Pre bore the chamber results?

[SKWERLZ]

it has nothing o do with reamer life.
it is all about putting the bullet at the lands inline with the bore AT THAT POINT.

I’m not sure I’m buying what you’re selling.

 

[LVLAaron]

I’m not sure I’m buying what you’re selling.

He's talking about (I think) the "gritters" method of indicating and dialing the throat vs both ends of the barrel. I think.

 

[RPSGuns]

What if you don't have a flush system? I would think that pre boring would would result in a better finish, due to less of a chip load, vs just using the reamer start to finish.

 

[DSMWerks]

Well since I have a 1630 Prototrak lathe I think I am going to write a program and profile the taper when I bore after drilling. I like the idea of the reamer making contact on the sides rather than the shoulder making contact first. It is a little more risky really with drill and bore that you might cut to big or to deep and ruin a barrel. I've got three Carbon fiber Proof barrels to do. Thats $2700 worth of barrels! Ouch.

 

[SKWERLZ]

He's talking about (I think) the "gritters" method of indicating and dialing the throat vs both ends of the barrel. I think.

But that has nothing to do with pre boring, unless I suppose you’re trying to use a short stem indicator.
I indicate the bore in the chamber/throat area using a long stem indicator and after that it doesn’t matter if I prebore or not.

On short cartridges time saved isn’t much but longer cartridges I can’t imagine preboring not being faster.

 

[Will Henry]

For thirty-some years, I roughed the chamber with a common drill bit. For anything but match rifles, I still do. I check concentricity of the drilled hole before reaming. If it is off, I can bore it. It is seldom off. For target rifles and for short cartridges (2 inch and under), I'll bore. Straight barrels make for easy set up. Crooked barrels are a pain. WH

 

[urbanrifleman]

What if you don't have a flush system? I would think that pre boring would would result in a better finish, due to less of a chip load, vs just using the reamer start to finish.

It does.

 

[butchlambert]

I’m personally pretty fresh to chambering, but pre-boring seems to be more work and more risk. I don’t find using the finish reamer the whole way to be that troubling. I’d rather send a reamer off to get resharpened after 15-20 barrels than deal with pre-boring even if it means doubling or tripling reamer life.

Honestly you know little about basic machining practice. As you progress through your learning curve you may then understand why drill, prebore and ream gives you a more precise job.

 

[butchlambert]

Ill keep on reaming. Never cost me any time over setup and potential failure of boring.

potential failure of boring???

 

[LVLAaron]

not, i clearly said look up jackie schmidt method

And I clearly said "I'm good"

 

[LVLAaron]

Did you ever work for the post office?

And, I said "I think" in my post, twice, because you just yell at lot and use broken sentences that people have a hard time understanding. My bad.

 

[WSnyder]

so why post a LIE that i am talking gordy gritters method???

C’mon! He said he “thought” you were talking about the gritters method. Why not just say you weren’t and expand on what you were talking about?

Why you so antagonistic all the time?

 

[Dusty Stevens]

potential failure of boring???

Going too far and having to start over

 

[LVLAaron]

Going too far and having to start over

You can measure.

 

[Judd]

I’m a self admitted rookie still, not sure I ever won’t be, because I’m not a machinist who learned to chamber but instead an anal shooter who learned to do his gun work.

So I rely on information I’ve seen or been given…Gordy’s book said .030 under shoulder diameter and .150-.200 short of the chamber. That’s where I started and I’ve went deeper but never more diameter, .030 ain’t much and it shows the way the reamer cuts that prebored area (I realize if you don’t cut the taper and I don’t that you’re really cutting more than that), it’s like butter and has to be better for the reamer.

I’m also a guy not doing it for a living and enjoys trying different ways and seeing the results on paper. I started by doing the reamer the whole way and have drilled/bored. I don’t know I’ll ever do another chamber without drilling…in my head it just does better. Is it straighter? In my eyes they are all straight if you start with the barrel straight.

Not saying I’m right but if you indicate both ends, in my mind you should be drilling. I’ve done both methods of indicating and I cannot tell a bit of difference on a target so I’m not going to say one is better than the other.

 

[Jud96]

Honestly you know little about basic machining practice. As you progress through your learning curve you may then understand why drill, prebore and ream gives you a more precise job.

I wouldn't say I know little about basic machining practice. I'm a machinist by trade and work for Pierce Engineering. In standard machining practice, you use a drill .010-.015 under the reamer size. I understand that, chambering seems to be some guys prebore and some guys don't. I don't understand why you chose to call me out when I said nothing negative about pre-drill/boring. I am not a chambering expert, and I noted that in my post. I simply said using just the reamer seems to be simpler and works for me. I never said drilling and boring was any less or more precise.

 

[Carl S]

Drills are for drilling.reamers are for reaming-not drilling.any form of reaming is better with a pre bored hole with minimal material left for the reamer to remove.dont take this wrong way guys I'm not telling anyone how to chamber a barrel and not saying anyone is doing it wrong..people do things differently and do what makes you happy.just my take on reaming.

 

[SKWERLZ]

Drills are for drilling.reamers are for reaming-not drilling.any form of reaming is better with a pre bored hole with minimal material left for the reamer to remove.dont take this wrong way guys I'm not telling anyone how to chamber a barrel and not saying anyone is doing it wrong..people do things differently and do what makes you happy.just my take on reaming.

That’s my take, you can really hog out some material fast, straighten it up a bit with a boring bar fairly fast then the reamer has an easy job and nice path to bring the hole or chamber to it’s final dimension.

Pecking 50 thou on a 2.75-3” chamber blows.

 

[gme]

so I'm not saying that any other method is wrong but to answer the question: pre-drilling and boring the chamber body section has nothing to do with tool life or time (though it is faster) what we are trying to do is eliminate the influence of bore curvature on the path of the reamer which manifest itself as chamber runout and/or an oversize chamber, all barrels exhibit some degree of bore curvature, which is best visualized as a minute "corkscrew" path left by the drilling operation, because of this we can only pick two spots in that bore that can be zeroed for runout, regardless of where those two spots are, the rest of the bore will "wobble" to some degree, creating a section of bore that is true zero runout for the reamer is the best way to achieve a straight and accurately sized chamber in my experience

 

[butchlambert]

so I'm not saying that any other method is wrong but to answer the question: pre-drilling and boring the chamber body section has nothing to do with tool life or time (though it is faster) what we are trying to do is eliminate the influence of bore curvature on the path of the reamer which manifest itself as chamber runout and/or an oversize chamber, all barrels exhibit some degree of bore curvature, which is best visualized as a minute "corkscrew" path left by the drilling operation, because of this we can only pick two spots in that bore that can be zeroed for runout, regardless of where those two spots are, the rest of the bore will "wobble" to some degree, creating a section of bore that is true zero runout for the reamer is the best way to achieve a straight and accurately sized chamber in my experience

Thanks Gary.