I think maybe I read something about the short, fat cases getting the same MV from less powder due to increased combustion efficiency or something. Can't remember where or anything.
At this point I would like a Kel-tec RFB with a 22" .243 barrel. It would suffice for long range, and be a good entry gun. Good for carrying into and out of buildings and vehicles, etc when compared directly to AR carbines.
Stan Crist had some things to say about a proposed "6mm optimum" cartridge, that would be just shy of a .243. 100 gr vld, .540 BC, 3000 fps, that sort of thing. .243 out of a semi-auto would probably run about those figures.
I know, I know, I just said Kel-tec. The shame.
7mm mag for sure would have the advantage of standardized and readily available brass and reloading equipment I bet.
I thought everybody had a clear understanding of the limitations of the .308 case lol.
155 gr Lapua at .508 seems the best arrangement. 155 Berger after being run through a bullet-pointing die is alleged to match that performance, and Bergers from what I read are more suitable for hunting than, for instance, that 155 Lapua. But don't know from experience.
Yes in theory the short , fat propellant column is more efficient , reality is that it's of very limited advantage and then only in lighter slug weights , when you get to heavier slugs the short mags are a 100 fps and more down on the Rem mag , the whole concept was an answer to a problem that really didn't exist in the 'sporting' sense , and the attempt to cram long-action magnum power into a short-action rifle is a failure as regards larger game , the SAUM , WSM and the Ultra are all less efficient of dangerous and large game than the original Rem-mag.
And rather humorous and telling that you mention 155 at .308 , keep in mind the Palma ammo is standardised at 155 and there are good reason for that.
And far be it from me to laugh at the concept of a Keltec or the like in .243 , or .257 roberts , .260 etc.etc. , I've never been a big fan of .223/5.56 and have always felt they should have looked very closely further up.
The .24 to .26 sweetspot is another of my favorites , particularly .243 and .257 and it seems that like 7mm rem-mag there's always a .243 of some sort in my safe , usually more than one.
Hmmm........entry dynamics. Sorry but I like smoothbores for the task , just a personal peculiarity. But then such things are a 'horses for courses and different jockeys' sort of thing.
The hardest thing to find in the world is the hypothetical ' all round rifle" , any such choice will inevitably leave a base or bases uncovered.
And then of course I tend towards the innately practical in some cases , folks can laugh all they wish but ( for instance) a Mosin-Nagant can be had DIRT cheap , they're dead nuts easy to work on ( not that the damn thing is going to ever break short of getting run over by a tank) surplus ammunition is ridiculously cheap. And ballistically 7.62x54r is essentially a very slightly slower '06. And hell you can pour vodka down the barrel or pee down it ( it's in one manual...seriously) to clean it.
And keep in mind what Simo Hayha did with one. Talk about Pyrrhic Victories , cost the Soviets a *lot* to take Finland.
If you * really* want a " crossover autoloader" , consider this.......buy yourself a BAR in the chambering and barrel length YOU want , with the BOSS system , throw premium glass on it and source high cap mags for it , yes they are around.
And you're still way less into it than a high end ARForgery or the like , the BAR is ultra reliable , even in *very* cold climates and in .338 win mag with ghost ring sights and the 8 round mags in quite likely the best big bear defensive rifle one can carry , though the model 95 Guide Gun in .45-70 is a very close second. And neither is unreasonable as regards recoil from my standpoint , but then I'm not real susceptible to recoil ( within reason).
As you can likely tell , I've a rifle 'Jones' , that's balanced by brutal sensibility and ruthless utilitarianism as regards sidearms. My views sometimes incite arguement though not intended to. And if a given sidearm isn't a shooter and deadnuts reliable it has a VERY short half-life here. I also like wheelguns , which is distinctly out of fashion nowadays , but I'm very good with them. I also dislike 9 x 19 and Plastic , and you couldn't give me another 1911 from Colt themselves if you PAID me to take it , not when you can get a SIG or Springfield and they shoot right straight from the box , few Colts will without any work.
And while I despise the spirit of Bill Ruger , well I sure as hell am not getting rid of any Ruger Wheelguns any time soon , not with the way they've performed over three decades and longer , yeah I like S and W , but the fact is they aren't nearly as tough or as reliable.
And then there are the well known Glock 'Kaboom' problems , the fact of which seems to upset some folks when you tell them to stick to over the counter pressures and not start hotloading it without an aftermarket barrel.