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what 6mm

 
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  #15  
Old 03-24-2013, 05:27 PM
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Re: what 6mm

I would be looking at the 6SLR or the 6 Creedmore w the
105 or Dtac 115's
7.5x 26" barrel
That is with AW mags.
If a hunting rifle only, the 6 Crusader looks interesting.
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  #16  
Old 03-24-2013, 05:44 PM
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Re: what 6mm

if your seeking a great barrel life with very good accuracey the first round to look at it the 6BR. Super efficient with a well designed case. Also well known for shoot far better than it looks on paper. Alot of guys like the Dasher, but I'd go with the 6x47L before I'd even consider the Dasher. The Dasher ain't exactly the greatest case design even though it evolves out of the 6BR. Just takes the 6BR's strong points and creates another problem. The 6XC should be OK, but you can do better as it comes with it's own set of problems. The 6BG is probably better than the 6X47L, but it's not enough to worry about. The 6/250 (XC or whatever somebody lays claim to) can be built out of 22-250 brass and several others. It's problem is that even with standard .243 Winchester brass being used to form the case you end up with too short a neck length. The 6BG is pretty much nothing but a stretched 6BR, but keeps the better neck and shoulder design. The 30 degree shoulder seems to do better with the dreaded doughnut than the 40 degree shoulders do. If you form your cases from .243 brass the case will shrink less, but still be about .330" at the neck.

After you look at these rounds, you move upto the big boys. The first would be the .243 Winchester. Known to be hard on barrels, and dosn't handle 100+ grain bullets as well as we'd like due to the base of the bullet often ending up in the shoulder area. The T.P. point is out at the case lips edge and that means a horrible throat life. But had an enterprising person been smart, and simply reamed the chamber with a 6mm Ackley reamer to a .243AI headspace he'd have one hot momma! Of course the cases would have to be formed out of 6mm Remington brass instead of .243. Barrel life would probably be double. Still kinda inefficient when compaired to the little 6BR. But the .243Ackley is now moved into the slightly overbore condition. No problem if your into the 100 grain bullets, but not so hot with 80 grain bullets or lighter. The 6mm is the next step upwards, and will have a much greater barrel life than the standard .243, but as Ackley said the case is about it for a 6mm bullet without going into overbore. The 6mm Ackley is overbore, but if you use the 105 thru 107 grain bullets it tends to over come most of this. There is the 6mm Vias, and this is a hot number! Nothing much but a 6.5x55 necked down to 6mm and improved. The shoulders are set back about .05". It'll push a 70 grain bullet faster than a Swift can push a 50 grain bullet! Still works far better with the heavier bullets. After this you get into the way overbore stuff that do only slightly better than a 6mm Ackley and eat barrels up

the 6HLS will drive a 107 grain bullet to about 2800fps without too much trouble (maybe even 2875fps). Not all that much slower than the standard .243 even though the case volume is less. The 6BR will drive the same bullet to about 2800fps! The 6BG will do 2975fps on even less powder. The .243 will do about 3000 fps with a very hot max load. (I think the 6BG uses 77% of the powder). The 6mm remington will drive the same bullet to about 3100fps (some say 3150fps). The 6mm Ackley is good for about 100 to 150fps more velocity in a very stiff load.
gary

Last edited by Trickymissfit; 03-24-2013 at 05:50 PM. Reason: spelling
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  #17  
Old 03-24-2013, 06:58 PM
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Re: what 6mm

Gary, whats the 6BG... parent case, etc?
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  #18  
Old 03-24-2013, 07:37 PM
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Re: what 6mm

Quote:
Originally Posted by liltank View Post
Gary, whats the 6BG... parent case, etc?
cases are usually formed out of .243 brass. The shoulder length is about 1.45" (I don't have the blue prints in front of me right now). The shoulder angle is 30 degrees, and the neck length is .35". Pretty much uses a full .243 case to form the case. Round is head spaced off a standard .300 savage headspace gauge, and I think the over all length is right at 2.04". Even with case shrinkage figured in, your gonna have a .32" or greater neck length to help you. Kiff has the reamer prints and head space gauge. The idea of using the .243 brass is that there is less movement of the brass during fire forming. Kinda like a Dasher on seroids with a much better neck design
gary
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  #19  
Old 03-24-2013, 07:40 PM
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Re: what 6mm

Quote:
Originally Posted by trueblue View Post
I would be looking at the 6SLR or the 6 Creedmore w the
105 or Dtac 115's
7.5x 26" barrel
That is with AW mags.
If a hunting rifle only, the 6 Crusader looks interesting.
another nice thing about the 6BG is that it just dosn't need a 26" barrel. A 24" barrel will work nicely.
gary
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  #20  
Old 03-24-2013, 07:48 PM
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Re: what 6mm

Quote:
Originally Posted by Trickymissfit View Post
another nice thing about the 6BG is that it just dosn't need a 26" barrel. A 24" barrel will work nicely.
gary
See, that is what I'm trying to decide. I wanted to go 6BR. But then I got to thinking the Dasher would give me the same accuracy potential as the BR with a little more horsepower. I am thinking of using the 105 Berger Hunting or the 105 A-max. I am mainly going to use this for a high volume of fire rifle for varminting and try my hand at F-open. I want something that will get me to 1000 with good accuracy, but not burn the barrel out in the first season of usage. That is where I figured the Dasher and highly considering the straight 6-250 Rem. I figured neither are really that overbore and should sustain a barrel life of 5-7000rnds. Am I on the right track? What kind of barrel life would I expect from the BG? I am also considering the possibilities of using the 115's.
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Matthew 7:13-14
"Enter through the narrow gate. For wide is the gate and broad is the road that leads to destruction, and many enter through it. [14] But small is the gate and narrow the road that leads to life, and only a few find it.

If you find your self in a fair fight, your tactics suck!- Marine 1st Sergeant Jim Ryfinger

Friends don't let friends develop canonitis!-chucknbach

arguing over the internet is like the special Olympics....even if you win, you are still...special!
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  #21  
Old 03-24-2013, 10:25 PM
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Re: what 6mm

The fact is barrel life and caliber depends on what you plan to do. Hunting rifle doesn't really matter what you use.

Calibers are regional and bias. Fact is I am favorable to a 6Dasher since one of the best benchshooters in the country lives here and was the first to use one. Information and help is easy to get. I know the history of the caliber, characteristics, and all the National Titles this little caliber has won since 2003.

Brent
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