Multiple cartridges based on the same case -- always choose 308/30-06 inside of 300-400 yards?

[Corn-Picker]

I ran some numbers for multiple bullets from cartridges based on the same case; i.e. 260/7mm-08/308 or 270/30-06. To make a long story short, inside of 400 yards, and especially inside of 300 yards (my max range), the 30 caliber option always seemed better (more velocity, more energy, less drop, and less drift). Looking at the data, it seems like the performance of the smaller caliber can always be exceeded by a light for caliber bullet in the 308/30-06. A 110 grain 7mm bullet is slicker than a 110 grain 30 caliber bullet, but the low BC of the 30 caliber bullet is more than offset for by the increased muzzle velocity, so it still carries more energy and drops less inside of 400 yards .

The only way that the smaller calibers won out is if ranges were over 400 yards or wind speed exceeded 10-15 mph. As a sanity check, I did a brief check of some larger calibers (e.g. 358 Winchester), and in that case the lower BC of a light for caliber bullet did result in worse drop/drift performance at 300 yards.

Maybe this is common knowledge, but I found the math interesting. It reaffirmed my suspicion that my next rifle will be chambered in 308/30-06. I guess you could make a sectional density argument for the smaller bullets, but I use copper bullets exclusively and have never had insufficient penetration even with light for caliber bullets.

 

[someguy2800]

I've found the same to be true in my research of the numbers. The larger the bore, the more surface area there is for the pressure to push on, and you get a higher velocity for the same weight of bullet. I'm not really a fan of overbore cartridges. Especially at short ranges which are the rule for hunting where I live.

 

[jmr40]

The rules are different for copper bullets. Generally lighter and as fast as you can shoot them gives best performance. FWIW 308/30-06 is also what I use mostly, but similar results can be found with most any combo. While there is nothing wrong with a 308/30-06 combo I think your logic is slightly flawed especially with standard bullets. The difference in SD is more important than you're accounting for, even with copper.

You can't compare equal bullet weights in different calibers. Comparing similar sectional density and ballistic coefficients is a better way to look at it. A 140 gr 7-08 bullet, a 150 gr 308 bullet and a 130 gr 260/6.5mm bullet can all be fired at about the same speed, will have nearly identical trajectories and perform about the same on game when they hit.

You are right about the larger calibers, going to anything larger than about 28-30 caliber in a cartridge based on the 308 or 30-06 is actually a step down in performance, not a big one, but a step down .

You also have to consider recoil. The 358 recoils almost as much as 300 WM. A 260 or 6.5 Creedmoor will have about 25% less recoil than 308, yet do about the same to game animals inside of 300 yards and beat it at longer ranges. That is the appeal of the smaller calibers.

After all is said and done there just ain't that much difference. With proper bullets every cartridge between 260 up to any 338 magnum can do the same job. I started with the 308/30-06 family and at this point won't change. I've added a 6.5 Creed for playing at the range, but it won't replace my other rifles for serious hunting.

 

[MCMXI]

Maybe this is common knowledge, but I found the math interesting. It reaffirmed my suspicion that my next rifle will be chambered in 308/30-06. I guess you could make a sectional density argument for the smaller bullets, but I use copper bullets exclusively and have never had insufficient penetration even with light for caliber bullets.

I use solid copper bullets exclusively for hunting too and it's one of the reasons that I don't have any interest in a 6.5 Creedmoor for hunting. I'll stick with the .308 Win for that if I want to use a short action rifle. The last time I checked 120gr is the heaviest solid copper 6.5mm (.264 cal) bullet available whereas a .30 cal can be had in 150gr, 165gr or even 180gr. If you compare the 6.5 CM shooting a solid copper 120gr bullet at typical velocities to a .308 Win shooting 150gr or 165gr solid copper bullets at typical velocities the .308 Win has more energy than the Creedmoor all the way out to 700 yards. You have to shoot the 143gr ELD-X if you want to beat either the 150gr or 165gr .30 cal and even then, the CM doesn't surpass the .308 Win in terms of energy until 500 yards. I can see choosing a 6.5 CM over a .308 Win if you don't have either, but I would never give up a .308 Win in favor of a 6.5 CM.

 

[cdb1]

You also have to consider recoil. The 358 recoils almost as much as 300 WM. A 260 or 6.5 Creedmoor will have about 25% less recoil than 308, yet do about the same to game animals inside of 300 yards and beat it at longer ranges. That is the appeal of the smaller calibers.

