Outside neck turning vs. inside neck reaming

[grodon of the north]

Hi Guys,
I've got 7-30 from .375 Win brass problems. :?
I'm trying to load some 7-30 ammo and the majority won't chamber easily after the bullet is seated. They chamber fine w/o a bullet. It seems that the hang up is in the neck area. Tried two different chambers from TC custom shop bbls.
The brass is Winchester brand and was acquired from Dustinbrass.com. It was necked down from 375 Win. brass.
From from I've been able to learn so far necking down that much leaves too much brass in the neck and it must be removed.
Most sources I've contacted say turn the outside of the necks. The good folks at RCBS recommended reaming.
I've ordered a Forster case trimmer and Outside neck turner attachment from Cabelas but they don't stock the reamer. At least it's not listed in their catalog.
Question is, am I going to have the equipment I need to finaly be able to load for and shoot my new barrel or had I'd bettered get a reamer on the way from some where.
One thing I've gathered from catridge specs in reloading manuals is that o.d. at the base of the neck appears to be .002 larger than at the case mouth which would seem to leave the necks thinner near the shoulder after outside turning.
Any insight will be greatly appreciated. This is all new stuff to me.
Thanks, Gordon

[Reed1911]

Okay,
Typically if the neck is in line with the flash hole, you outside turn to thin the neck, if the neck is a little off center, you inside ream using the flash hole as your point of center. But, in your case I think either way will work. Dustin does good work, so I'm sure it's on center, I'm surprised that he didn't turn them down for you. Then again it might be you just have a tight chamber. So, I'd go ahead and outside turn since you already have the equipment, if it causes any problems we have the Forester reamer pilots, I'll have to check if I have any 7mm in stock. Just let me know if you need one, they are pretty inexpensive.

[Varmint Hunter]

First - It would be very helpful to find out what the chamber neck diameter is. This will allow you to properly adjust the cartridge neck diameter.

Outside neck turning is preferable because it allows you to make infinite adjustments and it will leave the neck wall thickness consistent all the way around too. Reaming is fast & easy but the results are a bit of a crap shoot.

VH

[fffffg]

i had an inside neck reamer for my 22 250 made by lyman zero error years ago.. i really liked it. the only place to get them in the same type is from rcbs.. you put the case in a sizer type die and send the reamer down to cut the exact amount of metal each time of the inside of the case. this give no donut, and does not need to fired to give final loads. to oustide turn the neck is turned down and it cant get into the shoulder so this leaves a heavy spot.. then when you fire the case it is on the inside.. this is were experts seat thier bullet by hand for target shooting..  but again the case must be fired, then turned then fired then realaded to get where your going. inside turning  you fire the case and then turn then load. make sure your case length is notthe problem..  my 22 250 consistntly turned out bullets with .001 or less runout..  its the best way in my book.. rcbs will do it correlcty for your cartrige, send them a fired case  and bullet, and they will know what to do.. dave..

[Catfish]

Man I really don`t know. I load for several Wildcat and tight necked chambers and I only outside turn the necks down. But It seem to me that if you expand the necks to the correct dia. then your should be able turn the outside of the necks to the correct dia. I like .002 expantion in the neck, it seem to give me the best accuracy- case life. I`ve never inside turned so I really know nothing about it, I`ll be intersted in seeing other post on this one.

[grodon of the north]

Thanks everybody, for your thoughts,
Varmint Hunter, how would I determine my chamber neck dimensions?
  G.