Modern Smokeless 577/450 loads

Started by kombi1976, August 05, 2007, 07:28:35 AM

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kombi1976

There has been much discussion on a number of occasions both on this list and on others about the possible power of the 577/450 cartridge using modern smokeless powders, modern 458 cal barrels and bullets and Martini actions with smaller firing pins and sleeved firing pin holes.
Now, since I have a Martini Enfield action which is practically the same as the MH action with the exception of the extractor and reduced firing pin, surely the old 450 case could be pushed up to and over 40,000 psi, almost to 45k, which is the safe limit for 303 ammunition.
Could someone run some figures in QuikLOAD or a similar program to estimate exactly which powders would suit (please include ADI powders like AR2207) so that I could get an idea of the possibilities of such a set up?
Oh, and could you calculate it on a 480gr or 500gr bullet.
Cheers & God Bless
22lr ~ 22 Hornet ~ 25-20 ~ 303/25 ~ 7mm-08 ~ 303 British ~ 310 Cadet ~ 9.3x62 ~ 450/400 N.E. 3"


Brithunter

Hi Kombi,

   Man are you glutton for punsihment :eek: . At least the ME has a hardened steel breech block :smiley: which should help in action life.

   Now somewhere I have a couple of articles on handloading for the 577-450 one of which possibly includes hard cast bullets and smokeless powders. I will try looking them out.
Go Get them Floyd!

kombi1976

Well, I'm thinking, why not?!
The powder space has got to be considerable and so long as I don't start splitting cases the pressure should be fine.
The only real consideration in this experiment would be the extractor.
There were serious problems with the Martini Henrys at Rorkes Drift because they heated up and refused to extract.
There may be ways around it, like putting a light lube on the case to aid extraction.
But I think it's worth looking at.
And as you said, the Enfields have a hardened steel breechblock.
Besides, I can get Bertram 577/450 cases for under half the standard price.
They'd be about the same price as some of the more unusual RWS or Norma brass.
So I reckon I should have a good hard look at the alternatives.
Might even get it converted to a switch bbl.
Cheers & God Bless
22lr ~ 22 Hornet ~ 25-20 ~ 303/25 ~ 7mm-08 ~ 303 British ~ 310 Cadet ~ 9.3x62 ~ 450/400 N.E. 3"


gitano

QuoteCould someone run some figures in QuikLOAD

Gee... Who might that be?
 
I need more info though. First, enlarge that list of powders available to you  - QL has lots of international powders. Second, how much is the bullet going to weigh? Third, how long is the barrel? And finally, what specific chamber pressure limits do you want to use?
 
For example: A 405-grain Woodleigh bullet in a 26" barrel in front of 71 grains of AR2207 (70% of load capacity - not the best powder for this cartridge by any means) yields a muzzle velocity of 2268 f/s with a corresponding  muzzle energy of 4625 ft-lbs at a chamber pressure of 40,100 PSI.
 
On the other hand, using 111.5 grains of AR2213 (100% of load capacity), you can get that same bullet going 2404 f/s with a corresponding muzzle energy of 5194 ft-lbs at only 39,998 PSI.
 
The highest velocity (2487 f/s) is produced by 115.7 grains of Norma MRP (102.8% of case capacity) with corresponding ME of 5562 ft-lbs at a chamber pressure of 40,002 PSI.
 
Were it me, I'd use 83.1 grains of Accurate XMR 4350 (85% of case capacity) behind a Speer 400 grain bullet. That bullet would be doin' 2000 f/s at the muzzle with a coresponding ME of 3556 ft-lbs, and a max chamber pressure of 22,700 PSI. And I would expect it to be positively 'pleasant' to shoot 'all day'.
 
In closing, let me say:
 
DO NOT USE THESE LOADS. THEY REPRESENT MAXES! BACK OFF AT LEAST 10%, AND 15% WOULD BE WISER. FURTHERMORE, IN NO WAY DO I CONSIDER 40,000 PSI A "SAFE" CHAMBER PRESSURE IN THESE OLD ARMS. YOU'LL HAVE TO MAKE THAT DECISION FOR YOURSELF.
 