Recoil is the reason I went to a smaller cartridge. It had nothing to do with ballistics. I've had three shoulder operations and a few years ago my .270 began to bother me. I bought a 6.5x55.

 

[Gtscotty]

The last time I checked 120gr is the heaviest solid copper 6.5mm (.264 cal) bullet available whereas a .30 cal can be had in 150gr, 165gr or even 180gr.

Barnes currently offers a 127gr LRX, and a 130gr TSX in 6.5mm. The LRX has an SD slightly higher than a 170gr .308 cal bullet, and a decent BC of .468 G1 to boot. I've never used a solid copper bullet on game before, but I'm thinking about giving the LRX a try this year.

The only way that the smaller calibers won out is if ranges were over 400 yards or wind speed exceeded 10-15 mph.

That level of wind is pretty much a given where I hunt, but admittedly, for most people it's not. In the 0-250 yds in relatively calm wind where most people make their hunting shots, the differences between all the common high powered hunting cartridges are vastly overblown. Not so much true for longer range target shooting in brisk wind, but that's another topic.

 

[readyeddy]

The smaller diameter cartridges usually offer more MPBR which operates within the 300-400 yard window.

 

[MCMXI]

Barnes currently offers a 127gr LRX, and a 130gr TSX in 6.5mm.

I completely forgot about the LRX bullets. The 127gr LRX would help a bit and it kind of makes the 130gr TSX redundant. I haven't run the numbers on the 127gr bullet from Barnes but it sounds like a good option. However, I still doubt that the 127gr LRX from a 6.5 CM would have more energy than the 165gr TTSX from a .308 Win but if it has enough then who cares right? The recoil issue is kind of tricky since stock design makes a huge difference to felt recoil.

 

[Varminterror]

A guy shouldn't be surprised. In general, all of these are loaded to very similar pressures - so you have the same powder capacity, same pressure, and you're suggesting the use of the same bullet weights... The only thing changing is your bore. "Pressure" is a force per area - force per square inch - and a larger bullet has a larger base area where the force is acting - so more force acts on the bullet = greater net force applied to the bullet. That's before you even get into the minutia of lost case capacity for a smaller bullet diameter...

But then a guy has to ask the question - what's enough? I've found the 243win to be the most efficient deer killing cartridge on the market, and my 30-06 has 40% more recoil and takes 25% more powder... In a world where 243win is enough, it's easy for me to justify that 7-08 is enough more enough, but getting clear up to 308, then clear up another step to 30-06 just doesn't make much sense. I love my .30-06's, but if I could only have one deer rifle, it'd probably be a 7-08 (or 284win), not a 30-06.

 

[LoonWulf]

I think youve discovered that it really doesn't matter what 08/06bassed, or similar cartridge you chose for sub 400yd hunting. At the end of the day shoot which ever rounds you happen to like, for whatever reasons you like them.


I have shot a cartridge in every caliber from .22-.311 for deer. Ive seen that as you go up in bore dia you have a little more leeway for bad shots at each step. Ive also noticed that when loaded optimally the smaller bore dias will give a few more yards of mpbr.

Personally what i hunt with is mostly dictated by which rifle or cartridge im messing with right then.
If im unsure of the area, game, or something absolutely must die, ill go with a 7mm or 30 cal magnum, because i have a great deal of faith in those rounds. But that is, as they say, personal preference.

Im actually home on molokai this week, and have been hunting with my Springfield Xd .45 (we can call that 06 based right?), Since my rifle case wasnt up to par for the new airlines regs.

 

[Slamfire]

What I consider the basic problem is the absolute lack of objective lethality tests and data for any of the cartridges we use. Gunwriters are not objective, they are shills for the industry, nor are their tests calibrated against anything but expediency. Their test media consists of whatever is found around the house or garage: newspaper, phone books, soap, clay, duxseal, wood, etc. I cannot count (or remember!) the number of Gunwriter articles where I have read that deer (or any animal for that matter) are like wet newspaper, wet phone books, soap blocks, clay, duxseal, or wood, based on something standard the gunwriter has created.

From what I have read, Dr Martin Flacker used animal tissue to calibrate ballistic gelatin, and so for handguns at least, ballistic gelatin is currently being used as a lethality standard. Gunwriters are still shooting bullets into wet newspaper, wet phone books, soap, clay, duxseal, wood because that stuff is easy to find and easy to use. And they are still making lethality claims based on their “tests”.

