Just ordering my first ammo now, and having many problems due to shortages and high prices.

I like the reviews for 5.56 winchester 55gr ammo and ordered some on back order. Some local shops have .223 rem umc (a yellow box) for about half the price..... about .38 cents a round compared to .64 for the winchester back ordered.

What differences will I occur with shooting the different ammo? Will I need to resight for less then 100 yards or is it something that will be fairly close? Can't find much data on this....  Thank you.

ps yes normally I would buy both and check for myself no questions asked....but I am running short on funds just buying a AR, and want like 2k in add ons yet, all while trying to stock up on mags and ammo while prices are climbing on both

Welcome to the Dark Side.  I suspect that you won't see enough difference to worry about, unless you're trying for high accuracy.  The UMC may shoot a bit lower than the Winchester, but I would guess it'll be within an inch or so at 100 yards.

@ 50 yards the difference between the two will be minimal. @ 100 yards there will be a significant difference. 5.56 is generally loaded hotter than 223 and Remmy UMC 223 is generally weaker than most other 223.  I find that the Remmy 223 is just a touch better than the cheap wolf or Tula...mainly because of the reloadable brass cases and less cycling problems....expect shotgun patterns @ 100 yards.

I prefer my handloads, but as far as price -vs- dependability -vs- accuracy in a practice/plinking round, I highly recommend PMC 223 55gr fmj, even the 62gr stuff isn't half bad.

Great, thanks for the info.

I just did a little research and the spec for Winchester is 3270 fps and the UMC is 3240 fps.  That's closer than I was expecting and would indicate that they would be pretty close to each other in POI (point-of-impact) as well.  I don't think that the bullets have significantly different ballistic coefficients, which would affect the POI as well.  Of course the manufacturer's advertized velocities may not be perfectly accurate either.

That makes me feel that I have no issue buying the .223 in bulk for now just to keep some stored until prices come back down, if they do. Thanks for taking the time to do that. This forum has been helpful already in leading me to the e lander mags when I couldn't find anything in stock!

out to 300 you won't notice a practical difference, but with any ammo you plan to use you need to re-sight in.



 

Great point! Two loads with the same MV, same BC, and same mass will usually shoot to different points of aim even though they will have identical trajectories when launched at the same angle of departure. This has to do with the fact that barrel harmonics will normally be different with different loads. Your barrel that seems like hard, strong steel bends and whips around when you shoot, kind of like a tuning fork. However, like a guitar string sounds different under differing stress, the pressure curves of loads differ, and a barrel vibrating differently launches bullets differently. If you are OK being within 6-8 inches at 100 yards, sighting in may not be needed. For any sort of precision, sight in for the specific load. Once you know where different loads impact in relation to one another, note that in a log. Then you can just turn the clicks and fire three to verify.

Lots of times when i fire different brands of 55 gr ammo the poi will be different esp @ 100yds, sometimes 2-3 inches, 200yds much worse,50 not so much, and then there times you can have several different brands and there won't be much if any difference.