Sedgley sporter handbook

[madsenshooter]

I noted this on ebay. It was interesting to note that Sedgley thought the Krag action strong enough for the 250-3000. Pretty impressive with an 87gr bullet at 2700fps. That'd be a fairly mild loading, even milder than the start loads shown for the cartridge on Hodgdon's website. Makes my wildcat rimmed 6mm Niemiller look a little more doable. I recall reading somewhere that Sedgley would only work on Krag receivers that would take a file. http://www.ebay.com/itm/1930-The-Sedgley-Handbook-No-38-Sedgley-Springfield-Sporters-Krag-Winchester-/322219886887?hash=item4b05cd4927:g:VJ0AAOSw-itXp3Ld Oops, I goofed the 2700fps was for the 25-35 out of a Springfield, but many of the starting 250-3000 starting loads are within the Krag's pressure limit.

[reincarnated]

I have seen a few Krags in .23-35, never seen one in 250-3000. Sounds scary.

[madsenshooter]

@45000CUP on the upper edge. Maybe some bolt lapping involved to get the guide lug bearing and he wouldn't use the overheated receivers. I have a cracked one around here somewhere, in the 13000+ serial # range. Nice paperweight that was once attached to a rifle that became a parts guns once I found the crack. After the Roosevelt match this weekend, I'm going to get a machinist working on the barrel I need for the 6mm Niemiller Rimmed.

[FredC]

For curiosities sake what is a 6mm Niemiller Rimmed? I did a search and PTG will make a reamer for it and this thread comes up in Yahoo already, those were the only references I found.

[reincarnated]

So Sedgley's "file cut" test is a practical one? If someone were so inclined.

[FredC]

I am not sure that a file test would indicate anything. Krag actions and bolts were case hardened from soft "machinery" steel, that was probably close to our modern 1018. The original steel probably had less manganese than 1018, so it core will have almost no hardening effect whatsoever. If a receiver was thoroughly burned in heat treat or missed it altogether, it may have no hardness at all and be easily cut with a file. I think the krag parts that were case hardened were tempered after this and would have reduced the skin hardness a little. Again too much heat during tempering would soften the skin.
I have some tools that I sent out to get case hardened from 12L14 that would sort of resemble the steel in the Krags. The case is very thin and can barely be scratched with a file but it is pretty soft (and tough) under the case.
My way of thinking is a krag that has lived 100+ years was probably correctly treated. Building something new on one of these actions I would headspace towards the minimum to reduce hammering and moving the soft core material.
Modern case hardening steels like 8620 have very strong and tough cores, think Allen screws. You can mock harden 8620 with no case at all and it is about the same strength and hardness of 4140HT.

[reincarnated]

Thanks, Fred. It was merely curiosity. For those who would mess about with wildcats, there are far better & safer choices than a Krag.

[madsenshooter]

The Neimiller is simply a .243 Winchester with the shoulder pushed back .1". In my case, I already have a properly chambered .243 barrel that I'll have a machinist take .1 off the breechface. I'll cut the neck of the chamber forward that same .1. All I need for a die is a .243 die with .1" taken off the bottom. I'm going with a rimmed case for function, found some 6.5x57 rimmed that will be the parent case. The rim is a bit smaller than a Krag rim @.520", but should still work. Biggest reason for decreasing the length to shoulder of the chamber is to keep someone from using .243 in it. I have had 6mm/30-40AI reamer and dies for years now, but with the already chambered.243 Win barrel I recently got, the Niemiller seems to be the way to go.

I guess Sedgley thought the file test told him something.