45 Colt in 577/450 Martini

[timspawn]

Years ago I had a 577/450 Martini. It came with a chamber insert to allow it to fire 45 Colt. You would drop the insert in then put the round in the insert. I never fired it. My question is would this be safe to do?

[pietro]

I would think so, with factory/Cowboy loads - provided the 577/450 is safe to fire at all.

AFAIK, inserts are not meant for full-power loads, but rather as a smaller game sub-load for the main chambering.


.

[herbert buckland]

The bullet will be too small the groove diameter on a Martini Henry is .464 and that is after a 8 inch taper from about .473 at the end of the case

[curator]

If the gun is in reasonably good condition it is probably safe. However these chamber inserts do not provide any kind of accuracy since, as one of the other poster mentioned, the serious difference in the bullet diameter of the .45 Colt and the Martini-Henry bore size. A .452 diameter bullet would rattle down the barrel. Brass and bullets for the 577-450 are available from Buffaloarms and several specialized suppliers.

[timspawn]

Thank you gentlemen.

[pietro]

The bullet will be too small the groove diameter on a Martini Henry is .464 and that is after a 8 inch taper from about .473 at the end of the case

FWIW, that wasn't the OP's question, which was: "Would it be safe to fire a .45 Colt in a 577/450 chamber with an adaptor".

Too small a bullet is safe, although sloppy - too big may be unsafe.


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[enfield]

I got one that works fine, I use .457 round ball .

[herbert buckland]

FWIW, that wasn't the OP's question, which was: "Would it be safe to fire a .45 Colt in a 577/450 chamber with an adaptor".

Too small a bullet is safe, although sloppy - too big may be unsafe.


.As you had already adressed the safty isue I thought I would add that acuracy would be terible.With cast bullets the one that fits the chamber snugly is going to be the most acurate,you can not chamber a oversized cast bullet so that is not an issue.Incerts are fine in some rifles but if you want to hit somthing the 45 colt round is no good in a Martini Henry except as a shot cartridge at very close range

[gewehrfreund]

I had one of these chamber adapters for an 1874 MH and it worked just fine with factory "cowboy action" loads. Maybe the bullets in the ammo I used was very soft and obturated enough to contact the rifling sufficiently, because it was perfectly accurate enough to plink with at 50yds.
Obviously, your MH will never be a target gun with this set-up.

[Buckshot]

http://www.fototime.com/84C2840C23E9FD2/standard.jpghttp://www.fototime.com/B36421DF639D5DF/standard.jpg

.............I have one of those for my MkIV Martini-Henry. I bought it from the Old Western Scrounger several years before he sold out to Navy Arms (or whoever it was). It was pretty darn impressive accuracy wise considering the slug had to travel a couple inches before entering the barrel's leade. Accuracy became even better by only very slightly sizing just the top 3/8" of the Colt case to hold a .455" slug. I used the Lee 457-340-F afterwards. I Lube-sized it .458" and then ran it up through a .455" die I'd made. This was back when there was NO reloadable 577-450 brass other then Bertram. The reason the 45-70 case was there was because I was trying to figure out how to make an insert to use that case. Anyway, using regular 45 Colt book loads didn't cause any problems and would group 3-4 inches at 50 yards. Using the larger slug would shave 1-2" off so you could pretty well count on about 2" groups.

Back then one of the guys on the British & Militaria Board actually turned a Nylon insert to fit the body portion of the 577-450 chamber. He then bored it to accept a 45-70 case, and fire formed it. The exposed neck of the 45-70 case expanded into the neck area of the chamber locking the case into the insert. He was actually shooting it in his Martini like that using TD type loads. There was all manner of stuff going on as even with my 01 FFL Bertram brass was $87/20. When Mag-Tech (CBC) appeared with their brass shotshell cases you could (and still can) make 577-450 and 577 Snider brass from the 24 ga hulls. The bad thing was they were Berdan primed, which was bad enough but they came with CBC's #56 primers which would pierce if you looked at them sternly.

http://www.fototime.com/50D8EEB82833F33/standard.jpghttp://www.fototime.com/D7DD6B64206AB1A/standard.jpg

So if you could you either converted them to take the #209 shotshell primer, OR you cobbled together some tooling as above to flatten the Berdan anvil, drill a central flash hole and then swage the pocket down to take a Boxer pistol primer. Had to do the same thing with the 1895 Steyr straight pull 8x56 brass too. Anyway I called the Martini shooting 45 Colt with the adapter, "The Big Burp" as that's what it sounded like when the slug exited the 32" bbl :-)

.............Buckshot

[Ed in North Texas]

When Mag-Tech (CBC) appeared with their brass shotshell cases you could (and still can) make 577-450 and 577 Snider brass from the 24 ga hulls. The bad thing was they were Berdan primed, which was bad enough but they came with CBC's #56 primers which would pierce if you looked at them sternly.

So if you could you either converted them to take the #209 shotshell primer, OR you cobbled together some tooling as above to flatten the Berdan anvil, drill a central flash hole and then swage the pocket down to take a Boxer pistol primer.
.............Buckshot


Buckshot, I know you know this - but just in case some newbie wanders by - the Mag Tech brass shotshells are no longer Berdan primed. They have changed over to producing brass with standard Boxer primers.

Ed

[Buckshot]

Buckshot, I know you know this - but just in case some newbie wanders by - the Mag Tech brass shotshells are no longer Berdan primed. They have changed over to producing brass with standard Boxer primers.

Ed

..............Yes and a happy day that was too! :-)

http://www.fototime.com/7C6776752B29618/standard.jpghttp://www.fototime.com/FB833F810B2C0FE/standard.jpghttp://www.fototime.com/FEB48295FDD2804/standard.jpg

(LEFT)I was also using Mag-Tech 32 guage hulls to make 11.42R cases for a 1874 Comblain carbine. (CENTER)They were converted to 209 shotshell primers. (RIGHT) Even had to make my own size and seater dies, and shellholder! :-)

.............Buckshot

[Tom Herman]

Hey, Tim! I bet you can make this thing a bit more accurate: Use a soft cast hollow base 265 grain RCBS .455 Webley bullet! These things are essentially smokeless Minie balls... Mine cast about .456, and the bases should have no problem opening up to fill a .464" bore.
Just my two cents worth!
Happy Shootin'.

-Tom

[THerbert]

Actually, since the Martini-Henrys have become very popular lately because of the ones coming from IMA-USA in the Nepal cache, the bores have been found to vary widely. The British-made actions have had bores varying anywhere from the Mark I's and II's at .459" to about .464", to the Mark IV's at as much as .473"! I have a Nepal-made Gahendra rifle that measures .457", which makes it very easy to cast boolits for it.

[herbert buckland]

I belive the diffrent size bores reported in the British military MH to be from people not understanding how to measure the odd landes on the MH barrel.The British used guages for theres rifle barrels and they had to pass inspection or be rejected,bore size .449,groove size .464,the chamber size can vary from .475 to .468 though, wich may have lead to some confusion,the Gahendra rifle almost allways have Groove diameters smaller than the British made rifles

[Freightman]

I am working on a Gahendra that slugs at .456 and would like to find a insert to use 45/70 brass, thanks Buckshot for the information.

[JeffinNZ]

Depending on the throat measurement you might do better shooting a .480 Ruger.

[loiner1965]

I am working on a Gahendra that slugs at .456 and would like to find a insert to use 45/70 brass, thanks Buckshot for the information.
interested in one too