I generally don't have many issues working up a load to decent accuracy levels. However, I am frustrated with this new to me rifle and could use some advice.
Savage 116 6.5-284 with 24" varmint contour barrel. Stock rifle. Owner said 100 or less rounds. Barrel was heavily copper fouled. I stripped it out. Started over.
EGW steel 20 MOA base. Sightron S3 scope. Good rings, unsure of brand. Stock removed and torqued to 45in.
New lapau brass. 140 bergers. Retumbo. 1.832 head space on new brass. 1x fired is 1.838 which is where my die sets it. 1.841-1.844 seemed to be the measurements before resizing.
With new unfired brass the rifle likes .100 off the lands and 58 gr retumbo. 3000 fps, confirmed at 750 yards. Gives me .3 MOA at 200 yard zero. With 1x fired brass and the same configuration 58 produces some sticky bolt lift. Not bad, just a bit, and faint ejector marks. I don't like it and figured 58 grs is just too much pressure. 57.5 with 1x fired brass also produces a little lift and occasionally ejector marks. Therefore I concluded 57 is the safe level to work with. That began my long shooting sessions with frustrating results. It was hard to get consistent results.
All of my brass is now fire formed to this new chamber and all should be consistent for the next session. I burned up 150 rounds in 2 days working on an accurate load. The best I could do was .5 MOA at 200 zero. The last 10 cases of unfired brass gave me .25MOA at 200 but I feel this will change on fired cases. It was .075 at 56 grs. Seems to be around 2900-2920 fps.
Where should I begin with my next session to finish this up.
Forgot to mention that I am unsure if I should body size or just neck size the fired cases. I am trying to develop a method that is consistent and easy to follow so that consistent accuracy follows. Also, this new rifle throat is way different then my other savage 6.5-284. Seating to the lands on the new rifle is 2.537 vs my old rifle at 2.582. That is a difference of .045. Consequently that means the bullet is seating .045 deeper to start and it might not be problematic to seat to the lands, however, that bothers me for a hunting rifle. The picture above shows potential at .000 off the lands and I did not test seating into or just out of the lands. I did try .010 and it didn't care too much for it.
Sorry if this seems like a weird post and questions: I am just not sure what to do. I think I should explore 56 gr and .075 off the lands to see if .25MOA is really a consistent load or not. .050 and 57 seems doable and give .5 MOA at 100 and 200. 56.5 at .000 seems like .5 MOA as well.
Just reading your post, my first thought is that your gin likes new brass. Why, what's the difference? Case dimension. I would try sizing your fired brass in a full length die and loading it the same as your new brass loads.
And the differences between the throats of your old rifle and your new one may be in the number of rounds fired. In an over bored gun like the 6.5-284, the throat will grow longer as it is eroded by hot gases. I've had a throat grow by over .25" in a 22-250 to the point that I had to switch to 60 gr. bullets to keep them in the case neck. I finally had the gun, a Remington 40X-BR rechambered to a 22 Cheetah to
get rid of the throat erosion. I put a couple thousand more rounds through it before I finally rebarreled it. The barrel was just so accurate I didn't want toleit die.
Keep at it. You know it will shoot.
WHEN YOU HUNT LONG RANGE, SOME TIMES THE SHOT IS THE TROPHY.
The HS measurements from new. The old 6.5 was 2.582 and is now 2.584 with 1000 rounds down range. It is not giving me the love it used to. It liked .100/2.482 with 56.5 retumbo and 140vlds. .3 MOA consistently. Seems tired now and not consistent.
The new rifle dimensions are strange to me. Who knows. Perhaps savage changed reamers.
The case dimensions and HS are an issue. My redding Body die bumps the shoulder to 1.838 max. To go more I have to mod the die or case holder. It seems like it should not need that much HS though. I will remeasure the brass tonight and get an average. I am pretty sure it will be 1.841-1.843. Based on your thought I could just body and neck size like normal each time vs neck size only. I could fire a piece of brass 3 times and see where the HS ends up.
I keep toying with the idea of seating to the lands. If I recall correctly the entire length of the neck is filled with the bullet when seating to the lands. Perhaps this is not a bad thing?? I am used to my savages liking jump, perhaps this one is that way. Perhaps I need to change my approach to this rifles attitude?
Started over with 57 grains, I believe the max this rifle will handle, and round robin shot 2 rounds each at .025 .075 .100 .125 .150. at 200. .125 put the 2 almost in the same hole so I loaded a 3rd. That group was .365". Loaded 3 more, moved the reticle to what I thought would be a zero and shot this group.