Paul
Be nicer than necessary.

kombi1976

Quote from: gitanoGee... Who might that be?
Gee, could it be you? :undecided: :D
 
Quote from: gitanoI need more info though. First, enlarge that list of powders available to you - QL has lots of international powders. Second, how much is the bullet going to weigh? Third, how long is the barrel? And finally, what specific chamber pressure limits do you want to use?
For example: A 405-grain Woodleigh bullet in a 26" barrel in front of 71 grains of AR2207 (70% of load capacity - not the best powder for this cartridge by any means) yields a muzzle velocity of 2268 f/s with a corresponding muzzle energy of 4625 ft-lbs at a chamber pressure of 40,100 PSI.
On the other hand, using 111.5 grains of AR2213 (100% of load capacity), you can get that same bullet going 2404 f/s with a corresponding muzzle energy of 5194 ft-lbs at only 39,998 PSI.
The highest velocity (2487 f/s) is produced by 115.7 grains of Norma MRP (102.8% of case capacity) with corresponding ME of 5562 ft-lbs at a chamber pressure of 40,002 PSI.
Were it me, I'd use 83.1 grains of Accurate XMR 4350 (85% of case capacity) behind a Speer 400 grain bullet. That bullet would be doin' 2000 f/s at the muzzle with a coresponding ME of 3556 ft-lbs, and a max chamber pressure of 22,700 PSI. And I would expect it to be positively 'pleasant' to shoot 'all day'.
In closing, let me say:
DO NOT USE THESE LOADS. THEY REPRESENT MAXES! BACK OFF AT LEAST 10%, AND 15% WOULD BE WISER. FURTHERMORE, IN NO WAY DO I CONSIDER 40,000 PSI A "SAFE" CHAMBER PRESSURE IN THESE OLD ARMS. YOU'LL HAVE TO MAKE THAT DECISION FOR YOURSELF.
Paul

O.k., Paul, here are the needed details.....
 
Powder Choice: If I could I guess I'm after ADI powders. These are the most easily available for me, although include Hodgdon, Alliant and IMR for those who are interested in the performance of such powders more common is the USA.
 
Bullet Choice: I guess the main bullets I'll be using will probably be the Remington 300gr JHP and the Woodleigh Weldcore 450 Nitro 480gr RNSN and 480gr FMJ. The Rems are cheap and cheerful and would do impressive damage to big game and the Woodleighs are pure buffalo territory and also happen to be the original bullet weight for 577/450. It may be worth looking at the Woodleigh 500gr RNSNs and FMJs too but the 480gr is preferable in my mind. I'll also probably shoot it with cast bullets but it would be difficult to identify exactly which style as the ones I'd use would be locally manufactured items.
 
Barrel Length: 26"
 
Chamber Pressure: I'm saying 40,000 psi as the safe limit because I'm using a  Martini Enfield action and their limit was 45k psi due to the operating pressure of the 303 British cartridge they were chambered for. If it's still possible to develop 2100 to 2200fps loads with a 480gr pill by keeping it a fair bit under 40k psi then great. However the advice I've had from guys who regularly hunt buff is that you want the bullet to be moving in that MV range so that the impact velocity is still considerable. If someone actually made a 400gn solid for 45-70 I'd be there with bells on but the problem is all of the solids in 45 cal are designed for the 458 Win Mag or the Nitro Express cartridges and as such are 500gr bullets. The 480gr Woodleigh is the lightest FMJ I'm aware of.
 
BTW, I think this is important and from memory can be figured in......
 
Operating temp for both loads: 37 C - this is a common temp in Northern Australia and the last thing I want to do is load test in NSW in 25 C weather with no ill effects and then blow up the rifle when in the Northern Territory.
 
Thanks for this, Paul. :biggthumpup:
Cheers & God Bless
22lr ~ 22 Hornet ~ 25-20 ~ 303/25 ~ 7mm-08 ~ 303 British ~ 310 Cadet ~ 9.3x62 ~ 450/400 N.E. 3"


gitano

Hokay...
 
