Lapua brass booboo

[Maxwell Haus]

I trust Lapua . They don't sit behind a keyboard and speculate .

 

[Maxwell Haus]

Adding Knowledge .

https://forum.accurateshooter.com/threads/lapua-br-flash-hole-is-062-not-059.4014997/

 

[Unclenick]

Whether using small flash holes or small primers in place of large, as in Lapua's .308 Palma brass, the idea is basically the same: to limit the influence of the primer on final pressure, so the powder charge has more control of it. The Courtney's, the husband and wife physicists who've done work on primers for the military have found a milder primer influence does reduce velocity spread and cut group size, albeit slightly (about 0.1 moa at 200m), so these will be long-range factors and not matter much at the usual service rifle ranges. That's why Lapua offers the small primer in Palma (1000-yard shooting) cases but not in their standard .308 cases.

From this study:

In the 7.62x51mm NATO load, both primers produced an average muzzle velocity of 823 m/s, with the DDNP-based primer giving a smaller standard deviation (2.8 m/s) than the more powerful lead styphnate based primer (6.5 m/s). This agrees with the hypothesis…that having a primer that is not more powerful than needed to reliably ignite the powder charge produces more consistent muzzle velocities than a more powerful primer.

And from this similar study:

These results suggest that sorting the Federal 210M primer by mass will reduce variations in peak blast pressure. To test this idea, we sorted 100 Fed210M primers to obtain 10 measuring within a 1 mg range centered at 355 mg. These primers exhibited an average peak blast pressure of 440.7 psi and a standard deviation of 18.3 psi. Mass sorting to within 1 mg reduced the SD significantly from 32.4 psi to 18.3 psi.

So it makes a difference as to how much influence a primer has. It just isn't a huge one. Nonetheless, better is better and will occasionally get the target shooter an extra point, so whether or not you bother with this has to be judged on the results you get with them in your own rifle, and whether you are shooting at a level for which one extra point means the difference in your position on the podium or not. If not, you'll probably benefit more from wind reading and position repeatability and trigger practice.

 

[jetinteriorguy]

I don't blindly follow what I read on the internet . You will learn once you gain some experience.

Here is a FACT . New 308 Palma w/small primer pocket measure .062"...new 223 small rifle primer measure .079" . VERIFIED w/ pin gauges . Lapua makes small flash hole brass for high pressure loads like the 6BR or the jazzed up .308 Palma loads w/ SRP .

Reaming primer flash holes ? Pretty sure Lapua could make those holes any size they want , probably a reason for sizing them the way they do.

I guess handloading since 1984 just isn’t enough experience to be able to discern BS on the internet. The fact that I physically have the brass in front of me to actually measure and verify what I’m saying means nothing. You need to move on. Another one for the ignore list.