7mm wsm , 300 wsm case capacity
- Thread starter Chatrbaz84
- Start date
The 7mm WSM has a shoulder that is slightly farther forward, so it cannot be chambered/fired in a 270WSM. I believe The 270 and 300 are the same length. Thus, the 7mm should have *slightly* more capacity, although likely not much, particularly if you're going to use heavy bullets seated to SAAMI max OAL.
Looking at Nosler's load data, the case capacities they list put them pretty much equal - with 140gr/150gr bullets the 7mm is listed at 74.5gr/73.5gr water, while with 150gr/165gr bullets the 300 is listed at 75.1/74.0 gr water. So it will all depend on how deep you're seating your bullet, what length of bullet you're using, how long of a OAL length your magazine/chamber will allow, etc. - either one should have more useable case capacity if loaded longer than SAAMI OAL specs, compared to the other loaded at SAAMI OAL specs.
Looking at Nosler's load data, the case capacities they list put them pretty much equal - with 140gr/150gr bullets the 7mm is listed at 74.5gr/73.5gr water, while with 150gr/165gr bullets the 300 is listed at 75.1/74.0 gr water. So it will all depend on how deep you're seating your bullet, what length of bullet you're using, how long of a OAL length your magazine/chamber will allow, etc. - either one should have more useable case capacity if loaded longer than SAAMI OAL specs, compared to the other loaded at SAAMI OAL specs.
thanks a lot , can you share the resource ? pls
I knew a couple guys who went that way, their reasoning was the lack of 7 wsm brass. - dan
pete dobinson
CGN frequent flyer
- Location
- Courtenay BC.
The UK 1000 yard match record was broken by a 7mm-300wsm.
yeah interesting.
having spent some time with the 7 rem mag now, i can totally see the Ups to a Short action with the same ballistics.
Thanks guys (pete too)
I thought along similar lines, and bought/built a couple of 7 saum rifles. The cartridge has quite a following in LR circles stateside. So far, good accuracy and case life. Again though, hard to find components, though adg makes brass now. - dan
Yeah Dan, that 7 Saum is for some reason common in some LR circles, i know a bloke local to me a bit of a LR guru on the target scene, uses all sorts of calibres but one was indeed the 7 saum, that ones a little odd to me? seems the short case would hamper it somewhat but thats obviously not the case...
is there anything practical with the 7saum over the others, 7 RM even? or is it just a 'nice' fit
Much like the 6.5 CM was designed to sit longer 6.5 bullets in a short action, the 7 saum was similarly laid out for longer 7mm bullets to fit in a short action while not taking up too much of the case capacity. I can't think of anything other than that which would make it any better than a 7 WSM. - dan