Also, because of the endless repetition of what are untested theories from Gun Publications, we the shooting community assume that it has truth and relevance, and we tend to use the same standards of comparison that we read in print.

I did like Jack O’Connor’s comment on what was important was bullet placement and bullet construction. That more or less fits into Dr Martin Flacker’s ideas that the biggest through hole was the most lethal. (a vast oversimplification of what he wrote).

Based on that, I would go with the bullet of the largest diameter, because the hole won’t get any smaller, and a bullet that has enough weight to punch through any obstruction. This ignores shot placement, which is the most important factor of all.

But, without test data against a calibrated media, how is anyone to say that a .284 bullet (lets say 175 grs) is any better or worse than a .308 bullet that weights 175 grains? Can an animal tell the difference in the 0.024” diameter between these bullets? Can anyone say that one bullet or cartridge is 5%, 10%, etc more lethal than the other, and prove it?

Personally, I think the 35 Whelen would make an excellent choice out to 400 yards if someone was looking for a 30-06 based round. You have a .358 inch 250 grain bullet that is going to create a big through hole. Absolutely, probably over kill for any of the 120 pound deer in this area. I have one bud who hunt the things with 223 Remington out to 300 yards, he is an excellent shot, places the bullet where he aims, and he claims “bang, flop” when properly hit. He also has used the 270 Win and 30-06, those cartridges have killed a lot of deer in his hands, but, kick too much and therefore he wants something lighter and with less recoil.

 

[RussellC]

I end of the day i think youve discovered that it really doesn't matter what 08/06bassed, or similar cartridge you chose for sub 400yd hunting. At the end of the day shoot which ever rounds you happen to like, for whatever reasons you like them.


I have shot a cartridge in every caliber from .22-.311 for deer. Ive seen that as you go up in bore dia you have a little more leeway for bad shots at each step. Ive also noticed that when loaded optimally the smaller bore dias will give a few more yards of mpbr.

Personally what i hunt with is mostly dictated by which rifle or cartridge im messing with right then.
If im unsure of the area, game, or something absolutely must die, ill go with a 7mm or 30 cal magnum, because i have a great deal of faith in those rounds. But that is, as they say, personal preference.

Im actually home on molokai this week, and have been hunting with my Springfield Xd .45 (we can call that 06 based right?), Since my rifle case wasnt up to par for the new airlines regs.

What are the new airline regs for rifles? I have flown with handguns many times, and have TSA approved cases for AR 15 rifles, but havent flown with them yet. What am I missing?

More on topic, Ive been wondering about the recoil difference between 308 and 6.5 Creedmore. A new bolt gun is in my future and have been wondering.

Russellc

 

[LoonWulf]

What are the new airline regs for rifles? I have flown with handguns many times, and have TSA approved cases for AR 15 rifles, but havent flown with them yet. What am I missing?

More on topic, Ive been wondering about the recoil difference between 308 and 6.5 Creedmore. A new bolt gun is in my future and have been wondering.

Russellc

This was just interisland, the regs are now such that a case has to be rigid enough to keep someone from reaching in if the latches are undone but locks are in place. Wasnt like that when i went to lanai in March, infact i had the the same case with me that trip.

I cant give you numbers of the top of my head but there is a noticeable difference with the cm and 123s and 143s vs the .308 with 150, 180s which are generally the med-heavy bullet weights used.

 

[RussellC]

Oh, I see just an inter island thing. While I wish I was headed there, my flights are only on the mainland. My lockable (both key locks in 2 of the latches, plus master locks on the through holes) hard cases should be fine for my mainland flights.

Thanks,

Russellc

 

[RussellC]

This was just interisland, the regs are now such that a case has to be rigid enough to keep someone from reaching in if the latches are undone but locks are in place. Wasnt like that when i went to lanai in March, infact i had the the same case with me that trip.

I cant give you numbers of the top of my head but there is a noticeable difference with the cm and 123s and 143s vs the .308 with 150, 180s which are generally the med-heavy bullet weights used.

Ididnt think .308 was that bad, but it was a friends gun and I dont remember the weight of the bullets.

I am inclined to creedmore, but for a first bolt gun, bullet choices for .30 cal cant be ignored!

Thanks,
Russellc

 

[LoonWulf]

Oh, I see just an inter island thing. While I wish I was headed there, my flights are only on the mainland. My lockable (both key locks in 2 of the latches, plus master locks on the through holes) hard cases should be fine for my mainland flights.

