bore had an S curve in it.

What some are stating about finding the bore axis sounds like checking 2x4 studs for straightness by holding a 6" straight edge on each end.
 
TRA,
How are you going to move the barrel to indicate with the indicator rod if there is an s curve in the barrel or some other odd path. I think all you can do with your method is to hope it can be straight for a little bit before it moves.
Butch
 
"uses Gordy's method" but uses it ON BOTH ENDS!!
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If he is doing this to both ends at the same time...........I don't believe this is possible unless the bore is perfectly straight............
 
TRA, when you indicate two predetermined spots, then single point bore a 3d spot in alignment with those two spots, the rest of the barrel becomes a non issue......jackie
 
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