I ran a primer test. I had purchased Wolf and Tula7.62 primers and wanted to see how they compared to my other primers. Tula 7.62 were advertised to be the same insensitivity as CCI #34’s, which are a mil spec primer. Mil spec primers are less sensitive than commercial primers, due to a combination of a thick cup, different primer mix, and some other factors. They exist because military weapons often have heavy free floating firing pins. Heavy free floating firing pins have a tendency to ignite sensitive primers before the trigger is pulled. An accidental discharge will range from embarrassing to fatal accident.
My load is a standard match load in the Garand. Garands are not magnums and the loads they fire are in today’s world, mild. Heavier loads, powders like IMR 4350, will over accelerate parts in the Garands leading to malfunctions and long term will damage parts.
What I saw in my test, holding case, bullet, powder the same, was that velocities and group sizes change with change of primer.
My old standby of the nickel plated WLR and CCI #34’s shot very well, the Wolf and Tula primers also shot very well. I was disappointed in the groups with Federal primers. I have been getting excellent results with Federal primers with IMR 4350, 150 grain bullets, in the 30-06. Maybe it was just the day.
Because of their sensitivity, I do not recommend Federal primers in Garands. Federals are the most sensitive primer on the market and the most slamfiring primer ever in Garands/M1a’s. I use my Federals in bolt guns and they shoot fine. No adequately designed and maintained rifle should misfire with #34's, but one with a weak mainspring could. I won't use them in my 35 Whelen because I have had misfires with standard primers in that cartridge, the 35 Whelen has a slight shoulder and I am of the opinion that the slight shoulder allows the cartridge to be driven in as the firing pin hits the primer. I installed Wolff extra strength mainsprings and sized the cases to zero head space in my 35 Whelens, and I am using Federal primers. But for my 30-06, 270 Win, etc, never had an issue with a #34. I also wonder about the magnum claims, my velocities are not all that different from standard primers.
So I can say, primers make a difference. But if I varied powder charge with each primer, those primers that gave disappointing groups the group sizes might have improved. Conducting a test like that would have taken lots of work, but I am confident to say, group sizes change with primer changes.
30-06 Primer Test
Colombian Mauser Match 26" Wilson match barrel
174 FMJBT White Box 1968 NM M72, Headstamp LC67 match, box velocity 2640 fps
14 Nov 2011 T = 68 °F
Ave Vel = 2698
Std Dev = 51
ES = 117
High = 2771
Low = 2654
N = 5
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM CCI #34 OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2645
Std Dev = 12
ES = 42
High = 2671
Low = 2629
N = 10
Very good group
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM Tula 7.62 lot 1-10 primers OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2665
Std Dev = 9
ES = 28
High = 2677
Low = 2649
N = 10
Excellent Group
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM Wolf NCLR lot 18-09 OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2656
Std Dev = 15
ES = 36
High = 2677
Low = 2641
N = 9
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM Fed 210S OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2656
Std Dev = 13
ES = 34
High = 2674
Low = 2640
N = 10
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM WLR (Nickle) OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2665
Std Dev = 18
ES = 60
High = 2696
Low = 2636
N = 10
Excellent group
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM CCI200 OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2680
Std Dev = 14
ES = 56
High = 2712
Low = 2656
N = 10
V. Good group
M1 Garand BMR Receiver Douglas Barrel 1:10 twist
150 gr FMJBT 1966 Ball
14 Nov 2011 T= 74 ° F
Ave Vel = 2545
Std Dev = 20
ES = 68
Low = 2513
High = 2581
N= 8
174 FMJBT White Box 1968 NM M72, Headstamp LC67 match, box velocity 2640 fps
14 Nov 2011 T = 74 °F
Ave Vel = 2592
Std Dev = 28
ES = 103
High = 2647
Low = 2544
N = 10
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM CCI #34 OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2632
Std Dev = 20
ES = 60
High = 2671
Low = 2611
N = 10
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM Tula 7.62 lot 1-10 primers OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2582
Std Dev = 15
ES = 49
High = 2602
Low = 2553
N = 10
excellent group
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM Wolf NCLR lot 18-09 OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2607
Std Dev = 17
ES = 57
High = 2642
Low = 2585
N = 10
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM WLR (Nickle) OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2650
Std Dev = 19
ES = 68
High = 2688
Low = 2620
N = 10
Very good group
174 FMJBT 47.0 IMR 4895 Lot L7889 thrown LC62NM CCI200 OAL 3.30
14 Nov 2011 T = 74 °F
Ave Vel = 2599
Std Dev = 22
ES = 75
High = 2637
Low = 2562
N= 10
Very good group