martini henry accessories

[fg-machine]

for many many years now i have been on the look out for a rather hard to find martini accessory... the morris aiming tube .
it turns out they aren't easy to find here in the states . so i set out to make my own .

i have the proto type about 85% finished ... dont ask how many hours it took to get this far ... you dont want to know
i have heard some fellows on other forums say it looks like an easy bit of kit to make . don't believe it .

rather then type up a long post ... i'll just throw up some pics and let the questions commence .

i have the fit and function down ... it head spaces properly and extracts properly

[enfield]

What caliber, did you use a barrel liner ?

[fg-machine]

the plan is to make it as original as possible , so the plan is to make it .297-300 .
I am just using a piece of aluminum as the tube for the prototype .

so far it has been an issue finding someone to make a barrel liner or barrel long enough to make the actual tube .. I need to finish at 34.5 inches

I'm open to sugggestions

[Ballistics in Scotland]

TJ's will make them any length you want, up to about sixty inches I believe, and their Mike Sayers is very helpful. Here is his list, a bit out of date as regards prices and possibly items. You can also get them through www.trackofthewolf.com .

An original is likely to be expensive. I've just seen one with a poor bore and an estimate of $400=500 Australian in this auction:

http://www.australianarmsauctions.com/cat_online_4.html

It wasn't the most accurate cartridge in the world, but adequate for its purpose, and the tube system, capable of sliding longer or shorter as its temperature changes, has the potential to be very accurate. I think it needs a spring or o-ring under the muzzle nut to keep the tension even. If you plan to make much use of it, it would make sense to make or modify a Martini extractor for the small round, but that is going to cost you plenty in either effort or money. Here is one emerging from its piece of steel, but I won't be doing that again while I can get out of it.

[fred2892]

I bought one from IMA a couple of years ago when they had quite a few in stock. Great fun making the 297-230 morris rounds (not 297-300) from 22 hornet brass.
The tubes came chambered in both 297-230 long and 297-230 short. Mine was the long variant and came with a perfect bore. It slugged at .224 and suggested loads called for the use of the lyman 225438 without the gas check. It is loaded as a heeled bullet using the gas check shank to sit in the mouth of the case.
Accuracy was at best 4" groups at 25 yards despite many weeks spent on load development. I even bought a lyman 225107 clone to get closer to the original 40 grain loading but with equally disappointing results.
It was something I had wanted for many years, the fun lasted 3 months and it now sits gathering dust.


Edit: IMA still have them in stock, I got mine when they had them on sale at 50%.
http://www.ima-usa.com/original-brit...rris-tube.html
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[fg-machine]

fred

i have a few questions , first is , the bushing at the breech end of your tube , is it a fixed or sliding bushing like the muzzle bushing . and are you maybe able to measure the bushing and the tube diameters for me .
and also does your tube have an instillation key .

i took a look at the ima page .. and the price . if i dont charge myself for labor i think i can barely beat the price making my own .
plus i believe i can improve on the accuracy quite a bit by not having the long un-rifled section that the original does . at least thats my hopes
if i can get accuracy down to 2 inches or less at 25 yards or so i'll be quite pleased .

the first hurdle is the tube its self ,.. i have been trying to find something other then a hammer forged barrel liner for the tube with rather poor results .
i am not convinced that the hard as nails hammer forged liners are the best choice for an unsupported sub caliber tube ... but short of paying pac-nor considerably north of $600 to get a rifled blank long enough to start with it might be my only choice

[fred2892]

Chamber and tube


Muzzle end. Brass 'top hat' bush to the left slides on the tube and rests on the rifle muzzle. To the right is the knurled brass crown, this is fixed to the tube and is what you would use to finger tighten the tube to the chamber piece. In the centre is the nut which spins down on the threads to tighten the assembly onto the rifle.


Fixed brass bush at the chamber end to centralise the tube into the rifle bore.


Chamber piece showing slot and screw which secures the chamber/extractor together.


Chamber piece from the other side showing the extractor in the open position.

