Primer backing out 1/2way on a Martini Henry

[DxieLandMan]

Every time I shoot my Martini Henry, the primer comes out about 1/2 way and it will not eject so I have to take the gun apart every time I shoot it. I've tried reduced loads, commercial loads and the primer comes out of all of them to where it will not eject. I'm just about ready to retire this one and buy another one. Any suggestions to what I am doing wrong if any thing?

[Idz]

If this is a 577/450 cartridge it sounds like the headspace is way off. There should be about .005 - .010" space between the back of a chambered cartridge and the tilting block. I've also seen some of the Nepal MH with big gaps around the firing pin hole in the block.

[Preacher Jim]

What does that chamber look like? A rough chamber causing case to adhere and not set back against bolt can cause that. But headspace issue would have to be excessive also.
You may need to set barrel back and polish chamber.

[Nobade]

Or solder in a ring in the rim cut to correct headspace. If you set the barrel back you'll need a chamber reamer.

[DxieLandMan]

I'll check the headspace tomorrow morning. It is a .577/450 caliber and is not a Nepalese copy. It's a fun gun to shoot but it has just become a PITA after a firing session. It's an 1874 Mk II design. Long action.

[john.k]

There can be a fair bit of length variation in breech blocks.....One of my guns has a very short block,and no other block will close in the action.......Also check that you dont have a bushed 303 block that someone has lapped to remove a primer ring...I usually do this on rebarrels,as I will be adjusting the headspace anyway......just a thought...are you sure you dont have a KP block......?

[Ballistics in Scotland]

It is common for old rifles of moderate pressure to back their primers out, and it doesn't take any unnatural adhesion to the chamber wall to do it. My Winchester .40-82 backs out its primers by a harmless .005in. While that isn't ideal in a high-pressure rifle from which you expect the highest degree of accuracy, I can't see anybody getting into serious trouble with it.

But half the primer's depth is far, far too much. I think the most likely explanation is parts substitution, perhaps even from a Belgian Martini. Besides the Francotte design with the removable action frame, and a block rebated around its pivot pin, they did make copies of the British pattern. In Saudi Arabia I once found an old Societé Française des Munitions balloon head case with the head stretched to a ridiculous angle, although it hadn't ruptured. Not to mention the possibility that some intellectual realised that that case would hold a most exciting amount of smokeless powder, and when he picked himself up was too disoriented to notice that he had stretched the action sides. The only fractured Martini I have ever seen had a very slight crack that probably derived from using a pry-bar through the action to unscrew a barrel. But there are other ways of doing it.

When you find badly excessive headspace, you need to find out why it happened. Everybody makes a reloading mistake someday, or has an oily or wet chamber.

[Gunfreak25]

Yes, make sure you don't have a Nepalese copy like the Nepali Francotte on your hands. If it's a genuine Brit rifle, your headspace is off. My MKIV had a rough chamber but the cases never stuck one bit and it had tight headspace.

[john.k]

In the days when big Martinis were worthless,you used to see some real out of sight modifications.....the commonest being grinding of the block so a 303 smelly barrel could be used.The best being to wind copper wire in the gap between barrel and reciever.I also have a collection of twisted recievers,often with the gun held by the wood to unscrew the barrel......and getting the extractor jammed into the thread.But tempis fugit,and now these bits arent junk anymore.Twisted and cracked recievers are easily repaired,and a quick swish on a surface grinder removes the vice marks.....hint,press the middle in a bit,and the factory markings are preserved when you grind the sides.I even made up a small fixture to hold blocks at the correct angle to surface grind welded up breech faces.

[Ballistics in Scotland]

I suppose plenty of Martinis are just wall hangers even nowadays, and some of those "repairs" won't do any damage to the wall. But they just convert safe junk into potentially lethal junk. Twisting a receiver probably lengthens the sides, and twisting it back again certainly wont shorten them. I wouldn't trust a twisted one not to be cracked, either. The use of a Lee-Enfield barrel is fine (Enfield did it), except that you need to shorten its longer threads from the rear, which lets you in for needing a reamer to deepen the chamber.

