Help choosing 1,000 yard cartridge

[benzh]

I would appreciate your assistance in helping me fill in the holes in my thinking.

Goal: Picking a 100 to 1,000 yard cartridge for general purpose/tactical target rifle(paper,steel), Savage action (preferably short action), 20-22" match barrel, est. gun weight before scope, 8-10 lbs.
Constraints:Barrel life > 2,000 rounds, "easy to load", match brass must be available, would prefer it not to have heavy recoil, must have at least the ballastics (particularly wind bucking) of .308 win using 175gr SMK

My Short List
See attached table. For simplicity, I chose the highest velocity reloading data from Hodgdon website. I used highest BC Sierra MK's for each caliber. This was input into a ballistic program, assuming 10 mph 90 degree wind.

It seems clear that the .243 & 6.5x284 clearly outperform the .308 in terms of drop and wind due to speed and the higher BC's of the 6 & 6.5mm bullets. I understand the 6.5x284 is a "barrel burner" and I think the .243 is hard as well, but maybe not as much. So, my thoughts were, why not "download" the .243 from 2975fps to 2660fps (or maybe use a cartridge like the 6mmXC). This velocity allows the .243 load to still slightly outperform the .308 and I would assume it will be much easier on the barrel life.

I don't get to shoot at 1,000 that often; but when I do, I can use the hotter load. Otherwise I will use the lighter load since most of my shooting is at 600 yds .

Thank you very much for your feedback,
Howard Benz
Memphis

 

[Gewehr98]

Ok, first off...

I understand the 6.5x284 is a "barrel burner"

Who told you that, and how many rounds did they send downrange before their barrel throats were eroded enough to cause accuracy problems?

The 6.5x284 is nothing more than a necked-down .284 Winchester, which uses a 7mm diameter bullet. That 1/2mm difference does not a barrel burner make.

Same goes for my pet 1000 yard cartridge, the 6.5-06. Some folks have labeled it as a barrel burner, too. I find that humorous, considering that the .25-06 has been around for a long time, and folks aren't necessarily screwing new barrels into their .25-06 rifles at the drop of a hat. The term overbore often surfaces with respect to rounds that can burn out a barrel sooner than average. I've seldom heard the .25-06 referred to as overbore.

Let's make it simple with respect to what is, and what isn't, a barrel burner. Barrel life is best described as a direct relation to the number of pounds of powder sent through the bore over the barrel's life. A .22 rimfire barrel will most likely outlive the owner. A .22 Hornet will last many decades, too. A .223 Remington can measure barrel life in the tens of thousands of rounds. A .220 Swift may give up it's decent groups in as few as 2000 rounds. I know for a fact that a .22-.378 Weatherby wildcat will let go between 50 and 90 rounds. What's the difference between all the above? The powder volume consumed per each round. It would take a whole lot of .22 Long Rifle rounds to equal the amount of propellant that roached the .22-378 Weatherby barrel. BTW, the .22-378 can definitely be labeled as overbore.

The .284 Winchester case is very close in capacity to the .30-06. It does this by being 0.500" in body diameter, so it's shorter and fatter than the .30-06, allowing it to fit into a short action rifle. For all practical purposes, it could be described as a short and fat .280 Remington (aka 7mm-06) clone.

I wouldn't sweat the barrel life problem of the 6.5x284. Keep the barrel cool between rounds, no long strings of rapid fire, and use the slower number powders like H4831SC.

Now, about that Sierra 140 and 142gr 6.5mm MatchKing. You know there are better (higher BC) bullets out there, right? (Try Lapua Scenar, Berger VLD, Nosler Ballistic Tips, Hornady A-Max, etc)

The 6.5x284 has matured as a very capable 1000-yard target/tactical round. It does this feat with the added benefit of reduced recoil, compared to it's .30 and .338 caliber cousins.

 

[ocabj]

6mmBR Norma is gaining a lot of popularity. Check it out: http://www.6mmbr.com

Works in a short action, Lapua brass is available. Read the FAQ on 6mmbr.com.

 

["yote"]

Don't screw around; get a .338 Lapua Magnum with a good muzzle brake.

If you are into wildcats, try the 6.5 WSM. (6.5/270WSM). Been hearing some
really good reports on it.

 

[Fumbler]

Umm...would you tell a Marine Sniper he was screwing around by using his .308 for those 1000+ yard shots?

I hope you're joking.

 

[Lonestar.45]

"Umm...would you tell a Marine Sniper he was screwing around by using his .308 for those 1000+ yard shots?"

No, I wouldn't, but his CO might tell him to quit screwing around and get out the .50 BMG.

 

[Stinkyshoe]

What would you guys say about a 20" barreled 308 for 1000 yards? How much difference between that and one with a 24"?