As for a key, I did consider making one but in use I found it was unnecessary. It is easy to clock the chamber by eye and hold it in position with a thumb while tightening the tube from the muzzle end

Though I have reffered in the above to 'chamber piece', the actual chamber is of course in the tube.

I'll add the fixed bush dimensions in the morning. Its 11pm here now and god knows what beasties are lurking at the bottom of the garden where my workshop is.



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[Ballistics in Scotland]

TJ's liners aren't unduly hard in my experience, and that is not going to be the decisive factor, or perhaps any factor, in shrinking a 16 minute of angle group to 8 minutes. You would not get many inches per dollar by paying Pac-nor prices.

The liner shouldn't be unsupported. It should be supported by the bore, but it would be difficult and probably undesirable to try for a tight steel to steel fit. I've got some heat-shrink Teflon tubing I bought on eBay, with the idea of making Teflon coated bullets. It isn't consistent enough in thickness for that, but might be a good way of giving that liner a resilient surface. Or you could make it under size, and groove it or solder on bands to retain rubber O-rings.

I mentioned in the belief that a close copy of the original tube was intended, that some sort of spring under the muzzle nut would be desirable. But on reflection I think it would work best without a muzzle nut, simply being free to slide. With the original tube the insert rim would be drawn up tightly against the rifle rim recess, giving you whatever headspace the rifle had. But you would surely do better with an 0-ring in the front of the chamber insert, pressing the device against the breech face.

I didn't know that the originals were partly smoothbore, but it calls to mind a few historical examples. The German Paris Gun of the First World War did it. There was also, long ago, some interest in rimfire target rifles for formal indoor shooting which had the barrels bored out to leave only a few inches of rifling, to minimize the effect of barrel vibration. Finally I have seen pictures, although probably few people knew of its existence at the time, of a rifled brass shotgun shell, which was said to have some effect on accuracy in a smoothbore gun.

They add up to the suggestion that the smoothbore section needs to be either a close fit on the projectile, or so much oversize that there is no chance of contact, even with accumulated fouling, unburnt grains etc. There is an argument for using an all-rifled insert not much longer than a pistol barrel.

[fred2892]

Breech end fixed bush diameter 0.448".
Length 2.000".
Distance from tube end 1.700".
Tube diameter is 0.420".

Originally there was a leather washer between the muzzle top hat bush and the nut. Mine was badly deteriorated when I got it, so it is replaced with an 'o' ring when used.


297-230 Morris Long formed from RP .22 Hornet brass. 44 WCF to show scale.


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[fg-machine]

thank you fred . you have helped a bunch , i didnt know the crown nut was staked in place . and i wasnt to far off on my own wild guessing as to what the diameters should be .. i made my bushings .446 and the tube .426 .

i did make a slight change and moved the threads back a bit to be able to leave as much wall thickness as possible at the chamber of the tube .. maybe not correct but it makes me feel a bit more warm and fuzzy about it ..... progress yaaay .

[fred2892]

Glad to help, please keep this thread updated with your progress.

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[Cap'n Morgan]

There is an argument for using an all-rifled insert not much longer than a pistol barrel.

I made a rifled MH insert once with a spring-loaded extractor. Unfortunately I bored the insert offset, but parallel to the bore - I should have angled
it slightly towards the center of the bore: turned out the bullet would contact the rifling, and while it didn't tumble it was still enough to ruin accuracy. I could've made the rifled insert a little longer, but the falling block design doesn't like long cartridges and even two inches of rifling can be pretty accurate. One of these days I might give it another go...

[fred2892]

Thats impressive Cap'n. Did the spring loaded extractor throw the empty case clear of the receiver or did you have to pick the empty out?

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[superc]

I have ordered one. I too am thinking of using it as a model for making a new one. However, I am thinking in terms of .32 Short, .38 Speciall or even 5.56mm rather than a caliber I can't just buy a box at Walmart. The original Morris tube uses the Martini ejector to eject the Morris cartridge, so any modern clone should do the same thing. I feel this will allow just plinking with the Martini in situations where I don't need or want a full size .577-450.