gschwertley
saddle soap
Posts: 1367
(10/30/05 7:35 pm)
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I got a chance to get out to the Everett Sportsmen rifle range today and check out a few loads. I have had some 8x50R reloads of my own making here that I wanted to try out, for one thing. It was touch and go with the rain; the chrono got a little dew on it before I got done. Worse, I chronoed some brass case shotshell loads before working with the rifle cartridges, and fiber wad debris got blown all over the chrono. I had to clean this off before I could get good readings.
I had two loads prepared, one with a jacketed bullet and one with a cast lead bullet.
Starting with the jacketed bullet load, I used milsurp Turkish pulled 8mm (.323) bullets of 150 grains. More comments on this bullet later. The propellant charge was 37.0 gr. of milsurp IMR 4895. Primers used were WW LR.
For cases on these loads, I converted some Bulgarian surplus 8x56R 1939 and 1941 dated Berdan-primed cases to accept boxer primers. This is a story in itself. After conversion of the primer type, I cut them down and re-sized then to 8x50R. I have converted these cases before to accept boxer primers, but used them in their original 8x56R configuration with success. Apparently, it is asking too much from this old brass to it to take the re-sizing to 8x50R. Of the 20 cases I had converted, 16 failed at the new neck. Only 4 did not split. It was an experiment and I will close the book on this possibility.
The jacketed bullet loads with 37.0 gr. of milsurp IMR 4895 clocked an average muzzle velocity of 1646 with a standard deviation of 31.80 on one string, and 1645 with SD of 20.91 on another string. Accuracy was fair at 50 yards.
That muzzle velocity in the mid-1600's is too low, in my opinion, in relation to the potential of this powder. 38.0 gr. of IMR 4895 in a .300 Savage, for example, gives around 2400+ fps with only one grain more.
So what's going on with this powder? More like what's going on with the bullet. As we have discussed before, the 8x50R has a bore diameter of .329/.330 but originally used .323 bullets with an obturating base of some sort to seal off the gas. Also, the original bullet was much heavier, around 220 gr. or thereabouts, and had a long shank for better stability in a bore-rider design. When I use .323 Spitzer bullets of 150 gr., not only do they lack the long shank of the original bullet, but they do not have the obturating base so probably are not sealing the propellant gases off properly. With gas blow-by, the velocity goes down.
I also noticed plenty of evidence of unburned powder granules; this may re-inforce the gas leakage theory. If too much gas is lost too soon, all of the powder may not ignite properly and this would also cause a decrease in velocity.
My next experiments will be with jacketed .330 bullets.
The next load with a cast lead bullet was more satisfying. These were made with a nominal 205 grain lead bullet case from the Lee mould and sized to .329. The propellant was 16.0 gr of 2400 and WW LR primers were used. The average muzzle velocity was 1344 fps and the SD was 33.09. It didn't take long to figure out where the shots were printing and once I knew this, I could plop them all into the back ring at 50 yards. Because of their leisurely departure from the barrel, these lead bullets print about 4 inches high at that range.
The cases I used for this batch were Graf 7.62x54R, cut back and re-sized to 8x50R. The brass on this case is thinner than re-sized 8x56R, so it will not hold a .323 bullet. It holds a .323 lead bullet just fine.
"Sehr schwer, mein Herr"
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yockey5
Coffee Pot
Posts: 9013
(10/30/05 7:44 pm)
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New Post Re: Range report on 8x50R Good report Gary, all that I have is .338s resized to .330 and cast .330s that I will gas chk and resize to .329.
Don
When your firearms are taken, your democracy no longer exists.
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mikmarjon
Attic man
Posts: 4792
(10/31/05 1:40 am)
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New Post Re: Range report on 8x50R
Thanks Gary, I don't have anything in 8x50 yet but hope one day to have one and will need all of the reloading info I can get.
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Kar98AZfan
Greenstate Guru
Posts: 586
(10/31/05 8:28 pm)
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New Post Re: Range report on 8x50R Interesting about the 150gr/4895 combination.Your theory is
probably spot on-I've only ever used 170gr RN bullets with 41.0 grains of 3031 and never saw unburned powder,but the 170 has more bearing surface.Looks like I'll have to try some .329 cast bullets when I get some cast.-TR
No man's life,liberty or property are safe when the legislature is in session-Mark Twain (1866)
Edited by: Kar98AZfan at: 10/31/05 8:30 pm
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5thDragoons
The Editor
Posts: 629
(2/8/06 10:35 pm)
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New Post Re: Range report on 8x50R I juist had a chance to try the 2400 load with the Lee gas checked bullet. Very good results from my long rifle! SW
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"You cannot invade mainland United States. There would be a rifle behind each blade of grass." -
Admiral Yamamoto - Japan, 1941 
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