lengthening throat on 7 x 57

[wmitty]

Looks like the throat on the Midway barrel is too short to allow the 168 gr RCBS to be seated out far enough to keep the gas check in the neck of the case. I also am having a feeding problem from magazine to chamber with the boolit seated to chamber at the current throat length. Can the throat be lengthened by hand using a throating reamer, or does a lathe have to be used to keep it lined up with the bore? I see I can rent a 7MM throating reamer from Elk Ridge, but I wanted to make sure it is a job that can be performed manually.

[Nobade]

If you have a way to keep the throater straight and stop it in the right place the job can be done by hand. But I wouldn't try it myself. It would be much more likely to be successful if you rented a proper 7X57 chamber reamer and turned that in using a T handle, letting the weight of the reamer and handle provide the feed. That way when it hit the shoulder you would feel it and stop before lengthening the headspace at all. This prevents cutting a crooked or chattered or too long throat, and keeps everything straight.

Throaters are something you need to be extremely careful with, for all the above reasons. Trying to turn one in by hand and stop it exactly where it needs to be is a very difficult thing to do.

-Nobade

[wmitty]

Nobade

Thanks, I see what you are saying; there is no way to guide the throater.

[largom]

Look at PTG reamers. They have a throater with an adjustable stop and a "T" handle. Have used them several times with great results.

Larry

[La Dano]

I have the opposite problem, new barrel and to long of a throat. No where near short enough for mAgazine length, 1/4" jump to the lands.

[Skipper]

It's easy as pie. First rent a 7mm throater from 4D Products http://www.4-dproducts.com/displayitem.php?rowid=355&tname=rental
They waive the deposit if you pay by credit card.
The reamer is piloted,so don't worry about misalignment. Use a tap stock to turn the reamer after you douse it with cutting oil; a couple of turns with light pressure will get the job done. Mark your depth with a piece of masking tape on the throater.
If you need an extension for use in a bolt rifle, use a socket wrench extension or drill bit extension.

[sdcitizen]

Just cut a throat longer in an m1a, it can certainly be done by hand. I used soft lead pound casts to determine when to stop.

[kywoodwrkr]

It's easy as pie. First rent a 7mm throater from 4D Products http://www.4-dproducts.com/displayitem.php?rowid=355&tname=rental
They waive the deposit if you pay by credit card.
The reamer is piloted,so don't worry about misalignment. Use a tap stock to turn the reamer after you douse it with cutting oil; a couple of turns with light pressure will get the job done. Mark your depth with a piece of masking tape on the throater.
If you need an extension for use in a bolt rifle, use a socket wrench extension or drill bit extension.

This is absolutely correct.
Have throaters in 30 and 6,5mm. Both have removable pilots.
30 has pilots to set up for either US 30 or Swiss 30 as an example.
Get an accurate reading of your bore before either ordering one or renting one.
Look a whole lot like a taper reamer if you are familiar with taper pins.
This is worth repeating as well:
"couple of turns with light pressure will get the job done"
YMMV