338 Shortened

[Murphy]

Justin and I had our own thread going back in the mix and decided to start a new thread in case someone else might be interested.

Origiinal post from Adventures

Why is it that when I told the board in Jan. that I was going to make my .338 into a .338 ultra and cut the barrel down to 22" everyone jeered and snickered, but someone does that with a 375 (which basically has the same ballistics) and whoo hoo it's a great guide gun. I didn't end up cutting down the barrel due to everyone telling me not to including the gun smith the taxidermist and the grocery store clerk and then i took it to whitter last week and while I took a nice bear with it that dang thing got caught up on every dang branch I came across. I'd ahve to agree with the poster that said it's about the shooter not the rifle. I also hunt with a bow and it seems that if you thought your piece was inferior you just have to get closer.
Justin
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[Murphy]

Short and Sassy

Justin,

I guess I'm one of those who snickered and jeered but for different resaons than some. Your point is well taken, what's so great about a short barreled 375 H&H and so bad about a 338. Well for the record I would use a 19"-20" barreled 338 Win Mag or a 375 H&H with a 20" or a 458 Win Mag with 20 inch but nothing shorter. Now for a 338 Ultra Mag, I want no part of a 20" barreled rifle in this caliber. Way to much powder and no space to burn it. The powder will exit the barrel and make nothing but fire and smoke and recoil. Short and handy must be part of the compromise with rifle performance and a shooters ability to shoot it.

From the other view point. when in the woods, there will always be limbs to catch a 16" barrel on. It is certainly handier and quicker to handle in thick cover when the barrel is short and the weight light and if that's the most important thing then nothing else matters. It is, in my view point, always a mistake to shorten a barrel to make a rifle more handy and then rechamber to something that holds a lot more powder in an attempt regain that lost performance. You would be better served to go to a 16" barrel on a 376 Steyr than even a 20" on a 338 Ultra. Even the 458 Lott will be more efficient in a 16 barrel than a 338 Ultra with a 20". Sure a lot of boom and flash but the amount of energy dished out is way up there compared to the short Ultra.

I also find it odd that people can't carry an eight pound rifle anymore. We have to have 6000 ft. lbs. of energy in a four pound rifle with a 16" barrel and a 12 power scope with an extremely noisy muzzle brake because we can't handle the recoil and can't learn to shoot it because it hurts too much. At least half this forum is filled with folks asking what is the "best" rifle caliber for Alaska. The answer almost invariably will come to one of the hefty mid bores, and I don't disagree with that, but then we go on to say it's got to be light weight and stainless and synthetic and short, there comes a new problem. After the well researched purchase comes the inevitable question. "Ahh...where can I get a good recoil pad and muzzle brake"? Of course this is preceded by I can't get this thing to shoot. Which means; "This thing is kickin' my butt and I can't hit a barn from the inside." To this I will say, stick to the 30-06 Springfield, and get closer.

I ran into a young fellow in a local gun shop the other day, about 22 years old and weighed about 160 pounds,(if covered with mud) and was asking the clerk to order an ultra light something or other in a 338 Ultra Mag. I asked him why so much gun in such a small package? His reply was, "It'll reach way out and be easy to carry." Ever shot one? "Well, no but my buddy had a friend whose uncle saw one once" or something to that effect. What have you shot? "An AR-15" I guess a well experienced chap like that knows what is best for him!

I don't get it! I grew up in a time and a place when all that mattered was just hit the target. Marksmanship was the most important thing. I learned to shoot at a young age. I learned to shoot very well before I was twenty. I later became a gun nut. I like guns. I like the machinery, the technology, the physics, the ballistics, the accuracy, the noise and the impact of a bullet when working the pits. I was the best shooter the Navy had when I was 25 years old. I'm proud of that. I have taught many people to shoot. I'm proud of that, too. I know a lot about guns and shooting. Been there and done that, with bells and whistles and medals and trophys to show for it. Nobody cares. But I'm still proud of what I've done and what I know. I only voice my own opinion from my own experiences. I have not experienced everything but I ain't dead yet. My opinion is of no more worth than that of another, but often carries with it the depth of my experiences and accomplishments. I learn from the folks who post on this forum almost daily. I like that, too. We get out of this what we can, that's the way life is. This is a; "Get all you can, can all you get." kinda world. If we learn to sort the wheat from the chaff, life gets easier. Thanks for tunin' in and good shootin'.

