I'm not looking for THE answer here, rather just your opinions. I'm curious about what people think with respect to specific cartridge characteristics when constraints are applied.
 
What we have here is the 7.5x55 case necked up to .323, .338, .358, and .375. Bullets have been chosen based on their ability to deliver 2000 ft-lbs of energy to 300 yds (and no more), while keeping muzzle energy and chamber pressures as low as possible.
 
I am interested in the reasoning behind your choice among these four. You may not change bullets, you may not change the fact that the cartrdge must deliver 2000 ft-lbs to 300yds and no more. I'm including charge information in case that matters to you, but you don't get to change the charges.
 
Oh yeah... This is strictly for hunting purposes, not target shooting.
 
Here's the data for the four cartridges:
 
> > > > > Bullet > > > > > Charge > Pressure> > > Recoil > > Elevation @ 300 yds
.323 . . . . . 195 Hornady . . . 56.41 . . . 53,289 PSI . . . 3228 . . . . . . -6.0"
.338 . . . . . 225 Accubond . . 41.12 . . . 48,521 . . . . . . 2902 . . . . . . -9.4"
.358 . . . . . 250 Partition . . . 44.82 . . . 48,456 . . . . . . 3187 . . . . . . -10.2"
.375 . . . . . 260 Accubond . . 45.8 . . . . 46,697 . . . . . . 3121 . . . . . . -11.3"
 
In order to scale the bullet costs without having to find the cheapest price, or put them in Euros or AU$ or CAN$s, I have taken the Midway prices for each bullet and scaled them relative to the cheapest one - the 195 Hornady. In other words, if the cost of the 195 Hornady = "1" unit of cost, then:
 
195 Hornady = 1.000
225 Accubond = 1.846
250 Partition = 2.677
260 Accubond = 2.031
 
So... for example, you can buy 2.7 of the 195 Hornadys for every one of the 250 Partitions regardless of what country you might be in.
 
I would choose the .375 for the following reasons in order of importance:
 
1) Biggest around
2) Lowest recoil
3) Lowest chamber pressure
 
The cons are:
1) "Worst" (but tolerable to me) trajectory.
2) Bullet cost - Not as bad as the .358, but worse than the .323 or .338.
 
Charge is irrelevant to me as long as it is above 85% of case capacity, and all of these are.
 
Paul

Tell me what I'm doing with it besides "hunting".
 
Around here, they're all too big for me.
 
.375 bullets are the most expensive....
 
Guess I'm going with the .338. Best selection of bullets (eventhough I only get to choose one) and cheapest bullets so I can afford to practice with it, while having the least recoil and possibly the best trajectory and retained engergy of the bunch if I were allowed to change bullets.
 
.338 is plenty big enough for the biggest things I'll ever hunt.
 
.375 would be my 2nd choice. I have never cared for .323" or .358" for whatever reason and I think a .375" mould would be a fun thing to play with.

What velocity are they all going to meet your goals?

.375 . . . . . 260 Accubond . . 45.8 . . . . 46,697 . . . . . . 3121 . . . . . . -11.3"

This one.
Recoil between all four is probably not measurable by the shoulder method, even if it is this is real close to 30-06 levels if I remember correctly.
 
Bigger holes are also my preference. Now a days I am considering letting the air out of an ELK single shot or double rifle here I am assuming.
 
Powder consumption is not a factor to me on any of these listed, that is about what I burn in the 45-70 and 30-06 now.
 
Is the ZERO  at 100 yards to give the 11" drop at 300? If so I bet we can move the zero around until we get somewhere real near 6" high to 6" low over the entire 300, makes it a hold on shooter for me then over that range.

Subsonic,
 
The hunting 'constraint' was to exclude target shooting. There are target shooters that prefer larger calibers because in the case of the same point of impact of a .323 and .375, the .375 will 'cut a line' where the .323 won't.
 
Your reasons are certainly reasonable to me. I apprecitate that this case and these calibers might "seem" too big for the animals in your region, but remember, these are for the most part, fairly light loads. As AL noted, recoil is in the .30-'06-shooting-a-165-grain-bullet area. Bullet cost is precisely why I listed the specific bullet. It does matter.
 
The reason I can't let anyone change bullets, is because if the bullet is changed, the BC changes, and the impact energy at 300 changes. If another bullet makes it to 300 yds with 2000 ft-lbs by increasing muzzle velocity, the recoil goes up quickly... very quickly.
 
Al,
The zero is for a 6" target, meaning max 3" high. The zero range for each bullet as listed in the poll is the first table below. I recalculated the trajectories for a 12" target - max 6" high, and posted them below that.
 
