7 SAUM Build - What Chamber Neck Size?

[Ron Milby]

I plan to build a 7 SAUM and I noticed different neck size options for the reamers. What is the most common chamber neck size for the 7 SAUM? What is the common free bore? I have new ADG 7 SAUM brass for reloading.

 

[SealT5]

I would measure a loaded round and choose a reamer .004" over the largest measurement. Great choice for brass. Adg is top notch

 

[dok7mm]

It's smart to find a good, consistently available source for brass. Buy some and measure necks or load dummy rounds to measure loaded neck diameter. Then, pick your reamer neck for your chosen clearance. I like 3-5 thou clearance, .004" is good.

 

[Rhovee]

.321

 

[Ron Milby]

Thanks everyone! Great suggestions and .321 seems to be the standard.

 

[SealT5]

Report back when you get her built. I'm patiently waiting on a new Action to come out. When it does I will be building a saum or SS. Probably saum

 

[Ron Milby]

Report back when you get her built. I'm patiently waiting on a new Action to come out. When it does I will be building a saum or SS. Probably saum

Will do!

 

[Ron Milby]

I measured loaded rounds and they were .317. It looks like the .321 reamer will be perfect.

Thanks for the help!

 

[Rhovee]

Are you running it in a short action?

 

[Ron Milby]

Are you running it in a short action?

No, I will be running it in a long action (Tac 300) with an 8 twist (Bartlein Heavy Palma) barrel. I want the option to run the 184 and 195 berger bullets. The donor rifle is a 300 WSM with a Manners EH1 stock and a Jewell trigger. I shoot a lot of steel out to 1660 yards. It should be a great rifle for steel and medium size game.

 

[Rhovee]

Then I would run .235 FB. I have two barrels with that and it runs 184s perfect. H1000 has been excellent. If your really after speed Reloder 26 will get you there and is accurate. I'm at 2900 for 24" barrel and 2980 with 28" barrel and H1000 with 184's at 3.150