Are my in-puts correct? Specifically the boat tail parameters and seating depth?
- Thread starter oldiephrt
- Start date
Eight twist?
It's a bit hard to read, but I would increase the powder charge until barrel time hit 1.37135 which is halfway between OBT nodes six and seven, or reduce the powder charge until barrel time is 1.4343 which is probably too slow for your purpose.
I also find the closer Pmax is to Z1 the better the load.
These two points tell me there may be a better powder (H1000 maybe) for your purposes or shoot a lighter bullet.
It's a bit hard to read, but I would increase the powder charge until barrel time hit 1.37135 which is halfway between OBT nodes six and seven, or reduce the powder charge until barrel time is 1.4343 which is probably too slow for your purpose.
I also find the closer Pmax is to Z1 the better the load.
These two points tell me there may be a better powder (H1000 maybe) for your purposes or shoot a lighter bullet.
Thank you.
Yeah, 1-8 twist 5r groove, did I input that correctly?Do I let the program tell me what is good? Are three green checks on the OBT graph indicative of anything? I really am a novice with this new tech.. My thought is to do simulations with out expending too, many resources.I have always used reloading manuals and picked a load based what speed I thought I wanted without hitting max. New barrel, shoots my previous 130gr TSX load half the group size of the old barrel. I am trying to get the best of light and heavy. My thought is to do simulations with out expending too, many resources.
Eight twist is input correctly. The program only accepts the twist you input.
Muzzle velocity is calculated.
The other two are the standard coefficients for the powder lot they measured or the average data they obtained from the manufacturer, not the powder lot you are using. Powder burn rates can vary by 10% or more. I recommend shooting this load and recording actual muzzle velocity then going back and adjusting the ba coefficient until the predicted velocity matches the actual. Then readjust to OBT. I believe that is the clock on the top bar.
I have no idea what the green checks mean. This and QuickLOAD are not known for having good user manuals.
Your approach matches mine. Run simulations rather than using up components remembering these are only simulations that may or may not match the real world.
I would look at different powders based on the Z1 Pmax gap. I have no idea why but it has worked for me in the past.
Good luck.
Muzzle velocity is calculated.
The other two are the standard coefficients for the powder lot they measured or the average data they obtained from the manufacturer, not the powder lot you are using. Powder burn rates can vary by 10% or more. I recommend shooting this load and recording actual muzzle velocity then going back and adjusting the ba coefficient until the predicted velocity matches the actual. Then readjust to OBT. I believe that is the clock on the top bar.
I have no idea what the green checks mean. This and QuickLOAD are not known for having good user manuals.
Your approach matches mine. Run simulations rather than using up components remembering these are only simulations that may or may not match the real world.
I would look at different powders based on the Z1 Pmax gap. I have no idea why but it has worked for me in the past.
Good luck.
Hawk in WY Thank you , thank you!
I looked/searched "OBT" here and found some of your posts on the subject. Very helpful. I have shot 66gr of n570 heavily compressed (67gr was one sources starting load at my COAL with 170gr bullet) and thought it was very hot. Dropped to 64gr and it still seemed hot.(very flat primer, hard bolt lift) Was concerned with undercharging, hence the Gordon's subscription.
Remember simulations are just that. Trust what your rifle is telling you.
2900 fps with a 175 grain bullet is more than I would run given pressure signs at 64 gr.
Slow it down or go to a lighter bullet.
2900 fps with a 175 grain bullet is more than I would run given pressure signs at 64 gr.
Slow it down or go to a lighter bullet.
1. Reduce the powder charge until barrel time is 1.4343
2. Shoot to measure actual velocity
3. Adjust Ba until the prediction equals the measured velocity
4. Let us know how that shoots.
Good luck.
2. Shoot to measure actual velocity
3. Adjust Ba until the prediction equals the measured velocity
4. Let us know how that shoots.
Good luck.
I am trying to get the best of light and heavy bullets. My thought is to do simulations with out expending too, many resources. Resources are getting very hard to renew.
Maybe, I don't understand what you are asking. Specific bullet/ powder? OBT?
Thank you for any guidance you can offer.
Maybe, I don't understand what you are asking. Specific bullet/ powder? OBT?
Thank you for any guidance you can offer.
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