I'm having a Commercial Swinburn's Patent Martini restored and as part of the restoration process, it is being converted back to centerfire (it had been converted to .22 rimfire). I'd wanted to have it barreled and chambered for .303 (the British .303), but my gunsmith thinks the firing pin setup is not sufficiently strong for a cartridge of that pressure level. He's suggested I stick with a black powder cartridge from the era in which the original rifle was manufactured.

The two cartridges I'm considering are the .450 No. 2 Musket (which appears to be the cartridge for which the rifle was originally built) and the .450-400 BPE. Although I had fantasies of using it as a short range elk rifle, in reality the largest animal it will ever hunt is deer or black bear in the woods of Pennsylvania.

In terms of availability of components and the use for which the rifle will likely be put, would you favor one cartridge over the other? If so, why?

Can you point me toward a source for reloading components for either cartridge that actually has them in stock?

Thanks.

A great sounding project for a Swinburn! My choice between the two rounds you mention would be the 450/400 2-3/8" versus the 500/450 Musket No.2 even though .45 caliber bullets are more available. For one thing, brass is available for the 450/400 in the guise of the 10,3x60R metric equivalent as made by RWS and sold through Huntington's. It's also easy to form from 450 3-1/4" which is usually available - Buffalo Arms has some in stock. Original 450/400 2-3/8" barrels are usually around .416" in groove diameter but you can choose whatever diameter that suits your fancy and best matches the bullets you want to use. The rifle I had in that round was very accurate with 80-85 grs of Swiss and a 240 gr paper-patched bullet.

The principal advantage of the 500/450 is the availability of LOTS of bullet choices from the 250 Barnes TSX up to as much weight as your shoulder can stand. Cases are easy to form from either 500 Nitro or 50 Sharps. Pay attention to rim thickness as the rifle is set up and the differences between brass available. Original No.2 Musket rounds had a rim thickness intermediate between the usual British thin and typical American thick, like the other Westley Richards developed 500/450s.

Choose your brass first, or perhaps the dies first if you have any available, before settling on either round.

Dies are going to be the hardest thing to find these days.

Another possibility if you are willing to go with a non-British round, would be the 45-75 Winchester. Dies are available as is brass from Bertram. It is a Swinburn though, so I can understand the strong desire for a British cartridge.

I’d choose the #2 Musket.
As mentioned, brass is easily made from Starline 50Sharps and quite inexpensive.
The selection of .458 projectiles is endless and it does have the power to take that elk if the opportunity again presents itself.
Once you’ve got a supply of formed brass, loading is a snap even without the correct dies.
One more option would be the 500/450 No.1 Express.
I have a rifle being built up in that chambering and have bought reamers which are with the smith.
I own an original Swinburn chambered in the No.1 Express.

Yes! The No.1 Express is a great idea too, especially now that there's a known reamer in the world. It's essentially a 2-3/4" version of the No.2 Musket and a lovely cartridge if you are willing to go with that large a case capacity. The one I have holds about 105 grains of Swiss with Bertram brass. Also agree that once you have formed brass you don't need expensive dies to load for any of these. I've found that a Lee collet crimp die for 45 Colt has a carbide insert that's perfect for neck sizing many .45 rifle cases.

quote:

I've found that a Lee collet crimp die for 45 Colt has a carbide insert that's perfect for neck sizing many .45 rifle cases.

I’ve used a 30’06 FLS die to give a gentle squeeze to the mouth in the same way.

I can help with forming cases for either 450.
No.1 brass can be made from 500NE or 470 and headspace off of the shoulder.

The Starline 50Sharps brass makes beautiful No.2 cases though.

450#2 gets my vote. Brass is easy with the excellent Starline 50-90 as a base, plus you don't have to mess around headspacing on the shoulder. Bullets are a dime/dozen, jacketed or cast, and you can shoot black or smokeless depending on your mood of the day. Most any powder or mild loads that work in a 45-70 work here also. Sounds like a great project. A proper sporting stock and express sights and you'll be set to go.
Best

Huvius:

Please tell me more about forming the cases from 50 Sharps brass. If I decide to go the No. 2 Musket route, I'll want the rim cut to fit the Sharps rim thickness. Other than necking down the case, what else has to be done to make it fit?

50 Calshtr:

I've already got a sporting stock. This rifle was a sporter, not a military rifle. Pistol grip and nicely engraved receiver. I'm going with a peep sight (they turned up on original British stalking rifles) and a 28 inch barrel.

You guys are very persuasive.

Out of curiosity, are dies readily available for the No. 2 Musket?

Thanks.

Rem

Sporter or target rifle?

I ask because the hammer does not have a half cock notch.

A trigger block safety to be added possibly?

Steve

40X
Regarding forming cases, sometimes Starline brass can be a bit hard so I annealed it lightly then ran it thru the sizer. Trim it back about 1/4 inch and done. I did not have to make any rim modifications, it fits my rifle fine as is. CH4D is probably your best bet on dies, I don't know who made mine, the only markings are"MNO2MR", but they work. Lots of good info over on "britishmilitaria" by the way.
Best

Steve:

Mostly punching paper, but I do intend to use it in a deer stand in the PA woodlands.

I think the side lever on the Swinburn action is a cocking lever.

Rem

Remington40x,
I use my 461 Gibbs die to form the brass.
The No.2 Musket and the 461 No.1 Gibbs are very similar less bullet diameter.
Once the brass is fired in your rifle, no resizing is necessary.
Just come up with a bullet sized to slip snugly into the fired brass.
I also have not needed to thin the rim of the Starline brass fortunately.

50 Calshtr:

Which 50 caliber cartridge are you starting with? 50-90? And what are you using to trim the case 1/4 inch?

Thanks

Rem

I'm using Starline 50-90 brass and trimming it with a powered Lyman case trimmer. Remember, it's a bit of a PIA but you only have to do it once.
Best.