Thanks,

Russellc

That would be fine here too, my case honestly isnt very secure, but untill recently was perfectly legal to travel with. Im not sure how they would have gotten my rifle out even tho they could reach in, but wasnt gonna hassle them they were just doing their jobs.



The .308s not bad at all, in a very light gun or if fired alot it can be taxing, but recoil isnt "bad" by any measure. The CM tho is a real kitten with 123s (havent shot lighter), perhaps very slightly more than as an equal weight .243 and 100s.

 

[horsey300]

Ididnt think .308 was that bad, but it was a friends gun and I dont remember the weight of the bullets.

I am inclined to creedmore, but for a first bolt gun, bullet choices for .30 cal cant be ignored!

Thanks,
Russellc

If you don't wanna split hairs too much, recoil of a .308 weighing 7.5lbs with 150(2800fps)&165(2700fps) gr bullets should be 15.8 ft-lbs and 18.1 ft-lbs respectively and an 8 lb rifle firing 180gr bullets(2610fps) should be 17.5 ft-lbs.
The hair splitting comes in with the creed as ol chuck hasn't added that one to the list yet but he does have the Swede and .260 for comparison. With the .260 in a 7.5 lb rifle, the 120(2860)measured out at 13 ft-lbs (about the same as a hot deer load .243) and the 140(2750) in an 8.25lb rifle is hitting 11.5 ft-lbs.

I'm not looking to turn this into a peeing match between calibers but just to make sure we're clear, the "variety" of the .30 used to wow me, but I've since been converted. There are enough "Light" bullets from all the manufacturers to make a good varmint/plinking/small animal out of the 6.5 for ANYTHING that the .30 cal lightest loads would be used for. On the heavy end, you can load the 142ablr/143 eldx with a sectional density (.293 for the eldx) that makes it better suited to deep penetration than the .308 190(.286). Both calibers have support in the monometals and bonded and ballistic tip categories, making it a VERY even playing field. How much more variety could you ask for? if you're handloading, the .264 ranges from 85-160gr bullets in just weight. The .30 ranges from 100-240 but in the .308 cartridge, for practicality you're looking at 100-190. Soooooo if you're not handloading, you should be
ETA there is plenty of factory support for practical applications for both cartridges if you don't load, but it IS something worth doing.

 

[Art Eatman]

@jmr40: "You are right about the larger calibers, going to anything larger than about 28-30 caliber in a cartridge based on the 308 or 30-06 is actually a step down in performance, not a big one, but a step down ."

'Scuse my iggerance from never having used one, but a fair number of hunters here have spoken highly of the .338-'06 and the .35 Whelen. Hasn't seemed like a step down.

 

[Varminterror]

The .338 A Square and .35 Whelen hit like trucks. But there's a distinct reality, the .30-06 case doesn't have the displacement for such large bores. A guy can get as much out of a 200-220grn .30-06 as they can a .338-06. It doesn't mean the 338-06 or Whelen are a step down, just that they give up long range performance. They don't have enough powder capacity to launch full charges under the really aerodynamic heavy pills, and even their mid-weight bullets are still heavy. It's a lot like a 300blk - even a light 30cal bullet is too heavy for the blk case to really get good use of it down range. A .338-06 was one of my first wildcats, absolutely love the round - the blown out Improved version even moreso. For 0-500yrd game hunting, maybe 600, the 338-06 is a bigger hammer. For 600-800yrds, on whitetails I want a .30-06 over the 338 or 35, for anything bigger, I want a larger case.

A longer MPBR doesn't mean squat to me. None have a long enough MPBR to make one insufficient while another is sufficiently powerful. Alternatively, I'd rather deal with managing a bit more difficult trajectory at 600 and make contact with a 200grn bullet than I would a 115grn bullet, no matter what was happening in the race at 275yrds. The farther I am from an animal, the faster I want it to be laid down dead for recovery, so I want my bullets hitting hard upon arrival. the difference in a round with a 250yrd MPBR and one with a 280yrd MPBR is so insignificant, it's not worth touting. For one or two 25yrd increments, one has to start holding over while the other doesn't, and once we're beyond that, the race is even again. Again, if we're talking 308/30-06 progeny, give me that big bullet momentum if I'm gonna run into something at 600yrds. I've shot my .338-06 to 800 in the past. It's dicey out there, but it still moves the steel more than any 308 case cartridge I've thrown out there, and more than standard weights from the .30-06 case. But a 200-220 .30-06 will give it a run.