Barnes makes a 400 grain solid (and a 450 and a 500) and there are 475 and 480 solids available too from "PMP" and "GPA". So, using 100.9 grains of ADI 2209, a 26" bbl and the Barnes 400 grain solid, QL guesses that you can get 2369 f/s right at 40,000 PSI. Muzzle energy is a "healthy" 4986 ft-lbs at the muzzle, and 2600 ft-lbs at 300 yds.
 
Sighted in for a 12" target (plus or minus 6" above and below Line-of-Sight - seems reasonable for a water buffalo), the zero range is predicted to be 230m and the Maximum Point Blank Range is estimated at 270m. With that sight-in, the bullet will likely be about 6.7" low (17cm), at 275m (about 300 yds).
 
Other ADI powders that can get you to 2200+ f/s and stay below 40,000 PSI are 2208, 2213 and 2214. As for Hodgdon, IMR and Alliant, the "best" (defined by highest velocity) is IMR4895 at 2393 f/s at 40KPSI.
 
OOPs ... almost forgot about your temperature consideration. A point well-taken. At 37 degrees C here's the change for the 2209:
 
99.28 grains of 2209
MV goes up to 2376 f/s
Since these are all estimates, everything else remains essentially the same as 2369 and 2376 are only 7fps different.
 
So there you are. As we say "over here"; Knock yourself out... in this case, pun intended considering the almost 5,000 ft-lbs of muzzle energy. :)
 
Personally, in a Martini rifle, I'd be opting for the 577/450 over any of the "modern" cartridges. It's clearly got all the oomph you need, even for water buffalo, and it's a "natural".
 
Paul
Be nicer than necessary.

kombi1976

Thanks, Paul.
When this project gets up, and it appears it's going to be a "when" now that I've looked at the possibilities, I'll certainly be using these estimates as a starting point.
Cheers & God Bless
22lr ~ 22 Hornet ~ 25-20 ~ 303/25 ~ 7mm-08 ~ 303 British ~ 310 Cadet ~ 9.3x62 ~ 450/400 N.E. 3"


gitano

Waaallll... I'd be mighty carefull using these numbers. This is almost "back of the envelope" stuff. I realize you didn't just fall off the turnip truck, but there may be others watching that would benefit from some 'amplification' of the information and how to use it wisely. In that vein, I'll offer the following:
 
First is this issue of "chamber pressure". It's not as simple an issue as we are lead to believe. It seems straight forward enough, and it is at a certain level, but when one starts 'fiddling', one needs to at least consider all of the actual elements that act on an action during firing. Let's take the Martini as an example to consider.
 
Let's say the Martini action was originally designed to handle the 577/450 with a chamber pressure of about 25,000 PSI. However, since its creation, "things" have changed, and folks have been able to use cartridges that are generating chamber pressures of 40,000 PSI. It is easy to make the leap and say, "If so-and-so has used such-and-so cartridge in a Martini action, and that cartridge developes 40,000 PSI with the charges used, then, by extension, I should be able to load a cartridge that develops 40,000 PSI with no problem." Well... only maybe.
 
When I got my Martini Enfield, it was chambered in .22/.30-30. Not having any loading data for that wildcat, I started working my way up. I stopped at 4500 f/s with a 45-grain bullet. The chamber pressure was at least 60,000 PSI... and probably higher. When I considered rechambering to the .50 Alaskan, I had to decide on a max chamber pressure. Based on the experience with the .22/.30-30 it would have been easy to say I could load the .50 Alaskan to chamber pressures of at least 60,000 PSI. It would have been easy, but wrong. Here's why:
 
The area of the base of the .30-30 case is ~0.201 square inches. Multiplying the chamber pressure in pounds per square inch, by the area in square inches of that part of the case that presses on the breech face, yields the actual pressure that the breech will have to sustain at firing. For the .30-30 case at 60,000 PSI, that actual force on the breech (AKA bolt thrust) is 12,060 lbs. The area of the head of the 577/450 case is ~0.454 square inches... more than twice that of the .30-30. If I were to load the .50 Alaskan to a chamber pressure of 60,000 PSI, the breech would have a "bolt thrust" of 27,240 lbs (.454 x 60,000). It's clear to see that the same "chamber pressure" of 60,000 does NOT translate to the same force that a breech would have to withstand for different cartridges.
 
