[ftnspace]

Weight sorting seconds is usually a must to mitigate overweight or underweight bullets from causing fliers.

[ftnspace]

75 gr RMR 3GH LOT 2

I plan to get data on paper for a G7 estimate on the 75 gr when time allows.

16″ 1:7 twist medium contour barrel AR-15, 5.56x45mm NATO chamber, suppressed

Load: (work up, be safe, etc.)
LC 09 brass (1x fired, FL size, chamfer, debur, flash hole uniform; no annealing)
CCI No. 41 primer
23.8 gr Ramshot TAC
2.255″ COAL (PMAG Gen M2/M3 magazine length)
RMR 75 gr 3GH LOT 2
10 rd Avg Vel. 2,610 fps (LabRadar)
ES 32 fps (on progressive press)
8 shot group 0.33 MOA (actual MOA, not iphy)

Slightly flatter shooting than expected, but similar to SMK.

Performed well in 5-10 mph winds on 66% sized steel out to 700 yards, although my red dot limits me to 450-500 yards for reliable unsupported hits.

For the 69 gr RMR 3GH:

I can’t get the 69 gr 3GH to shoot well for me with TAC or AA 2460 at all, but I have a slow and a fast sub MOA node for 69 SMK with AA 2460.

I’ll try Shooter’s World AR Plus, which might be just the ticket.

I have my doubts that AA 2520, Varget, IMR 4895, IMR 4064 or CFE 223 will work well if AA2460 doesn’t, as they’re all a bit slow for that bullet in my 16″ barrel but I’ll try them regardless.

[ftnspace]

A load that worked well for me:

Rifle: 16″ 1:7 twist medium contour barrel AR-15, 5.56x45mm NATO chamber

Load: (work up, be safe, use at own risk, etc.)
LC 09 brass
CCI No. 41 primer
23.8 gr Ramshot TAC
2.255″ COAL
RMR 75 gr 3GH (LOT 2)
Avg Vel. 2,610 fps (10 shots)
32 fps Extreme Spread
8 shot group 0.33 MOA (actual MOA, not iphy)

I might try 23.7 and 23.9 gr of TAC as I just stumbled on to 23.8 gr of TAC.

I have no idea what the terminal ballistic performance is so I won’t speak to hunting suitability.

[ftnspace]

Feedback for RMR:

75 gr RMR 3GH LOT 2

Weights 74.9 gr +/- 0.1 gr (about 15% are 74.8 gr and 2% 75.0 gr, with remaining 74.9 gr and 1 of 500 at 75.1 gr. (Sample size 500)

I did not bother keeping these weight sorted for my habdloads, because I intend to bulk load these on a progressive press and have no intention of weight sorting future purchases, so long as the lots remain this consistent.

I found a nice accuracy and velocity node.

16″ 1:7 twist medium contour barrel AR-15, 5.56x45mm NATO chamber, suppressed

Load: (work up, be safe, etc.)
LC 09 brass (1x fired, FL size, chamfer, debur, flash hole uniform; no annealing)
CCI No. 41 primer
23.8 gr Ramshot TAC
2.255″ COAL (PMAG Gen M2/M3 magazine length)
RMR 75 gr 3GH LOT 2
10 rd Avg Vel. 2,610 fps (LabRadar)
ES 32 fps (on progressive press)
8 shot group 0.33 MOA (actual MOA, not iphy)

Slightly flatter shooting than expected.

Performed well in 5-10 mph winds out to 700 yards, although my red dot limits me to 450-500 yards for reliable unsupported hits.

Oddly enough, this load performed poorly unsupressed from a WarComp CTN; there must be a harmonic that works in my favor with the can on.

When I shoot again, I plan to gather detailed elevation information holds on paper, rather than steel)l at various distances (as well as the detailed LabRadar step trace data). That should be good enough to derive a rough estimate of the G7 coefficient for the given surface weather.

More to come, but I will be buying more of these regardless.

[Author]

Posts