I was sighting in my recently built AR and had some issues with RMR manufactured FMJ bullets.

I could shoot Rem. 55g FMJ factory loads into 4 shot groups at 100 yards with a group size of .9" after sighting in the rifle but when switching over to some reloaded RMR FMJ bullets the groups opened up to 3-5" at the same distance. This is the same load that will shoot 1.2-1.5" groups at 100 yards with another AR Sig I have all day long if there is no wind and I am working things ok.

I've been satisfied with RMR bullets for handguns to date and seem to remember that any other .223 bullets I ordered from them were Ok but this latest order seems to be bogus. They were not the pulled ones that they sell but rather the ones they indicate that they make.

Anyone with similar experience ???

Maybe there aren't a lot of folks using their rifle bullets ?????

I use Hornady and Speer.Tried Midway dog towns.Never even heard of RMR until now.Try them in your other rifle.Me,I will pay extra for known quality.I don't see any savings buying that brand.The cost is the same.Those bullets are like garbage bags,you buy them to throw away.

In my experience, the 55 gr FMJ bullets are plinking bullets. Even the best of them seem only capable of 2 or 3 inch groups at 100 yards. I have had much better accuracy with hollow point or soft point bullets. The Hornady 55 gr SP in particular shoots very well compared to the Hornady 55 gr FMJ. The SP with Cannelure is comparably priced when purchased in bulk. I don't plan on wasting any more money (or primers or powder) on 55 gr FMJ bullets.

Every bullet is different, even among the various 55 gr. FMJ offerings there will be a bit of difference in bearing surface and ogive as well as quality of manufacture.
Try working up a load for the specific bullet you are using rather than relying on a load for a different bullet, even of the same weight and type.

Gotta remember what RMR is.
So previously when Speer fell under the Defense Contractor banner of ATK, they were resigned to being a bullet beotch for Federal factory ammo. That is one of the reasons why you haven't seen anything interesting or new from them in some time. That is now changed, and they are doing an entire re-shoot and pressure testing to come out next year; also bringing a bunch of new bullets.

At any rate, because they are very close to Speer in Lewiston, they get rejected lots of ATK's ammo. So why did they get rejected, and what were they for is the question?

For plinking, they are fantastic! IF you want match grade, you gotta pay more than plinking prices.