Range Report Federal dumping light loads of .308 FGMM?

[dbooksta]

I've been wondering why .308 FGMM has been showing up under $1/round recently. I bought some 168gr and pulled a round and found it only had 40.3gr of powder, which IIRC is light for them. I chronographed the box at 2645fps from a 22" bbl. IIRC we could expect more like 2730fps out of 22" with 168gr FGMM, and that load would generally have at least 42gr of powder, but I can't find any of my notes on this because it has been years since I've shot it. Is my memory serving correctly?

Or is this standard performance for FGMM?

 

[308pirate]

2645 fps is right in line with their advertised velocity: http://federalpremium.com/ammunition/rifle/family/gold-medal/gold-medal-sierra-matchking/gm308m

 

[lash]

That velocity sounds right to me. Maybe the charge weight is different due to the use of a different powder.

 

[IanHusaberg]

I found 44.9 gn of mystery powder in the 185 juggernaut GMM load. I thought it was CFE 223(Looked like the same powder), It wasn't. Maybe MR2000?

Old load was 42.8 of IMR 4064. With 168's.

 

[tnichols]

As posted above, a powder lot switch (even commercial reloaders run into this) may have prompted them to reduce the charge weight. I find it amazing that the FGMM line is as good as it is, considering they have to load a round that is safe in ALL weapons and typically quite accurate.

 

[BangBangBlatBlat]

I think its common practice to load to velocity, so they might have gotten a lot of powder that runs a little hotter than the other lot that you sampled.