Case weight
- Thread starter DavieK
- Start date
Case weight is affected by brass thickness, which changes your powder capacity which in turn affects pressures slightly.......even if you're using a charge that does not fill the case completly the pressure will be slightly different because there is more or less space inside the case.
You mean to tell me you will get the same POI at 1000 yards regardless of a 5 grain difference in case weight
I have 1800 .308 Lapua cases that range from 170 gr to 175 gr. Just think of all the time I have wasted weight sorting
- Location
- Somewhere on the Hudson Bay Coast
Disregard for case weight variations may make no difference in a hunting rifle out to 300 yards, but in any shooting genre that requires quarter minute accuracy to be competitive it sure matters. This is particularly true for shooters who compete at long range where vertical dispersion will quickly eliminate you. For these guys, anything can can be measured matters.
So, you mean you've done your own evalution and found that sorting cases reduces the group from... to... ?
No, you have not. You speak of the matter you are totally infamiliar with. Do you know anybody who has done it? I think no. So, what is your opinion based on? On a pure myth.
Neither me - I've just read it. The guy I spoke about is no hunter - just a pure target shooter in the quarter-minute range.
I keep very good records of all my elevation setting for my target rifles. So I have a rather good idea on where my sights should be set for each range, 300-1000 yards. Now on any given day the "mean elevation" could be out +/- 1 to 1 1/2 minutes. I have not directly related this to case weight because I always shoot a match from the same weight batched cases. However I assume case weight has something to do with the difference in elevation settings and POI. Having said that, with case weight on both extreme ends (from 170gr to 175gr with my Lapua cases) could put me from 1 1/2 minutes high to 1 1/2 minutes low on consecutive shots with mixed weight brass. This will result in finding your name on page 3 of the prize list.
Maynard, it would be interesting if you could shoot a target with 170 grain weight, then another target, under same conditions, with 175 grain cases.
If your suggestion of about three inches difference at 1000 yards is about right, it would mean it could be completely ignored for sporting type everyday rifle shooting.
As a matter of fact, for general sporting rifle use, I would only seperate 30-06 cases if they were more than about 20 grains difference, and then only if I was using really heavy loads.
One other thing while you are here. I think the standard sight setting, to start with, for the 303 and standard military bullets, was 48 minutes for 1000 yards. What is it with the cartridges and bullets you use now?
If your suggestion of about three inches difference at 1000 yards is about right, it would mean it could be completely ignored for sporting type everyday rifle shooting.
As a matter of fact, for general sporting rifle use, I would only seperate 30-06 cases if they were more than about 20 grains difference, and then only if I was using really heavy loads.
One other thing while you are here. I think the standard sight setting, to start with, for the 303 and standard military bullets, was 48 minutes for 1000 yards. What is it with the cartridges and bullets you use now?
You asked a question and he answered. If you don't want to take offered advice don't ask. Handload for 20-30 yrs and you won't be asking this kind of question.
When I started I asked the same question about 30-06 cases,183 to 203.The answer I got was about two grains capacity. With any decent hunting load in a 30-06,two grains capacity won't matter. I stick to weight range,but not always brand.My hunting loads,not always, but should be that loose,5%,+ or -.
Impossible: the weight has to come from somewhere, namely thicker brass reducing case capacity. Having said that, I look forward to having you post his data and results. Ie: weight of case<-->volume (done by the water method), and either a constant volume or not statistical correlation.
Precision Shooting has done comparisons, and weights (on uniformed cases) do matter.
H4831, Not 3 inches at 1000 yards, 3 minutes or 3 MOA at 1000 yards. That works out to about 30 inches on the extremes. Like I said, 1 high shot in the 4 ring and one low shot in the 4 ring will put you on page 3 of the prize list
I don't know what my 100 yard zero is but from my 300 yard zero I come up 27 minutes to get out to 1000 on one rifle and 28 on another rifle. Shooting a .308, 30" Bartlein barrel with a 1:12 twist, launching 155 gr moly coated bullets at about 2940 fps.
You are correct in most hunting rifles the case weight doesn't matter, minute of moose at 300 yards or less is good enough. Of course if you require minute of prairie dog at long range that would be a different story.
- Location
- Somewhere on the Hudson Bay Coast
Yes I have and when I'm loading for precision I not only weight my cases, but I also weigh bullets, uniform primer pockets and flash holes, check neck and bullet run out, and I have shot groups in the .1's. At long range I am often below a half MOA. According to my chronograph my extreme spread is often single digit.
You seem to think you have some idea of what I do and don't do, but a hick like me has little to do but shoot and handload. So yes most of the time I have a pretty good idea of what works and what doesn't.
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