HL,
Short Mag. Advantages: (theoretical and actual)
- Case is 1/2" shorter and therefore has the equivalent of 1/2" longer barrel or, stated differently, 1/2" more barrel to accelerate the bullet. (Since most measure barrel length to the base of the cartridge)
- Fairly steep shoulder tends to increase brass life
- On average, the powder is closer to the primer which may give more consistent ignition (could help accuracy and reduce standard deviation of velocity)
- Get to use a short action rifle (slightly stiffer, 1/2" shorter. slightly lighter)
- There are no old rifles in existence that force the manufacturer to load at reduced pressures (results in a little more velocity for factory loads).
- The way the chamber is designed (neck, tolerances, etc.) results in a slightly more accurate rifle, on average.
- Brass tends to be more consistent since all forming equipment is fairly new using the latest techniques.
- No belt to mess with.
Short Mag. Disadvantages:
- Doesn't feed as well (on average, in all calibers).
- Not as many rounds in the magazine (as long as two will fit, not a big disadvantage for hunting)
- No cheap supply of brass (if that appeals to you)
- Grandpa didn't shoot it (matters to some)
- Not a military cartridge at this time (matters to some)
Of course it is driven by marketing as well it should be. I think there is a market for the short mags. That doesn't mean it will replace "standard" cartridges. Win has bested everyone else because it was first (and received more press) and because it has more capacity than the Rem version (more velocity). The Rem SAUM fits better in a Rem short action (due to it's length) and may have fewer feeding problems.
HogWild