Let me give another non-gun example that most everybody has experienced or can readily comprehend. Imagine holding up a playing card in a 20 mile-per-hour wind. No sweat. Now imagine holding up a 4-foot by 8-foot sheet of plywood in that same 20 mph wind. There'd be quite a bit of "sweat" trying to hold the plywood up. The same is true of "chamber pressures" (miles per hour), for different cartridges.
 
Finally. If a cartridge with a case head approximately the size of the 577/450 has already been loaded to 40,000-ish PSI chamber pressures in a Martini Enfield action, then I'd say you're "home free". I simply don't want to have anyone think translations from one cartridge to the next are simply a matter of equalizing "chamber pressure".
 
Again, I assume you're already aware of this Kombi. I was just 'elaborating' for the sake of lurkers.
 
Paul
Be nicer than necessary.

Paul Hoskins

And NEVER oil any cartridge.  ...........Paul H

kombi1976

Your theories on breech face pressure had already occurred to me and that's why I'd declared a maximum pressure of 40k, not 50k or 60k, as some brave souls are happy to try in Martinis with a range of cartridges.
In fact, if only to reduce the recoil from a bruising 60 ftlbs (which the 400gr/2369fps load develops in a 10lb rifle) to something less punishing, I'll be working up to the load to see what can be achieved with less pressure.
Pushing a 400gr bullet at that speed is only about 50fps behind standard loads in a 416 Rigby! :eek:
So I think it is perhaps a little excessive, as Asiatic water buffalo are less bad tempered than their African cousins.
But all in all, most of my shooting will be done with 300gr bullets like the Sierra Pro-Hunter 300gn HPFP so it should be less punishing and on game excluding buffs and  scrub bulls (feral cattle) will be ample fire power.
The only thing I could wish is that the 300gn bullets weren't designed for tube-mag 45-70s as they have the ballistic coefficient of a cement truck and, correspondingly, a similar trajectory. :(
Anyhow, your calculations courtesy of QuikLOAD are an indication of the MAXIMUM performance capable from such endeavours, no necessarily the most sensible or practical performance.
So have no fear, your warnings have been heeded and the roughly 5,000ftlbs of ME was enough to scare even me!
That's muzzle break territory and when I have to start considering that I've gone a bit far.
Besides, if I got a rifle with a muzzle break Brithunter would never forgive me! :D
Cheers & God Bless
22lr ~ 22 Hornet ~ 25-20 ~ 303/25 ~ 7mm-08 ~ 303 British ~ 310 Cadet ~ 9.3x62 ~ 450/400 N.E. 3"


Brithunter

QuoteThat's muzzle break territory and when I have to start considering that I've gone a bit far.
Besides, if I got a rifle with a muzzle break Brithunter would never forgive me!
:D
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   Ahhhhh Kombi,

        Just thought I should mention the fact that I did actually pick up that BSA Majestic in .243 Win which does have the BESA muzzle brake machined into the barrel :jumpingsmiley: . Although when and if a actually get round to shooting it is rather a moot point right now. According to my licence it's for collection only and so cannot be shot :mad: .

  Secondly .................... you are one heck of a long way from me so you shooting with a brake will effect me in no way what so ever :nana:  After all it's YOUR hearing and those poor souls around you that will be effected NOT ME!

   Funny thing is that I have not seen many of the braked rifles at the range although I have not been so often this year due to weather etc. But it seems that the fashion thing may be wearing off :jumpingsmiley:  let's hope so.

   Sorry no photos as I cannot get Mum's PC to coperate with my camera. It seems that XP Home is not compatable with the Olympus software :no: . Mum however is talking about buying a digital camera so hopefully I can steal hers to take soem photos :laugh: . Now I just have to tip her over the edge to actually getting it :yes: .
Go Get them Floyd!

gitano

QuoteThe only thing I could wish is that the 300gn bullets weren't designed for tube-mag 45-70s as they have the ballistic coefficient of a cement truck and, correspondingly, a similar trajectory.

