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Shooting & Reloading - Mausers, Big Bores and others >> Big Bore Rifles
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DoubleD
.400 member


Reged: 23/11/03
Posts: 2437
Loc: Retired in Oklahoma
577/450 BP Express?
      #21632 - 03/12/04 10:03 AM

Earlier this year I acquired this Martini sporting rifle. i have been trying to develop a smokeless powder load for the rifle with no luck.



The groove diameter of the rifle is .458. I have been working with .462 500 gr. bullets with groups that would not qualify as patterns let alone groups. Today I fired 8 rounds and only 4 hit the target board. The Target board is 6 ft. wide and 4 ft tall. The 4 that hit the target were in a group 14 inches wide by 30 inches tall. There was indication that the 4 that missed the target board went under and over the board.

I also brought along some .459 diameter 418 gr. bullets cast from WW. These bullets are from a Lyman 457193 mould. I got a 5 3/8 in group.



That red dot is 4 inches low and 4 inches left of my point of aim. But the that's easier to deal with once I get a load for the rifle.

On the way home from the range I got to thinking and decided to check the twist on my rifle when I got home. Turns out it is 1 in 33 inches.

I need a shorter-lighter bullet.

Was there an Express load for the 577/.450 Martini? I see the .450 BP Express loads were from .275 gr to .365gr.





--------------------
DD, Ret.

Edited by DoubleD (03/12/04 01:06 PM)

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Marrakai
.416 member


Reged: 09/01/03
Posts: 3592
Loc: Darwin, Top End of Australia
Re: 577/450 BP Express? [Re: DoubleD]
      #21651 - 04/12/04 12:52 AM

Yes there was. I have read about it a number of times. One reference to it is in the class rules for the Big Game Rifle Club. .577/.450 Martini Henry must use the 'express' load.

If I get time on the weekend I'll explore this further, meanwhile I'm sure other members will post in with first-hand knowledge.

BTW, the rifle pictured certainly looks like it should be chambered for the express cartridge. Very nice! Does it carry a maker's or retailer's name? I have a similar specimen with full-length rib in .303 by Army & Navy. Love it dearly!

--------------------
Marrakai
When the bull drops, the bullshit stops!
--------------------------------
www.marrakai-adventure.com.au

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DoubleD
.400 member


Reged: 23/11/03
Posts: 2437
Loc: Retired in Oklahoma
Re: 577/450 BP Express? [Re: Marrakai]
      #21656 - 04/12/04 02:55 AM

There is no maker or retailers name on the gun. The barrels and action does bear British proofs and view marks. But that really doesn't mean that much. I think the gun is a product of shade tree gunsmithing. The barrel did not fit the action when I purchased it. The barrel tenon is two threads shy of long eneough.



I bought it from a reputable dealer in Netherlands who specializes on old collectable guns. The dealer had the rifle listed in his stock for over a year. The dealer said nothing about the barrel. Everything else about his description later turned out to be spot on. I am in the U.S. so I had a friend from Belguim run over and inspect the rifle for me. He saw nothing wrong. So I made my offer. The dealer reduced the price 300 Euro's and we closed the deal.

It was only after I got it that I found the short barrel. I had the choice of returning the rifle and being out $100 in two way postage or getting it fixed. Since I am a Gunsmith, I choose the latter. See: Correcting barrel alignment and headspace for details on that.

The rifle weighs only 7 lbs and is breathtaking when firing 500 gr. bullets. I have fired 60 rounds through it using 460 and 500 gr. bullets with no luck. It was only yesterday after trying 418 gr. bullets that I got this wild idea to check the twist.


--------------------
DD, Ret.

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pwm
.300 member


Reged: 15/06/04
Posts: 216
Loc: Banana Republik of Germany
Re: 577/450 BP Express? [Re: DoubleD]
      #21665 - 04/12/04 06:10 AM

in the 1936 Kynoch catalog: 90 grain black, 325 grain lead copper tubed give 1600 feet per sec.
44 grains cordite, 365 grains metall based solid or copper tubed gives 1425 feets per sec.

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4seventy
Sponsor


Reged: 07/05/03
Posts: 2210
Loc: Queensland Australia
Re: 577/450 BP Express? [Re: DoubleD]
      #21674 - 04/12/04 10:43 AM

In reply to:

It was only after I got it that I found the short barrel. I had the choice of returning the rifle and being out $100 in two way postage or getting it fixed. Since I am a Gunsmith, I choose the latter. See: Correcting barrel alignment and headspace for details on that.




DD
Thanks for the link.
Interesting reading and great photos!

What camera did you use?

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DoubleD
.400 member


Reged: 23/11/03
Posts: 2437
Loc: Retired in Oklahoma
Re: 577/450 BP Express? [Re: 4seventy]
      #21694 - 05/12/04 02:10 AM

I found several Greenhill formula on line sites and they each give a slightly different results. But basically what I need is a bullet approximately 1.050 long weighing 350 to 405 grs. depend on which site you use.

Thanks for the feed back Gentlemen!




--------------------
DD, Ret.

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470Rigby
.333 member


Reged: 23/02/04
Posts: 328
Loc: Melbourne, Australia
Re: 577/450 BP Express? [Re: Marrakai]
      #21708 - 05/12/04 09:09 AM

In reply to:

One reference to it is in the class rules for the Big Game Rifle Club. .577/.450 Martini Henry must use the 'express' load.




The Big Game Rifle Club merely specifies the .577/.450 Martini Henry "Express" load as requiring a maximum bullet weight of 325 grains, over and above the general class requirement for a minimum case capacity of 90-gr of Black Powder.

However, using the definitions required for "Class 3" (Double Rifles of .450 bore) Express Rifles for the Field Rifle Trials of 1883, this would also extend to;

* Weight not to exceed 8 lbs
* Barrel length not exceed 28 inches
* Powder charge not less than 4 drams (109.375 grains)
* Bullet weight not to exceed three times the weight of powder (this would require a Black Powder charge of at least 108.3 grains for 325-gr bullet.)

So - the 325-gr Bullet/90 grain powder load is not strictly an "Express" load, if you use the definitions of the day! AND - considering that modern Black Powders are down about 20% in "grunt", a 90-gr powder charge would come nowhere near developing true "Express" ballistics!

Accordingly, no .577/.450 MH rifles were submitted for the 1883 trials, and IMO, it ill-behoves The Big Game Rifle Club to re-write history!

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