WW Greener says that the first .303 Martinis tended to deform the block, which was why a special block became necessary. (He may have meant hardenable steel and/or the firing pin tunnel ending further from the breech face as well as the inlaid steel strip version.) Apparently this wasn't dangerous, as it impeded opening first. But .577/.450 blocks were surely used unaltered, perhaps unofficially, and a concave block which has been shortened to "cure" the problem would explain the condition the OP found.

Welding up and smoothing off a block face seems totally legitimate though. I believe I would silver solder a little conical plug into the front of the firing-pin tunnel, and if that didn't leave enough spring space, use a shorter square-wire spring to put the required amount of assertiveness into the shortened tunnel.

I found something last week which shows how misconceptions in firearms history get around. I bought a bound volume of the "Illustrated London News" for the first half of 1858. It was slightly disappointing in one way, for some of the most dramatic events of the Indian Mutiny had got into the 1857 edition faster than I thought 1850s communications could do it. But in it, marking the article on the design for the English Channel tunnel (yes, really!), there was a letter from a schoolboy at Harrow (Winston's school) to his mother in Ramsgate. It bore a Penny Red stamp, and is dated 1871.

He says his new rifle hasn't arrived, and I presume he meant for the school cadet corps, even in those spacious days. But he doubts if he will ever receive it, as they think the Snider will be replaced by the Martini-Enfield. A little over two decades later that would be the official designation for a converted or purpose-built .303 Martini. But he obviously means a .450 Martini as made by Enfield. In India Jim Corbett was given his cadet corps Martini to take home for the holidays, shot his first leopard and followed it up wounded at the age of about twelve. Times have changed a lot.

[john.k]

With the dovetailed block conversion ,the block was softened at the front,dovetail slot cut,piece inserted and screw staked.....but the block was not rehardened,and is so soft that the extractor damages the front part.The insert is made from a high carbon steel,but not hard either.....The purpose made 303 blocks are properly case hardened.

[DxieLandMan]

Thank you for the replies. My problem is that it backs out just enough to so where I can cannot open the breech. I'm using less powder than recommended and I have this issue. I'll keep working it but it is really too fun to shoot to make a wall hanger. If this problem keeps up, that is what it will have to become. Too much of a PITA to take it apart after I shoot it one time.

[john.k]

I have see a similar problem caused by a badly corroded primer ring extending into the firing pin hole,and taking the whole surface where the primer seats against the breech face.....Its a bit difficult to see the breech face on a martini,and damage goes unnoticed on some guns that have been neglected.....cure is a replacement block,or weld up and reface your current one.

[Ballistics in Scotland]

Thank you for the replies. My problem is that it backs out just enough to so where I can cannot open the breech. I'm using less powder than recommended and I have this issue. I'll keep working it but it is really too fun to shoot to make a wall hanger. If this problem keeps up, that is what it will have to become. Too much of a PITA to take it apart after I shoot it one time.

Possibly they are a lot less than halfway out, or I would want something done before shooting it. One possibility would be to drill a piece of thin sheet steel for the firing-pin, and attach it with something like Brownells 355 silver solder, which comes in thin ribbons. About any steel should do for a .577/.450, but O1 tool steel takes on quite a bit of hardness from natural cooling after silver soldering. that is why I would drill it first, and use the hole to locate it. This would serve a double purpose if you have a rebarrelled Martini that could do with a smaller diameter firing-pin, or a closer fit between pin and hole.

I think you could open a Martini jammed in this way by moving the lever off the locking shoulders on the block, and tapping it downwards by not too immoderate blows of a wooden punch mallet. I can't see that removing the trigger guard would be much better, and if you do so, you should insert some kind of metal object in the tumbler slot in the firing-pin, to hold its tip out of the primer indentation.

A pretty original-looking British military block I have is 3.075in. from breech-face to the half-inch diameter part-cylindrical surface at its extreme rear. I think all the marks are the same, but if not someone will surely set us right. Making a new Martini block would be quite a job, but think how good you would feel when you'd finished. I'll probably have to do it one of these months, as I have a Francotte Martini receiver with the Cadet-style action frame, of which there appear to be a supply from ancient but unused factory stocks, in both military and Cadet sizes, on the French Naturabuy site.

