Shooting Holes in Wounding Theories:
It is important to compare apples to apples. The velocities is measured at 78 feet 26 yards from the muzzle. So M is rated at fps by the military at that longer measuring distance.
Predicted 26" barrel velocity is about fps at 15 feet. If you are getting fps out of your 26" barrel, that is about fps more than expected. Some of that may be the normal velocity tolerance of the lot number you have, and also perhaps you have a fast barrel.
But the main concern with getting higher velocity is pressure. Tests by the Navy showed 7.
By swapping bullets and primed cases around they were able to show the pressure difference was due entirely to how the powder aged in the heat. Apparently the deterrents had been deteriorated so that the powder burn rate increased.
Unexpectedly high velocity can be one of them. Originally Posted by Model 52 The gr SMK however is known for some pretty significant stability problems in transonic flight and with M ammo at an MV of fps will go subsonic right around yards.
Exactly where it gets into trouble with transitioning to subsonic flight is hard to call, it drops through fps at yards, and gets into trouble at some point past there, so fps is as good a guess as any.
This was just a couple hundred feet above sea level. The ammo likely held up to around fps, or Mach 1. Wind was 5 mph gusting to about 10 mph from 3: Average air pressure there is Stepping back a year, the first instance where I encountered the issue was at Gunsite in a Precision Rifle class.
We had to shoot across a valley at a steel popper that a laser range finder measured to be yards, and there was a stead 20 mph 9: So the bullets started out faster and slowed down more gradually. Everyone in the class had a 24" barrels, but some were 10" twist and some were 12" twist, as would be the case at Perry.
No one in the class could stay on that popper. I hit it once. I think maybe one other person hit it once and nobody else did at all, despite each of us taking several tries. I could see most of my impacts go left or right as I tried to use the mil dots on my sight to compensate.
They also went high and low, with the worst being about three feet out to either side. The yard targets at Perry are on 6 foot square paper, so this was less far off would have stayed on the corners of the paper by about half than the misses at Perry the following year.
Velocities should have been arriving at yards at to fps at that altitude, or about Mach 1. But they were clearly becoming unstable at around yards, where the velocities would have beenor Mach 1. The only major difference between the Camp Perry and Gunsite experiences I can point to that might explain the difference in Mach number at which the instability appears, was that difference in crosswind.
This will change the vertical POI, and maybe that mechanism is enough extra vertical force to tip the marginal stability over somehow.
It might also depend on momentary gust differences, as they change the size of the coning motion that tries to initiate recovery of flight pitch and that is responsible for vertical drift due to wind.
We never actually measured the ammo velocity, so maybe we got a slow lot of PMC. Using the actual drag function for thethat looks a little optimistic.
It appears to have a really large hump in its drag coefficient right near the speed of sound. Velocity is lost faster for a faster bullet anyway, but in the transonic range the difference for this bullet goes up a lot.
I show you would need an MV of fps fps at 15 feet to get this bullet to yards supersonic. The difference in velocity starts out at fps, is fps at yards, and just 79 fps at yards. SMK drag function for that MV range, again because of that big drag function hump.
But I think another point I should have brought up before makes the exact numbers moot. I think the 10" twist is probably going to cause core stripping if you try to launch a. Harold Vaughn found it happening in a. Groups open up with the core slipping inside the jacket.Vs Vs 30 06 Ballistics Chart On average, the are heavier than their counterparts.
It is however worth noting that other manufacturers do produce’s that go up to grains in weight. Let’s have a contest: Creedmoor versus Winchester. Which cartridge wins the race? In my ongoing campaign to shine the light of reality on the “ Creedmoor revolution,” I’ve decided to run this Creedmoor versus Winchester comparison.
Chuck Hawks selects rifle hunting cartridges for every caliber and category. History The has proven itself as one of the most versatile and effective medium game cartridges in the world.
It's effectiveness on game is so well embedded in our minds that we automatically use it as a benchmark when discussing other calibers. So the external ballistics of the trajectory put it slightly behind the Win, and we haven't even started looking at the drop charts.
However in terms of terminal ballistics (on impact) the is the winner at closer ranges ( yards and under). These formulas give approximate values for maximum penetration and cavitation diameter in inches, again for non-deforming bullets with a relatively broad flat nose.