I had to cure some terrible feeding issues. First, I polished the feed ramps until they are bright as a mirror. Second, I had to replace the standard carbine buffer with an H2 (extra heavy) buffer. Finally, I modified one of my two 20-round magazines with the YouTube infamous "magazine fix".
In the end, the Browning 124gr FMJ feeds, fires, and ejects flawlessly in the unmodified magazine. In the modified magazine this round gets caught
over the bolt when it closes. Conversely, the Hornady 170gr and Federal 160gr loads feed well from the modified magazine but when used in the unmodified magazine they get caught
under the bolt when it closes. So, two different magazines to use with different ammo. Since I have decided to use this primarily as a defensive weapon I will be purchasing four more of the 20 round magazines and I will leave them as-is. That will give me one mag in the rifle and four in an old M16 20 round magazine ammo pouch, for a total of 100 rounds. The modified magazine I will keep on hand for the off chance that I want to go hunting with the heavier ammo.
Browning also came out with a 155gr BXR plastic tipped cartridge. I am looking forward to trying that out. Hopefully, it will work out in the unmodified magazines. If so, then I'll be able to do everything with the two Browning loads and standard mags. We will see.
Here are the three loads I tried. L-R Browning 124gr FMJ, Federal Fusion 160gr, and Hornady American Whitetail 170gr
You can see how I had to cut down the feed area of one of the magazines to get it to feed the Hornady and Federal stuff. The blunt noses on those were catching on the edge of the magazine. Modified magazine is on the left, unaltered on the right.
The Browning FMJ load was very accurate. I shot this target at 25 yards from a supported kneeling position. This zero will keep the round within 1" of the line of sight out to 120 yards! It drops from there to 3" low at 150 yards.
The Hornady 170gr and Federal 160gr loads were not as accurate. I think that may be due partly to the recoil in this light rifle. Anyway, this group is representative of both of those loads. Note: The groups were higher than those from the 124gr FMJ load because I flipped the sight to the long range aperture for these heavier, slower cartridges. If I were to use it in the field that's what I would do. I'd use the near range aperture for the 124gr load and the long range aperture for the heavy stuff. That method would set it up for the best trajectories within 150 yards.
Another view of the carbine.