Fiftydriver
Official LRH Sponsor
Norhman,
About 10-12 grains of powder capacity is the difference.
Kirby Allen(50)
About 10-12 grains of powder capacity is the difference.
Kirby Allen(50)
-
If you are being asked to change your password, and unsure how to do it, follow these instructions. Click here
338 LM improved, 338/300 RUM, 338/416
- Thread starter lazylabs
- Start date
Help Support Long Range Hunting Forum
Fiftydriver
Official LRH Sponsor
The shoulder angle of 50 degrees will not make alot of difference in less case stretching compared to anything over 30-35 degrees in my experience.
Biggest issues concerning case stretching, alot of case body taper, high chamber pressures and excessive FL sizing.
You neck size or partial neck size only and leave that shoulder where it should be and a 30 degree shoulder will handle any case stretching under fire easily.
Kirby Allen(50)
Biggest issues concerning case stretching, alot of case body taper, high chamber pressures and excessive FL sizing.
You neck size or partial neck size only and leave that shoulder where it should be and a 30 degree shoulder will handle any case stretching under fire easily.
Kirby Allen(50)
I have some experience with the .338/300 Win Mag., plus the .338RUM. If there is a cartridge that comes close to that mythical perfection, it is the .338/300.
The big case ctgs have minimal flexibility compared to the .300 WinMag case. I reamed my own .338 sporter barrel and then worked up loads from extrapolation. I was shooting 65 gr of XMR 4350 in both 300Win and .338 Win with 200 & 250 gr Sierra bullets respectively, so taking that as my floor, the .338/300 with 250 gr bullet is like a kitten with 65 gr. I don't really know what the "max" load is in my rifle. I extrapolated data by comparing the .300 & .330 Dakota and .300 & .340 Wby ctgs. The Dakota cases have the same capcity, the Wby cases have the same dimensions. Basically, the .338/300 will duplicate the .340 Weatherby and be just under the RUM.
Benefits:
Cheaper & better brass is available for .300Win
Burns less powder = longer barrel life
Better magazine capacity
More efficient case, not greatly overbore
Using XMR4350 which likely is not the most effective powder, but I have a lot of it, I estimate I'm getting about 2700 fps with a 250 gr bullet.
With a Near Mfg base and a Leupold Mk4 M3 scope this is a longrange performer in a 12 pound rifle. I am using a basic Sendero barrel profile and H-S Precision stock. With a #3 contour sporter barrel mounted, the rifle is under 10 lbs.
One other nice thing about the .338/300 is the ability to use standard reloading dies with minimal alteration. A Redding .300WM Competition type S Neck Die die will work without alteration, aside from necessitating a reaming a Redding bushing or having one custom made. Similar work enables use of Redding's Comp bullet seater, or adjust a .338 Win seater to fit.
The Flexibility of the .338/300 is what makes it the Real Winner. Unless all you are concerned with is Pure Horsepower, (in which case as has been previously mentioned Go With The .338-378 or Lazzeroni if you want beltless), the .338/300 can work over a wider loading range. I have seen great response from 65-76 gr using 250gr bullets. The 160-300gr range of the .338 makes it Superb for almost any application except plinking; for that try cast bullets!
With power ranking right there with the 340 Weatherby, but greater flexibility, the .338-300 is an All-Around Proven Performer. Likely, barrel life is a lot better than the big-burners. Don't forget, you are burning barrel when you are burning Big Charges Of Powder.
If you are into lugging a 30lb rifle out to the canyon's edge and shooting off a tripod than, hopefully you are buying your barrels half a dozen at a time and enjoying those couple hundred rounds you get from each one after "dialing in your load". But, if you're like me, and enjoy hiking down the trail with a backpack and Need a fast handling relatively light rifle that can do it all; give a looksee to the .338/300 Win Mag.
The big case ctgs have minimal flexibility compared to the .300 WinMag case. I reamed my own .338 sporter barrel and then worked up loads from extrapolation. I was shooting 65 gr of XMR 4350 in both 300Win and .338 Win with 200 & 250 gr Sierra bullets respectively, so taking that as my floor, the .338/300 with 250 gr bullet is like a kitten with 65 gr. I don't really know what the "max" load is in my rifle. I extrapolated data by comparing the .300 & .330 Dakota and .300 & .340 Wby ctgs. The Dakota cases have the same capcity, the Wby cases have the same dimensions. Basically, the .338/300 will duplicate the .340 Weatherby and be just under the RUM.
Benefits:
Cheaper & better brass is available for .300Win
Burns less powder = longer barrel life
Better magazine capacity
More efficient case, not greatly overbore
Using XMR4350 which likely is not the most effective powder, but I have a lot of it, I estimate I'm getting about 2700 fps with a 250 gr bullet.
With a Near Mfg base and a Leupold Mk4 M3 scope this is a longrange performer in a 12 pound rifle. I am using a basic Sendero barrel profile and H-S Precision stock. With a #3 contour sporter barrel mounted, the rifle is under 10 lbs.
One other nice thing about the .338/300 is the ability to use standard reloading dies with minimal alteration. A Redding .300WM Competition type S Neck Die die will work without alteration, aside from necessitating a reaming a Redding bushing or having one custom made. Similar work enables use of Redding's Comp bullet seater, or adjust a .338 Win seater to fit.
The Flexibility of the .338/300 is what makes it the Real Winner. Unless all you are concerned with is Pure Horsepower, (in which case as has been previously mentioned Go With The .338-378 or Lazzeroni if you want beltless), the .338/300 can work over a wider loading range. I have seen great response from 65-76 gr using 250gr bullets. The 160-300gr range of the .338 makes it Superb for almost any application except plinking; for that try cast bullets!
