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Post by rangeball on Jan 22, 2009 16:23:35 GMT -5
Thinking out loud here, related to sabot bases blowing when shooting .40s from a .50.
Powder is poured, saboted bullet is seated firmly. 209 primer placed. Trigger pulled.
Do you think in the split nano-second that the primer fires before the powder charge is ignited there is enough forward push from the primer pressure to separate the bullet from the base of the sabot enough to allow the punch through when everything slams back together when the big light hits?
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Post by youp50 on Jan 22, 2009 16:36:37 GMT -5
I think it is more of an inertia thing. A body at rest tends to stay at rest. The sabot has less mass and therefore easier to set in motion than the bullet. The sabot starts down the barrel before the bullet has enough force on it to move it. The base of the sabot is the weak link here and the outside of the sabot is separated from the base.
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Post by smokeeter on Jan 22, 2009 17:20:30 GMT -5
Thinking out loud here, related to sabot bases blowing when shooting .40s from a .50. Powder is poured, saboted bullet is seated firmly. 209 primer placed. Trigger pulled. Do you think in the split nano-second that the primer fires before the powder charge is ignited there is enough forward push from the primer pressure to separate the bullet from the base of the sabot enough to allow the punch through when everything slams back together when the big light hits? That's my story and I sticking with it. I believe it is the cause for more bulged barrels than a double bullet/charge. especially the unexplained ones. |
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Post by rbinar on Jan 22, 2009 21:16:16 GMT -5
8-)Test your theory by gluing the bullet to the sabot base. However If you get the speed up I think you'll still find the sabots drilled.
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Post by tasaman on Jan 23, 2009 3:37:43 GMT -5
One way to find out is to push a bullet/sabot down the barrel with no powder charge. Measure the depth on the ramrod. Fire a primer then remeasure the bullet depth on the ramrod. Did it move? Only thing that might affect the outcome is if you don't have the powder charge will it be a perfect scenario or will you have to leave a air gap under the sabot to duplicate the seating depth on the powder? Let me know if you do it and it works. I remember an article a few years ago that a 32 cal ML was used to test primer push on the bullet and the doggone thing actually shot the out the barrel at a good pace with no powder only the primer!
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Post by mike.dawson on Jan 23, 2009 7:46:12 GMT -5
I shot a bunch of the Harvester 40x50cal out of my savage. Tried them bare, with sub bases, with a wonder wad, a alum. washer and they all drilled with smokeless at speed. Tried 5744, alliant 2400, n110, with loads only in the 32-36 gr. range they did not drill. This was with a Barnes 195. But with BH209 I shot them at a good speed with up to 140 gr. of BH209, step it up to 145 and they drilled. The only way I see us being able to shoot a 40cal bullet out of our 50s is the sabot makers need to come up with a stronger base. This harvester sabot is supposed to be stronger than the MMP
Mike
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Post by rangeball on Jan 23, 2009 12:57:39 GMT -5
Harvester told me their .50/.40 sabots were not designed for smokeless.
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Post by mike.dawson on Jan 23, 2009 14:51:00 GMT -5
I did the initial test on the Harvester sabot and told them they would not work at Savage speed, thus your statement, however they will hold up to 140 gr of BH209, I don't own a chronograph or I would have a speed for you with the BH 209
Mike
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Post by rangeball on Jan 23, 2009 15:57:51 GMT -5
Mike, knowing the speed would definitely be interesting. That's a bunch of BH209, isn't it?
Assuming speed was comparable, is it the pressure or hotness of the smokeless that's causing the bases to blow? Or probably both?
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Post by sw on Jan 24, 2009 10:57:02 GMT -5
I did the initial test on the Harvester sabot and told them they would not work at Savage speed, thus your statement, however they will hold up to 140 gr of BH209, I don't own a chronograph or I would have a speed for you with the BH 209 Mike I think the deal is pressure. Our pressures just go higher. I think you could shoot the 40/50 cal sabot fast if the smokeless powder was kept in the 20s pressure-wise. Possibly 50-60g H-4895, Varget etc. These loads are NOT recommendations; rather just examples of where I'd start if I wanted to shoot 200SSTs @ 2300+'/sec with smokeless out of a 50 cal. They'll shoot faster out of a 40 or 45  . A WW might help protect the sabot, somewhat. |
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. A WW might help protect the sabot, somewhat.