Acquired a 500 Nitro for Black - now what?

[rookhawk]

Incidentally, I was confused by the comments in the thread when comparing a 500BPE to a 500 Nitro for Black as people were treating them similarly.

The former has a muzzle velocity of 1400 and the latter 1900 so doesn't that alone make them completely different in there capabilities with the same 440gr bullet?

 

[flatwater bill]

Rookhawk...............what a great project. My experience with old rifles and jacketed bullets is a short half life. Soft swaged and copper jackets help, but most of these guns were designed and built in the lead bullet era, and metallurgy was different then. Still, we don't get to shoot too much nowadays, so it will likely last a hunting lifetime. There are dozens of molds for lead bullets of this size (.510 to .512) from, say, Mountain Molds and others. Depending upon the thickness of the brass, you can approach but not equal the original loading of 148 grains of Fg black. IMO the best powders are already chosen....4198 and 4759. Did you chronograph your load? Guessing about 1600fps with 53 of 4198? That would be a bit over 2500 ft lbs of energy. Make a good buff load..............with a PH and a 505 Gibbs closeby...................FWB

 

[rookhawk]

I didn't chrono that. I thought that a 53gr load of IMR4198 with a 440gr bullet in 500 express should be around 1900fps according to charts i'm looking at. Can you clarify the 1600fps comment?

Had not considered cast bullets and paper patches at all. Was trying copper jacketed woodleigh and hawk bullets. Not sure I have the talent to smelt and load lead.

 

[cal pappas]

You have it.
I shot my first African animal with my .500 bpe--an eland.
Use a stout bullet for hippo.
Cal

 

[CAustin]

Hope this all works out really well rookhawk. Maybe you will get a buff with it!

 

[flatwater bill]

Rook............I figured about 1600fps for your load. Maybe a little more. I didn't note whether you had the 3" or 3.25" case, and it makes a little difference. Also barrel length of course.
Here's why: I have never shot the 500 Express, but have burned pounds of powder in the big 50 Sharps. Bullet about the same (473 grain cast, but a little lighter with added hardening agent, hence 455 grains) diameter .510, to .512. This is a 2.5 inch long case. Best powders for me to duplicate BP loads 4198, 4759 and Re-7. I cannot get 1900 fps or even close. Even with 53 grains. about 1700 fps. Your case is larger, same amt powder, lower overall time-pressure curve, my estimate 1600's.
Old Frank Barnes in his classic book "Cartridges of the World" said 41 grains of 4198 would give 1560 fps. (I could not duplicate this, however). So 53 grains is 29% more powder, 29% more energy, so this corresponds to a velocity of 1770fps if you got 100% efficiency on this added powder. I have never seen 100% on anything, so maybe 1650.

Your rifle is regulated. So more likely to be reproducing original load. Original loads listed 1925 fps but this was with their 340 grain bullet, sounded better for ads.

Hope you prove me wrong by getting 1900 fps, thus over 3500 ft lbs energy, which would equal the original advertised power of the .577 BPE with its 648 grain bullet and 167 grains of Fg. But it seems unlikely to me............................Anyway, your rifle will have a lot of power and be fun to shoot..........more funner, according to my granddaughter............FWB

 

[rookhawk]

@flatwater bill i wanted to reply but never had my research handy to discuss with you.

The 1902-1903 kynoch data says my gun shot 55 grains of granulated cordite at 1850fps at 8.0tpsi from a 30" barrel

It says 55 grains stranded cordite @ 1900 fps at 10tpsi from a 28" barrel.

Both the above with "copper tube lead" aka wood Leigh copper jacket soft point 440 gr.

Page 217 of Graeme Wrights book says 57 grains of 4198 with a fed 215 primer and 440 woodleigh is 1910 fps at 8.8tpsi from a 28" barrel.

So if 57 grains is 1910fps, 56 grains is 1850fps, what is 53 grains? (26" barrel)

I think the confusion comes in because a "light nitro" we call a "nitro for black" is not really the same as a later nitro proofed BPE. My gun was made for nitro at birth and was made for 440gr bullets. It isn't a 340 gr regulated gun made for black.

Interesting foot note. It does not appear there ever was a black powder load for 440gr bullets? It was always a nitro load. The heaviest black load I found was 136gr black with 380gr bullet at 1850fps.

 

[cal pappas]

I seem to recall black powder loads for 440 grain and 480 grain bullets in the .500 3 1/4" case.
British ballistics were taken from 28" barrels.
Nitro for black is just that: a nitro charged case to equal pressure and accuracy of a bpe rifle
Light nitro were always nitro rifles with a lighter than normal charge
Your rifle will shoot 55-57 grains of IMR 4198 and a 440-grain cast or Woodleigh bullet with acceptable accuracy and safe pressure.
One grain of powder will not equate to 60 fps. Then, as now, there was blue sky in the ballistic numbers.
Cal

 

[rookhawk]

So @cal pappas , my loader will load 53gr of 4198 and a good stout DG thick jacketed bullet of 450gr.

He won't load higher pressure than that as he thinks Graeme was too risky.

Is a 1600fps load with that dangerous game soft point enough for a Cape buffalo side shot if that's what the speed really is? (PH will keep me alive with a 458 but think it's lame if I have to request him to follow up for me)

 

[rookhawk]

Nitro for black is just that: a nitro charged case to equal pressure and accuracy of a bpe rifle

Exactly. Equal to black powder pressure. Most people argue that it was to equal blackpowder velocity when in fact it was much faster, just at a similar service pressure. (Or actually faster at lower pressure according to Graeme's book)

So Cal, if my rifle has no BPE proofs and was born and made for a 55gr cordite load and a 440gr bullet, is it a light nitro or a nitro for black gun? Is it splitting hairs? What is the regulation load for a light nitro if different? It weighs 11.5lbs and was made circa 1904-1911.

 

[cal pappas]

Get a new loader.
I have known Graeme since the mid-1990s and his knowledge of double rifles will stand up to anyone.
If he thinks Graeme's information is too risky, I would be interested to see his credentials and experience with dozens of doubles.
1600 pfs will get the job done, 1800+ is better. We are not trying to magnumize the old doubles, but they are meant to be shot at their potential. I have been shooting .500 bpe since 1989, in many rifles, and 1850 fps has worked--safely and accurately--in them all. The same with many friends.
Again, get a new loader.
Cal

 

[rookhawk]

Update on the project.

The rifle is all set for Africa! She has a hideous (yet practical) green fiber front sight on it. I obviously kept the original so I can burn the modern one someday as penance.

I have a load that according to quick load is as follows, although I think the performance may be higher than published here:

500 nitro for black 3”
18,178 psi
Muzzle Velocity 1738
95% powder burn
450gr Woodleigh RN SN 06A (.065" thick jacket)
55 Grains of IMR 4198 powder
Taylor Knockout Value 56.9
70+ yard maximum point blank range
50 yard impact H.I.T.S. score of 1782

The above load opened up my regulation pattern a little. The Center to Center is about 2" for a composite group so I don't think I can push it any further. My loader certainly doesn't want to take it further so I'll have to experiment myself if I want to push my luck at some point in the future.

 

[cal pappas]

Great. Go toAfrica and kill a buffalo!
Cal