7mm-08 Rem - Rem.700 SPS Varmint 26"
Case: Remington (RP)
Bullet: Hornady 139gr SST - seated -.015" from touching, +/- .125" below cannelure exposed above case mouth.
Primer: Federal GM210M
Powder: Win 760
Average actual velocity @48.8 gr. was 3012fps compared to advertised 2900fps.
I tend to believe that the data in Hornady's 8th Ed. book is on the more conservative side. At least my experience with a good number of their loads being put over my chronograph has led me to that conclusion. This is debateable but has been my observation. Regardless I still work up from safe levels despite my beliefs.
To my surprise today I was getting higher velocities than their data suggests. No typical signs of pressure were noted. Although pressure signs can be notoriously unreliable I felt safe to continue. The groups opened up above 48.0gr @2970 so there is no need to push that hard again. All this while the loads I worked up with RL-15 were below average as usual. (Same components/SD)
Moral of this story: Never assume anything no matter what your experience level.
I actually prefer to have these anomalies every so often to keep me from becoming complacent and to remind me of the nature of what I am working with.
Case: Remington (RP)
Bullet: Hornady 139gr SST - seated -.015" from touching, +/- .125" below cannelure exposed above case mouth.
Primer: Federal GM210M
Powder: Win 760
Average actual velocity @48.8 gr. was 3012fps compared to advertised 2900fps.
I tend to believe that the data in Hornady's 8th Ed. book is on the more conservative side. At least my experience with a good number of their loads being put over my chronograph has led me to that conclusion. This is debateable but has been my observation. Regardless I still work up from safe levels despite my beliefs.
To my surprise today I was getting higher velocities than their data suggests. No typical signs of pressure were noted. Although pressure signs can be notoriously unreliable I felt safe to continue. The groups opened up above 48.0gr @2970 so there is no need to push that hard again. All this while the loads I worked up with RL-15 were below average as usual. (Same components/SD)
Moral of this story: Never assume anything no matter what your experience level.
I actually prefer to have these anomalies every so often to keep me from becoming complacent and to remind me of the nature of what I am working with.
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