Barrel Length For 300 Win Mag

Hammack

Senior Member
With the amount of powder that a 300 mag case will hold you will still be gaining velocity well out past 26". True, a 24" will work, but so will a 20" or 22" You just end up with less velocity and more muzzle blast. In my opinion if you feel the need to shoot a magnum then why go with a shorter barrel that will not let you utilize what the cartridge has to offer. On my 264 win mag that I built a couple years back I went with a 28" barrel, yes it's long, but it wasn't built for woods hunting either. With magnum cases to get all it has to offer you need the longer tubes. If not just shoot a 30-06.
 

TN deer hunter

Senior Member
Most test show that you will only gain or lose 30-40fps per inch. IMO a 26" Bbl is a pain to carry and does not balance well but that is me. Nothing you shoot will notice 60-80fps! It's your rifle handle a couple with different bbl lengths and see how it feels!
 

Cknerr

Senior Member
Math says around 21-3/4" is the optimum length of a barrel in regards to harmonics, natural frquencies, etc. However, as some already pointed out, it is a bit short to burn all the powder. You can change to a faster powder though. Might even work. THe longer your barrel is, the more chances you have of there being a fault in it. I try to keep them as short as I can get by with.

On another note, when you do get a barrel put on your receiver (tel the gunsmith to leave it full length), there is another way to determine length. Clamp the receiver in a vise with the barrel hanging out into space. Place 3 or 4 very thin wire loops along the length. Keep wacking the base of the barrel until the loops stop moving. Where they stay put will show you where your nodes are. This is where the barrel will be moving the smallest amount and where the most accurate barrel lengths will be. You will have several.....just pick one and have the barrel cut off at that length.

Chris
 

ScottD

Senior Member
Chris

Is it not true that when you change the length of the barrel the nodes move?

So when you cut 3 inches off the barrel and re "ring" the barrel all the nodes are in a different place.

That's the idea of a tuner - put the crown where you want it and then move the nodes to that point by using a tuner.
 

Scott 40s&w

Senior Member
I had a 28" barrel put on a 308 sniper rifle. It increased velocity from the factory spec of 2700fps to 2880fps as measured thru the chrony. At 500 yards the elevation difference was 9 clicks in the scope. That is 11.25 inches difference. I agree the reason for the magnum round is to increase velocity so why would you cut down the barrel. just buy a 30-06 or a 308.
 

CowtownHunter

Senior Member
I have a Browning A-Bolt in 300 win mag which has a 26" barrel but I am looking to get a similar gun for my son. But the brand/model I'm considering only comes in 24". Since he already has a 24" .30-06, he really doesn't need another with similar characteristics.
I don't know may be I should consider going with 300 WSM instead. With the short/fat casing of a WSM round it probably doesn't require a longer barrel to maximize it's potential.
 

Cknerr

Senior Member
Scott,
It won't change the major harmonics by much - some but less then youmight imagine. In most modern barrels there's only 3 (on average). There are 2 more minors that are pretty potent and they can move a ring just to confuse things. Shortening the barrel will be most effected by how far/close you are to one of those major harmonic nodes. Give or take 3 or 4 inches can keep you near the same one. 'course, the closer to a midpoint you are the less hope there is of hitting the broad side of a barn from the inside.

What the tuner will change are minor frequancies that are harmonics of the major frequancies. If you made a tuner approximately the size and weight of 20-30% of your barrel, you could seriously move a major node. (large caliber silencers can!) Tuners are a lot smaller, so you are playing with the minor frequencies only. Depending on what is needed, you can augment or produce beat frequencies with the tuner. You can augment a minor to partially dampen a major if you are away from the node, or a beat frequency to dampen some of the stronger minor frequencies if you are close to a node- the major frequencies are already minimal. In a perfect world the muzzle of your barrel will repeatable make a very smooth off centered egg shaped path time after time. We don't live in that world, so there are a whole lot of extra little wiggles in that path. By eliminating the worse of the wiggles, we get a more consistent path that can be repeated.

Naturally all the good stuff you can do with one can also double or triple the horrible side too...:D

Chris
 

Hammack

Senior Member
Math says around 21-3/4" is the optimum length of a barrel in regards to harmonics, natural frquencies, etc. However, as some already pointed out, it is a bit short to burn all the powder. You can change to a faster powder though. Might even work. THe longer your barrel is, the more chances you have of there being a fault in it. I try to keep them as short as I can get by with.

Chris

Not sure I agree the longer the barrel is the more likely it is to have a flaw. I wouldn't think that a barrel that has a flaw in it will more than likely tend to be in the muzzle end of it. If the barrel has a flaw it is just as likely to be in the middle or chamber end as the muzzle.



Cowtown, The case capacity (amount of powder burned) has more to do needed barrel length than the size of the case. A WSM case still needs a long barrel to get the full potential of the case because it has a larger case volume than the 30-06. Also the amount gained or lost will be more normally with a larger case than with a smaller one.
 

Cknerr

Senior Member
Hammack,
The barrel flaw comment is a statistical thing. The more barrel, the more chances to have a problem.