 

[LoonWulf]

The farther I am from an animal, the faster I want it to be laid down dead for recovery, so I want my bullets hitting hard upon arrival.

Lotta truth right there!

 

[adcoch1]

From my research the "step down" in performance in the plus 30 cal -06 case is mostly a range performance thing. At closer ranges, say 100-300 yards, the bigger diameter bullet makes a bigger hole still, while at longer ranges the 28-30 cal pills are still within there operational velocity for expansion. On deer it doesn't matter, but on bovine or big elk and moose it might help out having a heavier chunk of lead.

 

[Llama Bob]

Sectional density is MUCH more important than OP made it out to be. The only reason the copper bullets penetrate decently is that they have a very small expanded area. They're basically half way between a soft and a solid.

I'd much rather have a premium lead soft with substantial expansion, 100% weight retention, and the SD to get it through the animal. The net wound channel is much better than you get with copper. That approach generally favors smaller calibers, and the higher BC is just icing on the cake. Give me a 7mm mag or .264 mag before a .30-06 any day. The same or less recoil, more SD, more reach. If I had a .30-06 hunting rifle it'd just collect dust.

 

[C-grunt]

The 6.5 Creedmoor was specifically designed for target shooting. It might not be able to throw the heaviest hunting 6.5 bullets fast enough to match a heavy 30-06 for big game at distance, but that's not what it was designed for.

SOCOM is looking hard at the 6.5 Creedmoor for it's type of varmint hunting though.

 

[LoonWulf]

Again not trying to make an argument but just provide more info.
The CM can comfortably throw a 140 at 2750 (im breaking 2800), this compares well numbers wise to a .30 cal 180 at about the same speed, which is now a standard loading for the 06.

Downside is, as pointed out by guys earlier in the thread, lower mass, and smaller dia.

Like Lama Bob, I prefer cup n cores, but my preference runs towards the softer bullets. Again ive seen a difference in exit wound size as both bore, and bullet weight increase...this is considering a fairly constant velocity.
.270 with a 130 at 3100 will generally produce a smaller exit than an 150 from an 06. While dead is dead, bigger holes equal deader faster?

Again tho, the difference usually isnt enough to matter, except in unusual circumstances.

Also most of my experience is with 80-150lb axis deer, or similar sized game. The very large axis ive shot were in the 200-250lb range with one monster that had to be close to 300. These guys probably dont compare well to really big mainland deer and certainly not to elk.

I have experienced probably 20 feral cow kills with mostly .270s 06s and 7mm qnd .300 magnums. And honestly on those guys at shortish range there is very little difference between them.
I also watched my wife drop an 800lb cow with her .243 and 100grn sierras at 2850fps (pretty much same as winchester PPs launched from my gun), adequate penetration, with adequate expansion, and adequate shot placement, made a very big animal, very dead.
So I feel pretty confident in my original statement that any 06/08 bassed round is about as effective as the next in MOST circumstances, sub 400yds.

 

[Varminterror]

The 6.5 Creedmoor was specifically designed for target shooting.

There are lots of niches for which low aptitude rounds are designed, but the 6.5 creedmoor doesn't fit that description. At its core, the 6.5 wasn't designed "only for target shooting," it was designed to throw a high BC, high SD bullet at appropriate long range velocities, with moderate recoil, and with the consideration of mag & action length in short actions. While it might have been a solution to a question only a few shooters had asked, it effectively matched a number of highly versatile cartridges, including many historically popular cartridges. It falls in league with the .260rem, .243win, 7mm Mauser, 7-08rem, 6.5x55 swede, .25-06... All of which are incredibly versatile and venerable cartridges - and meets or beats many of the highly popular wildcat cartridges like the 6 Dasher, 6 & 6.5 SLR, 6 compmatch, 6XC... Why would the Creedmoor be any less versatile? If a guy steps away from a close minded, factory load only world, there are a lot of cartridges in class with the 6.5 Creedmoor which don't get the same criticism and flaming as the Creed.

Alternatively, consider a stubby cousin like the 6 BR or PPC which were "designed for targets," yielding much, much less down range killing power for game hunting. Or consider the niche application designed 300whisper, aka blackout - all of these listed cartridges are much less versatile than the creedmoor. But nobody gets out their pitchforks when a Dasher shooter comes to town.