FGMM 175gr Old VS New

[JINKSTER]

A coworker/friend of mine shared this with me so I’m sharing it here with you folks.

The top string is his old red box 175gr SMK FGMM…the bottom string is Federals recent FGMM 175 SMK’s…both strings shot from his 26” barreled REM 700 Varmint .308

 

[Mooseknuckles]

Seems slow for a 26 inch barrel. My 24 inch barrel FN is averaging 2605 with the newer FGMM. My 20 inch Howa 308 was averaging 2517.

 

[7mm-matt]

Interesting drop in speed. I have a few boxes left of the "old" and just picked up a couple of the latest boxes. I'll bring my chrono if I make it out to the range this weekend.

 

[1911hombre]

.

 

[Trigger Monkey]

New 175 FGMM was slow in my AAC-SD also, 2,488 fps from the OEM 20" barrel.

 

[ShaoKahn]

New 175 FGMM was slow in my AAC-SD also, 2,488 fps from the OEM 20" barrel.

Well that’s not good. I haven’t tried “the new” 175s but “the old” version was giving me 2505 fps out of a 16” barrel.

 

[Trigger Monkey]

Yeah I was pretty surprised too, it was accurate, no doubt about that but just slow.

Same for some new manufacture Fed 77gr GMM, it was really really slow out of an 18" barrel.

 

[AR-180]

My guess is lawyers.

 

[7mm-matt]

Ya that’s not great news as I’m running an 18” barrel so already running slower. Looked at my boxes and I have about 5 boxes with lot date of may 18. Than the two new boxes are sep 19 and jun 20.

 

[308pirate]

My guess is lawyers.

My guess is they're having to use different powders/powder blends based on supply chain availability

But lawyers sounds more fun

 

[Ledzep]

Pull one. Does it look like IMR 4064?

Could be many things. If the old lot was stored in a vehicle, the constant bouncing around and heat cycles can cause the retardant to slowly wear away and increase burn rate, pressure, and velocity. Could be polar sides of velocity/pressure corrections on a test barrel. Could be different powder, slow lot, etc...

 

[DJL2]

I recently chrono’d 2595 fps for FGMM 185 Juggs from a 20” bbl… seeing a 26” run 175s slower is mind blowing to me. The 168 TMK TRU was 2625 or so, the FGMM 168 SMK was 2605 or so. I guess in that context I can understand the 175 numbers (at least from my barrel)… but… why can’t they all be loaded like the 185 Juggs? ;-) For factory ammo so far, as far as reaching out there, I haven’t found anything that’ll touch those 185s. The TAP 168 ELD-M did 2725 fps or so, but that’s not enough at the muzzle… maybe the Superformance match?

 

[diggler1833]

Approaching 2,700 FPS with the 175s seems to be more of the exception and not the norm.

Many older threads on here have most of the shooters reporting 22-24" barrels running the 175 stuff in the 2550 - 2600 range. Some had crazy high numbers...but what kind of chrono were they running and under what conditions?

 

[7mm-matt]

Looks like I had 2584fps average in my ballistics for 175gr fgmm out of an 18” barrel.