Murphy

[Murphy]

Phases

Original post by Elmerkeithclone.

The shooting world is vast. There is such a wide spectrum that just when I think I got it all figured out someone enlightens me with something I didn't already know or something *****s my interest in yet another area related to firearms.

Most of us have gone through different spectrums of what the shooting industry has to offer at different points in our lives. I have spent time messing with blackpowders. I went through a phase where I built several of the long range beanfield rifles even though of the hundred plus deer that I have killed only one was over 200 yds. I went through a S&W 686 phase where I had my mind made up that I was gonna be as good with a revolver as anyone out there. I actually shot the rifling completely out of one of them. I got real good too. However its kinda like being the toughest guy around your only the toughest until you run into someone tougher and it will happen. I spent a couple winters sporterizing military mausers and some of the later ones were really nice when completed. I could go on and on about but by now you get the drift. However the one area that I have never dabbled with until recently is the medium to big bores. Never had a need for them in this part of the world. Then big brother lines up a brown bear hunt with Kenny Shoonhour (sp?) out of Hoonah Alaska. As a result he drags home a 416 Rigby. He gave me a real wry smile and asked me if I wanted to shoot it. So I got all snuggled into the big Ruger on the bench just like I had with various varmint guns for years. I happen to glance up at my brother and the ***** eatin grin on his face told it all. I squeezed the trigger and sent a 400 grain Nosler down range at 2500fps. At that point I had no clue and could have cared less whether that slug hit the mark or not. I got a scope gash, bent glasses and my hat knocked off all at the same time. The bullet did hit exactly where it was intended to. I cleaned my self up and shot it three more times. That experience along with input from you guys on this forum have combined to fuel my new interest in the big boomers.

[Murphy]

fair enough

Original post by Adventures

I guess I'm just going through the same phase right now this is the first time in my life that i've had the money to spend on changing something just to change it and make it different than any other gun. I've shot a fair share of 300 ultras and thought why not go to a .338 ultra instead. Eiether way I was going to have to pay for the rechambering no matter what I did.

Murphy,
This is where i get a little confused.

"Now for a 338 Ultra Mag, I want no part of a 20" barreled rifle in this caliber. Way to much powder and no space to burn it. The powder will exit the barrel and make nothing but fire and smoke and recoil. Short and handy must be part of the compromise with rifle performance and a shooters ability to shoot it."
When I look at the nosler reloading manual it says the .338 Ultra uses 79 gr of IMR4350 for a 250 gr bullet and pushes it 2876 fps that's 80 % load density the .375 has 2 tenths of an inch longer case to the neck than the .338 RUM
Now the .375 H&H uses IMR4350 78.5 gr of powder 260 gr bullet pushes it 2,707 fps with a 94% load density. So, if I'm reading this correctly the .338 RUM is pushing a slightly lighter bullet 169fps faster than the .375 H&H with less load density. Maximum overall cartridge length is the same. It seems pretty apples to apples to me what am I missing?
I'm not trying to mess you with you or anything and your credentials speak for themselves, you are obviously the authority of this subject. I'm just trying to learn a few things here.
Thanks,
Justin
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[Murphy]

Internal Ballistics

Justin,

You've picked a load for those two calibers that are very similar from any perspective, however one is typical the other is less so.

I'll try to keep this short.....but you know me.

Powder burning inside the gun barrel makes lots of hot gass which builds up pressure and pushes the bullet down the barrel. You probablly new that. What actually happens is the powder at the bottom, next to the primer, ignites and pushes the "top" powder which pushes the bullet. As pressure builds up and as time goes by this powder column is consumed by the fire and adds to the fire and the pressure and is further consumed. This takes time. About 3ms (.003 seconds) to consume 60 grains of H4350 powder, in a chamber/bore/barrel of some standard. (That is 24" of 30-06 barrel.)

