Ludicrous speed
- Thread starter Tikka bob
- Start date
What brass are you using? How much does it weigh? What primer? Are you jamming the bullet into the lands? How did you measure the velocity?
What length barrel are you using? Is the Hornady data base on a 24" barrel?
That low speed on Hornady chart looks to me like it's based on a 20" barrel??? And that'd be inline with my Varget data. Out of my 26" barrel I'd get ~2,393 using 37.5 grs, but typically, when I run Varget, I'm using 42.2 grs that'll give me 2,642 fps. It appears that your 37.5 grs is only filling your case to ~ 86% case capacity. Case fill that low just might be part of the reason for some higher velocity and might results in high ES's due to inconsistent ignition??? For sure, something isn't adding up???
Early Starline 308 brass was stupid heavy, almost 190 grains. It had a lot less capacity than other 308 brass, even military cases. If this is what you have then that might explain it.
20 inch 1/11 twistWhat length barrel are you using? Is the Hornady data base on a 24" barrel?
That low speed on Hornady chart looks to me like it's based on a 20" barrel??? And that'd be inline with my Varget data. Out of my 26" barrel I'd get ~2,393 using 37.5 grs, but typically, when I run Varget, I'm using 42.2 grs that'll give me 2,642 fps. It appears that your 37.5 grs is only filling your case to ~ 86% case capacity. Case fill that low just might be part of the reason for some higher velocity and might results in high ES's due to inconsistent ignition??? For sure, something isn't adding up???
Used win service rifle info, closer twist and length
Shoots soft and consistent
Even when allowing someone else to shoot, stays in 3/4moa or less
9 0z trigger takes a few shots to get used to.
On my 3rd different lot all same ish speeds so.....
This is where I am at with a 24” barrel.
Lapua brass with an average weight of 169.5gr.
Case capacity 55.62gr of water.
Lapua brass with an average weight of 169.5gr.
Case capacity 55.62gr of water.
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