[Ballistics in Scotland]

I have see a similar problem caused by a badly corroded primer ring extending into the firing pin hole,and taking the whole surface where the primer seats against the breech face.....Its a bit difficult to see the breech face on a martini,and damage goes unnoticed on some guns that have been neglected.....cure is a replacement block,or weld up and reface your current one.

I believe that problem could be fixed by thorough derusting of the pits with naval jelly or acid, and filling the pitting with silver solder alone.

I used to know a British gun dealer who warned customers never to remove the breechblock from the Greener GP shotgun (just a wider Martini) as it couldn't be put back by the user. He used to return them to the factory for the job. It was a couple of decades before I discovered that it might be a shade more difficult than the military Martini, but was nowhere near that bad.

[john.k]

because of the law here,I store and transport guns with the blocks in a locked ammo box...One day I arrived at a shoot a long way from home,and I had included the wrong blocks.......So I shot with them,one from a Mk4 was good,one was short ,and fired cases wouldnt fit the same gun with the correct block.I have one block where a dipstick has ground away the round part to fit a 303 without rechambering a smelly barrel...someday,I may build it up and reprofile it.

[John in PA]

Here's a short-cut to solving the headspace issue. This will work if this is the *only* .577-450 firearm you're shooting. Take your fired cases and, instead of FL sizing them, back your sizing die out a turn or two. Then size, try case in chamber, turn die 1/8 turn, try again, repeat till breechblock will just close on the empty case. This will allow your cases to headspace on the shoulder (like all modern rimless cases do), and will completely avoid any gunsmithing.
Note, this will NOT correct problems of too much gap between the firing pin tip and the hole in the breechblock, yielding primer flow back along the tip into the block hole. But your description stated the the entire primer backs out, so this sounds like a headspace issue if correctly described.

Also, cartridges sized to a custom length *may* not work in other firearms chambered for the same cartridge, unless they possess the same chamber dimensions.

[loiner1965]

Here's a short-cut to solving the headspace issue. This will work if this is the *only* .577-450 firearm you're shooting. Take your fired cases and, instead of FL sizing them, back your sizing die out a turn or two. Then size, try case in chamber, turn die 1/8 turn, try again, repeat till breechblock will just close on the empty case. This will allow your cases to headspace on the shoulder (like all modern rimless cases do), and will completely avoid any gunsmithing.
Note, this will NOT correct problems of too much gap between the firing pin tip and the hole in the breechblock, yielding primer flow back along the tip into the block hole. But your description stated the the entire primer backs out, so this sounds like a headspace issue if correctly described.

Also, cartridges sized to a custom length *may* not work in other firearms chambered for the same cartridge, unless they possess the same chamber dimensions.

interesting.....sure i heard about this on a youtube video with a great guy called iraqveteran....i have a few martinis and all headspace between 5 and 10 thou and no issues.
i did notice with some different makes of cases the headspace with differ as you well know.
i have some old berden primed kynock cases from the 1950s i guess and they headspace at 10 thou identical to newley made kynock cases.
do they still use the same tooling ?
i know the new kynock cases are a fresh batch as the company here in the uk emailed me when they were doing a new run.
i also have a belgium martini ( wall hanger ) and my rfd / engineer friend made me a new part on a lathe but noticed the breech block had excessive pitting around firing pin hole.....he measured where the hole was a mig welded the face and redressed it with a file and re drilled the hole, he even measured the headspace at around 5 thou.....is mig welding too severe?

[skeettx]

Here is something to try.
Place a sliver of scotch tape on the shoulder of the cartridge.
See if the lever will close.
If so, shoot the cartridge and see if the primer stays in the recess and
the lever opens the action.
Next when you reload the cartridge, do not size the ammo to the fullest so the
shoulder will remain forward.
Mike

[loiner1965]

Here is something to try.
Place a sliver of scotch tape on the shoulder of the cartridge.
See if the lever will close.
If so, shoot the cartridge and see if the primer stays in the recess and
the lever opens the action.
Next when you reload the cartridge, do not size the ammo to the fullest so the
shoulder will remain forward.
Mike

could he not mark the neck with a black marker pen and only neck size with the full length die ?
i had a die made up specially that only sizes the neck to around .468