It will take less time if the bore diameter is larger, and more time if the bore diameter is smaller, because the "space" in which the powder gasses are allowed to expand controls the speed at which the powder is "consumed". This is not the burning rate, this is the rate of consumption. Now, obviously, powders with a faster burning rate will be consumed faster than slower powders.

There are many other factors which affect this consumption. The bigest one is called rate of confinement. Rate of confinement is increased by heavier bullets, decreased by lighter bullets. Increased by smaller bore size, decreased by larger bore size (this with the weight held constant). Also when the bore is larger the gasses have more room to expand and therefore rate of consumption is higher. (The moving powder column is a short fat column in a larger bore)

This powder volume (quantity) in relationship to bore size is called expansion ratio. It is the cubic capacity of the powder volume compared to the cubic capacity of the powder volume + the bore volume. An example of a low expansion ratio would be the 264 Winchester (not much bore volume for such a large powder volume) and the 458 Winchester would be a good example of high expansion ratio. These two calibers are the exact same case. Now this bore volume is reffered to as the swept bore volume because as the bullet goes down the bore it sweeps past and expases more "space" on which the powder can burn and create expanding gasses.

Now back to "time". For larger quantities of powder of a given burning rate, in a given bore size, this time directly relates to barrel length, nothing else. With X powder and Y bore we need Z barrel length to consume the powder. If barrel is less than Z, some of the powder will be expelled at the muzzle and (some will be burning) therefore, only be used to add recoil to the rifle and more muzzle blast. (Note: The recoil equation includes the weight of the powder charge because it is part of what is propelled down the bore, the other part is the bullet.)

With a 250 grain bullet in a 338 bore and 78 grains of 4350 powder and a 250 grain bullet and 78 grains of 4350 powder in a 375 bore, the 375 will consume all the powder in a shorter barrel than the 338 will need. Now to be fair here, we need to include for "space" the volume of the powder 'canister' the case capacity, and the 338 Ultra is larger. What we must calculate is the expansion ratio. Actually to compare one with another we would calculate the volume of the powder + bore volume of each, and the smaller if ten percent smaller will take ten percent more barrel length.

I use the grains of water in Ken Howells book for the case volume. Change the grains to grams, the grams to CC's, the CC's to cubic inches then calculate the volume of the bore radius squared X Pi, X barrel length (minus the chamber length, just the swept bore length) and add those two together. I'm sure you're following this. Trust me, the 338 needs more barrel.

Also, this high pressure gas is measured in pounds per square inch (PSI). When the bore is larger, more square inches of bullet butt exposed to the expanding gas, the rate of energy transfer to the bullet is much higher than with the same powder charge for a smaller bore. This is more efficient.
Efficiency is decressed as the quantity of powder is increased, with a given bore size. A 358 Winchester is much more efficient than a 358 STA. (8mm Rem. necked up to .358") This loss of efficiency is because the powder column is expelled out the barrel just to make more recoil, and not burned inside the bore to push the bullet faster. Oh sure, the STA is faster but with 100 % more powder (twice as much) it gives us 25% more velocity. Which of those two would you want in an 18" barrel? This is fun, thanks for the space. Good shootin'.

Murphy

[Murphy]

Way off topic... but good stuff

Original post by AKWannabe

EKC,
I really liked your Phases post. I'm kinda liking the big guns right now too. The most powerful I've shot so far is the .416 Rem. Model 70 I sold not too long ago (couldn't pass up the opportunity to cash in!), followed by my current Mod. 70 .375H&H. My first big (medium) bore was a Mod 70 .338 with the BOSS. Sold that too to get the .375.

Anyway, I guess that I've been reading way too much Capstick, Ruark and Boddington lately. The elephant guns just kind of intrigued me. Certainly they aren't needed for most hunting, but what the heck, they're fun!

That would've made a good thread all on it's own.

Murphy,
WOW!

Keep it coming, if I print all these out, after a couple of years I'll have your book even if you don't get published!

Yikes! This tread has almost as many posts as my cartridge poll! Quick, someone write something over there...please. ;-)

Dave

[Murphy]

Holy smokes

Original post by Adventures

I asked for it Some of that is a little deep, but I think I get the main idea. The bore diamater has alot to do with powder burn and how much is used vs. how much is wasted.
seems like if you were to use all (most)of you powder within the rifle that this would make for more of a kick not the other way around but I'll take your word for it. You're the man!
Thanks Murphy,
__________________
Justin

[Murphy]

Kickin'...

