Chamber Ream and Free bore separate reams?

[hogheadv2]

Is there a reason Custom builds Do not Ream Chambers to fit, Then ream Free bore to fit the customers request? This would seem like an easy enough process. Fit the brass to the rifle, bolt, feed, etc. Next The simple ream of bullet dimension, no harder to keep strait than using a guided cleaning rod. Free Bore could easily be done after barrel was installed and Customers test [Dummy] cartridge was used. {Input welcome if I missed a fine point, I do home shop machining pretty well} (First to admit we all have room to learn) Thank you for your time.

 

[Jud96]

A lot of gunsmiths do this. A lot of them also have reamers on hand setup for the common and popular bullets for caliber that are used. Both methods can be done accurately if the setup is done right. If the chamber isn't dialed in perfectly, you could risk cutting the throat off center from the bore and the chamber.

 

[hogheadv2]

I have not seen it referenced. I have read my eyeballs raw,,, I have looked for reams and now resolved to make my own.

 

[bigngreen]

Personally I don't like throating a chamber separate from the chamberings process, I like everything done in one shot no room for error. Others prefer to have a zero freebore reamer and then set the throat to any spec. I just don't like to do all the separate measuring then it takes some feel to pick up your zero then cut, I like the whole chamber to be set up on that one bullet perfectly.

 

[EddieHarren]

OP, if you are skilled enough to grind your own reamer, and heat treat it properly, then you should have no trouble reaming a chamber, whatever method you choose.

 

[hogheadv2]

Eddie, Thanks. I had thought of the 2 cutter[ream] method. I had not been able to find source or information why it is or is not widely used.

I am not a stranger to flawed thinking, now and then My head kicks up a nice Sapphire or mildly flawed Jade.

 

[EddieHarren]

Then my advice would be, Keep on kicking!

 

[tobnpr]

IMO, it's preferable to to use a cutter that's been precision ground to the specific dimensions of throat diameter and freebore desired when possible.

This way, there is absolutely no question, as to what's down the bore.
It is "provable", so to speak- to a customer. Here are the specs you ordered, here is the reamer that's been ground to those specs.

If the chamber has already been cut, or the customer just wants more freebore than SAAMI but doesn't want to spring for a new reamer- then a separate throater can be used after cutting the chamber. Of course, there's labor associated with that extra step that offsets custom reamer cost.

 

[Mram10us]

Definitely smiths that do the 2 step. I agree with bigngreen, it is nice to do it all in one shot. The other night I lengthened the throat on a 300wsm I've been toying with and cut it longer than I wanted while watching youtube. Oh, and the stop was sitting next to my desk because I didn't want to mess with it. Dumb. We'll see if she still shoots

 

[bigngreen]

Doing a chamber in multiple steps with multiple tools does add versatility to your capability BUT you do have to think through the other issues it brings up like accurately measuring the current throat, zeroing the throater and dialing in and stopping at the desired depth of cut, on the other hand I've poked a throater in with a t handle and carefully cut the throat in a factory gun and it worked wonderful, the only place I've really screwed the pooch is with a throater though!

 

[hogheadv2]

Definitely smiths that do the 2 step. I agree with bigngreen, it is nice to do it all in one shot. The other night I lengthened the throat on a 300wsm I've been toying with and cut it longer than I wanted while watching youtube. Oh, and the stop was sitting next to my desk because I didn't want to mess with it. Dumb. We'll see if she still shoots

Lesson, not dumb... [no one is hurt] {May be able to shave the margins back .050 and touch it off with the ream if performance suffers.

 

[hogheadv2]

I am surrounded by professional machinist. Son-in-law does die build and repair to the point of TIG with microscope, Best friend plus a neighbor do one off and CNC to the .00001... Measure surface optically on some things. When I talk of .0005 +/- .0003 it like lobbing a football to them. {Great way to get your mill or lathe ways trued is have machinist friends help you}

 

[Mram10us]

I am surrounded by professional machinist. Son-in-law does die build and repair to the point of TIG with microscope, Best friend plus a neighbor do one off and CNC to the .00001... Measure surface optically on some things. When I talk of .0005 +/- .0003 it like lobbing a football to them. {Great way to get your mill or lathe ways trued is have machinist friends help you}

Send them my way

 

[captrjc]

[QUOTE="Mram10us, post: 1854482, The other night I lengthened the throat on a 300wsm I've been toying with and cut it longer than I wanted while watching youtube. Oh, and the stop was sitting next to my desk because I didn't want to mess with it. Dumb. We'll see if she still shoots
[/QUOTE]

I did the same oops on a factory model 70 300wsm. The gun now shoots better than it ever has, .180 jump with 180 accubonds