6.5 saum with 7 saum adg brass

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Sep 19, 2018
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I could not find any adg brass in 65 saum but was able to get 7 saum brass. My question is do I just have to neck the brass down to .264 or will I have to turn necks as well with 7 saum adg brass. I ahve seen several people take other manufactured 7 saum brass but had to turn the necks.

any advise is welcome
 

B23

WKR
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Do you know what the neck diameter is of your rifle because It'll depend on what the neck diameter of your 6.5 SAUM chamber is. Measure the outside diameter of the neck with a seated 6.5 bullet and compare that to the neck diameter on the reamer used to chamber your rifle. You want a loaded round to be at least .002 smaller then what the actual neck diameter is for your rifle and .003 is probably better. If you don't have at least a 2 thou difference you'll need to turn the necks or have a smith go back in and enlarge the neck diameter on your rifle.

The necks on my ADG 6.5 SAUM brass measure .014 +/- .005 and they measure .0145 +/- .005 after I neck them down for my 25 SAUM so I'd guess yours will go from .014 to .015 when you neck 7mm/.284 down to 6.5/.264 which will likely give you a outside diameter of .015 x 2 + .264 = .294 with a seated bullet so if your rifle doesn't have a neck diameter of at least .296 and I think .297 would be better you'll need to neck turn your brass or go back in and open up the neck diameter.
 

mpwolf

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B23 is spot on, but I would aim for more clearance if you can. In my experience, you are better off with a bit extra clearance, than just barely enough.
 
OP
R
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Sep 19, 2018
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Do you know what the neck diameter is of your rifle because It'll depend on what the neck diameter of your 6.5 SAUM chamber is. Measure the outside diameter of the neck with a seated 6.5 bullet and compare that to the neck diameter on the reamer used to chamber your rifle. You want a loaded round to be at least .002 smaller then what the actual neck diameter is for your rifle and .003 is probably better. If you don't have at least a 2 thou difference you'll need to turn the necks or have a smith go back in and enlarge the neck diameter on your rifle.

The necks on my ADG 6.5 SAUM brass measure .014 +/- .005 and they measure .0145 +/- .005 after I neck them down for my 25 SAUM so I'd guess yours will go from .014 to .015 when you neck 7mm/.284 down to 6.5/.264 which will likely give you a outside diameter of .015 x 2 + .264 = .294 with a seated bullet so if your rifle doesn't have a neck diameter of at least .296 and I think .297 would be better you'll need to neck turn your brass or go back in and open up the neck diameter.
.298 by the way on neck diameter of the reamer
 

B23

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.298 by the way on neck diameter of the reamer
You'll likely be ok but you will want to measure a loaded round to know for sure.

Some smiths think .001 per side is enough but IMO that's bare minimum and like I mentioned earlier I think 1.5 thou per side is better so if your loaded round neck diameter is .295 or less you should be in good shape without having to neck turn.

All of my rifles are "no turn" necks and they're anywhere from 3 thou to 5 thou under what the neck diameter of the reamer print says. I think the only one I have that's 5 thou is my 338 Lap Imp most everything else is 3-4 thou under.

Even if you have to neck turn it's not the end of the world and if you have the proper tools to do it right it's not that big of a deal. It's just one of those things I'd much rather not have to ever do.
 
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For future readers of this thread, my 7 SAUM ADG brass has necks that are over 0.016" thick. It is from what was probably the first run of ADG SAUM brass though so not sure if it has since changed.

I'm not sure what's out there for 6.5 SAUM reamers now but when I had a couple chambered the GAP standard reamers were 0.2964" necks that required turning of the R-P and Norma 7 SAUM brass that was available a decade ago but worked well with hornady and ADG 6.5 SAUM brass that came later. There was also 0.298" "no turn" necks that in reality were still too tight with unturned 7 SAUM brass. Suffice to say, the 16.5 thou necks on my 7 SAUM brass would need turning in both of those chambers if it were necked down.

A little further tangent - When i was building a 7 SAUM and ADG was just starting to make SAUM brass, a lot of gunsmiths had 0.315-0.318" neck chambers. That is not big enough at least for the ADG SAUM brass I have, gunsmith chambering my first barrel had to rent a reamer to avoid clearance issues or mandatory neck turning.
 

mpwolf

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Dec 8, 2023
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Yup- my reamer is .2964" and even though my loaded round is .291, a bullet still won't drop freely into a fired case. Makes me think the PTG spec is likely off a smidge. Let your actual fired case tell the story. Turning necks is a pain, but once it's done and you have your brass at a healthy spec, life is great.
 
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