what makes you choose 1 over the other in the same caliber? what do you gain or lose from 1 or the other? other than powder capacity savings as too stretch those extra rounds per pound out of it, what is in it for you? i have 264wm, 6.5prc and 6.5creed/260rem (not counting the 6.5gren) on hand. granted the 264wm is the ba i have and the rest are in ar's, so i kinda have a stopping point? some don't have the max velocity spread between them with the same bullet weight, but why-o-why do-you-do these things! i've been contemplating doing a short mag in a ba factor, but talk me in or talk me out of it?
short vs long mag
- Thread starter ARlife4me
- Start date
Help Support Long Range Hunting Forum
lancetkenyon
Well-Known Member
I love the SA mags. As with any SA cartridge, they don't compare to a LA mag of the same caliber. But they DO compare to a LA standard BF cartridge. The 7SS/7SAUM and .280AI are ballistic twins. But the 7RM outruns them both by 100 fps. But at about 10gr more powder charge. 28 Nosler outruns all of them by another 200+fps. But at 30gr more than the 7SAUM.
SA has an obvious shorter bolt throw. I have seen numerous guys short throw a LA bolt and not pick up the next round in the magazine, only to hear a "click" as the firing pin falls on an empty chamber. I haven't seen anyone short throw a SA bolt.
Short actions weigh a little less than a LA.
SA mags sometimes have feeding issues.
SA mags are usually run at max mag length, and limit COAL.
Short and fat are sexy (just ask my wife).
Barrel life in SA mags is usually a hint better than LA mags, just because of powder burn/flame. But to get best velocities, you have to run them warm, which increases pressure, the OTHER barrel life killer.
SA mags are popular. But you won't get the best performance possible from them. There is no replacement for displacement. More HP=more performance.
SA has an obvious shorter bolt throw. I have seen numerous guys short throw a LA bolt and not pick up the next round in the magazine, only to hear a "click" as the firing pin falls on an empty chamber. I haven't seen anyone short throw a SA bolt.
Short actions weigh a little less than a LA.
SA mags sometimes have feeding issues.
SA mags are usually run at max mag length, and limit COAL.
Short and fat are sexy (just ask my wife).
Barrel life in SA mags is usually a hint better than LA mags, just because of powder burn/flame. But to get best velocities, you have to run them warm, which increases pressure, the OTHER barrel life killer.
SA mags are popular. But you won't get the best performance possible from them. There is no replacement for displacement. More HP=more performance.
akmtnhnt
Well-Known Member
Short action mags run on medium or long actions gets about the most performance you're going to get out of something, but you're full custom to get there.
Except for tikka, you can just do a barrel on those.
A 7WSM with something like the 190 EOL seated out to over 3.00, out of a long or medium action with a proper throat to accommodate the much longer than SAAMI spec for it will actually outrun a 7RM seated to 3.34 with the same bullet because that bullet is so deep into the 7RM case.
No way I'd mess with any of this in a semi-auto.
Except for tikka, you can just do a barrel on those.
A 7WSM with something like the 190 EOL seated out to over 3.00, out of a long or medium action with a proper throat to accommodate the much longer than SAAMI spec for it will actually outrun a 7RM seated to 3.34 with the same bullet because that bullet is so deep into the 7RM case.
No way I'd mess with any of this in a semi-auto.
MagnumManiac
Well-Known Member
This has been my take on all magnum offerings.
I look for capacity to match bore diameter that will give great expansion ratio numbers.
For instance, the 300WSM is perfect for 25, 26 & 27. Loses out in 30 & 33. Same goes for RSAUM.
The 300WM is a niche size good for 6.5, 7 & 30.
The 300 Weatherby is great for 6.5 through 375, even 416 is doable.
The 8RM is great for the same above.
The 338WM is another niche size that can utilise 25 through 375 and maybe 416 if you like slow.
All the new magnums have pretty much had all the development in calibre already done.
Personally, my love affair with the 300WM will never sway, but I love the RUM nearly as much. I have a 300RUM, have had both the 7 and the Edge and looked very hard at both the 338 & 375 versions.
Cheers.
I look for capacity to match bore diameter that will give great expansion ratio numbers.
For instance, the 300WSM is perfect for 25, 26 & 27. Loses out in 30 & 33. Same goes for RSAUM.
The 300WM is a niche size good for 6.5, 7 & 30.
The 300 Weatherby is great for 6.5 through 375, even 416 is doable.
The 8RM is great for the same above.
The 338WM is another niche size that can utilise 25 through 375 and maybe 416 if you like slow.
