I do not believe this is totally correct. To the best of my knowledge that ammo is correctly loaded as intended by the factory. Barnaul (the factory) has made this same identical load in 55gr SP and HP for over a decade and they have always used a shorter projectile of similar OAL to a 223 projectile but properly sized down for the 5.45 barrel. Like most 5.45 ammo it is intended to be used in the AK74 and works flawlessly in such rifles. In some of the AR-15 conversions it does not work right because those conversions are new and have not had all the bugs worked out. Specifically, with some of these units the mags and uppers were designed and tested only with FMJ mil-spec loads and may not feed well with the slightly shorter hunting/sporting 5.45 loads like the 55 grain soft point and the hollow point, but it is really an issue with the 5.45 cal upper and mags not being properly designed to be used with the full line of ammunition manufactured in this caliber. The size and shape of the projectile of the current production is correct and consistent with the past history of this product and nothing is really new or wrong with the ammo itself, it just does not feed well in the AR platform and it was not designed or intended to be used in that platform. Its the same stuff Barnaul has been making for over a decade. The guys making these 5.45 uppers really need to make sure that they work right with all variations of ammo that is produced in this caliber, not just the mil-spec FMJ stuff. I'm not saying it is impossible that Barnaul could mess it up, but I am pretty sure its just as simple as these guns were set up to shoot 7N6 or other military spec rounds, not the sporting rounds that are loaded with a shorter projectile and they may need a different magazine for that ammo to work, or adjustments in the upper for proper feeding

I have the ammo in question, got it a long time ago, at least 5 or more years ago.  I have used it in two AK74 rifles made from Bulgarian parts sets with factory barrels.
I noticed right away that that short bullet lead to feeding issues.  I only use it for range ammo.  I would guess one in 100 will not feed correctly.   This is the only ammo that I have had problems with in these rifles.  The OAL is so different compared to the military ammo it looks like a problem waiting to happen.

I bought digital calibers over the weekend and measured the 55 SP and some 60 FMJ variations, as well as some different wolf 223 and there is a substantial and consistent difference. Like I said in my first post the size the bullet diameter down for the 5.45 loads. I think the issue in the AR15 is they are trying to tighten tolerances up to make the guns more accurate, but this cuts into reliability with some of the non-mil spec loads that they had not planned on being used. Perhaps the rifling in the throat is cut a little bit closer to the chamber and is engaging the projectile as it is chambered ? It might not be an issue on the long skinny FMJ projectiles but with the short/fat SP and HP loads it causes problems. I talked to my sales rep at Wolf about it friday and they said they had examined some of the returns and "that ammo was designed and intended for AK74 and will work flawlessly, but is going to have issues in the ARs". Barnual has been making this same ammo for a very long time, and the AR guns in 5.45 are almost a brand new thing, I'm pretty sure the reliability issue is something within the firearms tighter tolerances being used to make for better accuracy

For $30 at any auto parts store you could buy a set of digital calibers just like i did and measure yourself to be sure, but the 5.45 WPA SP I measured was basically the same as the 5.45 FMJ when measured at the case mouth, and substantially smaller than 223. As you go forward on the bullet the diameter of the SP does not start to taper down as quickly, so I think that the issue is that the SP/HP bullet may be engaging the rifling in the throat on the AR's. The diameter of the 223 and 5.45 projectiles is very close to the same to start with, but the factory sizes down the projectile for 5.45 to make them slightly thinner than the 223. I'm not 100% sure its safe in 100% the AR's because something about how they are building some of those guns is causing problems with this ammo. They made this ammo for the AK74 market and those guns are built a little looser to improve reliability, the AR's seem to be built a little tighter for better accuracy, and somewhere in the set up is an issue that is causing problems with this ammo