7saum question

[drdtmd]

guys im having a 7saum built right now and have a few questions. First what freebore should I run with the 180 hybrids to fit in a 700 s/a and still feed in a mag?second Anyone who has done this what velocities are you getting. Third what bottom metal should I run? I see that ptg has bm for extended wyatt boxs or should I go detachables? Which one would give me the most lenght. As far as I can figure for the coal with the should neck juncture to the back of bearing surface would leave me a coal of 3.033 (according to diagrams and berger info). Is this close? Can I get a box to fit? Thanks for the help.

 

[idahoorion]

Drdtmd,

I am looking at this caliber as well, in my research and in an additional contact with Pacific Tool and Gauge,
it was recommended to me, that freebore be .188 for the 180's, .170 for the 168's and .155 for 162grainers.

I am thinking I'll use 170 as I expect to be shooting under a thousand and that will handle the two lighter bullets.

I'll be using a long action 700 for my build, but I think I'll have to use something other than the orginal hinged floorplate. So I too would be interested in any feeding issues/info.


best
Idahoorion

 

[drdtmd]

idahoorion thankyou..170 does sound good. Your lucky you are using a long action no coal problems. All my parts are at my gunsmith so it wont be to long probably a couple months. Goodluck with your build

 

[idahoorion]

If you choose that length. I would consider renting the reamer from you or vis versa. I am thinking of a 315 neck that could require turning on some brass.

Idahoorion

 

[drdtmd]

ida thanks for the offer but my smith is going to get the reamer. im just trying to gather info since I cant even get a piece of brass for a dummy rd.

 

[drdtmd]

anyone else want to touch on these questions?

 

[lgsj27]

I too am thinking about a 7 Saum. on a Long action 700. Following this string of questions I do not see a responce about bottom metal with detachable mags? anyone out there have any knowledge on the subject?

 

[gme]

As a repeater with 180's that would work much better in a long action, the AI .338 (non CIP) magazine works well with no mods, for a short action consider going with the lighter bullets.

 

[drdtmd]

yep decided against the short action and picked up a stillar predator long action . Length is no longer a problem. My smith should have all the parts soon. Hope to have her back in a couple months. Thanks guys

 

[lgsj27]

Copy on the AI Mags! Last question on the subject of bottom metal anyone familiar with Kiffs (PTG) product? Looks good and a ton cheaper then Badger and takes AI Mags... ??

 

[Dave L Kiff]

100 % guarantee to be the best on the market and for 75 bucks to 128 bucks depending on the type you get, it cant be beat.

 

[mac86951]

guys im having a 7saum built right now and have a few questions. First what freebore should I run with the 180 hybrids to fit in a 700 s/a and still feed in a mag?second Anyone who has done this what velocities are you getting. Third what bottom metal should I run? I see that ptg has bm for extended wyatt boxs or should I go detachables? Which one would give me the most lenght. As far as I can figure for the coal with the should neck juncture to the back of bearing surface would leave me a coal of 3.033 (according to diagrams and berger info). Is this close? Can I get a box to fit? Thanks for the help.

I haven't seen an issue with powder volume so the 180 bergers loaded to mag length and ~53gr of H4350 works good for practicing. MagPro, and Retumbo produce interesting results, but Win Supreme 780 worked best from my findings (please try your own experiments). I used a throat reamer to get 0.020 off of the lands for the mag-length load which was jammed with standard 7mm saum reamer. These are loaded in AR10 magazines, so COL is 2.83ish"

Modified for typo. 63gr would be a quite hot load. 53 grains is closer to start, and work up from there.
My accurate load from mag-length is also near maximum (again I'm working the throat). 2850fps - 2900fps from a 26" barrel.
-Mac

 

[drdtmd]

thanks everyone for your replys