vtmarmot
P Magoon, Livin' Free NH
Hello. We’ve been down this road before, but this time I have more information for you.
The rifle is a modern Steyr SBS Ferdinand Mannlicher commemorative in 6.5x54 MS. This is essentially the same rifle as they are producing now in .300 Weatherby and other stout calibers, so strength is not in doubt.
I have not been able to find any loading data for this caliber in a modern rifle so I would like to concoct some.
I have tried the Buffalo Arms 160 grain loads and find them anemic, producing around 1950 fps. I loaded up some 120 grain Nosler Solid Base in new Norma brass with F210 primers and 41.1 grains of old stock IMR 4350, giving an average of 2420 fps out of a 21 inch barrel. I feel I can do much better than that.
The chamber is rather generous. Once-fired loads show case expansion of .009 when measured .330 from the base (.205 from the groove). This may be in part because the Norma brass is undersized, measuring .441 at this point when new, whereas new Prvi Partisan brass measures .446 at the same point.
The leade is long. No bullet even comes close to the lands, but the shoulder of the Norma brass did not move forward even .001 upon being fired once. The case length actually shrunk from 2.105 when new to 2.099 when fired, probably due to the take-up in the body.
The closest modern case to this is the 6.5 Creedmoor, with 5 percent more capacity than the 6.5x54 MS. I’m thinking that the Creedmoor loads, reduced by 5 percent, should work OK, working up carefully, of course. Does that sound reasonable?
I have an RDBS 3-die set with neck sizer. However, I’m thinking that I should have Whidden or Redding custom make a S-type bushing die for it. I just want to bump the shoulder .001 or .002 and not work the body too much. I use S-type dies a lot in other calibers.
I’m thinking that despite the body expansion, I’m not in danger of case head separation because the shoulder is not moving forward at all. I’m thinking that the long leade is depressing pressures quite a bit.
I’m hoping to get 2800 fps out of 120’s, 2700 fps out of 130’s and 2600 fps out of 140’s. Am I out of line in my thinking?
The rifle is a modern Steyr SBS Ferdinand Mannlicher commemorative in 6.5x54 MS. This is essentially the same rifle as they are producing now in .300 Weatherby and other stout calibers, so strength is not in doubt.
I have not been able to find any loading data for this caliber in a modern rifle so I would like to concoct some.
I have tried the Buffalo Arms 160 grain loads and find them anemic, producing around 1950 fps. I loaded up some 120 grain Nosler Solid Base in new Norma brass with F210 primers and 41.1 grains of old stock IMR 4350, giving an average of 2420 fps out of a 21 inch barrel. I feel I can do much better than that.
The chamber is rather generous. Once-fired loads show case expansion of .009 when measured .330 from the base (.205 from the groove). This may be in part because the Norma brass is undersized, measuring .441 at this point when new, whereas new Prvi Partisan brass measures .446 at the same point.
The leade is long. No bullet even comes close to the lands, but the shoulder of the Norma brass did not move forward even .001 upon being fired once. The case length actually shrunk from 2.105 when new to 2.099 when fired, probably due to the take-up in the body.
The closest modern case to this is the 6.5 Creedmoor, with 5 percent more capacity than the 6.5x54 MS. I’m thinking that the Creedmoor loads, reduced by 5 percent, should work OK, working up carefully, of course. Does that sound reasonable?
I have an RDBS 3-die set with neck sizer. However, I’m thinking that I should have Whidden or Redding custom make a S-type bushing die for it. I just want to bump the shoulder .001 or .002 and not work the body too much. I use S-type dies a lot in other calibers.
I’m thinking that despite the body expansion, I’m not in danger of case head separation because the shoulder is not moving forward at all. I’m thinking that the long leade is depressing pressures quite a bit.
I’m hoping to get 2800 fps out of 120’s, 2700 fps out of 130’s and 2600 fps out of 140’s. Am I out of line in my thinking?