Justin,

Your assumption is right. A rifle does kick less, sometimes, when short.

But we should have our own thread...

We weren't talking about recoil specifically but there are two types of recoil, even though, they are still the same.(!%#@^!) Newton recoil (His third law): For every action there is an equal and opposite reaction. For the energy given to the bullet, going one way, the equal energy is given to the rifle going the other. Of course the rifle weighs more so it is accelerated less, that's another Newton Law I guess. (Mass at rest, Mass in motion)

Lear effect: (My term) Then when the bullet exits the barrel, the hot gasses exit behind it and give a jet thrust effect to further send the rifle rearward.
This effect is greater with higher capacity cases (greater gas volume) and for slower burning powders (higher exit pressure).
(In case you're taking notes this second (Lear effect) action is my own theory, well tested and proven by me, I just call it the Lear effect for Bill Lears thrusty little biz jet)

Now the first half of this is the calculation that includes the powder charge weight as part of the projectile weight, is actually sometimes less in a short barrel because the powder isn't burned. (Probably would be less in a short barreled 338 Ultra, when compared to a long barreled 338 Ultra) And also the Lear effect may be less due to lower gas volume but exit gas pressure would certainly be higher. That's a big factor and adds to the thrust and blast. (noise)

Of course, the Lear effect is defined by Newtons third law, also, but the equation for recoil calculation have nothing in them to quantify this thrust, and it is well described by shooters. This calculated recoil is based on the energy contained in the moving bullet, there is some energy in the exiting gasses. And it is this energy that gives us the Lear effect. Certainly exit pressures vary from load to load and cartridge to cartridge. And, of course the muzzle brakes would not reduce the felt recoil if there wasn't any energy in the gasses left at exit. See how easy that was.

Simpification:
Burning smokeless propellant and pushing a bullet down the barrel of a rifle is a predictable event. At ignition, the pressure starts to build and the projectile starts to move, pressure continues to increase as bullet is accelerated. At some point along the path the pressure reaches it's peak (maximum) pressure, yet the bullet continues to accelerate. (there is still a lot of pressure). After peak pressure, there is a decay in pressure, (decreasing). The pressure will continue to decrease, but still impart energy to the bullet (accelerate) until the bullet exits the barrel. At exit, in a "normal" length barrel, there is still some gas pressure exerting force on the bullet. "Some" = More than zero and less than peak (maximum) pressure. (With the 30-06 and 24 " barrel and 56 grains of 4895 powder and a 150 grain bullet, this exit pressure is approximately 14,500 psi.)

We plot this rise and fall of pressure on a two axis curve, Vertical represents pressure quantity and Horizontal represents time. It will look like a mountain. If life were perfect, we could lay the barrel of the rifle along the base of this mountain and it would be the same length. If we cut this barrel shorter, the bullet will run out of barrel before we ran out of gas pressure. As you cut the barrel shorter you can see how the exit pressure is progressively higher and higher.

We can say that powder is still burning as long as we have a mountain. This mountain peak is typically 60,000 psi high and the time line is a few milli seconds long. With each given cartridge (powder charge, bullet weight, bore diameter) we will have a slightly different mountain (different peak and different length base), but all very similar. A 300 Ultra has a bigger mountain than a 300 Savage. The size of this mountain, the area under the curve, represents velocity. Pure and simple, the area under the curve represents velocity. (Did I say that twice?)

If we shorten the barrel we cut a big chunk off our mountain, an abrupt drop to approximately zero pressure, so we loose velocity. Faster burning powders have a smaller base to the mountain and can use shorter barrels, but can reach the same lofty peak. Area under the curve will be less, (less velocity) but that's the trade off.

This all came from my well used head at way to early in the morning after only one cup of coffee (well, actually tea I don't drink coffee) I think I'll talk to David about a ballistics forum......Hmmm!

Good shootin'.

Murphy

[Murphy]

why is that...

