? chucking up a barrel ?

Paul,
It ain't as quick, but it can be done. Only had one in my life and it didn't shoot well. Have you tried doing an 8 groove?
Butch
 
Ken Worth said:
I'm not a machinist either but I can answer that. An indicator is not supposed to have rythm, its supposed to be zero. If it is rythming back and fourth, you aren't there yet. What is so hard about that???
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I understand the rhythm in an indicator that occurs when something is rotating at a constant rpm while being indicated... I don't indicate that way, I rotate by hand... I still don't understand what's so funny about it. No one sweat over it though, we all have a different sense of humour.
 
pbike said:
Hey Jerry Sherrett,

Do you only use 4 and 6 groove barrels? What or how would you indicate a 3 or 5 groove barrel? When the lands and grooves are opposite each other the way they are in one of those barrels. I can see where it would be easy to see the highs and lows and indicate where the lands and grooves are and to adjust for that when they are opposite each other, but with a 4 screw spider or a 4 or 6 jaw chuck? What am I missing here?

Paul
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Well, I still think this expression "rhythm of the indicator" is a bad way of putting an exercise where you are striving for a zero indication. Sure the reading is different in the case of a rifled bore, an elliptical object, a faceted object or any irregular entity. But in the case of this rifled barrel we are striving for a reading of zero on the lands and a reading of zero on the grooves.

Over the years I have chambered 3-groove Harts and 6-groove Harts, 5-groove Spencers and 6-groove Spencers, 4-groove Kriegers and 6-groove Kriegers, not to mention Shilens and a few others. In all cases, I was looking for a zero reading. Zero on the highs and zero of the lows.
 
..and the rhythm from the lands to the grooves to the lands to the grooves to the lands, etc... is there... just a different perspective on rhythm ...
 
Butch Lambert said:
Paul,
It ain't as quick, but it can be done. Only had one in my life and it didn't shoot well. Have you tried doing an 8 groove?
Butch
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Butch,

No I haven't done an 8 groove I try to stay less than 6 but more than 2 that only leaves (5, 4, and 3).

My best barrels have been 5 and 3 groove barrels. I've had good 6 groove barrels, but they haven't lasted as long as the 3 groove barrels, and I've never had a bad 3 groove. The 5's have been good too. And I've had plenty of bad 6 groove barrels. The High Power guys seem to like the 4's, but the 5's are more available through my channels.

At each land or groove you would have to mark what the rise in the indicator is, in order to measure the height of the land. Then on the opposite side you would not have that land so the math would have to be done and assumtions made (I hate having to do that). Seems like a lot of hocus pocus, but i suppose it can be done (Or is being done).

Another thought... As far as test indicators go... Could it be that if one is strong enough to deflect the indicator rod, you either have too tight a spring on the test indicator (not likely), or you don't have a good fit in the barrel, or your Magnetic Indicator Base is cheezy weak (Maybe it even has rice heritage)?
 
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pbike said:
Butch,


At each land or groove you would have to mark what the rise in the indicator is, in order to measure the height of the land. Then on the opposite side you would not have that land so the math would have to be done and assumtions made (I hate having to do that). Seems like a lot of hocus pocus, but i suppose it can be done (Or is being done).

Another thought... As far as test indicators go... Could it be that if one is strong enough to deflect the indicator rod, you either have too tight a spring on the test indicator (not likely), or you don't have a good fit in the barrel, or your Magnetic Indicator Base is cheezy weak (Maybe it even has rice heritage)?
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Paul, forget the ZERO digit on the indicator face. Get the zero reading in your mind of where the hand actually is stopping on the highs and lows.

A couple of other things while we are on the subject of dialing in barrel bores;

1) don't use a stylus with a small ball tip (like 1/32 or 1/64). Use one with a ball about 1/16 to about 0.080".

2) on odd numbered grooved barrels like 3 and 5, rough the bore using the bore of a reamer bushing set at the proper location. Then finalize indicating the actual lands and gooves. (But would not that just kill the rhythm??)
 
Butch Lambert said:
Paul,
It ain't as quick, but it can be done. Only had one in my life and it didn't shoot well. Have you tried doing an 8 groove?
Butch
Click to expand...

Butch, I had some Harold Broughton barrels that were nine groove .224's. That will let you watch an indicator bounce over lands and grooves.
 
I step bore the body... about 10 thou under at the shoulder and large enough at the rear so the reamer goes in about 400 thou before cutting. The neck has been drilled short and just over the lands so the throater doesn't have to work through the neck area.
 
OK...to taper bore you find the amount of taper in the reamer and set the compound to half that value......how do you figure out the actual taper?
Thanks,
Jonathan
 
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