Reamer spec for 7 SAUM

thaught

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Jan 6, 2016
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362
Location
AZ
I am building a rifle for my son who is serving for the next two years. When he gets back I want to hand him his new 7 SAUM. I plan on ordering the reamer pretty soon and would like y'alls thoughts on how it should be designed. We would plan on the 175 Elite Hunter Bullets or 180 VLD, so Im thinking .200" of freebore to maximize case capacity? Also, does lead angle matter, if so, what do you recommend? I appreciate your input.
 
I am building a rifle for my son who is serving for the next two years. When he gets back I want to hand him his new 7 SAUM. I plan on ordering the reamer pretty soon and would like y'alls thoughts on how it should be designed. We would plan on the 175 Elite Hunter Bullets or 180 VLD, so Im thinking .200" of freebore to maximize case capacity? Also, does lead angle matter, if so, what do you recommend? I appreciate your input.
Contact whoever the reamer manufacturer you are going with (Manson, JGS, etc) and ask for their reamer blueprint and modify from there or consult with them directly.
 
I am building a rifle for my son who is serving for the next two years. When he gets back I want to hand him his new 7 SAUM. I plan on ordering the reamer pretty soon and would like y'alls thoughts on how it should be designed. We would plan on the 175 Elite Hunter Bullets or 180 VLD, so Im thinking .200" of freebore to maximize case capacity? Also, does lead angle matter, if so, what do you recommend? I appreciate your input.
You're spot on with the fb. A 0.190" to 0.210" works perfect. I have 3 reamers .190, .200 and .230. The .200 gets used the most. The .230 I use for the 190+ bullets
 
My 7mm RSAUM is 0.140" freebore which is perfect for the Berger 168 VLDH bullet. Using a heavier bullet, particularly if I'm running Hornady, I would certainly opt for a longer freebore.
 
I had my reamer built with .210 fb. It's about perfect for the 180 vld. If I was building it specifically for the 175 EH I'd probably have shortened it .020 or so. I had originally thought I'd shoot the Hornady 175 eldx but never had any on hand to measure when I built my reamer. They've got a bit longer bearing surface than either of the Berger's in discussion. If I had been specifically been set on the eldx I'd have wanted more freebore. At least another .020. Best of luck to you and your son. Mine just returned a couple of months ago from being gone for a couple of years as well. It's been good to have him home. He hunted with a new 6.5 saum.
 
Contact whoever the reamer manufacturer you are going with (Manson, JGS, etc) and ask for their reamer blueprint and modify from there or consult with them directly.
These 2 reamer makers are who I would recommend if you're considering. This is good advice as well.
 
Just make sure whichever FB you go with, that the loaded round fits in the magazine/box at your max CBTO to lands. If using a Short Action, this will require a shorter FB. If you are using an XM or LA, you are golden.
 
I had my reamer built with .210 fb. It's about perfect for the 180 vld. If I was building it specifically for the 175 EH I'd probably have shortened it .020 or so. I had originally thought I'd shoot the Hornady 175 eldx but never had any on hand to measure when I built my reamer. They've got a bit longer bearing surface than either of the Berger's in discussion. If I had been specifically been set on the eldx I'd have wanted more freebore. At least another .020. Best of luck to you and your son. Mine just returned a couple of months ago from being gone for a couple of years as well. It's been good to have him home. He hunted with a new 6.5 saum.

Just make sure whichever FB you go with, that the loaded round fits in the magazine/box at your max CBTO to lands. If using a Short Action, this will require a shorter FB. If you are using an XM or LA, you are golden.
It is a long action
 
So with a 180 berger how long of a coal are ya'll running? I know with a wyatts extended you can get 3.0" with a short action. What kind of magazine setup are ya'll using with the mediums and how long can you load?
 

So with a 180 berger how long of a coal are ya'll running? I know with a wyatts extended you can get 3.0" with a short action. What kind of magazine setup are ya'll using with the mediums and how long can you load?
With .210 fb I'm at 3.049" case overall length with the Berger 180 vld. With my Lone Peak Fuzion build I'm using Hawkins medium bottom metal in an M5 hinge floor plate configuration internal box length is 3.200". If a person really wanted a short action, I also built a 6.5 saum with a .220 fb on a Lone Peak Fuzion short action. I'm using Unknown Munitions short action detachable bottom metal and magazine set up. Their short mag XL magazine is 3.150" inside length. I had to do a slight modification to the action but it worked out great.
7saum medium
IMG_8181.jpeg

6.5 saum short
IMG_2791.jpeg
 
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