Please decider this for me. I've read the OCW method and after I shot this I'm confused. This is 243 105gr with H1000. 46gr to 47.5 in .3gr increments. Any thoughts are great
OCW help please
- Thread starter poke5353
- Start date
I think you may be dealing with some bullet instability at the 100 yard point, but that's just a guess.
I would work with 46.3 grains, and alter seating depths to see if things tighten up. The node around 46.3 looks to be pretty stable (as far as point of impact).
I would work with 46.3 grains, and alter seating depths to see if things tighten up. The node around 46.3 looks to be pretty stable (as far as point of impact).
Just to clarify. The loads are as follows
No number is 46
1 is 46.3
2 is 46.6
3 is 46.9
4 is 47.2
5 is 47.5
No number is 46
1 is 46.3
2 is 46.6
3 is 46.9
4 is 47.2
5 is 47.5
I'm curious to know what makes you think they are not stable? Please don't take that wrong. I'm just not sure
It's a guess, based on the bullet type (the longer, higher BC bullets can take more than 100 yards to stop yawing, which causes them to corkscrew around the perfect bullet path for a bit.
Shot dispersion around a central point (nice, even triangles) at various powder charge levels makes me suspect this. This does not mean it's a bad load... check it at 200 yards and see if MOA reduces.
Try shooting 46.3 grains at a longer range and see how it goes. Maybe try two or three additional seating depths at that same charge level and report back.
Shot dispersion around a central point (nice, even triangles) at various powder charge levels makes me suspect this. This does not mean it's a bad load... check it at 200 yards and see if MOA reduces.
Try shooting 46.3 grains at a longer range and see how it goes. Maybe try two or three additional seating depths at that same charge level and report back.
Great thanks. Hopefully I can get to the range this weekend. I'm gonna load 5 different ogive length. Gonna adjust those per .01.
Here are my results at 200yds. Bolt lift was fairly heavy on the 2.29. What do you think?
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This is a new rifle with me so I dont have any previous results to go off of for this set up. Most 308 rifles I have shot in the past have shot .5-.75 MOA if I done my job. Also this is from a factory Rem 700 9 1/8 twist varmint barrel.
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My 243 has a 1:9 1/8 twist and would not stabilize. I ended up going with the Berger 90gr
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I liked the 2.28 group but my only concern is the bolt lift was heavier on it compared to the others. I guess bc of the less capacity bc of the depth of the bullet
If that's the primer in the photo... it looks fine. Did all of the shots at that seating depth have sticky bolt lift? I see swipe on the case head, but I'd guess that more from case sizing being long... (did you just neck size these)... as I'd think that pressure issues would flatten the primer before sticking the case.
Yes that is one of the cases from 2.28. And yes just neck sized these. I'll push the shoulder back some and shoot more of them. Thanks for the help
This may be a stupid question but does this mean that my rifle like this seating depth with just this powder or will this seating depth work well with other powders. I understand that there is a lot to consider but I'm just wondering if that could be expected. H1000 is hard to find right now but I can get some H4350
The seating depth is simply a fine tuning stage of load development, done *after* you find the right powder charge. It affects barrel time, which affects the point on the muzzle's vibration pattern where the bullet is let go... you see one depth (2.31) that has two different points of impact, as it appears to be releasing bullets all along that elliptical path (this assumes perfect shot execution on your part)... what you want is for the bullets to be released at one extreme of the muzzle's movement or the other, where the muzzle is just getting ready to reverse direction... at that point in time, there is a wider window of opportunity for bullets with slightly different barrel times (think muzzle velocities) to be released on the same flight path, from the same point in space, which is what gives good accuracy.
In short... barrels nor bullets necessarily "like" one particular seating depth. The notion persists because folks think that "this bullet 'likes' to be 20 off" or "this bullet wants to be jammed into the lands" and they begin with that seating depth and tinker with the powder charge to make it work. This is like beginning with a particular set of carburetor jets on a race engine, then swapping pistons out until you find a compression ratio that allows the engine to run its best. Then concluding that this engine "likes" these jets.
In short... barrels nor bullets necessarily "like" one particular seating depth. The notion persists because folks think that "this bullet 'likes' to be 20 off" or "this bullet wants to be jammed into the lands" and they begin with that seating depth and tinker with the powder charge to make it work. This is like beginning with a particular set of carburetor jets on a race engine, then swapping pistons out until you find a compression ratio that allows the engine to run its best. Then concluding that this engine "likes" these jets.
Explained well. When I get some H4350 I'll start over. Doesn't hurt to have a couple go to loads I guess. Looks like I'll be trying 95gr Berger VLD also bc the Hornady 105gr BTHP are hard to get as well. I appreciate the help Dan. I'll post more when I get more data.
The seating depth is simply a fine tuning stage of load development, done *after* you find the right powder charge. It affects barrel time, which affects the point on the muzzle's vibration pattern where the bullet is let go... you see one depth (2.31) that has two different points of impact, as it appears to be releasing bullets all along that elliptical path (this assumes perfect shot execution on your part)... what you want is for the bullets to be released at one extreme of the muzzle's movement or the other, where the muzzle is just getting ready to reverse direction... at that point in time, there is a wider window of opportunity for bullets with slightly different barrel times (think muzzle velocities) to be released on the same flight path, from the same point in space, which is what gives good accuracy.
In short... barrels nor bullets necessarily "like" one particular seating depth. The notion persists because folks think that "this bullet 'likes' to be 20 off" or "this bullet wants to be jammed into the lands" and they begin with that seating depth and tinker with the powder charge to make it work. This is like beginning with a particular set of carburetor jets on a race engine, then swapping pistons out until you find a compression ratio that allows the engine to run its best. Then concluding that this engine "likes" these jets.
I like the analogy.
