I'm mostly settled on a straight (or improved) 7mm SAUM / Blaser Mag or 7-270 WSM for my next build and I plan on running two different setups but identical chambered rifles, one for hunting and the other for target and steel shooting. The plan is to run 175gr-195gr bullets between 2950 -3100 fps with one of the colder burning powder, under 60k psi and also being able to run decent brass. I'm also leaning towards the sort of characteristics (broad tune window, inherent accuracy etc.) that the F class shooters normally look for in cartridge.
My first choice is the 7mm SAUM with a longer neck and shorter powder column, but I'm conscious of the fact that the type of performance I'm after could be at the upper end of the cartridge's ability, reducing brass life. Second would be either the 7mm Blaser or 7-270 WSM. I prefer the longer neck on the BM and the bigger case capacity, but unsure about the proven accuracy potential and ease of load (broad tune window). If it wasn't for the shorter neck on the 7-270 WSM (assuming that it is not much longer than the 7mm WSM), I would most likely have gone with it given the 35* shoulder on the 7-270 WSM and capacity balance between case in question and assuming the required performance is within the capability of the cartridge.
I'm also wondering about the improved versions of the BM and RSAUM.
Yes, I have considered the Sherman Mags and especially the Max, but I recently immigrated to New Zealand which makes things a little more complicated in sourcing/importing the items. So I have been playing around with some shoulder angles on the SAUM and BM, and "SLR" the 7mm Blaser to 35* as per the attached illustration loaded with the 195gr SMK (nts). I also included a 7mm PRC and an SLR 35* version to tickle the mind.
Question, can anyone verify the exact neck length for the 7-270 WSM or 7-300 WSM and how much of drawback is the shorter neck?
Any load data and experience that some of you could share with regards to an improved version of the Blaser Mag or RSAUM?
I suppose the SLR will result in some doughnuts forming at the neck-shoulder junctions. Best approach to eliminate or manage them?
My first choice is the 7mm SAUM with a longer neck and shorter powder column, but I'm conscious of the fact that the type of performance I'm after could be at the upper end of the cartridge's ability, reducing brass life. Second would be either the 7mm Blaser or 7-270 WSM. I prefer the longer neck on the BM and the bigger case capacity, but unsure about the proven accuracy potential and ease of load (broad tune window). If it wasn't for the shorter neck on the 7-270 WSM (assuming that it is not much longer than the 7mm WSM), I would most likely have gone with it given the 35* shoulder on the 7-270 WSM and capacity balance between case in question and assuming the required performance is within the capability of the cartridge.
I'm also wondering about the improved versions of the BM and RSAUM.
Yes, I have considered the Sherman Mags and especially the Max, but I recently immigrated to New Zealand which makes things a little more complicated in sourcing/importing the items. So I have been playing around with some shoulder angles on the SAUM and BM, and "SLR" the 7mm Blaser to 35* as per the attached illustration loaded with the 195gr SMK (nts). I also included a 7mm PRC and an SLR 35* version to tickle the mind.
Question, can anyone verify the exact neck length for the 7-270 WSM or 7-300 WSM and how much of drawback is the shorter neck?
Any load data and experience that some of you could share with regards to an improved version of the Blaser Mag or RSAUM?
I suppose the SLR will result in some doughnuts forming at the neck-shoulder junctions. Best approach to eliminate or manage them?
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