Well, I have good news and bad news. The good news is that there is a .458", 300-grain bullet with a sufficiently large BC so that its 300-yd trajectory is in fact "not so bad". The bad news is, it's a Winchester, so good luck getting one. Nonetheless, here are some numbers for it:
 
300-grain Winchester JHP (Jacketed Hollow-Point)
108.1 grains of AP2214 (at 37 degrees C)
Muzzle velocity = 2264 f/s
Muzzle energy = 3416 ft-lbs
Chamber pressure = 29,200 PSI
 
The trajectory of which is, when sighted in for a 12" target, using a 'scope whose centerline is 1.5" above the centerline of the bore:
100 yds - +5.5", 2800 ft-lbs delivered energy
200 yds - +4.3",  2285 ft-lbs delivered energy
250 yds - zero range, 2060 ft-lbs delivered energy
291 yds - -6" (MPBR- Maximum Point Blank Range), 1885 ft-lbs of delivered energy
300 yds - -7.4", 1850 ft-lbs of delivered energy
 
A decent trajectory, only 29,000 PSI chamber pressure, an ME in the mid-30s, and delivers 1850 ft-lbs (in a .458" bullet) out to 300 yds. That ain't too shabby. It is however, dependent on a couple of crucial factors though - the acquisition of the Winchester bullet, use of a 'scope at 1.5" above the C/L of the bore, and sight-in for 12" target.
 
Changing the powder to AR2208, and allowing the chamber pressure to rise to 40,000 PSI, you can get that bullet doing 2641 f/s at the muzzle. If you instead sight it in for a 6" target, and leave open sights on it (Line-of-Sight 0.75" above C/L of bore), you get these results:
 
92.8 grains of AP2208 (at 37 degrees C)
Muzzle velocity = 2641 f/s
Muzzle energy = 4647 ft-lbs
Chamber pressure = 40,000 PSI
 
The trajectory of which is, when sighted in for a 6" target, using open sights whose centerline is .75" above the centerline of the bore:
100 yds - +2.9", 3868 ft-lbs delivered energy
200 yds - +0.6",  3196 ft-lbs delivered energy
210 yds - zero range, 3135 ft-lbs delivered energy
247 yds - -3" (MPBR- Maximum Point Blank Range), 2914 ft-lbs of delivered energy
300 yds - -8.9", 2619 ft-lbs of delivered energy
 
Nine inches low at 300 yds (274m) delivering 2600 ft-lbs of energy, "ain't too shabby either" if you don't mind the 4650 ME and 40,000 PSI chamber pressure.
 
The BC for the Winchester bullet is listed at 0.275. There were several other 300 -grain bullets with BCs of .200.
 
Paul
[/COLOR]
Be nicer than necessary.

kombi1976

#12
Quote from: BrithunterAhhhhh Kombi,
 
Just thought I should mention the fact that I did actually pick up that BSA Majestic in .243 Win which does have the BESA muzzle brake machined into the barrel :jumpingsmiley: . Although when and if a actually get round to shooting it is rather a moot point right now. According to my licence it's for collection only and so cannot be shot :mad: .
AHHH!!! You dirty hypocrit...actually buying a braked rifle! :D
Mind you, those laws of yours are clearly the product of delusional tossers! :mad:
 
Quote from: Brithunter[/COLOR][/SIZE]Secondly .................... you are one heck of a long way from me so you shooting with a brake will effect me in no way what so ever :nana: After all it's YOUR hearing and those poor souls around you that will be effected NOT ME! [/COLOR]
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C'mon, BH, sure as Shane Warne loves mobile phones, if I turned up at your range with braked 577/450 Martini you'd be all over me like a cheap suit.
 
Quote from: BrithunterMum however is talking about buying a digital camera so hopefully I can steal hers to take soem photos :laugh: . Now I just have to tip her over the edge to actually getting it. :yes:
[/SIZE][/COLOR][/SIZE]
Didn't you tip your mum over the edge years ago? :huh2: :D
Cheers & God Bless
22lr ~ 22 Hornet ~ 25-20 ~ 303/25 ~ 7mm-08 ~ 303 British ~ 310 Cadet ~ 9.3x62 ~ 450/400 N.E. 3"


