Home Forums Hunting & Shooting Hunting Rifles Short Fat Crtge Accuracy Theory

I don't shoot bench rest nor do any of my friends. But nonetheless I have heard and read the theory of the shorter fatter cartridge being inherently more accurate. The 6mm PPC, the 308 edging out the 30.06 etc.

So now that the new fangled shorts are out there all over the place, is it true? Or did we get hoodwinked by the gunmakers. How is it fairing in the field?

Montanna Marine's super accurate 30.06 tends to make me believe that the short fat cartridge, "inherent accuracy" theory is just a bunch of hooey. But hey! I'm might be wrong.

i am extremely impressed w/ all aspects of my 300 wsm. i would bet that in appropriate hands, a 7 wsm, or 6.5 wsm would be one kick-ass competition cartridge, especially for 1000 yard shooting.

I believe the short case does have a proven accuracy edge, all other things being equal. But I don't think the edge is too apparent until serious BR reloading, shooting, and rifles enter the equation.



In other words .5 moa or so is all the accuracy I want/need, and the 30-06 can deliver that. But for competitive BR, it just cant hang with ctgs like 6mmBR that can shoot consistently under .25 moa with proper ammo/rifles.



MM

After screwing with a couple of them, my intuition tells me that while there probably is something to the increased accuracy theory, the benefit rates far down the list behind barrel, bedding, and sighting.

Point being that a well built 300 H&H will most likely outshoot a slapped together 300WSM.

The shorter powder column is more consistant. There is an edge in accuracy. But it requires the very best benchrest rifles, equipment, and shooter to realiaze that level of difference. I doubt that it would ever make a difference that could be seen in a hunting rifle.

I have owned by actual count(all bolt actions), 2 different .223 Remington's, 3 different .22-250 Remington's and 3 different .220 Swifts. The M70 Coyote I have in .223 WSSM is more accurate out of the box then any of them. Groups started out at just over 3/4" and now are under 1/2" for five shots @ 100 yards. The .223 WSSM IS over 200 fps. faster if a person wants to load that high. Yeah, the short/fat cartridge works in conjunction with the new shorter/stiffer actions available on rifles today. You may not like the short/fat cartridges(WSM, WSSM and even the RSAUM) but they do work and that isn't to be denied. Lawdog

Lawdog-My 40xbks in 6mmrem easily averages under 1/2" and the 6mmrem is not a short fat cartridge by any means.My cheap smith&wesson .223rem varmint rifle would also average 1/2" or better.My friends savage in 22-250 will also accomplish this kind of grouping.If you go to the thread on M700VS accuracy Jamison has had two .223rem's that are shooting much better than 1/2".The only explanations for none of your previous rifles displaying this type of accuracy would be that you have had very bad luck in buying those rifles or you just didn't find the right load for them.

I think MontanaMarine mailed it a few posts back. Until one gets down below the 3/8 MOA level or so, cartridge design has little visible effect on groups. It has much more to do with the quality of the rifle, shooter and straight ammo.



In serious BR competition at shorter ranges up to about 200 yards, with groups around the 1/8 MOA level, the short fats are the way to go as the 6PPC has proven time and again. When ranges get a bit longer, and wind drift and other conditions enter more into the equation, many cartridges are competitive as the shooter's ability to read the conditions is much more important.



In hunting rifles the short fats may provide an accuracy advantage, but I'm convinced it's really a non-issue. For example, if a 300Wby produces group sizes of 0.6", and a similar rifle in 300WSM produces .55" groups, is that really a more accurate rifle as far as "hunting rifles" go? Not with the animals or targets I hang around with.



If you have an accurate hunting or varmint rifle chambered to a "short fat" cartridge, enjoy it! But don't be surprised if it gets outshot by a similar rifle chambered to a longer, skinnier cartridge.



My long-winded two cents...

stubblejumper,



All the previous rifles I stated started out, accuracy wise out of the box, in the 1 1/2" area and did work down to 1/2" but after a bit of playing around with different load variations. I milked everything I could out of those rifles but was never able to get the accuracy I am getting now. I haven't had to do that much with my .223 WSSM. It started out more accurate(3/4") and is getting better with each new load. I have had some groups measure just over 0.267"(my best so far) for 5 shots @ 100 yards. I stand by what I said the short/fat theory is a fact. Lawdog

I think the 6 PPC is just a freak cartridge and everybody tries to use the short fat theory using it as an example to prove the theory works.
In actual fact from the rifles I have owned a 222 built to the same standard as a 6 PPC will be just as accurate but has the disadvantage of lighter bullets and so is not the choice for BR competition past 100 yards.
If you have owned a BR rifle in 22 PPC or 6 BR you will find it is nowhere near as flexible in regards to powders and accuracy as the 6 PPC,so how does the theory stack up there.
When factory rifles are involved it is just a lucky dip and I do not think that any worth while comparisons can be made especially if 1/2 inch groups are the standard you are judging at.
My 30-378 WBy would easily do better than that and it is as far removed from the short fat theory you can get.
I have seen enough 300 Magnums and other cartridges like 280ACk built in BR rifles to realise that it is a good discussion point and marketing excersise but the short fat theory just does not stack up in the real world.

Regards,
Charlie
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I like short action chamberings simply because I like short action rifles but for hunting rifle accuracy how the rifle was built has far more to do with its accuracy than the size of the case. IMHO, hunters can get more than enough accuracy from a well built standard or long action chambered rifle and should leave the short vs. long accuracy issue to the benchrest crowd.

Does the short/fat cartridge make a difference? Yes and No. Let's take a closer look at the benchrest wonder cartridges. The 6ppc is without a doubt, the most accurate cartridge in use. It came about because the dimensions of the case, volume and primer hole were found to be ideal for igniting the powder used to send the 6mm match bullets down range at the optimum velocity. About a decade ago, good brass for ppc cartridges was tough to find, so many switched over to Remington's version of the "short/fat" cartridge known as the 6mm Benchrest. However, the Remington 6mm Benchrest could not hold a candle to the 6 PPC, so everyone (or near everyone) switched back to the PPC.

Now, it's obvious the short/fat PPC cartridge is more accurate, but the Remington version shows that just any short/fat cartridge does not work. It's possible that one of the new short mags does provide the "optimum" cumbustion chamber for ONE of the calibers, but I don't have the resources to determine that. Furthermore, if the cumbustion chamber is the "perfect" size and shape, it is probably only for a limited range of bullets and with a limited range of powders and a limeted number of primers in a limited velocity range (just as with the PPC).

The apparent accuracy increase with the newer cartridges is probably due more to better manufacturing of the rifle. I know I step on a lot of tows by saying this, but I really don't think ALL of the new short mags are in themselves more accurate.
John

yeah, but those chubby little cartridges use up a lot of magazine space. still, I think the 300 wsm is hard to beat. a littler better than the 06 and close enough to the 300 wm. my various 300 win mags were all kickers and I sold them. the 300 wsm is a joy to shoot. may be all in my head but that's my take. still, I can barely close the bolt with three in the mag. I just carry spares in my pocket now.