Reloads vs. Factory Ammo?

Question

Last weekend I was at a range shooting my .243 Model 70 Winchester. The range was only 100 yards, and last year I had zeroed my rifle, with my reloads, at 200 yards. Same reloads I've used for years - 85 gr Speer BTSP pushed by 40.8 grn of 4350. Maybe a little high or low, but no left right varying at all. So I'm good with that. Then the factory ammo - Remington 80 grn PSP all shoots high and right, averaging 5 inches out. Its cheaper ammo sure, but at 100 yards I didn't think I would find that much difference. If factory ammo is supposed to be better than it used to be, what gives? I didn't change anything while shooting. Any ideas? Barrel heat, daytime temp, wind and humidity - all pretty much the same for the two hours I was there.

Ok - for some who have responded - Cant isn't an issue because there is a level on the scope. I agree with the velocity differences but that is only really going to affect high low, not make a different round move 5 inches to the right. And for the genius answer of 'different bullets shoot different' REALLY???? Thanks for the enlightening info. I've only been shooting this rifle for 15 years. I might have tried out a few different rounds in the past 1 1/2 decades. And, its only 100 yards - I'm guessing the wind, cant, etc don't really make that much difference until you get out to the 300 plus range.

Answer 1

That's why we reload, to develop the most accurate round for the particular firearm we use. Usually groups just open up when we use less than optimal ammunition, but sometimes the group moves (in your case high and right). I'm not an engineer, so I can't explain it; I just know that it can happen. If the size of your group is satisfactory (even though off center) then the factory ammunition is consistentt and therefore usable with a scope adjustment. I think that factory ammunition is more consisten than it ever has been, but the optimal loads for my firearms always seem to be the ones I work up myself.

Answer 2

I'm with WWD. If your reloaded ammo consistently groups in one area, and the factory ammo consistently groups in another, it's probably barrel harmonics.

You might not believe it, but when you fire a gun, the barrel flexes. Not much, but it does. You can see it happen if you have a very high speed video camera. This bending of the barrel isn't going to make a huge difference at close ranges, but you'll see differences between loads as you push, say, 100 yards.

One reason why handloads often beat factory loads in accuracy is that handloaders can take the time to select the most consistent components. They can weigh each bullet, gauge the volume and length of each case, and weigh every powder charge to a hundredth of a grain.

When you're that picky about your ammunition, you can ensure that every round leaves the barrel at the perfect time--meaning the barrel will be in the same state of flux every time. This consistency is what creates great accuracy.

Factory loads might be good--but are frequently just good enough. You can't make ammo at a profitable rate if you pay that much attention to every single round.

(Here's a video on YouTube that shows an AK47 barrel flexing under fire: http://youtube.com/watch?v=G6BpI3xD6h0
Most rifle barrels are not going to flex that much, but the flex is there, nonetheless.)

Answer 3

When you zero a rifle, you adjust the sights to get the center of the group to match your aiming point. The ammo is still a variable. Variations in height, suggest differences in muzzle velocity. Use the ammo that consistently gives the smallest groups. Be sure to note the wind direction. The high and right or low and left variation can be caused by canting the rifle. That is, tilting it slightly. This would be typical for a right-handed shooter. Also, be sure the barrel is properly bedded. Higher muzzle velocities and differences in powder burn rates can affect the barrel's reaction.

Answer 4

For whatever reason you get different impact points with different ammo. Some weapons digest some types of ammo better and don't like certain types; don't ask me why; I still talk to my old GMC and praise it; sometimes metal objects develop personalities, as do computers. In any case make sure you fire at least five fouling shots before you settle down to see how something shoots. A clean barrel will throw the first five into a different location; after that you start hitting at its designated impact point.

Answer 5

Depends on how high, and how right. Probably it's just a matter of different barrel harmonics throwing you right, but it's also possible your forend contact has shifted. Were your groups tight, and if you were using your chrono, was your standard deviation OK? Have you run a dollar bill down the barrel? Chances are, it's a normal change, considering all your components are different, but it's worth a check if you're going to be switching back and forth between the two loads.

Answer 6

From what I've read of the responses, everyone is missing the major points.

1 - different bullet types
2 - different bullet weights
3 - different velocities

For both to hit the same point of impact would verge on the miraculous.

Brian, you just cannot expect a rifle zeroed with one bullet and velocity to have the same point of impact when you change bullet types, bullet weight, and velocity.

I am rather surprised that a rifleman of your obvious experience didn't already know that.

Doc

Answer 7

It appears from the details you already know more than the average bear about your rifle and the ammo.
Try this for a theory: The riflings have a right hand twist and at a certain speed causes the bullet to go to the right.
Just in case you overlooked this fact, every load needs to zero'd, no two are alike.

Answer 8

Whether you like the answer or not, different loads shoot different and that's reality. Right, left, up, down. If all you have seen in the past is vertical variation then you have not shot enough to see the range of possibilities. The people who told you that are trying to help you and by insulting them you have shown yourself not worthy of their advise. When you decide to change your attitude and accept what they have told you, you will be a more knowledgable shooter, and your shooting will improve.

Answer 9

as for left and right Remington bullets fly different than speer bullets do
anything you change even little things can make a big difference bullet, powder, powder charge, OAL, and even primers
you changed so many things at once that it is hard to even guess
80grain bullets to 85 grain bullets
speer to Remington bullets
4350 to a proprietary powder
boat tail to a flat base bullet
ect

Answer 10

factory ammo has different levels of quality, cheap to preimum, plus different loads hit different places though they shot high and right how tight was the group high and right in one hole adjust the scope and go, this is really not and easy answer more of a discussion, but its all about the group size in terms of accuracy and quality and repeatability not hitting the same spot with different bullets and loads.