Original post by Adventures

most suff I read makes me feel like I just got dumber for having read it, but somehow most of the stuff you post makes me feel super intelligent afterwards? LOL You even have your own theory with a catchy name and everything.
Makes sense to me so if I'm reading this right if i go to a faster burning powder I may be able to reach my peak velocity (where i'm running out of barrel now even with a 26") but the recoil will increase (shorter span between the base of the mountain means a shorter burst of energy with roughly the same force so you get it all at one time)
I'll buy that, hell I allready did!
Thanks as usuall,
Justin
P.S. Maybe we could just paste these last 4 or so in a seperate thread so people that weren't interested in the Savage 375 can benifit from everything you've written to me about.

[Jeff L]

Murphy...

GREAT THREAD! To ALL the hunters out there that want a short-barreled, ultra-light, overbore magnum the real truth has been told! I have told many guys who just have to have that 7mm Mag barrel at 22" or that .264 WM at 24". Just buy a .270! Trying to explain to some that the cartridge itself is not the end all of ballistic performance gets you the "weird" look. When I have tried to explain bore capacity their eyes glaze over. Murphy, all Saami spec cartridges have their optimum bore capacities/barrel length. Taking the bullet sectional density of lets say .250, could you list the optimum barrel lengths for popular AK calibers starting at maybe .270, and going up to .416? Just a thought that might help guys out there trying to decide on cartridge/barrel-length choices. Also,you might touch on the pressure curve/bullet exit, and why that short, over-bore magnum can de-stabilize a bullet at the muzzle. Thoroughly enjoyed this thread! Thanks, Jeff L

[BrownBear]

I own or have owned shortened rifles in a variety of calibers. For my own comfort and entertainment, I started messing with faster powders to try to get the most from the short barrels while cutting down on flash and blast. Works great, even if the slow burners still give a few more fps in many cartridges. If you're a handloader, I'd sure do some messing with IMR 3031, 4064 and 4320 and others in that burning rate. While the really fast ones like 4198 have trouble competing for velocity, they are even more comfortable to shoot. I also work up other loads with the velocity toned down to 2000-2200 (much like the 30-30) for goofing around loads which can also be used for game. After all, the whole point of owning these wonderful contraptions is to enjoy them.

[Kabluewy]

Big Bore, Short Barrels

This is an interesting thread. Most of this stuff I somehow already intuitively knew, but I would certainly have trouble saying it as well as Murphy and the rest of you guys. All this talk about over-bore, expansion ratios, short barrels, big bores, etc. makes me think about some of my experiences and current projects. I also went through the phase of wanting rifles capable of long range potential, but I never made the mistake of cutting one of these barrels off too short. Now that I have rifles capable of 300 yard shots - plus - if I can shoot that well, the opportunity just doesn't present itself often - if at all. I don't even remember the last time. Over time, I have more and more become willing to trade velocity for bullet diameter, and sectional density.

About 15 years ago I got a 458 WM on a commercial Mauser action, Parker Hale I think. I took it in settlement of a debt, which I may have not collected otherwise, as the guy was moving to Florida - no place for the 458. It had a 24" barrel, and I think it weighed over 12 pounds. It actually had lead inserts in the forearm and butt stock. I removed the lead, bedded everything properly, had the barrel cut to 20", good recoil pad, sights, three position safety, and some other improvements. It carried easily. I could not resist shooting factory loads, and thought my shoulder had been almost dislocated.

Hand loads enabled me to work up to some pretty stiff loads - over time. I got a moose with it using the bear claw 400 gr bullets at about 2100 fps. Very effective. Yet, I always thought it was too much gun, so I sold it when the offer was right.

It has been one of those rifles which I have missed. It was fun to develop loads for, and I also experimented with different powders to get a clean burn. I've tried that with other calibers since. I even took it out at night, and shot loads with different powders, looking at the muzzle flash, just to see if they all seemed the same or if some had less flash. I was able to see significant differences, which at the time I figured that the powder with less flash was probably burning mostly in the barrel.

