Point of impact difference

Has anyone tested to see where M855 will impact at 100yds when the gun is sighted in with M193? It's a M4 with an ACOG. Thanks!

http://www.m4carbine.net/showthread.php?t=65679

scroll down there is a ballistic graph of the two.

Me I zero at 50 meters, but shoot at 100 as well. The 50 meter zero with 62 grain bullets has proven most useful. Now all I have to do is see a second deer this season I want to shoot!

Thanks! That's exactly what I needed.

Every individual gun is different. Three of mine have virtually no impact shift from M193 to 855 and one has a 2 MOA lateral shift and a couple have vertical shifts. The only way to know is to shoot it and record it. That graph tells you nothing in regards to your question......

Originally Posted by Formidilosus

Every individual gun is different. Three of mine have virtually no impact shift from M193 to 855 and one has a 2 MOA lateral shift and a couple have vertical shifts. The only way to know is to shoot it and record it. That graph tells you nothing in regards to your question......

Kinda my thoughts when I looked at the graphs. They are probably close enough for most uses, but I'd prefer to actually paper both bullets.

I'm a bit confused here. In the OP it seemed that he was asking what the shift would be with Greentip at 100yds if the gun was zereod with M193. To the there is no answer. Now if he were asking about trajectory differences like most seem to be answering then the charts would be helpful.

Originally Posted by Formidilosus

I'm a bit confused here. In the OP it seemed that he was asking what the shift would be with Greentip at 100yds if the gun was zereod with M193. To the there is no answer. Now if he were asking about trajectory differences like most seem to be answering then the charts would be helpful.

There is a single chart showing the M193 and M855 both zero'd at 100 yards. You have less than 1/2 inch in trajectory difference out to 250 yards.

From that you can deduce that if you have sighted in with M193 at 100 yards, the change in POI with the M855 would be negligible and lost in normal group dispersion.

Originally Posted by MichiganScott

There is a single chart showing the M193 and M855 both zero'd at 100 yards. You have less than 1/2 inch in trajectory difference out to 250 yards.

From that you can deduce that if you have sighted in with M193 at 100 yards, the change in POI with the M855 would be negligible and lost in normal group dispersion.

Negative. The trajectory may be similar, however POI between them is probably not. Every single gun will be different. You can not assume that different loads will shoot to the same point of impact. As I said before, between personal and Mil issued M4/AR15's only about half have same POI for both M855 and M193. I have a brand new SOPMOD M4A1 that has a 4MOA shift at 100m between M855 and M193. I also had an SPR that had identical POI for MK262, M855, and M193.

Yes if both are zeroed for 100 meters than the trajectory will be close. However just because you zeroed M193 does not mean that M855 will be zeroed. You have to check it.

you have a point, I think sometimes I get wrapped up in ballistics charts to much.

Originally Posted by Formidilosus

Originally Posted by MichiganScott

There is a single chart showing the M193 and M855 both zero'd at 100 yards. You have less than 1/2 inch in trajectory difference out to 250 yards.

From that you can deduce that if you have sighted in with M193 at 100 yards, the change in POI with the M855 would be negligible and lost in normal group dispersion.

Negative. The trajectory may be similar, however POI between them is probably not. Every single gun will be different. You can not assume that different loads will shoot to the same point of impact. As I said before, between personal and Mil issued M4/AR15's only about half have same POI for both M855 and M193. I have a brand new SOPMOD M4A1 that has a 4MOA shift at 100m between M855 and M193. I also had an SPR that had identical POI for MK262, M855, and M193.

Yes if both are zeroed for 100 meters than the trajectory will be close. However just because you zeroed M193 does not mean that M855 will be zeroed. You have to check it.

I'm thinkin' you and I are in total agreement, but just saying it differently.