I'm working up a load for my 338LM using Lapua brass (250gr Scenars, H1000). I was just given 100 pieces of new Hornady brass. Is there enough variation that I shouldn't plan on mixing brass until I have a load developed with my Lapua brass. Is there enough variation in this cal that I need to work up a load for each brass manufacturer. Thanks in advance.
338LM brass differences
- Thread starter heydavemd
- Start date
Re: 338LM brass differences
Most certainly work up load interdependently for each brass manufacturer. It is not a safety issue but an performance issue.
Most certainly work up load interdependently for each brass manufacturer. It is not a safety issue but an performance issue.
Re: 338LM brass differences
Thanks, thats what I suspected the answer would be. Thats why the Hornady brass is still just sitting there. I appreciate the quick response.
Thanks, thats what I suspected the answer would be. Thats why the Hornady brass is still just sitting there. I appreciate the quick response.
Re: 338LM brass differences
I weighed 10 cases of each Hornady and Lapua and the averages are:
Hornady -
Empty weight with dead primer = 314.9 gr SD = 1.8 gr ES = 5.6 gr
Full of water with dead primer = 435.4 gr SD = 1.4 gr ES = 4.8 gr
Capacity 115.5 gr of water
Lapua -
Empty weight with dead primer = 326.5 gr SD = 1.5 gr ES = 4.8 gr
Full of water with dead primer = 445.2 gr SD = 1.5 gr ES = 4.6 gr
Capacity 113.7 gr of water
The Hornady brass holds on average 1.6% more water than the Lapua brass.
I weighed 10 cases of each Hornady and Lapua and the averages are:
Hornady -
Empty weight with dead primer = 314.9 gr SD = 1.8 gr ES = 5.6 gr
Full of water with dead primer = 435.4 gr SD = 1.4 gr ES = 4.8 gr
Capacity 115.5 gr of water
Lapua -
Empty weight with dead primer = 326.5 gr SD = 1.5 gr ES = 4.8 gr
Full of water with dead primer = 445.2 gr SD = 1.5 gr ES = 4.6 gr
Capacity 113.7 gr of water
The Hornady brass holds on average 1.6% more water than the Lapua brass.
Re: 338LM brass differences
I've (re)used plenty of both Hornady and Lapua 338LM, and I don't notice any big difference in MV's between the two brass types. I haven't specifically measured one against the other, but in recording strings of loads, where I switched brass back and forth, I didn't notice anything out of the ordinary. If there is an effect with 1.6% more volume than it may very well be minor. Just chron identical loads in both and see what happens. That's the ultimate answer.
I've (re)used plenty of both Hornady and Lapua 338LM, and I don't notice any big difference in MV's between the two brass types. I haven't specifically measured one against the other, but in recording strings of loads, where I switched brass back and forth, I didn't notice anything out of the ordinary. If there is an effect with 1.6% more volume than it may very well be minor. Just chron identical loads in both and see what happens. That's the ultimate answer.
