577/450 Martini Henry Case Problem

[rescuerandy2]

Good Afternoon. Been shooting a Mark I/II for 4 years and just use 80gr FF with carded wool to fill the airspace. The smell is interesting and I do get a slight snowstorm but no other issues. In fact, this beater of a rifle hits the black at 100 yards with me shooting off the table, trifocals, and a 60 year old pair of hands. My cartridges are 24ga formed metallic shotgun shells and they started splitting after 3.5 years of moderate use and abuse. Keep it simple and enjoy, Randy.

[bigbore52]

If I can add my two bobs worth - been shooting the 577/450 for many decades now and never had a separation.....I would suggest it could be a combination of factors such as have already been described. Either a weakened case, wrong loads or fillers and or a combination thereof...

Can I suggest you try going back to basics with it? By that I mean trying to duplicate or as close as possible the original loads they used as some knowledgeable folk have posted already?

For example, I use Bertram Brass with 90gn of Swiss Fg under a cardboard spacer then felt wads to take up the volume so there's no air gap under the pill..I do not compress the powder and wad merely lightly tamp it down with a wooden shaft to sit them snug ..on top of that I use a lubed 570gn lead pill based loosely on the Postell but at .460 diameter (mould made by CBE) and with a 20:1 (Pb:Sn) brew. There's really no need to harden it with Sn but I add it because I make other loads with the same batch..... .the Postell will work just fine as it is but accuracy may be affected if your bore is not 458 and I can guarantee you it won't be ... I will often use a bees wax lube cookie under the pill but as the pill is already lubed it's not that necessary and often I don't bother with that separate lube.....the original load did use it........

I have used a variety of fillers over the years and they all gave me headaches of one sort or another but eventually settled on felt wads as that was what was originally used...and believe it or not, I get the best results from it...........interestingly the felt I use comes from the same company that made it a hundred years ago in the UK - they will do mail order and you can order it in a variety of sheet thicknesses to make up the gap space you need - details are : Hardy and Hanson in West Yorkshire http://www.hardy-hanson.co.uk/felt_strips.htm - worth dropping them a line and asking.....

you need to ensure there is minimal air gap between the powder and the pill........easy enough to work out the thickness of wad you need and then just order that thickness sheet or make it up form different sheets as I do......

I use their felt in most of my BP loads in other calibers and have never had any issues or problems with it.....just make your punches to suit or you can buy them at various sources such as Track of The Wolf and others.... ..when it's all said and done with these old rifles, it behooves a certain feeling to use "original" components wherever possible.......good luck with it and I hope you sort it out quickly....Lee

[toot]

i use a cotton ball over the powder, it weights nearly nothing and takes up the air space in the case. then a grease cookie under the bullet.

[yulzari]

I have tried most fillers in the 577-450 cases over the last few years bar granular fillers as these clump into a hard plug just like the dry sharp sand used to block the open end of shot holes in blasting rock. I finally settled on raw wool, of which I have an infinite supply free, packed in fairly firmly. Then I was led to try foam backer rod. The closed cell foam sold in rolls to take up the gap when installing windows. Available at any hardware emporium. Ideal. Just measure off enough to slightly over fill the gap and cut as many as you need to the same length. Same weight every shot. If you do not crimp your bullet and find that the foam's 'spring' pushed the bullet out a bit further than you wanted? No problem. When chambered the bullet will bottom out in the throat and get pushed back in to the ideal just touching the rifling. The same every time. Whilst I just leave air in service 85 grain charges I can get down to 45 grains for 100 metres with all the space filled up with foam backer rod.

[mzlldr]

I used to use semolina as a filler in some of my bp cartridge loads , but stopped doing so when a fellow shooter at my club told me that he had experienced problems with the semolina " caking " in the cartridge case and adding quite significantly to the rifle's recoil . I never experienced any problems , but decided to stop using it anyway.

[Newtire]

I have tried most fillers in the 577-450 cases over the last few years bar granular fillers as these clump into a hard plug just like the dry sharp sand used to block the open end of shot holes in blasting rock. I finally settled on raw wool, of which I have an infinite supply free, packed in fairly firmly. Then I was led to try foam backer rod. The closed cell foam sold in rolls to take up the gap when installing windows. Available at any hardware emporium. Ideal. Just measure off enough to slightly over fill the gap and cut as many as you need to the same length. Same weight every shot. If you do not crimp your bullet and find that the foam's 'spring' pushed the bullet out a bit further than you wanted? No problem. When chambered the bullet will bottom out in the throat and get pushed back in to the ideal just touching the rifling. The same every time. Whilst I just leave air in service 85 grain charges I can get down to 45 grains for 100 metres with all the space filled up with foam backer rod.

I have heard of the foam backer rod so loaded some up using that but wasn't too sure about trying it out. Once it warms up a bit and I have recovered from getting a new knee, I'm gonna go out & try this gun out.

[john.k]

I havent tried the foam rod yet,but if I can get it here I will.Its recommended by a number of notables in the component supply trade.It may well be the answer to shooting smokeless in these cases.......in regard to cases,I use 24ga CBC,and Ive found that with paper patched bullets cases last indefinitely,as there is little or no neck expansion.......but when I use tightly seated 476 bullets,necks expand out to chamber size,and it appears the cases are under considerable stress.
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[DxieLandMan]

i use a cotton ball over the powder, it weights nearly nothing and takes up the air space in the case. then a grease cookie under the bullet.