With power ranking right there with the 340 Weatherby, but greater flexibility, the .338-300 is an All-Around Proven Performer. Likely, barrel life is a lot better than the big-burners. Don't forget, you are burning barrel when you are burning Big Charges Of Powder.
If you are into lugging a 30lb rifle out to the canyon's edge and shooting off a tripod than, hopefully you are buying your barrels half a dozen at a time and enjoying those couple hundred rounds you get from each one after "dialing in your load". But, if you're like me, and enjoy hiking down the trail with a backpack and Need a fast handling relatively light rifle that can do it all; give a looksee to the .338/300 Win Mag.
davewilson
Well-Known Member
Lester,thanks for the info but i think the 338/300 they're referring to is the 300 ultra mag necked up to 338 caliber.
[ QUOTE ]
My smith was talking about this round he made with a 338/300 and a 50° shoulder. It's going to be a single shot so I was considering it. Just wondering if anyone has heard of this and if there are any case separation issues. It gives less bolt thrust, brass lasts longer, no trimming, but more expensive dies. Is it worth it?
[/ QUOTE ]
Cruizin,
I agree with Fiftydriver you can go too far on shoulder angle without gaining anything and giving up a lot. I know people that have wildcats with 60degree shoulders, they are great until it comes time after 5 or 6 firings to set the shoulder back. they collapse like a pop can instead of pushing the shoulder back. IMHO dont go past 40 degree shoulder.
UB
My smith was talking about this round he made with a 338/300 and a 50° shoulder. It's going to be a single shot so I was considering it. Just wondering if anyone has heard of this and if there are any case separation issues. It gives less bolt thrust, brass lasts longer, no trimming, but more expensive dies. Is it worth it?
[/ QUOTE ]
Cruizin,
I agree with Fiftydriver you can go too far on shoulder angle without gaining anything and giving up a lot. I know people that have wildcats with 60degree shoulders, they are great until it comes time after 5 or 6 firings to set the shoulder back. they collapse like a pop can instead of pushing the shoulder back. IMHO dont go past 40 degree shoulder.
UB
C
Chawlston
Guest
[ QUOTE ]
[ QUOTE ]
My smith was talking about this round he made with a 338/300 and a 50° shoulder. It's going to be a single shot so I was considering it. Just wondering if anyone has heard of this and if there are any case separation issues. It gives less bolt thrust, brass lasts longer, no trimming, but more expensive dies. Is it worth it?
[/ QUOTE ]
Cruizin,
I agree with Fiftydriver you can go too far on shoulder angle without gaining anything and giving up a lot. I know people that have wildcats with 60degree shoulders, they are great until it comes time after 5 or 6 firings to set the shoulder back. they collapse like a pop can instead of pushing the shoulder back. IMHO dont go past 40 degree shoulder.
UB
[/ QUOTE ]
P. O. Ackley figured that out years ago during his experiments. Get a copy of his books they are a very good read.
James
[ QUOTE ]
My smith was talking about this round he made with a 338/300 and a 50° shoulder. It's going to be a single shot so I was considering it. Just wondering if anyone has heard of this and if there are any case separation issues. It gives less bolt thrust, brass lasts longer, no trimming, but more expensive dies. Is it worth it?
[/ QUOTE ]
Cruizin,
I agree with Fiftydriver you can go too far on shoulder angle without gaining anything and giving up a lot. I know people that have wildcats with 60degree shoulders, they are great until it comes time after 5 or 6 firings to set the shoulder back. they collapse like a pop can instead of pushing the shoulder back. IMHO dont go past 40 degree shoulder.
UB
[/ QUOTE ]
P. O. Ackley figured that out years ago during his experiments. Get a copy of his books they are a very good read.
James
Fiftydriver
Official LRH Sponsor
Depending on what degree of improving the wildcat design has you could see as little as 25 fps velocity gain or as high as 100 fps on this case. That said, the only way to get the upper end velocity gains is to reduce body taper to an absolute minimun which gives slightly more case capacity but at a cost of feeding and extracting with high pressure loads.
I would also like to agree with Uncle B. with these larger cases, after a few firings, the cases really lose their abilty to be sized easily and even a slight bump on the shoulder to get it back just enough for easy chambering can result in a colapsed shoulder.
A good neck and shoulder anneal can help this but with the smaller advantage in velocity you get I would really recommend the same and stay less then 40 degrees in shoulder angle.
Kirby Allen(50)
I would also like to agree with Uncle B. with these larger cases, after a few firings, the cases really lose their abilty to be sized easily and even a slight bump on the shoulder to get it back just enough for easy chambering can result in a colapsed shoulder.
A good neck and shoulder anneal can help this but with the smaller advantage in velocity you get I would really recommend the same and stay less then 40 degrees in shoulder angle.
Kirby Allen(50)
[ QUOTE ]
What about a 338 edge with an improved shoulder? Anybody do any of these?
[/ QUOTE ]
Hi i am in the process of building a 338 WBX it has a 60 degree shoulder.
I have spoken to JD Jones about ti and their are a few tircks to make it work well he has a lot of cartriges based on a 60 degree shoulder for his TC Encore hand cannons and does not have any problems.
Cheers Bill
Australia
What about a 338 edge with an improved shoulder? Anybody do any of these?
[/ QUOTE ]
Hi i am in the process of building a 338 WBX it has a 60 degree shoulder.
I have spoken to JD Jones about ti and their are a few tircks to make it work well he has a lot of cartriges based on a 60 degree shoulder for his TC Encore hand cannons and does not have any problems.
Cheers Bill
Australia
