Wallhanger ..... :(

[Bob S]

You're right, Bob, 4895 is known for being very stable in reduced charges, so this should not have happened. Throat in my rifle is not rough.

BTW, I was nowhere near it when I fired these two rounds ... fired with a lanyard.

Searching for a receiver or barreled receiver ...

Resp'y,
Bob S.

[madsenshooter]

Should have known you'd have enough sense not to endanger yourself. In digging around on the web I've found a few other folks having similar problems with the things. First shot ok, next shot, blown primer. Though they look like an interesting rifle which should make a good vintage match rifle, I don't think I'll ever get one with shooting it in mind.

[Kragrifle]

Bob,
Check your private messages

[Bob S]

Mike,

Thanks. You have a PM.

Resp'y,
Bob S.

[Rick the Librarian]

Should have known you'd have enough sense not to endanger yourself. In digging around on the web I've found a few other folks having similar problems with the things. First shot ok, next shot, blown primer. Though they look like an interesting rifle which should make a good vintage match rifle, I don't think I'll ever get one with shooting it in mind.

As I recall, one of the managers of Sarco (?) was killed shooting one a few years ago.

[Dracster]

As I recall, one of the managers of Sarco (?) was killed shooting one a few years ago.

He was fire-forming brass.

[Bob S]

He was fire-forming brass.

I've heard about a dozen conflicting stories about that incident, but that's the first time I've heard that one. Interesting, because no fire forming is needed.

Resp'y,
Bob S.

[madsenshooter]

Let me see if I can find it, the story told by someone who was there. Even it has it's flaws, anyone make a 150gr 6mm bullet? http://www.msgunowners.com/t22036-a-...illed-a-friend. Elsewhere I also found mention of one of the rifles that was repaired via welding, after splitting like yours Bob. Why even try that, I don't know. I'm wondering if the makers perhaps had problems with barrel steel similar to that experienced by the armory when making Krag rifles. Steel that was not up to smokeless pressures.

[Bob S]

Bob,

I don't think that the steel quality was an issue in my failure. The fired case indicates a VERY high pressure excursion. The geometry of the locking surfaces are such that increased backthrust on the bolt forces the front of the bolt down into the receiver ... this is so it can't unlock under duress. As is was forced down HARD in my case, the round bolt head acts as a wedge, and the receiver material gave a little and then cracked. If it had been too brittle, it would have shattered. If it had been too ductile, there would have been some permanent deformation, which there wasn't. In fact, the headspace didn't change by any measureable amount. The cracks do not propagate through the metal (by visual inspection only), but if I had fired another round, even one of the "good" ones, there would probably ben a catastrophic failure.

I did some further investigation, and the throat is long enough so that I could not seat the 100 grain spitzer out to engage the "lands" (if that's what you can call them in Metford rifling). The throat is rough; indeed the whole bore is. And that 1-7" twist is absolutely insane. When I slugged it with a cast bullet, pushing the bullet from breech to muzzle, the bullet just stripped through the rifling. When I pushed a lead slug into the muzzle, and then pushed it out, the groove diameter at the muzzle proved to be .244. I didn't measure the throat. When I pull the barrel off the receiver, I'll be able to inspect the throat withou peering through 8" of receiver.

I'm convinced that the problem here was a rough bore, too fast twist, a bullet with a very long bearing surface, and maybe a powder with a too-fast burn rate. The bullet meets the lands, and comes to a screeching halt, or close to it, and the pressure rises quickly. I think I mentioned that an original bullet was measured and was substantially tapered, and the jacket material was mild steel. If the old Norma steel jacketed Match ammuntion is any indication, those original steel jackets were probably softer than the gilding metal we use for jackets today. So for original barrels, light bullets with short bearing surfaces and thin jackets, and maybe a slower powder would seem to be called for.

I have thought about getting a new barrel made for some time now; a modern button rifled 6mm barrel with a 1:9 twist. Of course I would have to have reamers made, and my little pipsqueak lathe won't handle a 28" barrel, so I'd have to farm it out. I have found at least one guy, in Wyoming, that says he can still chamber in 6mm Swift, which would be close to identical to the 6mm Navy but with the short neck of the 220 Swift. For those not old enough to remember the heyday of the 4000 fps 220 Swift, 6mm Swift was a wildcat to "salvage" all those burnt out Model 70 220 Swift barrels by reboring to 6mm.

Too many project ideas, not enough money ... and not enough time left :-(

Resp'y,
Bob S.

[madsenshooter]

Wouldn't you know it, one of those loooong 6mm molds I told you about came up for auction recently. The Lyman experimental 6mm mold from the 1950s that flopped because it wouldn't stabilize in the slower twist of a modern 6mm. Oh well, if 5R rifling is anything like the Lee's Metford rifling, cast would have been a challenge anyway.

[madsenshooter]

If you can find which modern powder has a burn rate close to Lafflin &Rand's WA 30, a fellow from the international ammunition association pulled down an original 6mm Lee that had a cracked neck. It contained 32gr of powder identified as WA30. Since WA 30 didn't work very good in the later 30-03 and 06 with their heavy bullets, I'd guess it is somewhat faster than 4895. 42gr was the charge initially used in 30/40 ammo (1898 ammo?). Of course that charge varied, dependent on the characteristics of the particular lot, so for this particular lot, burn rate would have been close to today's IMR 4350. I would think that in most lots, the charge of WA30 used was smaller.

Anyway, my guess is that the same phenomena we've seen with the 6.5 Swedes is what got you. Long, rough, throat and bore, small charge. Things could have been worse, some of the Swedish mausers that went through it are minus the top of the receiver ring and other pieces. Considering the price that the Lee's bring, I guess it would be worth fixing, if possible.

Time left, I'm beginning to wonder about that myself after recently finding out that many, many people my age were given contaminated polio vaccines circa 1955-1963. At least 25% of those standing in line next to me to get that shot in 62 are gone, and that's just the one's I know about.

[madsenshooter]

Bob, I found that the burn rate of WA30 was between RL7 and RL12. That's a pretty big spread. RL12 is getting near 4895's burn rate, but still faster. Hercule's Lightning was WA30 with a different cut. With 4895 being slower, you'd likely have been better off, and safe, with another five grains of powder. Hindsight, we hates it!

[Bob S]

Bob,

Where did you get this? Are you looking in Sharpe's book? That was long before the ReLoder series.

I'd be better off with a modern barrel. I'm workin' on it .....

Resp'y,
Bob S.

[madsenshooter]

Off castboolits Bob, a fellow who just happened to be reading Lafflin and Rand stuff last night answered my question. I had sorta figured the WA30 was faster than 4895 due to its performance in the 03 and 06.

Here's where he got his info: http://www.castpics.net/subsite2/Gen...-Smokeless.pdf