7 SAUM throating question

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I ordered my 7 SAUM barrel yesterday. I am trying to figure out the best way to go about the chamber. It is hard to find bullets so I am a little uncertain what to do. I found some 175 ELD-X which is a bullet I would be happy to use but I dont know for sure it will shoot well without testing. I would like to find an accurate load using something in that 175gn area like the ELD-X or the 175 or 180 Bergers. I could even test the 168 Berger. Do I just send my dummy rounds with the 175 ELD-X and assume it will be close enough for other bullets in that weight class? I have 162 ELD-X and can get the same ELD-M or the 168 Berger locally so worst case is I use them and I am sure they would also be fine but I would have to jump them a ways if I chamber to the 175.

What would you do?

To add, I have enough H4831sc and H4350 to last me a couple seasons. I hope to get some H1000 but I may have to use what I have for a while. Not sure if that would play in to your advise for me.
 

BBob

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You didn't say and the answers might have a bearing on what you're asking about. What action? Mag fed? Box fed? If box what length box is your action setup for?

You ask about just sending a dummy round so I assume you are sending it off to a gunsmith for the work? If so you might consult your gunsmith as to what he might think.
 

Harvey_NW

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+1 on consulting with your smith. But out of curiosity I did some quick searching and Hornady doesn't have actual spec sheets but I found some posted bearing surface lengths to compare to Berger specs, posted as follows:
180 eldm - .535"
175 eldx - .570"
180 hunting VLD - .491"
175 elite hunter - .478"
168 classic hunter - .483"
168 hunting VLD - .417"

So if you have the capacity to load as long as you want, with the bottom edge of the bearing surface seated to the neck/shoulder junction you'd have an estimated .153" maximum difference in jump, not including leftover freebore. If you're sending a dummy round then he's likely custom throating it for how much jump you want or where he recommends with that specific projectile. Lots of variables that depend on where you prefer to be in terms of jump when loading. If you're a .020" off the lands guy, looks like you have a decision to make. But if you're a bottom of the bearing surface near the neck junction and fiddle til she shoots guy (that's me), make sure the chamber has enough freebore to load the 175 and send it.
 

XLR

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Like Bob said, the biggest thing to take into consideration is your COAL. If you are running an XM then throat that pig out! If you are running it in a short action then you will be limited. We did an article on the XM actions and their benefits so it might be something for you to check out if you are not familiar with them!

 
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MuleyFever
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+1 on consulting with your smith. But out of curiosity I did some quick searching and Hornady doesn't have actual spec sheets but I found some posted bearing surface lengths to compare to Berger specs, posted as follows:
180 eldm - .535"
175 eldx - .570"
180 hunting VLD - .491"
175 elite hunter - .478"
168 classic hunter - .483"
168 hunting VLD - .417"

So if you have the capacity to load as long as you want, with the bottom edge of the bearing surface seated to the neck/shoulder junction you'd have an estimated .153" maximum difference in jump, not including leftover freebore. If you're sending a dummy round then he's likely custom throating it for how much jump you want or where he recommends with that specific projectile. Lots of variables that depend on where you prefer to be in terms of jump when loading. If you're a .020" off the lands guy, looks like you have a decision to make. But if you're a bottom of the bearing surface near the neck junction and fiddle til she shoots guy (that's me), make sure the chamber has enough freebore to load the 175 and send it.

Thanks. That’s what I was looking for.
 

BBob

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You can’t totally hang your hat on bearing surface lengths. They are certainly useful to a point but the various types of ogives between bullets can differ quite a bit from front of bearing surface to land contact. A hybrid to tangent might be fairly close to one another but either of those to a secant VLD is going to be further apart.
 

Ucsdryder

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I’d throat it .020” longer than a 180eldm and go from there. If you want more jump you can seat bullets a little longer. If you want to shoot 160 class you can jump farther or seat out longer. I can go measure cbto on a 180 and adg if that helps.
 
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