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DLH4570
Guest
What is the advantage of a floating pilot chamber reamers, over a solid pilot?
Butch Lambert
Active member
I personally believe that if you drill and taper bore your chamber, a bushing type reamer is not necessary.
Butch
Butch
JerrySharrett
Senile Member
If you were assured that all your barrel bores would be exactly the same diameter then a solid pilot reamer would be better since it is some cheaper. However, barrel bores, the lands, where the pilot rides vary. Even within the same brand barrel and same land diameter.
For example, a 6mm Krieger in their catalog size bore of 243/237 will vary from about 0.2367"-0.2372" and Krieger is as close tolerance as you will get in any brand. Then go to a Shilen 6mm 6-groove, it will be some different from the Krieger. Most of this variation is caused by each benchrest quality barrel being hand lapped before the rifling is cut or swaged.
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Con Cross
Guest
Gentleman would you believe, that you can actually change the pilot to suit your actual bore size.
Con
Butch Lambert
Active member
Mr. Conman,
With your infinite wisdom, tell me how you determine your bushing size? Could you tell me why it would be better. You need to tell us how you set it up so that we can see why you say what you do!
Butch
With your infinite wisdom, tell me how you determine your bushing size? Could you tell me why it would be better. You need to tell us how you set it up so that we can see why you say what you do!
Butch
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Dennis Sorensen
Guest
The biggest advantage is when you have a "tight" barrel you can simply change pilots... it is not a good thing to force a tight pilot in to a bore and even worse if it does not rotate.
Butch Lambert
Active member
Dennis,
I have 2 solid pilot reamers and neither has a pilot that is large enough to touch the top of the lands on a tight bore. That is one of the reasons to taper bore to within about .010. Let the reamer follow a hole that is concentric to your indicated throat and not a bushing following a crooked bore.
Butch
I have 2 solid pilot reamers and neither has a pilot that is large enough to touch the top of the lands on a tight bore. That is one of the reasons to taper bore to within about .010. Let the reamer follow a hole that is concentric to your indicated throat and not a bushing following a crooked bore.
Butch
JerrySharrett
Senile Member
Butch is correct in the method of preboring. Personally though I like a tight slip fit on the pilot bushing for two reasons 1) if the bushing is sized to where the one used is 0.0001" smaller than the bore at the chamber there is no danger of getting a chip between the pilot OD and the lands ID, whereas if there is 0.0003"-0.001 or more clearance there is a danger of getting a chip between and scarring the bore. And 2) it just gives me a better feeling knowing that at the point of leade/freebore intersection that there will be no possibility of lead-off.
I use a cleaning rod with an adapter to fit the bushing pilot before installing it on the reamer.
Butch Lambert
Active member
Jerry, I guess it may be possible for a chip of .001 size to go forward. I think that it is unlikely. You do know,of course, that there is .0002-.0003 clearance between the reamer and the reamer bushing? Splitting hairs but wouldn't that allow a reamer to be off that much if it were following a crooked bore? Remember that I am not a machinest or toolmaker. I'm just sitting here thinking about what happens.
Butch
Butch
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wnroscoe
Guest
That has been the million dollar question for as long as I've been studying this and you'll probably get several different answers. Both methods will and do work well. I think in the end it boils down to the individual doing the chambering and what he's comfortable with and has faith in. I use piloted reamers with bushings and don’t prebore but, I can see that drilling/preboring does have advantages. I bet you could find rifles chambered using both methods on the point blank line and shooting in the .2's and .1's
Good luck
William
JerrySharrett
Senile Member
Butch, I'm not concerned about the clearance between the reamer and the pilot bushing bore. I can't control that. But add that 0.0002/3" to another 0.0002/3" on the pilot OD to bore and pretty soon......
As Confucius say, many cats, many ways to skin them. Or as Dick Cheney says, SO!!!!
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J. Valentine
Guest
Good stuff I just learnt something.
Butch Lambert
Active member
Jerry,
My thoughts are that the reamer is following the bored hole and the solid pilot is actually doing nothing.
Butch
My thoughts are that the reamer is following the bored hole and the solid pilot is actually doing nothing.
Butch
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Dennis Sorensen
Guest
I think a reamer will follow a bored hole but if the bored hole was off, a pilot would then affect that somewhat... I know good chambers have been cut with no pilot at all...
I prefer to pre bore and use a removable pilot.
I prefer to pre bore and use a removable pilot.
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chino69
Guest
Pre-boring chamber
Would there be any advantage/disadvantage to pre-boring the chamber and then using a floating pilot reamer? I understand that if you indicate the bore in true and then pre-bore, the reamer will follow the true hole and it doesn't matter about solid or floating pilot.
chino69
Would there be any advantage/disadvantage to pre-boring the chamber and then using a floating pilot reamer? I understand that if you indicate the bore in true and then pre-bore, the reamer will follow the true hole and it doesn't matter about solid or floating pilot.
chino69
JerrySharrett
Senile Member
If you are using a snug fitting bushing and preboring also you are taking every advantage. Nothing wrong with taking every advantage is there???
The nose of a HSS/CO reamer fitted with a snug fitting bushing WILL follow the barrel bore, wherever it goes. A solid carbide reamer will not flex but a HSS/CO will.
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chino69
Guest
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Big Al
Guest
Years ago, I had a conversation with KEITH FRANCES about this same issue. I asked him why people bought solid pilot reamers? " I don't have a clue, except they are cheaper"!
I got a kick out of the guy that had a reamer pilot that was so tight he had to "Hammer it in".
I got a kick out of the guy that had a reamer pilot that was so tight he had to "Hammer it in".
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