A Bullet In Flight Part II – How A Bullet Flies To The Target

Lately I have been using the word “Practical” a lot in my writing as observations have shown the opposite of practicality at the range and in the hunting field which causes new hunters to just plain fail and lose interest. Since I deal a lot with Military shooters, I find that many like the AR-15 platform and the Remington 700. This is reasonable as they are both what the sharpshooting military carry into combat.

All too often however, a military person will want to go hunting but they rig themselves out with a combat style weapon. Of course there is nothing wrong with a Sniper rig to hunt deer with if you are hunting from a box stand, a 308 is a 308. However, you will soon find out the extra weight of a 17 pound rifle is just not practical in the deer woods. A light sporterized Remington 700 is really what you are looking for. If it is a .308 Winchester (7.62 NATO), it is a fine deer rifle built on the same action as your military sniper rifle and it will do the same thing. It is all about knowing the trajectory of the round.

Bullet Travel 101

Lets get this straight first, a bullet when it leaves the gun barrel does not travel in a straight line to the target anymore than a baseball thrown from center field travels in a straight line. It does in fact travel in an arch known as the Arch of Trajectory. Depending on how fast the bullet is traveling determines the degree of the arch, or how flat the gun shoots. In general, the faster the bullet the less arch there will be. This lack of arch in trajectory makes hitting the target easier although there are many variables to think about first.

The line of sight is straight however, so the barrel of the rifle is tilted up slightly. When fired the bullet crosses the line of sight twice, once at short range about 25 to 30 yards. The bullet then rises to its maximum height of trajectory as much as 4.5 inches above the line of sight. As gravity takes over the bullet then drops crossing the line of sight again between 250 to 300 yards depending on the distance of desired zero, and the type of cartridge.

For general big game hunting taking a shot beyond 300 yards is a rarity. 308 (short action) and 30-06 (long action) class cartridges are ample for the job on deer sized game. You may want a little more punch for Elk, but if you keep shots inside 250 yards you really don't need the extra power unless its a special situation. The two situation are long range and or heavy cover.

I would not want to go after a grizzly in the alder thickets of Alaska, again, or even a white tale in a Louisiana briar patch. So this makes me a pontificator of a cartridge a little bigger than the norm for myself. If I hunted bear in Alaska it would be with a 416 not a 300 magnum for this reason. My standard choice for deer is not a 243 preferring a 308 or 30-06, while the properties of the 325 WSM have hooked me due to lack of recoil and much added knock down power. What I like about it the most is, with the 220 grain bullet it has the same speed and trajectory as the 165 grain bullet of a 30-06.

Cartridges with a muzzle velocity of 2600 to 2900 feet per second have a secret ingredient of plus or minus one inch with a 50 yard zero, being dead on at 100 yards. That goes from everything from a 7mm/08 to a 375 H&H magnum. This puts these cartridges in the practical hunting division of the easy to understand 300 yard trajectory on a horizontal deer target. The kill zone target on a deer is about the size of a sheet of typing paper, not a difficult target for a trained shooter out to 300 yards.

If we are talking deer rifles you will find that white tales are engaged at 30 yards to a little more than 100 yards most of the time. Mule deer are most likely taken from 100 to 200 yards. Practically a 30-06 will take care of both situations very well. With the new Hornady Super Performance rounds a 30-06 now has the ballistics of the old 300 H&H magnum sending a 165 grain bullet out at better than 3000 fps. So if you want magnum power all you need do now is change ammo. Now a days if you own a 270 Winchester an upgrade to a 7mm magnum is not needed, nor is a 300 magnum. A practical jump from a 30-06 is a 325 WSM or a 338 Win. Mag.

There are special situations. If I were to go Pronghorn hunting in New Mexico I'd probable carry my 270 Winchester with 130 grain bullets. Now with that I would sight in about 2 inches high at one hundred and that would be about right for dead on at 250. Now Jon Ballard would most likely take his 257 Weatherby magnum, very well the best Pronghorn caliber ever made. A two and a half inch high zero at 100 will put him dead on at 300 yards with 100 grain bullets. In this case the extra speed is needed due to the increased possibility of a longer shot in open country on a small target.

The 270, 7mm and 300 WSM rifles would be my choice for hunting American Sheep. The 270 WSM especially as it is not a kicker and is what the famous sheep hunter and great outdoor writer Jack O'Connor would have been impressed with, a 130 grain bullet over 3200 fps.

Personally, for most of my hunting I don't need a flat trajectory rifle, I need knock down power coupled with extreme accuracy. I need to knock a deer flat out, with no blood trailing. I can do that with the 30-06 and even better with the 325WSM. Shall I say the 45-70 is even better.

I played with my Bushnell laser range finder all season last year, and found I only had one deer stand with a view of more than 100 yards. That was a logging road and I made a shot at 168 yard with a 50 yard zero holding dead on, with the 325, a no brainer. Although a 200 yard shot does happen once in a Blue moon, the 45-70 or the Thompson .50 cal muzzle loader can handle it with a top of the back hold. Notably I use Hornady 325 grain Leverevalution ammo in the 45-70 or 3 pyrodex pellets and a Hornady 300 grain lock and load sabot bullet for the Thompson.

In Summary

For those who aspire to shooting long range magnums the classical Weatherby zero of 3 inches high at one hundred yards will put you dead on at 300 yards. After that it will require a great deal of study, practice and special equipment to go further.

For cartridges just under 3000 feet per second either a 50 or 100 yards zero will work depending on the expected average range of the game hunted. Holding slightly high of the center line of the animal at 200 will be a kill shot and right at the hairline of the back at 300 yards. This covers all 308 and 30-06 class cartridges give or take about an inch in trajectory or about the width of a cross hair. Of course practice makes perfect so range test at different ranges and develop your own drop table at various ranges to fine tune.

For the Primitive Weapon hunter and big bore shooter at close range this is a good practical zero. Dead on at 25 yards will put you 1 inch high at 50 yards and about 1 inch low at 100 yards. A little light at the top of the back at 200 yards will nail a deer dead center. Once again check your particular rifle at the range. This includes the 44 magnum carbine, 45-70, and 150 grain charges for the 50 cal. Black powder gun.

Then there is the point blank zero used by the military before the advent of the M-4 and M-16 A-2 which seriously decreased the muzzle velocity of the M-16 A-1. The old zero for the M-16 with a 55 grain bullet 5.56 NATO (223 Remington) when the bullet traveled 3250 fps was dead on at 25 meters, making it dead on again at 250 meters, and 6 inches low at 300 meters.

Remember that is shooting at a vertical man target instead of a horizontal deer target. You can convert meters to yards to give yourself something to do as you come to the understanding the bullet crosses the line of sight twice during its flight, in this case at 25 meters and then at 250 meters. A 270 WSM with a 130 grain bullet has about the same trajectory.

Read Part One- Understanding Bullet Ballistics

These are just some basics, so now you have to do your homework, and study the ballistic charts and tables of the different ammunition companies and calibers, as well as the range testing and practice. One of the best, and the most fun, is Winchester's online Ballistic Calculator. When you get all this done, you will be a much better game shot, and have a good basic understanding of external rifle ballistics. Pass it on.

325 WSM Ballistics Chart