577-450 with smokeless

woodchopper

woodchopper

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Well its been a while and I think that this needs its own thread

Now I know there will be someone along shortly that will pronounce that in their internet expert opinion it is fact that if you load up black powder rifles with smokeless powder first your #### ewill fall off and then the gun will explode. Because smokless powder burns too fast.

Well I guess I'm stupid, and my smokeless powder is defective. But really the data that I'm looking at tells me that smokeless is both faster and slower it depends on what you choose. So rule of thumb is slower then 2400 is fine just don't stuff the cases.

So where was I


first loads

IMR4895, 35 grn, with a 350grn jacketed projectile, large rifle primers, with wadding, poor ignition rate, really un-spectcular, more of a pop then a Boom

IMR4895, 35 - 37grn assortment, 350grn jacketed projectile, large Magnum primers, with wadding, much better ignition, 37 grain loads were almost like firing a rifle. still fairly un-spectacular


Now with some quick load data (thanks to gunnutz) I see that IMR4895 is way too slow and will never generate enough power or burn 100%

IMR4198 is faster and the quick load numbers are starting too look better, a max load is about 60% fill with about 95% burn

So I checked my powder shelf.... IMR 4350, H380, win 760 and 748 hmmmm no 4198.

Well I need different bullets anyways so off to the shop.

I now have some nice RN lead 405grn bullets and decided to go with IMR4227 so my next load will be with those componants

I'll have to do some thinking but I suspect that 25-35grn range is where I will end up.
 
woodchopper said:
IMR4198 is faster and the quick load numbers are starting too look better, a max load is about 60% fill with about 95% burn
.
Click to expand...

Without measuring the actual amount, 60% fill of a martini case sounds like an awful large amount of powder. Unless you have some numbers from a knowledgeable person, I would start with the 4198 load for a 45-70 and work up carefully from there
I have shot a number of black powder cartridges with fast burning smokeless powders but never the 577-450 so I don't have any numbers to give you.

cheers mooncoon
 
Oh don't worry, if I think the load may be ok at 30grns I'll start at 20grns and work my way up :)

You don't get old doing stupid stuff :D

and yes those cases are HUGE. I think they hold 100-120grn of black powder
 
That case is huge - almost twice as large as the 45/70. It just might not be a good candidate for smokeless. I found the 577 Snider a tough one - it was best with medium speed pistol powders, as the fast rifle powders gave incomplete burns and erratic velocities.

I'd try:

Unique - 10.0 to 13.0 grs (or max 1000 fps)
2400 - 20.0 to 25.0 grs (max 1200 fps)
SR-4759 - 25.0 to 30.0 grs (max 1300 fps) - my first choice
H4198 - 35.0 to 40.0 grs (max 1500 fps)
IMR-3031 - 45.0 to 50.0 grs (max 1600 fps)
 
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I've been doing a lot of internet searching on this subject and haven't found very much useful information. I look forward to reading about your results. Good Luck.
 
in all my searching this is the longest list I found

I have an old Handloader Magazine article (Nov-Dec 1978) by Jim Jukes on
just this subject,
and it gives the following data:

.577-.450 Load Data

Powder Charge(grains), Bullet Weight (grains) Velocity(fps) Remarks
Gibbs Long Rifle:
IMR-4759 27 Lee 400 1,172 Mild load
Blue Dot 27 Lee 400 1,422 Blue Dot good with lighter bullets
Unique 16 Lee 400 1,124 Light recoil
Green Dot 16 Lee 400 1,094 Nice-shooting
Red Dot 16 Lee 400 1,136 Nice-shooting
Herco 20 Lee 400 1,272 Efficient load
Nobel 100 51 Lee 400 1,390 Some powder left in bore but ignition OK
IMR-3031 45 Lee 400 1,424 Powder left in bore - wadding essential
Blue Dot 19 (Loverin)457121 475 1,075 Nice load. Accurate
Blue Dot 22 457121 475 1,220 Very uniform, with wadding
Blue Dot 25 457121 475 1,374 Powerful, but OK pressure and very uniform velocity
IMR-4759 23 457121 475 990 Very accurate, mild
IMR-4759 25 457121 475 1,109 Very accurate, mild
2400 20 457121 475 1,132 Wadding a great help
IMR-4756 20 457121 475 1,082 Very accurate load
IMR-7625 18 457121 475 1,069 2-inch 100-yd group from benchrest
Herco 20 457121 475 1,213 Good Ignition