kombi1976

Wow....0.275 is a decent BC for a 300gr .458" cal bullet.
But I fear you are right in terms of availability.
The Remington 300gr HPFP is the most easily available and, I might add, the cheapest.
So it's probably likely to be the common choice of bullet, unless it shoots "minute-of-mastadon" of course.
But with 3400fps of ME using the 29,000psi load I may well end up using it.
Ok, so the plus/minus 3" MPB range of that load with the Rem bullet is just over 200yds with around 1500ftlbs of retained energy at that distance but even a sambar deer, which are similar to elk, wouldn't know the difference.
In a 10lb rifle that equals roughly 44ftlbs of recoil, which is kinder both to me and the rifle than the 2641fps/40,000psi load which packs about 48ftlbs.
Personally, I reckon I'll feel ever extra ftlb of recoil.
The other aspect of hunting sambar deer particularly is that most shots are around 100yds and sometimes less as they live in dense mountain forest and you take your shots when they come into view.
The whole aim with this rifle is to develop a rifle I can use on big game and then, when the opportunity arises, use on REALLY big game.....arguably dangerous game, although not in the same sense as African dangerous game.
Incidentally, I gather you mean AR2214 and AR2209 when you wrote AP2214 and AP 2209.
Thanks again, Paul.
Cheers & God Bless
22lr ~ 22 Hornet ~ 25-20 ~ 303/25 ~ 7mm-08 ~ 303 British ~ 310 Cadet ~ 9.3x62 ~ 450/400 N.E. 3"


Brithunter

Hi kombi,

QuoteAHHH!!! You dirty hypocrit...actually buying a braked rifle! :D
Mind you, those laws of yours are clearly the product of delusional tossers! :mad:
[/COLOR][/SIZE]

   Who said anything about laws? there is nothing in law about this! The Police use "Conditions" on the certificate to limit use. Conditions are decided by the Chief Constable (yeah right) and these Conditions are very hard if not impossible to fight or arguee with. The whole system is a farce :frown .
 
[/COLOR][/SIZE]

Hmmm I did tell you I was getting it. It does have a "Range Adaptor" which clamps over the brake to shut it down and once I got that off I am inclined to believe that it's nevver been removed since the rifle was new :eek: the crud that is burnt on under it has to be seen to be believed.


Even after soaking in P-H 009 nitro solvent I have had to resort to using a wood chisel to scrape the deposits off and even then it's hard going :frown I will have to touch up a couple of scratches left by doing this and the deposits have marred the blacking under the adaptor on the outside of the barrel. Next I need to get a tin of the Forrest Foaming bore cleaner to de-copper the bore then clean with 009. Once all this is done I will attempt to repair the bedding and barrel channel where some "en-lightend" previous owner free floated the barrel :Banghead: . I found three card shims between the bootom of the recoil lug and the stock holding the action off the stock bedding.


Despite the fact that the bottom of the recoil lug should not touch the stock nor the sides and front only the rear should contact :Banghead: . When in town today shopping for the weekly food etc :stare: I will see about gettign a tube of Platic Padding's "Plastic Wood" to repair the barrel channel and use to bed the action to bring it up to it's proper place in the stock. This stuff has some elasticisity in it so does not crack and is stainable to match the wood. With the light recoil of this rifle it should work well :biggthumpup: . Then I only have to work out the correct pressure on the barrel at the fore stock :confused: if this defeats me then I will have to contact Bob Harvey and see if he will do the job.


Only having seen BESA equiped rifles in books I was quite stunned to be shown one, and one that had the range adaptor as well :smiley: . Oh it even had a set of P-H rings attached.


QuoteDidn't you tip your mum over the edge years ago?
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Hmm I didn't know that you and Mum were aquainted! :confused: Hmmm I will have to tackle her about this...................................   Well just did so and she denies knowing a strange Australian :greentongue: although she did say that betwen me and my father we tipped her over the edge years ago :eek: .

QuoteC'mon, BH, sure as Shane Warne loves mobile phones, if I turned up at your range with braked 577/450 Martini you'd be all over me like a cheap suit.
 
[/COLOR][/SIZE]

   Hmmm not so sure on that :confused:  it would depend wholly on the overall style of the rifle. Classically styled well yes there is that possibilty but with modern styling I would only be mildly curios :greentongue: .
Go Get them Floyd!

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