BCB
07-29-2017, 03:07 PM
As we all know, changing a component can mean many different things when the hammer is dropped…
I finally got the Encore with an MGM barrel in 30-40 Krag shooting to quite good accuracy. This accuracy, or more correct, inaccuracy issue was discussed on another thread. But, I got that resolved (an interesting find and solution) so now I am able to detect changes in performance when components are changed…
I have been shooting the N.O.E. 311-202-RN and 49.0 grains of WC-872. Velocity is at 1953 fps. I had developed this load using Graf brass. Recently some of the Graf brass has begun getting split necks—not from lousy brass, but from being reloaded and fired at least 15 times (pressure is so low that I don't even us lube to size them) according to the number of boolits I have cast and what remains. So, I had some R-P brass that I had previously fired in the same barrel, about a dozen pieces, and I loaded them with the same recipe—all well and good until I went to the range…
I had the Graf rounds sighted in to be 2” HIGH at 150 yards. So, to begin using the R-P brass I fired a round at my 150 yard steel groundhog silhouette. It hit 2” to the RIGHT of P.O.A. So, I fired 2 more rounds and they all hit within about 1.25” group. I then fired 3 of the Graf rounds and they all hit within about the same 1.25” sized group, BUT 2” high as could be expected…
I was surprised at how much difference brands of brass make. I never saw such changes so distinctly in my entire shooting career that began in the mid-60’s…
Some numbers: The R-P brass will hold 52.9 grains of water with the N.O.E. boolit seated to the accepted O.C.L. The Graf brass holds only 49.2 grains of water with the boolit seated to the same O.C.L. Not much, but still the R-P has a greater capacity by 7.5%. Since QL indicates that only about 74% of the total charge was consumed during the firing of this round, I didn’t think that the extra space in the R-P brass would really matter—Seems it does matter…
The WC-872 is slightly compressed in the Graf brass, but not touched in the R-P brass. I wonder if this is what might be the difference—better ignition with the slightly compressed charge?...
Always something, but sometimes not a bad something--Just knowledge gained...
Good-luck…BCB
I finally got the Encore with an MGM barrel in 30-40 Krag shooting to quite good accuracy. This accuracy, or more correct, inaccuracy issue was discussed on another thread. But, I got that resolved (an interesting find and solution) so now I am able to detect changes in performance when components are changed…
I have been shooting the N.O.E. 311-202-RN and 49.0 grains of WC-872. Velocity is at 1953 fps. I had developed this load using Graf brass. Recently some of the Graf brass has begun getting split necks—not from lousy brass, but from being reloaded and fired at least 15 times (pressure is so low that I don't even us lube to size them) according to the number of boolits I have cast and what remains. So, I had some R-P brass that I had previously fired in the same barrel, about a dozen pieces, and I loaded them with the same recipe—all well and good until I went to the range…
I had the Graf rounds sighted in to be 2” HIGH at 150 yards. So, to begin using the R-P brass I fired a round at my 150 yard steel groundhog silhouette. It hit 2” to the RIGHT of P.O.A. So, I fired 2 more rounds and they all hit within about 1.25” group. I then fired 3 of the Graf rounds and they all hit within about the same 1.25” sized group, BUT 2” high as could be expected…
I was surprised at how much difference brands of brass make. I never saw such changes so distinctly in my entire shooting career that began in the mid-60’s…
Some numbers: The R-P brass will hold 52.9 grains of water with the N.O.E. boolit seated to the accepted O.C.L. The Graf brass holds only 49.2 grains of water with the boolit seated to the same O.C.L. Not much, but still the R-P has a greater capacity by 7.5%. Since QL indicates that only about 74% of the total charge was consumed during the firing of this round, I didn’t think that the extra space in the R-P brass would really matter—Seems it does matter…
The WC-872 is slightly compressed in the Graf brass, but not touched in the R-P brass. I wonder if this is what might be the difference—better ignition with the slightly compressed charge?...
Always something, but sometimes not a bad something--Just knowledge gained...
Good-luck…BCB