300 blk M80 vs. FMJ-BT

[ruchik]

I was looking around for some 300 BLK ammo the other day, and ran across two different loadings. One is a 147gr M80, and the other is a 150gr FMJ-BT. I'm fairly sure the latter is a boat tail, but apart from that, what's the difference? The weight difference seems minute, and I can't decide what makes them any different.

[Onyx Z]

From my understanding, 147gr M80's are pulls from 7.62 and I bet the 150gr FMJ-BT are new bullets. The 150gr will probably be more accurate as some M80's I loaded couldn't shoot better than 3-4 moa. I have some 150gr fmj-bt, but I haven't done much load development on them yet.

[crawlin95]

All the m80s I've seen are great for close plinking but not too good for accuracy.

[1slow01Z71]

Be careful with the FMJ BTs, they don't allow enough bullet in the neck. The general rule is 1/4" and at least with the 150gr hornady FMJ BTs I bought there isn't even close to a 1/4" of neck purchase on the bullet. I did not load them and will use them for plinking in my 308 or 300wm. The M80s while their weight varies wildly(Ive measured 9gr ES) and aren't the best for accuracy even when weight sorted they do not have much of a boat tail and provide plenty of purchase for the neck to hold the bullet. If it was in a bolt gun Id try the FMJ BTs but the couple I tried could be pushed in with a little pressure on my bench. Maybe with a lee FCD you could get away with it but I didn't want to chance knocking the cartridge concentricity off and beating the hell out of my chamber. Stick with the M80 pulls IMO for cheap plinking.

[GunnutAF]

1slow01Z71
I have no problems loading Speer 150 gr BT's for my 300 Blk. In fact thats my deer load. Never had any problems with set back or not enough neck tension. If thats a concern one could alway put a little crimp on the bullet.;)