October 2, 2022. Same Ammo in Four Barrels — Surprising Velocity Testing Results. You’ll notice a wide variation in muzzle velocity when you put the same load into different barrels (with the exact same length and chamberings). It’s not uncommon to see a difference of up to 100 fps between barrels. This was demonstrated by a comparison test with Lapua factory ammunition.
We chronographed Lapua factory ammo 105gr 6mmBR factory ammunition in three different 8-twist barrels at our Southern California test range years ago. These results were amazing. Based on Lapua testing the ammo with its 26?, Lapua rates it at 2790 fps. Test barrel. Based on three tests with aftermarket barrels, we observed a speed variation of 67 fps.
Brand ‘S’ and Brand PN were pre-fit barrels that were shot on Savage actions. Brand ‘K” was fitted to a custom-made action. All test barrels were throated to accommodate 100-108 grain bullets. However, there may have been slight variations in barrel freebore. The rounds averaged 2824 fps and were 2.330? COAL. This was 67 fps quicker than the slowest barrel. The slightly longer length (27) can be attributed to a slight increase in speed of 10 fps. vs. 26? 26 Click Here to see the results of the 6mmBR Barrel Velocity Test. We won’t publish the names of barrel-makers because it would be incorrect to assume that ‘Brand X is always going to perform better than ‘Brand Y’ based only on results from a single barrel. Two identical-spec barrels of the SAME manufacturer can produce speeds up to 100 fps. You can have two identical-spec barrels, one 8-twist and one 26? You can have two 8-twist, 26? barrels from the same manufacturer.
Men often complain that they don’t understand why they can get 2900 fps using their 6BRs, while I can only get 2840. The barrel may be slower than the average. You can use more powder if your barrel is slow, but it will likely never run as fast or as efficiently as an inherently fast one. It is not a good idea to try to replicate the speeds of someone else. You must work within your barrel’s limits. Factory ammo provides a benchmark
We recommend that you purchase a box of factory-loaded Lapua ammo if you own a.223 Rem or 6mmBR,.243 win, 6.5×47 Lapua and 6.5 Creedmoor. This ammo will shoot well (typically at half-MOA), and can be used to establish how your barrel stacks up speedwise. [Editor’s Note: This test was originally conducted in 2008. Your results might vary due to the fact that current-production Lapua factory ammunition may have a velocity that is higher or lower. It’s a smart idea to chronograph your new 6mmBR rifle with a box of factory ammo. This will give you an instant indication of whether your barrel is slow, average, fast, or fast. This will allow you to set your velocity goals. If the factory 6BR ammunition runs between 2780 and 2790 fps in your gun it has an average barrel. It should run 2820+ in a 26. barrel (or 2835 feet per second in a 28). barrel (or 2835 fps in a 28?
