Chamber reamer extension?

[11A-18A Vet.]

I have bought a PTG chamber reamer to open up the chamber (a tiny bit) in a custom-barreled 300WM which is a bit tight. I want to use the reamer without having to take off the action. What can I use to extend the reamer so I can turn it from behind the action? Thanks.

 

[Buttermilk]

They sell extensions for just such a purpose. Check with Brownells.

 

[AkleyFan]

A chamber reamer extension - look on eBay or the other supply shops like MidwayUSA, Brownell's, etc. They come in various lengths.

 

[Laguna Freak]

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[William Cameron]

PTG has a T-handle for their reamers/throaters. I bought one to do a 338 federal that wasn't headspacing in an AR, did it with the barrel in the receiver.

 

[BillLarson]

I have bought a PTG chamber reamer to open up the chamber (a tiny bit) in a custom-barreled 300WM which is a bit tight. I want to use the reamer without having to take off the action. What can I use to extend the reamer so I can turn it from behind the action? Thanks.

any square drive 3/8"drive...... 7/16" socket will work....

 

[11A-18A Vet.]

Thanks for the great info and suggestions! The idea with the 7/16 socket involves tools I already have, so I'll try that first.

 

[BrentM]

any square drive 3/8"drive...... 7/16" socket will work...

This is what I do as well.

 

[Joe Entrekin]

What part of your chamber is too tight? And how much too tight? If it's not much you will do a lot better by opening up the chamber with abrasives instead of the reamer, especially doing it by hand. You can use a wooden dowel with abrasive cloth and light oil, or you can even make a lap from a fired case and use 125 and 250ish grit lapping compound. Trying to open a chamber by hand with a brand new sharp reamer especially in stainless steel is a risky proposition. Sometimes no matter how careful you are the reamer will want to chatter, ask me how I know.

 

[eshell]

Rifle chambers can become work-hardened with use and can dull a reamer before it makes progress.

 

[R. Cram]

I turn a 3/8 drive extension around backwards to put the female end on the reamer and the male end sticks out past the back end of the action then put a tap wrench on the male end that sticks out

 

[11A-18A Vet.]

Very good advice. I have two rifles chambered in 300WM. To extend case life, I neck size cases. These fit nicely in the rifle with the more loose chamber, but bind in the rifle with the tighter chamber. The cartridges bind on the side of the case, just below the shoulder, and lack about a half-inch in being fully chambered. The object is to get the tight chamber opened up a bit so the same cartridge chambers easily in both rifles.

I thought a gentle turn with a chamber reamer would do the trick. Is that a bad plan?

 

[Willys]

Very good advice. I have two rifles chambered in 300WM. To extend case life, I neck size cases. These fit nicely in the rifle with the more loose chamber, but bind in the rifle with the tighter chamber. The cartridges bind on the side of the case, just below the shoulder, and lack about a half-inch in being fully chambered. The object is to get the tight chamber opened up a bit so the same cartridge chambers easily in both rifles.

I thought a gentle turn with a chamber reamer would do the trick. Is that a bad plan?

Well to go fatter you may have to go deeper - keep that in mind - get your go-no gage ready.

 

[Joe Entrekin]

Sounds like you are only talking a few thousandths still. Based on my own experiences I think I would take a couple fired cases from the looser chamber and cut the necks off, then drill out the primer pocket and thread the hole 1/4-20 so you can screw a rod in and run a nut against the back of the case. Now you have a brass lap and you can get the lapping compound from Brownell's and gently have at it until you get your desired chamber. Gentle, by feel because it will want to bind if you get too agressive, slow with lots of cleaning then checking and pretty soon you will have the chamber where you want it.
On the other hand you can try it with the reamer but if it grabs even one time you will be in for a new barrel. With a reamer I really recommend it be done with barrel off in a lathe, it's just too easy to screw it up doing it by hand.