dylan_b

i was out shooting recently with a friend. both of our loads are carbon copies of each other. both loads were ladder tested and it just so happened that we needed the same powder charge. the only difference being brass. my loads call for 44.8 grains of rl15 with a 178 amax, cci br2 and a hornady match case trimmed to 2.000''. his loads are exactly the same but with lapua brass thats relatively fresh compared to my old brass. the loads come from the same dies, press, cans of powder and boxes of bullets. to boot, they are usually loaded on the same day, shot on the same day on the same targets. it seems to be a general consensus that lapua blows hornady out of the water but in both of our rifles the hornady brass has a slight edge at 3/8 moa vs slighly sub 1/2.

my best explanation is that my brass has been worked in. i was fist thinking it had something to do with case capacity but his rifle was specifically ladder tested with lapua and 44.8 was found to be the very best so in theory the better brass with a optimised loads should be more accurate.

SecondChance

No brass does not need to be "Worked in". You stated the obvious difference. The brass itself. Lapua brass is FAR better brass then any other on the market. They have more strict tolerances than the others out there. Thats why you pay what you do for that brass. As far as one outgrouping the other by such a minute margin, could not be contributed to the brass, just the shooter on a good or bad day.
Now, I would say that after 20-30 groups showing a group increase of over 1/2MOA or more, that would be enough to say that one was more apt than the other. It just may also be that that particular rifle just happend to like the way that load reacted with that brass due to its internal capacity for that load. Try a water volume test between the cases and see what you get.

SecondChance

Now your going out on the wild side of things. With your multiple firings of fireformed, basic custom brass, you may have expanded the interior capacity just enough to find its sweet spot of that particular lot of brass.
Hey RR, did it do this with various brands/lots of brass or just that one batch? The OP did not state what type of rifle he was acheiving these results from.

dylan_b

i never really did enough testing to fully determine the effects. on the day we noticed a difference we conducted 4 or 5 groups of 4 shots at 100 and 500 yards. the rifle in question is my friends remmy 700 5r but we alsotested with my rem 700 xcr LR. i know that there might be some question about a factory rifles consistency when it comes to load development but i personally feel very confidant after seeing what these rifles do with hot heavily fouled barrels. testing was done on the same day by both shooters.

while talking with my friendhe brought up a good point, lapua brass doesn't run well through my die (full length) and it is possible that neck tension isnt perfect because lapua is so tight through the die where as the thin walled hornady runs smooth. he is buying new dies as soon as the are locally available.

bronko22000

dylan's thread has just too many vaiables to determine if its only the brass. To begin with the two different brass are being shot out of two different rifles by tow shooters. No mention to the fact that both rifles shot both types of brass. So you have different chamber dimensions - no matter how slight - which can cause different pressures. Yes, both loadings came out of the same dies. But that is only one constant as is the charge and other components. Besides like Secondchance stated you are only talking 1/8" difference in group size. At 100 yds this variance is insignificant.

emtrescue6

More than a few articles have reported over the past 2-3 years that Hornady Brass preformed equally or better then Lapua...for the price, the one and only match load I load for (a Savage Model 10 FLCP-K in 308 Win) has been getting Hornady brass and I have been very happy for it. I saw no noticeable improvement when using the one box of Lapua brass I have. Nosler brass also performed very close to the Hornady.

dylan_b

it has took a little while but i may have found the answer. my buddy did no real testing for clean barrel vs dirty barrel. the loads were developed from a mostly copper free barrel and velocity was on the higher side. i chorny'd the load not to long after we first noticed the change and the loads were a little running slow, i assumed it was the powder at the time. all this time i had assumed he was properly cleaning the barrel. finally after having to clean his barrel myself we started seeing the results we had seen initially from the lapua brass. with these things now in mind, i chrony'd 2 batches of hornady brass. some was freshly annealed some was not. the freshly annealed brass was running slower then the brass with about 10 sizings. im concluding that our loads are on the tail end of a optimal harmonic node/apex and dropping velocity off more then 25 fps will hinder accuracy in my friends rifle. the downside is that we are pretty much running as hot as any .308 should ever be run and cannot reach a little deeper into the harmonic node. 45 grains of rl 15 is not rated by all sources to be safe for a 178/180 grain bullet (we are going off alliant data).