Re: 7mm SAUM + 180 Berger Hybrids
I'm planning to build a 7mm SAUM on a modern Winchester "Classic" controlled-push round feed action with CDI bottom metal but I'm finding it tough to decide on long vs. short action. It looks like the only way to mag-feed a good Berger 180gr. VLD load from even the longest short action mags (Alpha Mag = 2.985") is to throat the chamber a bit shallow but then I read this advice in the 6mmBR.com article:
<span style="font-style: italic">Additionally, the SAUM case has a slightly longer neck. This gives you greater flexibility in bullet seating. With a long neck you can set the throat so the long 180gr VLDs are above the neck shoulder junction, yet you can still seat shorter hunting bullets close to the lands. Additionally, long case necks, some believe, cause less throat erosion than shorter necks. That's not "hard science" but it is certainly a view shared by many experienced shooters. </span>
<span style="font-weight: bold">1. Do the long action magnum DBMs feed 7mm SAUM well?</span>
My maximum mag capacity would drop from 10 rounds in a short action to 5 rounds (or maybe 6 rds with the AM double stack, single feed from Accurate-Mag?) with the long action, but that's not a terribly big deal.
I reading reports of 1:9 and 1:8.5 twist.
<span style="font-weight: bold">2. Is there much chance of a longer/heavier bullet entering production?</span>
It seems to me that 180 isn't as "heavy for bore" as a lot of 30 caliber bullets.
<span style="font-weight: bold">3. Should I go for 1:8.5 or even 1:8 or stick with 1:9?</span>
I'm planning on 28" of barrel to hit the 2950-3000 fps node but I'd go longer, if necessary.
Hopefully, my questions will help to bump this thread too!
I sure would be greatful for help on planning my first long range hunting and entry F-class rifle.
-Cal