Largest Bottleneck Case loaded ?

[Earlwb]

and of course a 4 bore rifle too

[Bad Ass Wallace]

58-95-620 or 577 Super Snider. In an 8lb rifle this one gets your attention!



620gn plain base minnie

[martinibelgian]

Quite a few of the Brit express cartridges would surpass by far the 45-125... Quite a few were BN too. relation powder/bullet weight was around 1/3 to 1/2 on those... But then they had african big game to deal with.

[BrentD]

Gert, what was a "normal" load of powder for a 577-450? Seems like it would hold 120+ grains easily. I can't recall what I used but it was something close to that I think. And in a light rifle too. Maybe 8 lbs.

[missionary5155]

Greetings
50-95 is the most 3F I have stuck into a necked cartridge. If I am remembering you can get about 90 grains under a 300 grainer and 86 grains under my preferred 350 grain 40-1 cast. That gets you to 1465 fps in a 26 inch repro rifle.
Mike in Peru

[Lead pot]

I loading my .44-90bn right now with 100 gr of 1.5. I don't think the 577-450 will hold that much.

[sharps4590]

577/450 and 11.15 X 60R. the load I ended up with for the 577/450 was 80 grs. drop tubed and there was room for quite a bit more if I remember remotely close. I wouldn't guess how much but I believe it would hold 100 grs. I was able to get something less than 4 inch groups out of it even with those rudimentary sights.

The 11.15 X 60R is in a German double rifle I have and I ended up having to duplex it with 5 grs. of SR-4759 and I believe 63 grs. of black, (I'd have to check my records), to get it to regulate. It shoots better than the 577/450 did at 100 yards, hovering slightly above or below 3 inches, composite group.

[BrentD]

Oh yeah it will, Kurt. I put 107.5 in my .45-2.6. The 577-450 will hold much more

[Earlwb]

In further reading about it, the .577-450 appears to have used a 85 grain military powder charge. But depending on the case used, you could get upwards of 115 grains or more of black powder into it. They used paper cases, brass or copper foil cases, and brass cases. Then there were the brass shotshell conversions as well. Today some are made by turning on a lathe and those may be more thick and have less powder capacity. So it tends to depend on what the cartridge case is as to max capacity.

[martinibelgian]

Brent,

Current brass will easily hold somewhere between 110-120grs of Swiss without any wads - and without any compression or droptubing, depending on make. Converted CBC 24-gauge will hold most.... I Use the LoC load, which is 85 grains - with air as a filler, and a thick grease cookie/wad column filling up the neck. And a 540 grain bullet.

[JTCoyoté]

Largest bottleneck, huh... for starters there was the 'scaling up' of the Westley Richards 500/450 #1... introduced by Alexander Henry in 1871, it was built on a drawn 2 3/4 inch 20ga. case... the neck down scaled perfectly to .577. It was packed with 6 1/2 to 7 drams of fg, pushed 620 to 650 grains of paper-patched lead, and was aptly dubbed the 20/.577 BPE... examples of which still exist.

There were other attempts during this time period to take on the big straight cased "Bore and Gage rifles" by necking their cases down a notch or two, lengthening out the smaller diameter boolit to close to the same weight as the Bore or Gage gun had, add about the same charge of black powder behind it, slide it in, close the breech, and see what you get on squeezin'...

A 577/450 MH scaled up on a 12ga. fits a 2 3/4" case at .577 boolit diameter perfectly as well. This scale up is rumored to have been toyed with at that time also... can't prove it's existence with examples or period texts though, only have this "I read about it somewhere a long time ago" recollection to go on... in any case the 577/450 CBC case will hold 125 grains of 1 1/2 Swiss under a 500 grain bullet with a .150 thick lube cookie and be just touchin'...

[ascast]

.577-450 or 375 H&H

[JTCoyoté]

If you would like to see a sweet example of an Alex Henry 20/577 double rifle built as a 12 bore in 1868, then re-barrelled to 20/577 in 1900 click here . In any case these big bottlenecks were loaded well into the 20th century. There weren't a lot of them though, but a few still survive. I did a little playing around with these large bottlenecks a few years back to show their actual size... "Have I seen it all". This thing will swallow a 375 H&H case...


Vintage 20/.577 cartridge and headstamp

[Huvius]

Did you ever get around to building that 12-577?

[Ballistics in Scotland]

The 577-450 with it's short wide diameter case and long neck looks like it should be a pretty efficient powder burning shell that would increase the velocity of the gases getting forced down like a rocket engine increasing bullet velocity.
My .44-90 Bn has a higher velocity with the same powder load of a straight wall case.
I never has a 577-450.

It looks that way, but it doesn't. As a rather sweeping generalization, increasing the amount of black powder, above a rather modest limit, doesn't much increase the velocity, but increases the weight of the bullet it will drive.

I'd agree that the .338 barrel and something like the .338 Lapua case will produce fouling problems that aren't worthwhile unless setting some kind of record is all you want. Especially since you have a barrel, as it is probably too fast a twist. The faster the twist, the more it encourages the fouling solids to lodge. I'd prefer the shallow rifling you can get away with when you use black powder and smokeless, and that isn't suitable for the use most modern .338 barrel blanks get put to.

[Ballistics in Scotland]

If you would like to see a sweet example of an Alex Henry 20/577 double rifle built as a 12 bore in 1868, then barrelled to 20/577 in 1900 click here . In any case these big bottlenecks were loaded well into the 20th century. There weren't a lot of them though, but a few still survive. I did a little playing around with these large bottlenecks a few years back to show their actual size... "Have I seen it all". This thing will swallow a 375 H&H case...

Sweet indeed, and that one has surely seen a lot of safe shooting in its 1900 form. If that is a refinish, I wouldn't judge it the way people do on cap and ball Colts, say. The first purchasers of guns like that sometimes brought them in for rebluing. Mr. Henry would have wanted it done.

But 1868 is a long time before they did all that really needed doing to the double-barrelled action - say 1895 or so. I would be very wary of doing such a conversion to an old gun today, as this particularly suitable example. The back-action lock leaves the action much stronger than front-action, and especially the bar-in-wood, with wood around the front of the lock, which was originally inherited from the muzzle-loaders. The rotary double grip underlever is also a source of strength - not in holding the barrels down, as the stress is in a longitudinal direction, but by leaving more metal in the action bar.

[heelerau]

577-450 martini henry

[heelerau]

Be like firing anvils downrange !!

[JTCoyoté]

Did you ever get around to building that 12-577?

Huvius,

All the design work's done, the barrel and reamers are built... I decided to test it in a Greener Martini first to wring the bugs out of this late 19th century wildcat on a known stable platform before plugging it into the '87/'01 Winchester clone.

The work stopped in 2009 as events beyond our control often turn things, and everything went into storage. Only in the last year or so has providence said "Okay, son... give 'er another shot." I will get back to it this winter...