7RM + 180 ELD-M and reamer selection question

[ChubbySquirrel]

Greetings!

I'm building a rifle this winter but have some questions in regards to reamer selection or creating a dummy round to have blueprinted for reamer design. 7 Remington Mag caliber (new to me caliber....I'm a 260 shooter traditionally) and I'd like to shoot Hornady's 180 ELD-M at about 2900 fps with H1000 and Federal brass. This will be a magazine fed rifle (Defiance action, AIAX LA chassis and mags) so OAL is of concern. I figure that I'll be rebarrelling this rifle annually, so I'd really like to own the reamer.

What I need:

- Match chamber
- Throat for ELD-M 180's
- Room to chase lands
- Conscious of magazine length requirements
- No neck turn brass

I don't want to reinvent the wheel, just get an optimal design for a popular bullet that someone has figured out already.

I refuse to order from PTG as their customer service seems to have gone sideways. I did contact JGS and they told me to prepare a dummy cartridge that data could be pulled off of for the reamer...BUT I have no idea what seating depth I can get away with for the speed I want and how the throat and jump to lands might play out. Seems too easy for me to mess up and I'd rather not. The gunsmith who will be building it doesn't have a reamer for exactly what I want...plus I'd just like to own it anyway.

Suggestions? I'd be happy with a reamer spec order number or some specific case dimensions.

Thank You,
CS

 

[idahoorion]

CS, I suggest a min sammi spec on the case body, some tighter match chambers will be so tight a off the shelf die might not be enough, I have one of these and get "clickers" unless I use a small base die. mine is a .188 freebore, and it's about perfect for 168's , 180gr. bearing surface is seated just under neck shoulder junction so it could be longer for them. I was told .220 was what the 180's need. No turn neck, I would think you want .003 to .004 clearance at least. get a piece of brass, I suggest Norma, seat the bullet the way you want it (check for mag length fitment) and send it in (no primer no powder of course) and let them get the specs for your reamer from that.

good luck with your new hammer
Idahoorion

 

[ChubbySquirrel]

I'm going to mock something up and toss the measurements on here once my die arrives. Thanks for the input!