This is what I use too. 75 grains of 2FF black powder, a cotton ball and then a grease cookie.

[toot]

I fill up the air space in mine with RICE CRISPIES weigh nothing and do not turn into a solid slug when fired. smells like you are baking cookies!. I have used this method for many years with success.

[bob208]

in George note's book cartage conversions he advises against cow filler in bottleneck cases. he also showed a outer case turned with a .45-70 case inside.then you can have reduced case volume.

[Newtire]

That sounds like a good plan! Also good for emergency rations.

[superc]

That is a fairly common seperation, especially with 'new' Kynoch loads that have sat on a shelf or in a garage somewhere for 70 years before you purchased it. I am not at all sure the filler had a durn thing to do with it. If my Kynoch loads fire without splitting, I anneal them before reloading. I use 85 gr of FF and half a cotton puff as the filler. Every 4 reloads I anneal again.

[john.k]

Season cracking of drawn brass can happen anywhere ,not just cases.My take with Kynoch cases is to pull the bullets and empty them.....then anneal them,without firing....I dont worry about annealing the head either,as the working pressure will be low.I also fill the cases with dry lime,which hopefully will absorb the mercury released by the primers if they go off.If not,its unlikely they ever will.Its worth the trouble to me.because new made cases here cost $7.50 each.When decapping,I wear adequate eye and ear protection,just in case.I then enlarge the twin flashholes enough to take a decapping pin,and there you have new/ish cases.Kynoch cases take 303 Berdan primers ,not the 24ga Berdans used in CBC home market cases.....the difference is .250" vs .254"..Both are RWS numbers.......I believe the correct primer for the Kynoch case is the "Express Rifle Berdan",not quite as deep as a 303 berdan,but if you arent regulating barrels,near enough.

[Newtire]

I havent tried the foam rod yet,but if I can get it here I will.Its recommended by a number of notables in the component supply trade.It may well be the answer to shooting smokeless in these cases.......in regard to cases,I use 24ga CBC,and Ive found that with paper patched bullets cases last indefinitely,as there is little or no neck expansion.......but when I use tightly seated 476 bullets,necks expand out to chamber size,and it appears the cases are under considerable stress.
.

Finally got a chance to try the foam backer rod. Home Depot had it in stock. Used 25 gr.SR 4759 and 3/4" rod to bottom of case neck, then 1/2" rod to within 1/2" of top of case and seated a 475gr. X-ring Services boolit on top of that. Put a light crimp on them to keep the slightly compressed foam from pushing the boolit out. All 25 of them went bang with no ill effects. I was using the X-ring cases formed from 24 gauge brass since am just getting started. His company did alright by me and his products were all very nicely made. Anyhow, the backer rod worked and the bore cleaned out with some CLP that a friend gave me. I got this load out of some Handloader #76 data shot in a Gibbs rifle . As usual, if you suffer any damages using this information, that's on you.

[Tracy]

Uncorned homemade black powder might work well in .577/.450, being less dense than commercial BP. 85 grains would probably fill the case.

[DxieLandMan]

Well, the primer keeps coming out just enough that it takes a few taps on the falling block to break off the primer to where I can unload it. I took it to a local gunsmith and lo and behold, I have a MkII and the falling block was from a Mk IV. Maybe this could be a problem so I ordered a MkII falling block and spring to install in my MH. Hopefully this will take care of the issue. I hope it will. I will try to install it this week and let everyone know how it works.

[john.k]

While the block being from another rifle is obviously the problem,its too short....or...the reciever is too long.Ive got some commercial made MHs that wont close on a block from an Enfield made rifle,one LSA needed 010 taken from the block,before it would even close too tight...............Incidentally,about headspace.......the Lee Enfield crowd obsess over headspace,but its a fact that military 303 Martinis have a rim recess in the barrel..(smelly doesnt have this) that is .080" deep,so headspace cannot be less than this,and is often +005 to 007 more...A Martini actually sets its own headspace,as the rim recess fills up with crud,and keeps the cartridge pressed against the blockface.

[Newtire]

I have only tried one method and it seems to work so I see no need to switch. This load gives 1060-1080 FPS and gives pretty consistent groups. I have been using 24 grains of SR4759, a 1” (approx.) Foam 3/4” backer rod to fill to the shoulder and another1/2” x 1/2” length of backer rod to fill the neck space to 1/4” from the top of the case. On top of that, I seat a 500 gr. Xring services bullet out to the origin of the rifling. I have been getting 2” groups at 50 yds. Better accuracy than with the Lee 400 gr. bullet.

[toot]

This is what I use too. 75 grains of 2FF black powder, a cotton ball and then a grease cookie.

yes I am also a cotton ball, grease cookie man! and never had a hiccup! 85 GRS, if 2fg. a half of a cotton ball.then push the case neck into a mixture of bees wax and tallow.way to go. jmho.

[elk hunter]

I'm shooting 25 grains of Trailboss behind the Lee HB 45-70 bullet cast soft patched to .473-.474. No filler needed and it shoots as good as I can hold it.