What is the difference between Lapua 308 (LU4PH7217C) case and Lapua 308 Palma (LU4PH7226)?
- Thread starter Jdaniel343
- Start date
The Palma cases have a small primer pocket I believe.
Thanks
Would this be good or bad for long range shooting with 308.
Would this be good or bad for long range shooting with 308.
Depends on whom you ask...general "concencus" is that small rifle primer and flash hole generally aid accuracy in small benchrest size case (think 6BR and smaller). As cases get larger, cocensus diminishes on accuracy effects. As we enter the tactical arena, opinions also differ, as some guys become increasingly concerned with absolute reliability over questionable improvements in accuracy.
Jdaniel343,
As the rest of the guys have already spelled out here, the difference between our standard 308 Win and 308 Palma cases are the small primer pocket, and the use of the 1.5mm flash hole. These cases were produced specifically for, and at the behest of, the US Palma team shooters. The big advantage of the Small Rifle primer is that they don't generally show near as much variation in accuracy at long range as the Large Rifle primers do. Normally, selecting/sorting primer lots for Long Range is a major concern, as things that make no difference at all at the shorter lines show up very clearly when you move out to the 800, 900 and 1,000 yard lines. Large rifle primers show considerable variance from one lot to another, making it crucial that you find one which gives minimal deviation, and shows up well on target. The Small Rifle primers just don't seem to be nearly as finicky in this regard, which is why the demand for these cases arose in the first place. Not a new idea, and the original impetus came from copmpetitive shooters who tried the old Remington UBR cases that were made back in the 80's; a thin-walled 308 Winchester case configuration, with a small primer pocket, intended to be formed into 6mm or 7mm BR cases, which at that time were still at least semi-wildcats. Some LR shooters tried them for their shooting, and discovered that the primer issues were helped by the use of the smaller primer.
There is, however, no such thing as a free lunch. The potential drawback here is that 40-45 grains is about the outer limits of what a small primer can reliably ignite. Even then, it needs to be used under good conditions; relatively warm weather, combined with a mid-burning range powder like Varget (probably the most commonly used powder for Palma shooters), N140or 4895. Throw a monkey wrench into the mix by using a very slow burning powder, a ball powder, or shooting in very cold conditions, and you'll start to experience hang-fires, or even outright misfires. If you're shooting Palma or other long range matches (which are usually shot in warmer weather), with an appropriate powder, you'll be fine. If you anticipate using these rounds for hunting applications (generally much colder weather) or are using a harder to ignite powder, then stick to the standard Large Rifle primer 308 case.
Hope that helps clarify the situation.
As the rest of the guys have already spelled out here, the difference between our standard 308 Win and 308 Palma cases are the small primer pocket, and the use of the 1.5mm flash hole. These cases were produced specifically for, and at the behest of, the US Palma team shooters. The big advantage of the Small Rifle primer is that they don't generally show near as much variation in accuracy at long range as the Large Rifle primers do. Normally, selecting/sorting primer lots for Long Range is a major concern, as things that make no difference at all at the shorter lines show up very clearly when you move out to the 800, 900 and 1,000 yard lines. Large rifle primers show considerable variance from one lot to another, making it crucial that you find one which gives minimal deviation, and shows up well on target. The Small Rifle primers just don't seem to be nearly as finicky in this regard, which is why the demand for these cases arose in the first place. Not a new idea, and the original impetus came from copmpetitive shooters who tried the old Remington UBR cases that were made back in the 80's; a thin-walled 308 Winchester case configuration, with a small primer pocket, intended to be formed into 6mm or 7mm BR cases, which at that time were still at least semi-wildcats. Some LR shooters tried them for their shooting, and discovered that the primer issues were helped by the use of the smaller primer.
There is, however, no such thing as a free lunch. The potential drawback here is that 40-45 grains is about the outer limits of what a small primer can reliably ignite. Even then, it needs to be used under good conditions; relatively warm weather, combined with a mid-burning range powder like Varget (probably the most commonly used powder for Palma shooters), N140or 4895. Throw a monkey wrench into the mix by using a very slow burning powder, a ball powder, or shooting in very cold conditions, and you'll start to experience hang-fires, or even outright misfires. If you're shooting Palma or other long range matches (which are usually shot in warmer weather), with an appropriate powder, you'll be fine. If you anticipate using these rounds for hunting applications (generally much colder weather) or are using a harder to ignite powder, then stick to the standard Large Rifle primer 308 case.
Hope that helps clarify the situation.
