Are you turning your necks? If so, play with neck tension first, then play with seating depth. (52.7gr)
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Extreme spread and standard deviation vs accuracy
- Thread starter southernfella
- Start date
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bonie
Well-Known Member
try Superformance. Offhand the charge escapes me I think its around 59.1. but I get 2992 fps average out of a 5 shot group with and SD of 4.5.the 5 shot group 1/2' measure to the outside not with bullet diameter subtracted as in Benchrest. i tried many powders this was the most consistent.
bonie
Well-Known Member
I have a 6.5 PRC load with Staball HD out of a Browning Hells Canyon with a 26" barrel the shoots well under 1/2" MOA. at 2992 fps average ,charge weight of 59.7 COL for me is 2.8645. I've tried US869 and many others ,most with fair results but this at out to 530 yards groups best by far. at 530 Only 2-2 1/2" in height left to right was fro 6" to 8 1/2 " with no wind hold. this load is going on my Elk Hunt in a few weeks. hey give it a try, play with your charge weight and good luck.
Mike Matteson
Well-Known Member
Low SD/ES has much more to do, with brass prep, and loading quility. Your accuracy/group size is influenced more on the consistent release/ exit of the bullet. Consistent release of the bullet when fired. Petey308 has a lot of info on this ES/ED information. Also in setting or placement your bullet.
Mike Matteson
Well-Known Member
IMR 4831 has one of the highest veloicty spread in temp changes. It's about 1fps per degree in temperatures change.
Maybe....depends on what is in front of it and behind it. Nice group.
I'm not talking 3 shot wonder, a load that will repeat on different day.
Or very close
If it repeats even remotely close that then yes it's worth keeping. Sub 1" groups with a hunting rifle at 600yrds doesn't happen everyday.
SSG Graybush
Well-Known Member
Learn how to do load development. All your doing is taking shots in the dark. Do a ladder, find pressure and find a speed node to start with. Then test jump from there. Then adj charge again, then jump again, etc if needed. Look up OCW and Satterly load development.
Allen Lone wolf
Well-Known Member
I use H1000 with CCI BR primers starting with low powder charge at 20 thou off the lands I landed at 55 thousands off the lands.I then started working the powder in 1/2 gr increments my end result was a muzzle velocity of 3025fps no pressure signs. I shot 3 two shot groups back to back .279, .280, .283. Sorry I can give my powder charge but I'm no home at the moment and my part-timers is kicking in. Must have lost that. 279 photo, my apologies.
Attachments
Good info here for what you're doing. This should help. I run the 144 Berger in mine. 54.5 of H4831SC and CCI250 works great with ADG Brass.
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This has worked for me…
Step 1). Load 1 each (2,3,5,10 doesn't matter much) powder charges at 0.3 to 0.5 grain increments at the closest seat depth to the lands that you will run. Shoot at any distance as long as you do not shoot at a target (do not look at groups) and record velocity up the ladder until you DO see pressure signs (smudge on the back of the case, heavy bolt lift, black smoke around primer, etc…). Graph out the velocities. There will be a node, flat spot, a place where the velocity increased less than the other increments.
Step 2). Choose a powder charge in the center of that node. Load that powder charge, 3 each at seating depths 0.003" increments for a total of at least 30 rounds. Shoot them slowly and carefully at a target set at 100 yards. Select the best group.
Step 3) Now using that seating depth, load 3 each with powder charges in 0.2 and 0.4 grain increments up and down From previous load. Shoot at 100 yards, select the best group.
Step 4) Shoot another 2500 rounds at that powder charge and seating depth. Purchase a new barrel and repeat Steps 1 through 4.
Have Fun!
Step 1). Load 1 each (2,3,5,10 doesn't matter much) powder charges at 0.3 to 0.5 grain increments at the closest seat depth to the lands that you will run. Shoot at any distance as long as you do not shoot at a target (do not look at groups) and record velocity up the ladder until you DO see pressure signs (smudge on the back of the case, heavy bolt lift, black smoke around primer, etc…). Graph out the velocities. There will be a node, flat spot, a place where the velocity increased less than the other increments.
Step 2). Choose a powder charge in the center of that node. Load that powder charge, 3 each at seating depths 0.003" increments for a total of at least 30 rounds. Shoot them slowly and carefully at a target set at 100 yards. Select the best group.
Step 3) Now using that seating depth, load 3 each with powder charges in 0.2 and 0.4 grain increments up and down From previous load. Shoot at 100 yards, select the best group.
Step 4) Shoot another 2500 rounds at that powder charge and seating depth. Purchase a new barrel and repeat Steps 1 through 4.
Have Fun!
PNWdude67
Well-Known Member
Seating depth has more to do with group size than powder charge in general. What are you doing to ensure consistent neck tension? Using a mandrel expander die will solve a lot of inconsistencies.
