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gschwertley
saddle soap
Posts: 761
(6/4/05 8:55 pm)
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Cast Bullet Data for 8x56R Austrian
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I'm fearful of posting any more data on our board, but here goes.
Thought I would pass along some cast bullet data so as to help someone else interested in the same for 8x56R Austrian.
Rifle used was one of the typical recent Steyr-Mannlicher Model 1895 imports from Bulgaria reworked circa 1939-40 and stored away. The one I chose for testing this data had a small "s" marked barrel, no date, indicating it was newly installed by the Bulgarians and accordingly bore conditon is excellent. It is a short rifle.
First data offered:
115 grain hard-cast bullet sized .330 (originally intended for Lebel 8mm revolver)
Primer used: WW large rifle
Propellant used: 6.0 grains Unique
Case used: Graf boxer primed (recent Serbian manufacture)
This is a sub-sonic load, in the spirit of the great Finn P.T. Kekkonen and clocked an average of 977 fps. out of my test rifle. The standard deviation in muzzle velocity was 3.21 fps. which is pretty good. The only downside was some smoking of the cases, which is to be expected with a charge this small not being able to completely seal off the case neck at time of firing. Steyr-Mannlicher Model 1895 commonly have generous chamber sizes as well.
The accuracy of this sub-sonic load was a two and one quarter inch group (with one flyer) of five shots and it printed two and a half inches high from point of aim (center of target). The range at which fired was 50 yards. I like to start at 50 yards with cast bullets in unknown loadings, as you never can be sure where they are going to end up. Besides, I am an old geezer now and shooting with open sights limits my capabilities anyway. Added to that, right now I am wearing a neck brace following a cervical fusion surgery, so I didn't do too badly at that.
This .330 115 grain bullet is not commonly available. If you are very devout, NEI can make you a mould for $80.00.
Another load I can pass along data on is based on the C.E. Harris formula of 16.0 grains of Alliant 2400. Over this I used a hard-cast 200 grain lead bullet cast in an inexpensive Lee mould and sized .329 with a .32 Hornady gas check. The same Graf brass and WW primers listed above were used.
This load clocked an average muzzle velocity of 1412 fps. and had an standard deviation of 8.78 fps. which I think is good for a load that C.E. Harris recommends for many difference but similar cartridges. Same M95 rifle was used as above. Test shots were fired at 50 yards and printed a two inch, five shot group four inches low from point of aim at center of target.
The usual caveats apply, be sure you use a weapon that is safe to shoot, if in doubt check with gunsmith; your rifle is different from my rifle and results my be different; use safe loading techniques, etc.
This was my first trip to the range with my new chronograph. I did fine with the M95 and with some 9mmP lead bullet loads, but we won't talk about the disaster with the M38 Mosin Nagant loads.
My trip to the range was not to the usual indoor range where I am a member. The chrono needs an incandescent light source for the sky screens indoors, so with the other hassles of using the chrono at this range, I gave it up. Then I thought of an outdoor range north of me a ways that another shooter told me about last year, called "Everett (Washington) Sportsmen" which is outdoors, located out on some river bottomlands. So I went up there, had a great time, met a few great people and found out they only have a little over 100 members. Looks like I will have to buy another membership.
Edited by: gschwertley at: 6/10/05 11:58 pm
yockey5
Coffee Pot
Posts: 6152
(6/5/05 8:55 am)
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Re: Cast Bullet Data for 8x56R Austrian
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Sounds as if you found a nice and new sandbox to play in Gary! It's always good when we can meet new people. Thanks for your info.
Gary, if you bumped up the light load to seal the cases when fired would it hinder accuracy?
Don
Yesterdays Weapons forums
http:pub151.ezboard.com/bsteyrmannlicher.
gschwertley
Posts: 763
(6/5/05 3:15 pm)
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8x56R CB loads
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Don:
I fired a test string of the same thing with 7.0 grains of Unique and lost a little accuracy and deviation increased. My goal is to keep this load sub-sonic, that is, under the speed of sound, so as to be as quiet as possible. The speed of sound in our atmophere varies of course with the humidity, elevation, temperature and other things. Let's just say for the purposes of estimation it is around 1,115 feet per second. My loads of 7.0 grains of Unique clocked an average of 1,089 fps. and this is getting pretty cotton-pickin' close to the speed of sound. In fact, on some days it could exceed it, given the variables involved. Yesterday, it did not, because I could tell by the sound as well as the chrono. It made more of a "pop" and had no "crack" to it.
When I test again, I will go for 6.5 grains of Unique and see how that does. I don't think it will make much difference on the smoking of the cases; with 7.0 grains, there was some smoking, maybe a little less than when using 6.0 grains. The smoking isn't bad; no carbon blackening; it just looks like candling. Also remember, those short 115 grain bullets have a fairly big leade to jump in these rifles.
The problem with getting more of these bullets is a bigger challenge. The vendor I was getting these from in Oregon quit making bullets. After his modest supply is gone, I have to decide if I want to go for that expensive NEI mould. The mould costs about what one of the M95 carbines are worth! Yes, you can re-size .357 bullets down in stages, but not only do they not look good (does that count?), but they won't have a shape that allows them to feed multi-shot through the magazine, in my opinion.
One other thing that I forgot about. I was advised that if you get the speed up too much on those short bullets, they will lose stability and will tumble. This was from a reloader who had experimented with the Graf jacketed .330 pistol bullets made by Hornady. There is no reason that these Graf jacketed bullets could not be loaded sub-sonic, just like the lead ones. At these lower speeds, these bullets would be sure to stabilize.
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