.323 - 6" target zero is 231 yds . . . +3" @ 132 yds . . . -6.0 @300 . . . MPBR (-3") is 270
.338 - 6" target zero is 208 yds . . . +3" @ 117 yds . . . -9.4 @300 . . . MPBR (-3") is 245
.358 - 6" target zero is 205 yds . . . +3" @ 115 yds . . . -10.2 @300 . . . MPBR (-3") is 241
.375 - 6" target zero is 200 yds . . . +3" @ 112 yds . . . -11.3 @300 . . . MPBR (-3") is 236
 
.323 - 12" target zero is 300 yds . . . +6" @ 165 yds . . .. 0.0 @300 . . . MPBR (-6") is 353
.338 - 12" target zero is 276 yds . . . +6" @ 149 yds . . . -2.6 @300 . . . MPBR (-6") is 327
.358 - 12" target zero is 271 yds . . . +6" @ 146 yds . . . -3.3 @300 . . . MPBR (-6") is 319
.375 - 12" target zero is 265 yds . . . +6" @ 143 yds . . . -4.2 @300 . . . MPBR (-6") is 312
Maximum point blank range = MPBR.
 
There ya go.
 
Paul

I went with the .323 as my first choice with the .358 being a close second. I eliminated the 338 because I have a 338 Win Mag. I like the trajectory of the .323 and it has ample power and size for what I would use any of these cartridges for and that's elk hunting.

Subsonic - I forgot the MVs for each for you.
 
8mm/195 - 2730 f/s - Impact velocity 2145 f/s
.338/225 - 2412 f/s - Impact velocity 2003 f/s
.358/250 - 2395 f/s - Impact velocity 1900 f/s
.376/260 - 2336 f/s - Impact velocity 1863 f/s
 
I think all of the impact velocities are sufficient to cause expected/typical terminal performance from each bullet type.
 
Paul

Paul, I'd go with the 250 grain .358. But (there's always a but) I'd use a 250 grain Hornady spire point. At that low of a velocity (not sure what it woukd be but I don't think it would break 2400 fps) it would be more than ample for killing just about anything it encountered, even if it had to penetrate heavy bone. Sorta like my 35 Whelen in that respect. The elk I've killed with it, it seems like there was no stopping it even after penetrating both shoulers, busting a rib or two AND taking out a humerous. That bull didn't make it another step.

The hornadys are about 1/2 the price of the Partitions to boot.

Just my nickle's worth.

RJ

RJ,
 
I don't care for the price of Partitions either,:no: or Accubonds for that matter, and I like "plain ol' Hornadys" too... but I can't keep the chamber pressure below 57,000 PSI with the Hornady bullet. In fact, in order to get that bullet to 2000 ft-lbs at 300 yds, I've got to raise the MV to 2500 f/s which raises the ME from 3187 to 3473 (above a .338 WM and 200-grain bullet), and most importantly, to reach that MV the chamber pressure has to go to over 60,000 PSI.
 
I also forgot to mention that all of these figures are for a 24" barrel. Increase the barrel length to 26" - say in a short single-shot like a No. 1 - and the Hornady bullet would get closer - but not reach - the stated goals within the stated constraints.
 
I understand that that much energy may not be required. It's just a benchmark that can be reached without "straining" either a shoulder or an action. Keep in mind, most folks that are trying to "match the .375 H&H's performance" would sneer at these MVs as 'anemic'. I'm not trying to convince anyone of anything, I'm just keeping the constraints in the forefront.
 
Fish3006... No comment??? It is the "why" that I am most interested in.
 
Paul

Paul, I don't think the lower velocity would be detrimental to bullet expansion. That particular bullet accounted for several elk coming out of a 358win in a 99 Savage. And I know Dad wasn't one to overload things.

RJ

QuotePaul, I don't think the lower velocity would be detrimental to bullet expansion.

No argument from me on that note.
 
Paul

A 250 grain Hornady round nose would be pretty sweet too. With a sectional density of .291 and a ballistic coeficient of .313 they might have a rainbow tragectory but oh would they pack a WHALLOP!!! That was the bullet of choice back in the day for the 35 Whelen AND the 358 Winny.

RJ

Hmmmmmm!:undecided:

I voted for the .375.....why?.....'cause I don't have one!:greentongue:

Ol' John..

All these rounds would be fine / overkill for the type of hunting I do and all the projectiles would perform without fault, so it basically comes down to cost. The cheaper it is to reload the more shooting I can do.

How did this get back at the top???
 
Paul