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  #1  
Old 07-28-2019, 05:36 PM
ihc53 ihc53 is offline
 
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Default Load question.

Loaded up some 147gr fmj (Chilean pulls) using 43gr of IMR 4895, a CCI #34 primer and a new Winchester commercial case.

My 10 shot average speed was 2694 fps. How many grains, if any should I knock it down for a military case? These are not accuracy loads by any means, just cheap steel plate ringers.

As an aside, 10 rounds of PPU M80 ball ammo (control) was averaging 2832 fps.

7.62 for the M1A.

Brain fart. Again

Last edited by ihc53; 07-28-2019 at 07:56 PM.
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  #2  
Old 07-28-2019, 06:29 PM
nf1e nf1e is offline
 
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Shouldn't IMR 4595 actually be IMR 4895?

I know it's being picky, but numbers do matter when dealing with loads.
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  #3  
Old 07-28-2019, 06:43 PM
ihc53 ihc53 is offline
 
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Quote:
Originally Posted by nf1e View Post
Shouldn't IMR 4595 actually be IMR 4895?

I know it's being picky, but numbers do matter when dealing with loads.
Typo. Thanks for the catch.
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  #4  
Old 07-28-2019, 07:31 PM
78jeep 78jeep is offline
 
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none, if you are talking 30.06, they are the same military or commercial, sine the military came out with it first. 308 Winchester was first, the military 7.62x51, came later, those cases have less volume, and you should back off your load for 308, not 30.06.

you may want to try a bit more for your load. somewhere between 45 and 47 grains should work out. also most folks, me included, don't have great luck with the 147's. all most any other commercial bullet shoots better, IMO.
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Old 07-28-2019, 07:44 PM
ceresco ceresco is offline
 
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I believe the OP is asking about 308win/7.62mm. Winchester brass is probably the lightest of all the commercial or military brass. At low load levels, case weight will not make a significant difference. At mid to high levels, it will. You cannot (perhaps, should not) use the old axiom of military vs commercial case weight. More accurately, "case weights vary" and it sometimes does matter. Good Shooting...
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Old 08-07-2019, 05:23 PM
Unclenick Unclenick is offline
 
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...And the axiom only ever applied to .308/7.62 anyway. Lake City 5.56 actually have a little bit more capacity than commercial. In .30-06, Wm. C. Davis, in the 1981 NRA compilation book, Handloading, mentions a Peters case that weighed 215 grains. I've never seen a Lake City .30-06 much over 197 grains that I recall, though I'd have to check my notebooks. In any case (pun intended) nothing remotely close to that Peters case.

It used to be Winchester .308 was thinner. I have some I bought bulk about 15 years ago that averages about 156 grains. I read this was a holdover from changes they made in the design for the 1992 Palma match ammunition they made the brass for, at Mid Tompkins's request, trying to get an extra couple of grains of capacity from them to maximize muzzle velocity. But a Palma team member who shot a lot of that ammo says it isn't so, and so I am left wondering what to think. They went to their semi-balloon head at some point around then or shortly thereafter, and it serves no other purpose. But these days, most folks report Winchester brass in the 160s of grains.

Since the head contour tolerances alone allow case weight to vary 7 grains just by taking the dimensional tolerances from one end of the range to the other, all without changing head thickness, you can get that much variation with no capacity difference. The bottom line is, you have to compare actual case water overflow capacity and not count on weight to tell you the tale. A chart of more recent .308/7.62 case capacities on another board showed they no longer have the kind of volume differences they once did. The highest volume measured was 56.2 grains and the lowest 53.8, a difference of 2.4 grains, and both extremes were among LC13 cases.
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  #7  
Old 08-10-2019, 06:31 PM
mac1911 mac1911 is offline
 
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Quote:
Originally Posted by Unclenick View Post
...And the axiom only ever applied to .308/7.62 anyway. Lake City 5.56 actually have a little bit more capacity than commercial. In .30-06, Wm. C. Davis, in the 1981 NRA compilation book, Handloading, mentions a Peters case that weighed 215 grains. I've never seen a Lake City .30-06 much over 197 grains that I recall, though I'd have to check my notebooks. In any case (pun intended) nothing remotely close to that Peters case.

It used to be Winchester .308 was thinner. I have some I bought bulk about 15 years ago that averages about 156 grains. I read this was a holdover from changes they made in the design for the 1992 Palma match ammunition they made the brass for, at Mid Tompkins's request, trying to get an extra couple of grains of capacity from them to maximize muzzle velocity. But a Palma team member who shot a lot of that ammo says it isn't so, and so I am left wondering what to think. They went to their semi-balloon head at some point around then or shortly thereafter, and it serves no other purpose. But these days, most folks report Winchester brass in the 160s of grains.

Since the head contour tolerances alone allow case weight to vary 7 grains just by taking the dimensional tolerances from one end of the range to the other, all without changing head thickness, you can get that much variation with no capacity difference. The bottom line is, you have to compare actual case water overflow capacity and not count on weight to tell you the tale. A chart of more recent .308/7.62 case capacities on another board showed they no longer have the kind of volume differences they once did. The highest volume measured was 56.2 grains and the lowest 53.8, a difference of 2.4 grains, and both extremes were among LC13 cases.
i found this to be very true on my recent water testing.
i also found I could get some inconsistent testing results with water making it tough to come to a conclusion for my brass.
Im also one tbat tends to load on the mild side
https://www.hodgdonreloading.com/data/rifle
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  #8  
Old 08-11-2019, 05:50 AM
8milimeter 8milimeter is offline
 
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My match load for SAI M1A is 45.0g IMR4895 125g TNT, Rem case, Rem9.5
When I switched to LC09 case I had to drop to 44.5 to attain the same accuracy. I say you load is not max so .5 grains should be sufficient.

NOTE: My new Winchester cases average 158g, New Rem 166g, 1X-LC09 179g, 1X-LC08 175g
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  #9  
Old 08-17-2019, 07:54 AM
mac1911 mac1911 is offline
 
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Quote:
Originally Posted by 8milimeter View Post
My match load for SAI M1A is 45.0g IMR4895 125g TNT, Rem case, Rem9.5
When I switched to LC09 case I had to drop to 44.5 to attain the same accuracy. I say you load is not max so .5 grains should be sufficient.

NOTE: My new Winchester cases average 158g, New Rem 166g, 1X-LC09 179g, 1X-LC08 175g
Could the percentage of alloys have a 17gn ish swing in total weight? What about deviation from case to case in the same lot?
How much do different primers weigh?
How much residue could be on the inside of a once fired case. Having a influence on both case weight and capacity.
Does it matter much if using tap water vs distilled water when doing a H02 volume test?
I have some 1x LC 14 kicking around , if I think of it when processing some brass I will do a H20 test.

Also how much today is the case differences from 50 years ago?

Last edited by mac1911; 08-17-2019 at 07:57 AM.
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