I do disagree with you assessment of cartridge performance. (man, I am on a tear this morning)

Powder burn between different cartridge makes all the difference in the world. Short magnums with the abrupt shoulders burn very different then the long/straight(ish) tube styles. Short fat cartridges with steep shoulders are designed to keep the powder in the cartridge as it burns. The standard types with smaller shoulders throw some to most of the powder charge down the bore.

Ignition is at the base and the gases immediately try to push powder out of the cartridge (everyone knows that I think). When thrown down the bore, ignition is not consistent. Reliable, but there are small variations from shot to shot. The WSM's shoulders and fat cartridge contain the combustion inside. Shock waves off the shoulder do most of the work to keep the powder contained and tumbles it so the burn is very consistent from shot to shot. You will note there are few differences in muzzle velocity, energy,etc. between a regular 270 and the WSM version. When you look at how well they group, it takes on a whole different story!

So with the cartridge effects mentioned above , what hapens with the longer barrel. Ya, common sense is correct here. If it is a short magnum, just hot air push the bullet longer and very consistantly. Standard cartridges can use it to burn more powder in the bore. Now things get complicated. Using a standard cartridge, does your rifle "see" a constant pressure to accelerate the bullet, a swift kick at the beginning and constant moderate pressure raise, no kick with fast rising pressure, combination of the above? a fella could hurt himself thinking about this. Sharp pressure rises or kicks are usually not the best for consistance. Constant acceleration from constant pressure usually results in the most consistant (accurate) shooting.


Chris
 

miles58

Banned yankee
Rifles with heavy 26 inch barrels tend to be heavy buggers. Rifles with heavy 26 inch barrels tend to want to turn nose down on you when you carry them in a sling. Rifles with heavy 26 inch barrels tend to be most useful on a bench or other really solid rest.

A sporter weight 24 inch barrel will handle much better. A sporter weight 24 inch barrel can be very, very accurate.

A 22 inch barrel cannot compensate for what's lopped off and anyone who tries to tell you it can is looking out his belly button hole.

What you are going to do with a 300 WM is what you should base the length on. If you are just hunting deer in Georgia with it then you already have way more gun than you need anyway and you might as well make it a little shorter/lighter since accuracy is not much affected by length per se. If you are going to make some serious use of it out at 500 yards and beyond then that begins to be another story. A 24 inch barrel on a 300 WM will deliver right on 3500 FPS with a Barnes 130 TTSX. That's more than plenty to kill the biggest moose that ever walked this continent, and your chances of stopping one inside a moose are just about zero. Was I going to shoot targets at 1000 yards, I would look closely at the Remington Sendero SF II in 300 WM as a production rifle capable of doing what I wanted. If I needed more than that it would be a custom job all the way.
 

TN deer hunter

Senior Member
Rifles with heavy 26 inch barrels tend to be heavy buggers. Rifles with heavy 26 inch barrels tend to want to turn nose down on you when you carry them in a sling. Rifles with heavy 26 inch barrels tend to be most useful on a bench or other really solid rest.

A sporter weight 24 inch barrel will handle much better. A sporter weight 24 inch barrel can be very, very accurate.

A 22 inch barrel cannot compensate for what's lopped off and anyone who tries to tell you it can is looking out his belly button hole.

What you are going to do with a 300 WM is what you should base the length on. If you are just hunting deer in Georgia with it then you already have way more gun than you need anyway and you might as well make it a little shorter/lighter since accuracy is not much affected by length per se. If you are going to make some serious use of it out at 500 yards and beyond then that begins to be another story. A 24 inch barrel on a 300 WM will deliver right on 3500 FPS with a Barnes 130 TTSX. That's more than plenty to kill the biggest moose that ever walked this continent, and your chances of stopping one inside a moose are just about zero. Was I going to shoot targets at 1000 yards, I would look closely at the Remington Sendero SF II in 300 WM as a production rifle capable of doing what I wanted. If I needed more than that it would be a custom job all the way.

+1 :biggrin2:
 

Buckhead

Senior Member
While generally true, a longer barrel does not guaranty greater velocity. Some 22" barrels are faster than 24s, etc... A lot of it has to do with unique characteristics of a given barrel. (rifling, bore variances and powder/load tested) Bullberry is a custom barrel maker and on their website (bullberry.com), they publish barrel length velocity tests. They chrono a barrel blank as it is test fired and shortened, inch by inch. While they don't test a .300 mag, they do test the .204 Ruger. Theoretically, the .204 Ruger should be more sensitive to a short barrel than a .300 Win. Anyway, in Bullberry's .204 test, 23" yielded the fastest times. I have seen other barrel length studies in other calibers that had similar results.

As others have said, a shorter barrel will always be "stiffer" and theoretically more accurate. Bench rest rifles typically have 21 - 22" barrels. Harmonic studies have proven that this is an optimum length for accuracy. Not that I am a proponent of short barrels, just things to consider.

Personally, I place a higher emphasis on accuracy than anything. A high powered long range rifle isn't worth having if it won't shoot sub MOA. At long ranges, accuracy is more of a limiting factor than energy and trajectory.
 
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