All the new magnums have pretty much had all the development in calibre already done.
Personally, my love affair with the 300WM will never sway, but I love the RUM nearly as much. I have a 300RUM, have had both the 7 and the Edge and looked very hard at both the 338 & 375 versions.
Cheers.
I think the short mags have benefitted by some new powders since the early 2000s when they were introduced. With a powder like Retumbo you can squeeze an extra 50-100 fps where we were back then. But if you shoot those long high BC bullets you will run out of COL quick. I open the R700 actions up a bit to maximize my COL and take advantage of another 1/8" or so. Personally I love both, but Shorts is where it's at. You never know exactly how much you will like it until you try it, even in an AR.
I don't have a whole lot of experience with the short mags only 1 so far 270 wsm.
Had 2 long action mags 300 & 7mm Rem. For me I just had to much problems with the wsm
For what is gained from it.
1-the brass would open up primer pockets after the 3rd firing.
2- Brass always had to be annealed for me to get the shoulder bumped back consistently .002
3- the brass was always harder to find and more money.
4- my rifle would some times jam if I loaded 3 rounds in the box magazine. Missed a cow elk because of it.
I really do like my Kimber 8400
In 270wsm. light weight very good looking wood balanced excellent and didn't need a 26" barrel. But the older I get for hunting the 30-06,270 and the standard length cartridges are what I like more and more no fussing around.
For target shooting I like the 25,260,7-08 but that's just me.
Had 2 long action mags 300 & 7mm Rem. For me I just had to much problems with the wsm
For what is gained from it.
1-the brass would open up primer pockets after the 3rd firing.
2- Brass always had to be annealed for me to get the shoulder bumped back consistently .002
3- the brass was always harder to find and more money.
4- my rifle would some times jam if I loaded 3 rounds in the box magazine. Missed a cow elk because of it.
I really do like my Kimber 8400
In 270wsm. light weight very good looking wood balanced excellent and didn't need a 26" barrel. But the older I get for hunting the 30-06,270 and the standard length cartridges are what I like more and more no fussing around.
For target shooting I like the 25,260,7-08 but that's just me.
More powder, more velocity. More velocity, more range. It depends on your needs.
I built a 6.5 SAUM to have the ability to push a heavier bullet faster but in a short barrel over say my 260AI.
For example my 260AI runs the 142ABLR at 3000fps in a 24" barrel. My 6.5 SAUM Improved runs the 153.5 LRHT at 3050fps in a 21" barrel.
For example my 260AI runs the 142ABLR at 3000fps in a 24" barrel. My 6.5 SAUM Improved runs the 153.5 LRHT at 3050fps in a 21" barrel.
sesauk
Member
The 264 WM is very hard to beat, now that the bullets and powder have finally caught up to it.
Muddyboots
Well-Known Member
Peterson 300WM and 7RM long brass is game changer for me for added brass life due to elimination of the 1st firing insane case stretch.
Have 300WSM and if pushed hard to "max" out instead of accepting what it is causes all the comments posted, primer pocket life sucks, web expansion issues, factory rifle action magazine capacities versus freebore. Etc.
I used to drive it hard with bigger bullets and paid the price. Now? I run 150-165 type bullets and it does great. No doubt everyone tries to "make" a lesser cartridge be "equal" to a higher capacity cartridge.
The big brother 300WM is still my go to for heavier longer bullets. No replacement for displacement is true.
Have 300WSM and if pushed hard to "max" out instead of accepting what it is causes all the comments posted, primer pocket life sucks, web expansion issues, factory rifle action magazine capacities versus freebore. Etc.
I used to drive it hard with bigger bullets and paid the price. Now? I run 150-165 type bullets and it does great. No doubt everyone tries to "make" a lesser cartridge be "equal" to a higher capacity cartridge.
The big brother 300WM is still my go to for heavier longer bullets. No replacement for displacement is true.
I had good success with 270 SM. Anyone have any tips on how to get the short mags to feed better? D.
... and barrel twist - mine has a 26" 1:7" primarily built to propel the heavies, i.e., 156 Berger.
BTW, IIRC, @Mike D Texas has an improved version.
Last edited:
sesauk
Member
I had mine made up with a Proof Research 1:7.5 twist Carbon Fiber and is also a 26" length. I can shoot > 1/4 inch but I am still trying to decide which bullets to use. I am mainly looking at the Berger, Hammer and Nosler. I want to get set up on one bullet for each 264WM's that I have then I don't need such a variety of things around.
I love the Berger 153.5's @ 3311 fps out of my 31" PRC. they'll go faster in the .264!