For years, I have avoided the really big bores, being satisfied with the 338, 9.3, and 375, but lately I've been thinking of having a rifle made in 416 or 458 something. I want a carbine, easy to carry and handle. I consider a big bore rifle to use for shots under 150 yards, mostly under 100 yards. So long range ballistics is irrelevant to me in this rifle. I'm interested in short range thump. Accuracy is always important.

The only rifle I'm interested in is a bolt action. I just don't feel comfortable with a lever action, otherwise the Marlin 45-70, with Buffalo Bore ammo, would probably be at the top of the list. Since I expect to use it near salt water most of the time in SE Alaska (Hoonah), stainless/synthetic is my only choice as well. I do not like muzzle breaks, and refuse to have a rifle with one of those contraptions on it. Of course, I value a good recoil pad a lot.

A good double rifle would be excellent, but unfortunately not in the budget.

That narrows the choices somewhat. I'm thinking of three - 416 Taylor, 458 WM, or the 450 Marlin. The action of choice is a Ruger 77 MKII SS or perhaps a Montana Action, if I can get one. I am leaning toward the 450 Marlin because it will duplicate or exceed the performance of the 45-70, and I’ll never take it to Africa anyway.

Any thoughts or feedback? Thanks.

[BrownBear]

Sounds like our minds work a lot a like, so agreeing with you like I do doesn't prove much. I'm a lefty and as a result have an assortment of Ruger #1's in my rack. The 458 is a bit light for a steady diet of full factory loads, but it's so short and handy that it's great to carry.

It's a sincere hoot to shoot with 400 grain bullets and especially with big, heavy, slow lead bullets. Mine is an unbelievable tack driver with the long lead ones at about 1200, and when you stretch the range way out there it's really fun to wait a while for that big slow bullet to hit. If you don't have your heart set on a bolt, the #1 is a quick and easy way to come up with a handy rifle with a large hole down the middle.

[Kabluewy]

Big Bore, Short Barrels, Single Shot

Brown Bear,
The #1 is interesting, but I opted for the Encore about two years ago. I had a factory Encore barrel in 45-70 but didn't like it. I think this was mostly because it was the 18.5" with the muzzle break. The blast was horrific with Buffalo Bore ammo. I don't remember the recoil at all - just blast. I never did try normal loads, and it took almost two years to sell the barrel. I shot only four or five rounds out of the box of Buffalo Bore, and gave the rest away. Only one of those rounds was fired without hearing protection. One was enough to let me know this barrel was not for me. I always use hearing protection at the range, and informal shoorting, but most of the time I don't when I'm actually hunting. The rifle was short and handy, but I can't afford to shoot something like that because it will definately cause hearing damage if hearing protection is not worn for every shot - no exceptions.

I kept the Encore frame and had three barrels made - all custom 24" - 7x65R, 7.62x53R, and 9.3x74R. I believe a single shot should be a rimmed cartridge. The Europeans got it right a long time ago in that catagory. I really haven't had time to test them, but so far I think maybe the 9.3x74 is enough in that light of a rifle. It has pretty good thump anyway. In 45-70, only the heavy loads exceed the muzzle energy of the 9.3x74.

My point is that I wanted the 45-70 is because I thought it would be short and handy, and it was, but I still consider the single shot as enough handicap to make me nervous in big brown bear country. I just want the extra assurance of a magazine, especially if I'm carrying a so-called dangerous game rifle.

I also enjoyed shooting reduced loads in the 458WM I had, and plan to do it again in the new rifle, but I consider this a bonus, and not my main reason for having such a rifle. I want to carry such a rifle with complete confidence, knowing it will feed perfectly. The reduced loads will come in handy for allowing me to shoot it often for practice. I don't mess around with reduced loads in any of my other rifles, but I know that the 458WM or the 450 Marlin will be easy to work with in this regard. I don't know for sure, but I suspect the 416 Taylor would work equally well with reduced loads.

Regards.

[Ronnie]

big bore shorties

One of the nicest rifles I have shot has been a 45-70 with a 20 inch barrel on a mauser action and as you have said you can load up or down and in that bolt action velocities approach 458 mag with hot loads.I think your M77 Ruger in 450 Marlin caliber is a even better idea better brass and I really like the bulldog strong Ruger action please let me know how yours turns out if you decide to go that way..Good shooting Ronnie