7RM+180 ELDM reamer/cartridge design specs question.

[ChubbySquirrel]

Greetings! Long time reader, first time poster.

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

 

[lennyo3034]

Greetings! Long time reader, first time poster.

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

Did you get this figured out? Either way, let me know. I had one built by PVA and it seems to satisfy what you need.

180 ELDm @3035fps with 30" barrel. Easily able to fit in mag.

 

[AckleymanII]

Going with a detachable magazine is a bad idea if you want to chase lands. Starting off with OAL of a magazine would be the first place to start. Chase down various lengths of actions and a trued 700 with the Wyatt's mag box, mag well opened up around .120 to give you more length is a great consideration.