Unique 6 457121 475 1,197 Duplex load. Clean-burning
FFg Black 52

IMR-4759 8.5 457121 475 1,102 Duplex load. Clean-burning
FFg Black 50

Nobel 100 51 457121 475 1,378 Only 23 fps velocity spread
Nobel 101 45 457121 475 1,342 Only 28 fps velocity spread
IMR-3031 45 (Lyman)457125 500 1,582 Plenty recoil. Some powder kernels in bore
IMR-4064 50 457125 500 1,529 Unreliable ingition. Wide velocity spreads. Low reading was 1,270 fps.
Reloder 7 37 457125 500 1,416 Unreliable Ignition
IMR-4759 27 457125 500 1,170 Good-shooting load
Nobel 101 50 457125 500 1,540 Plenty recoil but extraction OK

Army & Navy Carbine:

Blue Dot 22 457121 475 1,145 Good load
IMR-4227 30 457121 475 1,144 Wadding a must

1877 Enfield Carbine:

Blue Dot 22 457121 475 1,160 Wadding a must
IMR-4759 8.5 457121 475 1,042 Duplex load. Clean-burning
FFg Black 50
Click to expand...
 
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Thanks. I have been thinking of trying the IMR 4759, but I have Blue Dot and some of the others on hand already, so I may try that first and see how she goes. I've been wanting one of these old bangers ever since I saw Zulu some 30 odd years ago.
 
I've noticed on my burn rate chart that IMR 4759 is very close to IMR 4227, with IMR 4227 being the slower of the 2.

I'm really thinking that 30grns of IMR 4227 with a 405grn lead RN is looking like it should be fine. (I'l be starting at 20 grns and working up)
 
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Are you using any kind of filler? I've read of people using dacron and other stuff to keep the powder near the primer.
 
well I've been out of town and now that I'm back I can report that 28grns of 4227 is not enough. I'm not getting enough presure to fire forming the cases properly yet.

got some quick load data that looks good and matches my observations so next batch will start at 30grns and work up to a comfortable level :D I'll look at the data again before I get too far down that road. I think that 45grns is in the dangerous level, and can't think of any reason why I would even try that.
 
woodchopper said:
well I've been out of town and now that I'm back I can report that 28grns of 4227 is not enough. I'm not getting enough presure to fire forming the cases properly yet.

got some quick load data that looks good and matches my observations so next batch will start at 30grns and work up to a comfortable level :D I'll look at the data again before I get too far down that road. I think that 45grns is in the dangerous level, and can't think of any reason why I would even try that.
Click to expand...

I wouldn't use "properly fire-formed" cases as your indicator of safe pressure in these old girls. The hardness of brass can vary a lot, and the low pressure these old girls are designed for "balloons" the brass more than forms it into a distinct chmaber-shaped profile.

The better indicator is MV, which with IMR4227 and a 405 gr bullet, should not exceed 1400 fps IMO. I think that the 35grs you are talking about would be about a top load.
 
A brief range update:

The Lee mold for the 475 Linebaugh, a 400gr PB that drops at about 0.476", can be sized down to 0.465" and still retain sufficient lube grooves to be effective. I add a bit (of Alox) to the nose after seating.

This bullet shoots well over 25.0 grs of SR-4759. I find SR-4759 to be about the slowest smokeless powder to work effectively in large capacity cases (the 577-450 being an extreme example) without wadding. Unique and Trail Boss and other faster powders also work well without wading, but you will not get anywhere near the MV as SR-4759.
 
I'm making bullets for folks in that cal. that are either .468" or .475" and 480grs. I don't believe good accuracy will be had with .458" bullets, from what i've heard.
 
Hey woodchopper, I know this is an older thread, but how did you make out with the IMR 4227? get any good results? also has anyone had any good results with a .458 bullet? My Martini is a MkI and I've heard that the MkIs had the smallest bores on the spectrum?
 
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