 

[Fumbler]

I think 20" is too short.

I don't know how much velocity you would lose, but my T3 in .308 with its 22.5" barrel gets about 75-100 fps less velocity compared to a 24" barrel.

 

[Wildalaska]

Plug 6.5x55 with a 140 MK or a 139 scenar at 2550 fps and see what ya get

Hint...aint gonna burn your barrel either


WildandnorecoilwhatsoeverAlaska

 

[artherd]

Umm...would you tell a Marine Sniper he was screwing around by using his .308 for those 1000+ yard shots?

OVER 1k with a .308? Yeah, I would tell the guy he was screwing around. .308 just barely gets to 1000 supersonic with 180-190gr SMKs, and dosen't have a lot of energy left.

.338 Lapua (or certinly the .50BMG) is a much better choice for 1000 "plus" yard shots (as in, 1000 yards OR MORE), especially if you expect to do anything more than annoy paper.

 

[artherd]

What would you guys say about a 20" barreled 308 for 1000 yards? How much difference between that and one with a 24"?

Hrm, that'll likely be pushing it past the limits. I don't think even the 190s will quite get there supersonic.

And as a bullet goes subsonic, the transition generally throws any kind of precision accuracy to heck.

 

[redneck2]

I have three friends that have certificates from VHA for confirmed 1,000+ yard kills on prairie dogs. Two used custom 6.5-06's, the other used a .308 Steyr with military ball ammo

My 1,000 yard gun is a 7mm Rem Sendero, 8x32 Burris with .020 bases. I'll use either 168 SMK's or 162 A-Max

There's a 1,000 yard forum at Benchrest Central that may help.

 

[montyh]

i kinda like the .264 Win Mag for long distance work. sure it has a short case neck and has a reputation as a barrel burner, but if you find one that likes the 140 SMK the barrel life with the these heavier bullets isn't that bad. 2,000 rounds is possible WITH heavy bullets. if ya plug in this cartridge to the equation you'll be surprised.

monty

 

[Black Snowman]

For a long range gun I'm looking at the 243 WSSM. Not much selection for brass yet but it has all the properties people seem to want in a long range and high accuracy cartrige. With the 105 and up bullets at max loads it's still supersonic at 1200 yards.

It's very similar in appearance to the 6mm BR and with the heavy bullets has not been reported to be hard on barrels from those who have shot in quantity. Now the 55 gr going 4000 FPS, they can hurt a barrel in pretty short order if I'm to understand correctly. You can always down load it to standard 243 velocities and it would then be plenty gentle to the barrel.

 

[Sven]

Of the options you listed, I'd go with the 6.5x284. Been hankering to get a Cooper chambered in this caliber... someday.

 

[Jonathan]

Goal: Picking a 100 to 1,000 yard cartridge for general purpose/tactical target rifle(paper,steel), Savage action (preferably short action), 20-22" match barrel, est. gun weight before scope, 8-10 lbs.
Constraints:Barrel life > 2,000 rounds, "easy to load", match brass must be available, would prefer it not to have heavy recoil, must have at least the ballastics (particularly wind bucking) of .308 win using 175gr SMK

If you avoid rapid fire such as you might see in F-class, you might be able to make the 6.5x284 work past 2,000 rounds. Downloading might also help you to achieve this. But in either case, can you really be effective with a 20-22" barrel? I really don't think this is your best choice.

The .308 will certainly be an improvement for barrel life, and you should see less waste than the 6.5x284 going to the shorter barrel. However, this will be at the bottom of the pack for ballistics (mostly).

I really think the way to go would be with the 6mmBR. Efficiency should be great, even in a shorter barrel, and barrel life isn't a concern. Match brass is available and recoil is low. The only drawback is that you end up with little momentum on target, and this shouldn't be a problem unless you're looking to drop steel targets, instead of just hitting them.

 

[benzh]

Regarding "barrel burner" and overbore.

Who told you that, and how many rounds did they send downrange before their barrel throats were eroded enough to cause accuracy problems?

I wouldn't exactly say he "told" me that, but from reading David Tubb's writings and from other folks it was clear that the 6.5x284 round can be hard on barrels. In Tubb's book, "The Rifle Shooter", about his wildcat 6mm-.284, "it shot well for long range, and may well be on of the ultimate varmint rounds, but its barrel life was atrocious - no more tha 1,000 rounds at peak accuracy. The larger 6.5mm bullet increases the area for gases to expand in and, therefore, reduces the intensity of flame cutting in the throat area. Barrel life is not an asst with the 6.5mm-284".

Regarding the .243 Tubb wrote, "in my opinion, .243 Win is at least some-what overbore. It has a lot of excess propellant burning in a small diameter bore. That, of course, results in excessive throat erosion."

