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Posted: 5/13/2010 8:05:38 PM EDT
| I recently picked up some Nosler CC (seconds) and am wanting to develop a load to use in an M1A, well my Nosler manual advises that if using Milsurp Brass I reduce the charge due to case volume but they did not say how much, their range for a 168 Nosler CC is 39-43gns of IMR 4895 and 39.0 was their accuracy load so where would I start and end ? |
| imo 2 grains below stated start load . gas gun show pressure signs early , i would check 2 or 3 manuals for start loads and drop 2 grains and work up from there. My ar10 showed pressure signs with 43 of varget and the start load stated was 42g . I did some ladder loads starting at 39g and found the magic load at 42g using LC brass. |
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10% is normally recommended with mil 7.62 x 51 brass. This a valid warning.
With 5.56 brass, no reduction is needed, the loading manuals err here. Only heavy 223 / 5.56 brass I have come across is PMP from South Africa. Use 2 grs less than you would for Win / LC cases. |
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Quoted:
10% is normally recommended with mil 7.62 x 51 brass. This a valid warning. With 5.56 brass, no reduction is needed, the loading manuals err here. Only heavy 223 / 5.56 brass I have come across is PMP from South Africa. Use 2 grs less than you would for Win / LC cases. So if the range for using IMR 4895 is 39.0 - 43.0 (checked Sierra, Nosler and Speer manuals and all are pretty close) I would start at 35.0 min and 38.7 max ? |
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Quoted:
Quoted:
10% is normally recommended with mil 7.62 x 51 brass. This a valid warning. With 5.56 brass, no reduction is needed, the loading manuals err here. Only heavy 223 / 5.56 brass I have come across is PMP from South Africa. Use 2 grs less than you would for Win / LC cases. So if the range for using IMR 4895 is 39.0 - 43.0 (checked Sierra, Nosler and Speer manuals and all are pretty close) I would start at 35.0 min and 38.7 max ? I would start at 35 and work my up in .5g increments to 42 g maybe 10 to 20 loads in 3 shot groups each and check for pressure signs and accuracy. Then find the load that was best and fine tune it till i had the accuracy i wanted without pressue signs , i would likley see pressure signs before the 43g max anyway. |
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Resized, trimmed and deprimed the cases usually weigh close to 179 grains - LC .308
NRA conducted testing and came up with 40.5 grains of IMR-4895 as a maximum load. Winchester standard large rifle primers and OAL of 2.800" Velocity from an M1-A should be around 2500 fps, from a 24" bolt action closer to 2600 fps. This happens to be a common load in NRA high power tournaments. I'd start at 39.0 and go up .5 grain at a time. |
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