Trajectory graph from 0 to 50 yards for 30-30 Win.

[Mike-in-WV]

Anyone know if a trajectory graph exist for a 170 gr 30-30 from 0-50 yards? There are many of them from 25-100 or 50 to 100 and so on but nothing from say 10 yards to 50 yards. Mike

[Cast Bullet Hunter]

It would be almost a straight line at that range, less than 1" variation. Actual measurements would depend on actual zero range, but if zeroed at 50 yds. the bullet would start the distance down that it is from the sight line to bore center and rise to the aiming point without ever crossing the line of sight.

[Mike-in-WV]

It would be almost a straight line at that range, less than 1" variation. Actual measurements would depend on actual zero range, but if zeroed at 50 yds. the bullet would start the distance down that it is from the sight line to bore center and rise to the aiming point without ever crossing the line of sight.

That as my thinking to over the years of playing with this stuff but.....If you sight in a 30-30 dead on at 12.5 yards it will be close to dead on at 50 yards or just a scosh high and will rise 1" high at 25 yards. So how does it rise between 12.5 and 25 but come back down to line of sight at 50 yards then only 2.5 low at 100 yards? This is with my Trapper and I do realize that not all guns are not same but this is strange to me for a 170 gr. 30-30 Mike

[Bob A]

You can use the ballistics calculators on this site to find the answer.
All you need is MV, Zero point, Ballistics Coefficient and site height above bore. For a 170 grain 30-30 the BC is prob about .200 (unless its a Speer hot core, then its .300)

I think you will find that the site height is very important when you are talking about short distances. But no matter the site height, if you are Zeroed at 50 yards it is a very straight line climbing to Zero at 50 yards and not crossing Zero until 50 yards.
If you Zero at 12 yards, it is still climbing at 50 yards and will be between 2 and 4 inches high at 50 depending on the site height.

Check it out

http://www.eskimo.com/~jbm/calculations/traj/traj.html

Bob A

[Mike-in-WV]

Bob. Thanks for the info and the link but as I said before, what has me stumped is the fact that if I sight in dead on at 12.5 yards it will be real close at 50 yards but about 1.5" high at 25 yards. To me it should not raise up at 25 yards if I'm dead on at 12.5 and close at 50. It just doesn't make sense. Unless it has something to do with my XS Ghost Ring sights and the fact that my front sight is really high compared to the original front sight. Mike

[Pete44ru]

The reason it has you stumped is that you're forgetting just how far below the line of your sights the bore is - an inch to an inch and a half.

12.5 yards from the muzzle is way too close for any effective zero.

If you zero your rifle, so that the bullet first crosses the line of sight at 25 yards (zeroed) on it's way up, the rifle should be shooting about 3/4"- 1" high at 50 yards, with the bullet again crossing the line of sight (zeroed) on it's way back down at about 100 yards, give/take.

If you need to hit a very small target at, say, 10 yards, just hold 1/2" high(with this zero).

[Griff]

Ballistic generators are nice and all, but... rifle weight, recoil and muzzle jump all factor into the effect you're actually seeing on targets. Using the same round, & speaking in generalities, a lighter, shorter barreled gun will have more muzzle flip than a heavier, longer barreled version using the same ammo, all other factors, chamber size, bore and groove diameters, etc.

Using iron sights, generally put at ¾" above the bore (as on my Winchester 94, .30WCF), the bullet starts out that slightly below that ¾" below the muzzle as it rests in the cartridge in the bore. Remember, your barrel is now at a slight incline, as the rear sight is generally less than ¾" above the centerline of the bore. By the time the bullet has exited the muzzle, here is where rifle weight and muzzle rise plays a part, the bullet may have already risen higher than the sight was located, at rest. So, from the point of ignition until the bullet exits the bore you have an upward trajectory of the bullet. If you're sighted in for 50 yards, you've shortened the period of time the bullet will be above the line of sight and the line of the bore, at rest. Remember, the line of sight is like a lazer light, it goes in a straight line from your sights. However, the line of the bore is also a straight line along the centerline of your bore. Where those two intersect is the point of zero of the gun, at rest. Recoil and muzzle rise during the time of bore travel will affect actual bullet flight path, which will differ from both the line of sight and the line of the bore of the gun at rest. Actual line of flight will ALWAYS be in a straight line from the line of the bore AT THE TIME THE BULLET exits the bore to the point at which gravity overcomes the bullets momentum and yanks it out of the air. Which is why a 'bore-sighted' rifle is only an approximation of where the bullet will impact as it can't take in account that muzzle rise and recoil.

Just my observations, I ain't an expert, nor did I stay in a Holiday Inn last nite.

[Mike-in-WV]

Thanks Griff, What you said makes alot of sense to me. I guess I just need to play with this Trapper a little more if the weather ever gives me a break! Mike

[Griff]

Thanks Griff, What you said makes alot of sense to me. I guess I just need to play with this Trapper a little more if the weather ever gives me a break! Mike

That's good, I wasn't sure I was explaining it well. BTW, I have my .30-30 Trapper sighted in for 125 yard zero. If you run your load thru the Bob A. provided, you'll see that it gives a good trajectory out to 150 yards.

[Mike-in-WV]

Griff, The biggest reason I have been playing with this trapper so much is because I want to carry it while scouting for Bear this summer around here. We have alot of Rattlers and they are the mean type, Timber rattlers who get big around as your arm and they like to strike silent as you walk by. If that's not enough we have so many Copperheads it's not funny and they look just like the leaves they are laying in.
I have two other Win 94's but this one is fast becoming my favorite for in the woods. That's one of the reasons for sighting in at 12.5 yards and it works perfect for plinking or close in critters and it's almost dead on at 50 yards also. I was just having problems with the rise at 25 yards and it had me scratching my head.
Most shots in my area at Deer or Bear or Hog is 75 yards or much less so I don't bother to much with sighting in over 100 yards. If I'm going to hunt the farm fields ,power lines and so on I will take my 308 with the 3-9 redfield, Mike