short vs long mag

[Rosebud]

At some point you will not get the return of performance for the amount of powder used. Is it worth the extra boom and recoil, muzzle blast plus the need for magnum action. Short and fat cases in short actions will get you 90% of the speed and energy, less powder lighter rifle, quicker handling. memtbs answer is probably better. I use small words. I'll use the 6 ARC as an example. Does what a .243 does more efficient.

 

[memtb]

At some point you will not get the return of performance for the amount of powder used. Is it worth the extra boom and recoil, muzzle blast plus the need for magnum action. Short and fat cases in short actions will get you 90% of the speed and energy, less powder lighter rifle, quicker handling. memtbs answer is probably better. I use small words. I'll use the 6 ARC as an example. Does what a .243 does more efficient.

I think that did a fine job of explaining……without the extra baggage that I added! memtb

 

[Rosebud]

My bad, was about to send same information, again. I'm not a tech guy.

 

[Txcowboy50]

I have a 300 wsm and it is a ballistic twin to 300 wm with factory ammo. The advantage, of the sort mag is 10 gr less powder and slightly less recoil. If you hand load I see and advantage to the long action mags in that you can shoot the heavier , higher BC bullets and not as limited to length of your magazine plus about 50 fps faster. I am shooting 190 gr Bergers at 2900 and 205 Bergers at 2850 with H4350 both >1/2 moa in a short action. That good enough for me and for most big game in North America.

I can swap the 300 wsm barrel with my 6.5 PRC barrel and I am good for goat and deer.

 

[Terry Kiever]

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.

Many years ago P.O. Ackley wrote two books. He Talked about bore ratio capacity, a point where a increased percentage of charge got diminished percentage of velocity. Also a minimum taper case caused pressures to equalize on the sides and lessened neck and rim pressure which decreased case stretching which minimized case trimming. (as I remember)

 

[Terry Kiever]

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?

;Being an (old) Ackley fan have you thought about a .260 AAR

 

[downandlow]

Always the short vs long debate. Not really a debate as they are different animals.
Shortmags can be housed in lighter shorter handier rifles and give better overall ballistics than long mags.
They lose less velocity in shorter barrels than long mags.Their design by nature lends itself to better accuracy over a long belted mag. Also less recoil if put in a same weight rifle as a long mag.

Long mags you should be able to squeeze out more velocity in a properly barreled rifle than a short mag.

For me, the short mag wins out because an extra 100 fps isnt worth the extra overall rifle length with added bonus of less recoil.

 

[Phil Rizzo]

Not a debate for me, anymore.!

 

[MagnumManiac]

I've been a lurking and learning member for a number of years. I'm 76 and have been a reloader sine around 1965. I got into reloading to improve the accuracy of my Rem 700 and to allow me to shoot more on my limited paper route earnings. This is my first post. Your comment "capacity to match bore diameter that will give great expansion ratio numbers" is a mystery to me but it seems like something I should understand. Would you mind explaining the concept or pointing me to where I can get an explanation?

Expansion ratio is the case capacity divided by the calibre hole in the barrel. The larger the case capacity and the smaller the calibre gets, a smaller amount of gas expanding behind the bullet which diminishes the return from the amount of powder burned.
This is often called 'Overbore' by many pundits, but this will turn heads, I don't believe Overbore is a real thing if there are powders slow enough to gain more velocity over previous powders available at inception. The 264WM is still in manuals with powders that were around when it was incepted, modern slow powders bump the performance considerably, such as RE25, H1000, Retumbo, Magnum, US869 & N570. Even H50BMG gains excellent velocities and the Overbore Monica is not a thing… Two of the best expansion ratios to be found is the 338-06 & 35 Whelen, the case capacity to bore is about perfect.
Another great example; the 6.5-300 Weatherby has been around a long time, Weatherby tried releasing it in the 60's, but powders back then weren't suitable. Today we have a plethora of suitable powders that can bring the full potential of the cartridge to life.

Cheers.

 

[ARlife4me]

;Being an (old) Ackley fan have you thought about a .260 AAR

never heard of it, but that doesn't mean much?

 

[ARlife4me]

Always the short vs long debate. Not really a debate as they are different animals.
Shortmags can be housed in lighter shorter handier rifles and give better overall ballistics than long mags.
They lose less velocity in shorter barrels than long mags.Their design by nature lends itself to better accuracy over a long belted mag. Also less recoil if put in a same weight rifle as a long mag.

Long mags you should be able to squeeze out more velocity in a properly barreled rifle than a short mag.

For me, the short mag wins out because an extra 100 fps isnt worth the extra overall rifle length with added bonus of less recoil.

not as much of a debate, but what makes your choices. with improved angles along with longer necks to contain flame in the case rather in the chamber it's available in many case designs. some want that 35* and others choose 20*. does 1 feed better than the other? on dbm's the feedlips can be tweaked to feed better and reliable, but w/o dbm's i couldn't tell you?

 

[Rosebud]

never heard of it, but that doesn't mean much?

Me either, remember the 260 Panther made by Jim Carmichael. IE, 260 Rem.

 

[Calvin45]

I'll admit I have zero experience with any short mag, and very little with short action cartridges in general. Maybe if I tried them I'd see the light and never look back haha but I for one love my long and magnum length action cartridges.

I do see the merit in short barrel performance in a light handy rifle tho, the newer 6.8 western especially is honestly is the most appealing of the short mags to me were I do desire one, the original .300 and .270 wsm cartridges are certainly worth being here as well.

But one thing I never quite understood is what on earth people really notice regarding bolt throw length on a .308 vs a .30-06. I know the .308 is a bit shorter…I don't think it matters and I don't notice it in the field or at the bench enough either way to desire the short action for that reason, it's not a very good reason as far as im concerned.

The other thing I dont get is the purported weight savings IF you're comparing short mags to 06-length standard cartridges. Yes the action/receiver is shorter but it needs to be fatter/beefier too! If the stock and barrel weight are equal, would a .300 wsm rifle really be any lighter than a .30-06 rifle with its 1/2" shorter action? I doubt it. Now it would outperform it a bit, which is fully acknowledged and fine, performance is great, I've heard short fat cartridges are more inherently accurate and efficient, no argument here, I just don't buy the marketing side of things that makes it seem like the difference in bolt throw and rifle weight are what make short action magnums appealing. I certainly don't notice it in the real world and couldn't care less either way.

I'm trapped in the past I suppose though, somehow all 4 of my magnums are not only long or magnum length actions, but they're BELTED too

At present the magnums are .257 weatherby, 300 win mag, .358 Norma mag, and .450 ackley. Still have my .270. Used to have a .308 and a .223, sold them, don't miss them, they didn't do anything for me. Also had a 8x57, a "medium" action haha that was nonetheless no shorter than a .30-06 action, sold that, don't miss it either.

The only short action rifle I have right now is a .243 win in a savage 99 that is a family heirloom and I honestly don't shoot it much at all, some years never. I guess I just don't like the shorties.

 

[memtb]

Calvin, thanks for opening-up and sharing. I'm sure that you must feel better about "coming out"!

I too must confess, I have one short action rifle which I actually like a great deal. It's a .223 Rem……I like to think of it as a 22 Magnum. I guess that I have some sort of magnum fetish. memtb