30-06 loads much slower than expected

[targetterror]

I'm getting much lower velocities for my 30-06 loads than I expected based on published data. I'm loading for a WWII Garand, and a Remington 1917 (1917 Enfield). The 1917 has been sporterized, but I think it is still the original barrel, which is 26 inches.

Components with all loads was Lake City Brass, CCI 200 primers, and IMR 4064.

My Garand data with a 168 grain SMK is (average velocity for 10 shot strings, giving the barrel time to cool in between):
43gr - 2185fps
45gr - 2285
46gr - 2359, 2385 (second string done on a different day)

My 1917 data with a 175grain SMK is (average velocity for 10 shot strings, giving the barrel time to cool in between):
47gr - 2473
48gr - 2558
49gr - 2597

Every load above is a good 200fps or more slower than pretty much every published load. I don't think my chronograph is off, b/c my Savage F/TR registers ~2800fps with a 175grain SMK (30 inch barrel, .308win).

Any ideas? What kinds of velocities are other people getting with IMR 4064 in 30-06? Neither the 46 gr load in the M1, nor the 49 gr load in the 1917 showed signs of pressure, though 49 grains is about published max.

 

[Country]

Re: 30-06 loads much slower than expected

Your load with the 168 SMK is a bit low and could be increased. Also the Garands gass system may be sucking of a bit of pressure. Large military chamber could be reducing chamber pressure .
The load with the 175 is getting up there but a large miltary chamber may be reducing chamber pressure.
Also the IMR 4064 batch may be a bit slower than normal.
If no pressure signs are obvious and the chronograph is correct then gently increase the loads watching for pressure signs.
Published velocities are not exactly correct for every gun and every batch of powder. They are just a guide.
You have to find a safe load that gives the best performance from your gun . Don't work up maximum loads in cold weather because they might pop primers in hot weather.
I load a 180 grainer at 2650 fps in my 30-06 and that is about as far as I want to go.