#311284 & Krag sizing question

[Tedly]

I have a sizing question concerning my 1898 Krag sporter. I'm shooting #311284 ACWW sized to .311"dia. and have always left the .308"dia sizer in place since jacketed sessions long ago. Since I'm sizing for .311" dia. #311284 should I size my cases with the .308"dia.sizer or swap it out for the .311" sizer from my 7.62x54R set ? Thanks

[GBertolet]

I imagine you are using a Lyman M expander die, or equivalent. That should take care of making the case necks the appropriate size. I have two Krags, and this works satisfactory. You can take this one step further, and get a Lee .303 collet neck sizer die. This works perfect for the Krag. The .303 is designed for .311 bullets. You can reduce the diameter of the mandrel slightly if you wish, to fine tune the finished internal neck diameter. With the collet sizer, you need no lube, and the cases last a long time, as you are only working the neck. I can reload these cases many times before full length sizing is necessiary.

[Mr Peabody]

When I use .311 bullets I use the 31r M die instead of the 30r M die.

[Char-Gar]

OK Krag rifle cast bullet shooting 101:

Krag rifles have a quite large and long throat. The cast bullet axiom is to use the largest bullet possible without shaving lead when chambering the round. A Krag rifle throat will take a .313 bullet and deliver fine accuracy. .313 has become my standard sizing diameter for my cast bullets in the Krag rifle, and I have four of them. .314 also delivers good accuracy, but in some Krag chambers bullets that size make the round hard to chamber and gives no room for the neck to expand when the round is fired. Cases can be neck turned to thin the neck brass a smidge and elevate this problem.

As to expanding the necks, you don't want to distort a oversize bullet horsing it into a case neck that is too small. RCBS sell a 30 caliber rifle neck expander with various spuds in .308, .309, .310 and .311. This give the reloader a choice of the correct expander to sit the bullet size by simply changing the spud. The expanding die comes with one spud and you must then buy the other sizes.

I would not seat a cast bullet in a rifle case neck that was more than .002 less than the bullet. So my rule of thumb a .308 expander would be too small. So, if you don't wish buy a new expander, then by all means use the expander from the Russian die.

Addendum: The earlier Krag rifle barrels have groove diameters that varied quite a bit. A 1895 vintage rifle of mine has a .312 groove, a 1901 vintage has a .3095 groove, and the other two are near the end of production life and have true .308 groove diameters. It took a while and Harry Pope for Springfield to get it right. Even though the barrel groove diameters tightened as production continued, the chamber throat/leade/ball seat did not.

Townsend Whelen wrote a piece "Days of the Krag" telling about his experience in the Army when the Krag first came on line. It is well worth a read for the Krag fan. He tells of some rifles with groove diameter up to .314. The Krag replaced the 45-70 Trapdoor rifle with it's black powder ammo. The Trapdoors did not have consistent barrel groove diameters and it counted to the explosive shot of the powder ignition to expand the lead bullet to fill the barrel groove. This worked just fine, but when the Krag transition came about with smokeless powder and jacketed bullets, the problems in inferior accuracy stated to take place.

Krags are wonderful rifles and are noted for their smooth actions. That aside, the 1903 Springfield was a far superior rifle in any way that counts.

[Der Gebirgsjager]

The standard answer, of course, is to slug your barrel and find out just exactly what you've got. They seem to range from .308 to .312, and rarely even larger, but anything between those two diameters is common. I can not say if it was loose tolerances in manufacturing, or if it's because the youngest Krag is 115 years old, and if they retain the original barrel they have been shot and shot and the bores are worn to varying degrees. Speaking only of cast bullets, not jacketed, I've always started right out with a .311 bullet and usually gotten pretty good accuracy. I wouldn't make that assumption with jacketed bullets.

[JMax]

I use a .311 sized an NOE 314 202 for both my Krag made in 1902 and my 03 made in 1934, both slug .308 to .309.

[HangFireW8]

Adding to what Char-Gar said, Phil Sharpe investigated the origin of what he called THE RULE of sizing at least .003" over (hmm what was old is new again). He figured it was because of Krags (common on the market at the time) and their variations in caliber. As we all know, oversize boolits usually work well and undersized usually don't. Since Krags varied up to about .003" over, that was a size that always seemed to work in those rifles. Sharpe didn't feel the need to over-generalize that finding into the rest of casting applications.

[Char-Gar]

The standard answer, of course, is to slug your barrel and find out just exactly what you've got. They seem to range from .308 to .312, and rarely even larger, but anything between those two diameters is common. I can not say if it was loose tolerances in manufacturing, or if it's because the youngest Krag is 115 years old, and if they retain the original barrel they have been shot and shot and the bores are worn to varying degrees. Speaking only of cast bullets, not jacketed, I've always started right out with a .311 bullet and usually gotten pretty good accuracy. I wouldn't make that assumption with jacketed bullets.

It was loose tolerances. Springfield got complaints about Krag rifles not being competitive in the Palma Match. The arsenal call in Harry Pope the barrel wizard to find out why. Harry about stroked out about the loose tolerances in barrel groove diameter. His purposed fix was to tighten the tolerances and make the barrels .308 for sure and for certain. This was done on later production rifles.

[Krag1902]

I have five Krags and size all bullets to a compromise .311. I get some incredible groups.

[avogunner]

When I use .311 bullets I use the 31r M die instead of the 30r M die.

I don't have a Krag but this is my practice for my 1903. My Lyman 30r plug measures .307 and the 31r plug is .309. I size my cast to .311 so to get .001-.002 neck tension the 31r is right for me.
Although I haven't used them yet, I've just picked up the Lee universal expander die and a couple of NOE's "M type" expander buttons to use with it. They have a more extensive selection of diameters than Lyman produces so finding one for a specific application shouldn't be too hard.
Semper Fi.

Sent from my LG-H820 using Tapatalk

[gnoahhh]

I follow the protocol of measuring and sizing to throat diameters and ignoring groove diameters. I use the .30 RCBS neck expander/mouth belling die, and choose the plug of .001" smaller than the cast bullet, ie: .309" plug for .310" bullets.