Granted Tubb is not the end all, but he probably knows a thing or two about this stuff.

In other words, 100 pounds of propellant ain't going to burn out a barrel with a diameter of 500mm. But, narrow the diameter and at some point too much "fire" is trying to get down a small hole and you will more quickly burn it out (it at least it'll not be accurate enough).

 

[Quintin Likely]

6mm and 6.5mm seem to be magic numbers for wind cheating cartridges. 6BR Norma, 6.5/284, 6XC, 6.5-06, .260 Remington, etc. I think in Tubb's case, his experience comes from pushing his equipment to the absolute max, which depending on what you're intending on doing, might not matter to you.

I've got a hankering to turn my Savage into a .260 someday for prone or 3x600 matches. Lots of good info on long-range.com too.

 

[Jim Watson]

I am not an experienced Long Range shooter, but I have shot a very little and I know an enthusiastic LR man.

He has a 6mm Remington that is likely a bigger case than absolutely necessary to get a 107 grain bullet to 1000 yards supersonic, but it sure is accurate. One of the many short 6mms would be about right if you don't mind fooling with a wildcat.

I don't understand your interest in a snubnose, though. A long barrel is free muzzle velocity which means you use less powder and are easier on your bore. A 28"-30" barrel like a Palma rifle would make sense to me unless you were trying to control barrel harmonics like a 100-200 yard benchrest shooter. I would not consider anything shorter than 24" for a target rifle.

 

[Sir Aardvark]

Here's something in .308 with a 20" barrel, and it's fully accurized:

http://www.remingtonle.com/rifles/700pltrtws.htm

Although, I believe that something with a 26" barrel would be more appropriate for a long range rifle; you just lose too much velocity with a short barrel (look at the .300 mag):

http://www.remingtonle.com/rifles/700p.htm

For myself, I would get a stainless Remington 700 action in .338 Win Mag and go from there - stock, barrel, trigger, etc.

 

[benzh]

Barrel Length Vs. Velocity Loss

I've tried to find more info regarding barrel length vs. velocity loss. I think a lot of folks, including me, "think" (ie, hold onto a belief without any facts to support it) a longer barrel is "necessary" to shoot long distance.

Understand, in the original question, I stated the desire for a general purpose/tactical rifle with a 20-22" barrel because I intend to shoot from "any" position. So maybe standing at 100 yards or kneeling. I know that my 24" heavy barrel in my Choate varmint stock is damn near impossible for me to hold (for any length of time) standing. And if I had been exerting any energy before hand, the damn scope would be moving all over the place! So, the desire for a lighter, more balanced and easier to maneuver weapon is very important.

With all of that said...I found this article: http://www.tacticaloperations.com/swatdec2000/index.html

Bottom line. They took a .308 and .300 Winmag, started with barrel lengths of 26" and cut them down an inch at a time while measuring the muzzle velocity. The loss in velocity for the .308 going from 26" to 18" was 32fps.! They found complete propellant burn occurred at 20"

The loss for the .300winmag was none going from 26" to 22". Velocity loss began to occur at 22" and they stopped at that point.

Each gun shoots 1/4 moa at 100, per the article.

HB

 

[Jonathan]

Howard:

It's worth noting in the article that the load they used for testing was the relatively tame 168 FGMM. I think you'll find that competitive loads for 1000 yards will require more barrel for efficiency, with the exception I mentioned earlier.

 

[benzh]

Jonathan: re

It's worth noting in the article that the load they used for testing was the relatively tame 168 FGMM. I think you'll find that competitive loads for 1000 yards will require more barrel for efficiency, with the exception I mentioned earlier.

Good Point.

In the article they also wrote: For heavier bullets or hotter loads with slower burning powders, Rescigno recommends a 24- to 26-inch barrel. The longer barrel length is necessary for complete powder combustion with these loads. Rescigno adds that he has a 24-inch barrel on his personal .300 Win. Mag. just in case he wants "to shoot the heavier 220-grain bullets with a lot of powder."

I guess my question would be this. If I do choose the .243/6mmbr/6mmXC pushing a 107 gr (or similar) bullet at 2900-3000fps will I really be giving up much with a 22" barrel?

 

[Stinkyshoe]

Benzh
Are you saying that a 20" 308 is going to have enough barrel for out to 800 yards? That is what I interpret from what you said. Your opinions are appreciated much.
Could a 700 short action be rebarreled for 300 WSM? Would this be any advantage for "getting out there" or is this cartridge not proven for accuracy yet?
Thanks
Ss

 

[theCZ]

The part about the 20" barrel doesn't make sense to me, you are looking for a precision 1000yd cartridge right? Then you shouldn't do things like cutting the barrell down when you do not need to. Just my .02.