Thought I'd do a little test this morning and share the results with you guys. After watching the video Shawn Carlock posted about reducing ES and the video by Annealing Made Perfect where they brush out the inside of a case neck and then measure seating force, I wanted to see what effect both brushing out necks and graphite had on ES in one of my rifles. I normally don't do either of those things in my reloading operation.
So, I took my 6.5 Creed and loaded up a total of 40 rounds. 10 control rounds (C) that are loaded the same as usual 10 where I brushed the necks with a single pass of a nylon brush in and out (B), 10 where I applied graphite to bullet base (via the Imperial graphite dry lube little ceramic bead applicator deal) prior to seating (G), and 10 where I both brushed the necks and then applied graphite to the bullet prior to seating (Bg). I then shot them over my Magnetospeed round Robin Style (I.E. 10 groups of 4 comprised of 1 of each CBGBg), at 30-45 second intervals between each round, so that the effects of barrel heat would be similar across all groups. The results were somewhat surprising.
ES was lowest in the brushed only group and went in the following order. B<C<G<Bg.
When I throw out the highest and lowest velocity shot from each group the ES' were as follows:
B:20
C:24
G:28
Bg:53
It was also interesting to see how a 40 round group printed. The rifle will pretty routinely shoot groups in the .2s and .3s at 500. I shot at 525. The group ended up being just over 1 MOA. I suspect this is due to multiple things, zero/POI shift due to heat being one of them, especially since the 1st 8 rounds impacted in essentially the same spot. That said it was a pretty educational morning. I don't think I'll be using graphite.
I'm going to load up 10-15 more where I brush the neck out and see if anything changes from an accuracy standpoint. If they shoot the same then that was a pretty easy way to improve the long range potential of a load.
So, I took my 6.5 Creed and loaded up a total of 40 rounds. 10 control rounds (C) that are loaded the same as usual 10 where I brushed the necks with a single pass of a nylon brush in and out (B), 10 where I applied graphite to bullet base (via the Imperial graphite dry lube little ceramic bead applicator deal) prior to seating (G), and 10 where I both brushed the necks and then applied graphite to the bullet prior to seating (Bg). I then shot them over my Magnetospeed round Robin Style (I.E. 10 groups of 4 comprised of 1 of each CBGBg), at 30-45 second intervals between each round, so that the effects of barrel heat would be similar across all groups. The results were somewhat surprising.
ES was lowest in the brushed only group and went in the following order. B<C<G<Bg.
When I throw out the highest and lowest velocity shot from each group the ES' were as follows:
B:20
C:24
G:28
Bg:53
It was also interesting to see how a 40 round group printed. The rifle will pretty routinely shoot groups in the .2s and .3s at 500. I shot at 525. The group ended up being just over 1 MOA. I suspect this is due to multiple things, zero/POI shift due to heat being one of them, especially since the 1st 8 rounds impacted in essentially the same spot. That said it was a pretty educational morning. I don't think I'll be using graphite.
I'm going to load up 10-15 more where I brush the neck out and see if anything changes from an accuracy standpoint. If they shoot the same then that was a pretty easy way to improve the long range potential of a load.
