I picked up a case of this stuff the other week at a sale price of $4.75/box 50. Didn't expect much of it but the price was right and I figured it should be decent enough for silhouette, offhand shooting, hunting, Mapleseed, etc. Well, I was very pleasantly surprised by the excellent overall performance! I revisited the mid-high 100 settings for my Harrells tuner, after reading some Bill Calfee posts. I had been shooting with it in the 400's for most of the year. Keep in mind this rifle has to "puke" every so often, and this has nothing to do with "shooter error" or any of that nonsense. There is no ammo, no tuner setting, and no hold technique that can get rid of the rifle's tendency to do this. Another reason for buying a case of this ammo was to just dump cheap ammo through the rifle to get the round count up and help the leade become a smooth and fluid transition to the bore, as this transition not being perfect (no freshly cut chamber is, either post chamber lap or shoot a case + for natural wear in) is the primary cause of a rifle "puking", when it can otherwise drill a number of shots through one hole.
So, the ammo! It is BBM (Battle Born Munitions) Semi-Auto, and is made by RWS in Germany. It could possibly simply be RWS Semi-Auto rebranded, but while some have speculated Federal UM is repackaged R-50, I recall a post on RFC where someone deconstructed a Federal UM round and an R-50 round, and found them to contain different powders and slightly different lead bullets. It is perhaps more accurate to say Federal UM is made to R-50 specifications, so whether the BBM is a separate product made to RWS specs, or a rebrand, we'll probably never be told the truth. I bought myself another two cases of it before letting y'all know about it
But not to worry, the supplier says he has over 200 cases so plenty to go around. They are not a site sponsor, but there are only so many wholesalers of rimfire ammo in Ontario... I'm sure you can track it down, but do note the website lists it as RWS Semi-Auto (I was a little surprised when I opened up the case to find BBM!). The small boxes (one is R-50) show RUAG Ammotec, Germany, where RWS is made.
And performance! What was really exciting is that for the first time in the year I've been shooting it, my CZ 455 Custom has finally put together 5 groups sub 1/4"! Of course, it was due to puke after that 5th group. Now I know the gun can do it, maybe not so consistently just yet, but it is obviously possible. Trouble will be getting it to happen on a qualifying target, as while the groups were consecutive, the order of the bulls would have meant that each row represents a challenge "attempt", and I would have two "failed" attempts at the 1/4" club here. Otherwise, 38/40 groups sub 1/2" with 22 of them being in the 0.2's or better is just awesome for the price!
So, the ammo! It is BBM (Battle Born Munitions) Semi-Auto, and is made by RWS in Germany. It could possibly simply be RWS Semi-Auto rebranded, but while some have speculated Federal UM is repackaged R-50, I recall a post on RFC where someone deconstructed a Federal UM round and an R-50 round, and found them to contain different powders and slightly different lead bullets. It is perhaps more accurate to say Federal UM is made to R-50 specifications, so whether the BBM is a separate product made to RWS specs, or a rebrand, we'll probably never be told the truth. I bought myself another two cases of it before letting y'all know about it
But not to worry, the supplier says he has over 200 cases so plenty to go around. They are not a site sponsor, but there are only so many wholesalers of rimfire ammo in Ontario... I'm sure you can track it down, but do note the website lists it as RWS Semi-Auto (I was a little surprised when I opened up the case to find BBM!). The small boxes (one is R-50) show RUAG Ammotec, Germany, where RWS is made.And performance! What was really exciting is that for the first time in the year I've been shooting it, my CZ 455 Custom has finally put together 5 groups sub 1/4"! Of course, it was due to puke after that 5th group
. Now I know the gun can do it, maybe not so consistently just yet, but it is obviously possible. Trouble will be getting it to happen on a qualifying target, as while the groups were consecutive, the order of the bulls would have meant that each row represents a challenge "attempt", and I would have two "failed" attempts at the 1/4" club here. Otherwise, 38/40 groups sub 1/2" with 22 of them being in the 0.2's or better is just awesome for the price! 
