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Posted: 11/22/2016 4:24:29 AM EDT
I have a Remington 700 sps tactical LT chambered in 308win, and I hand load 178gr Amax's to about 2700 FPS. I was wondering how standard ball ammo would shoot or of my gun so I shot a box of Winchester white box at 100 yards. The difference in POI is almost a foot higher and to the left than my hand loads. A shift of similar distance happens with my hand loaded M2 AP rounds. I never knew that there would be so much POI shift between different loads at only 100 yards. Is that normal?
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"The beauty of the Second Amendment is that it will not be needed until they try to take it." - Thomas Jefferson
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I have a POF P415. Very accurate with most ammo. I use hornady 75 bthp and it will shoot at roughly. 6 groups. I then put in some xm193 and those shot at about 1.5-except 8 inches higher and 4 inches to the right. So it happens.
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Different powders, primers, OAL can do that. Since you reload and you like the commercial ammo, you can adjust your reloads to mimic the commercial rounds. I do this on my AR10 with 168 A-Max and 150 FMJ so they are close at 100 yards. Took me awhile but got it down pretty good.
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"a foot" is a bit on the high side for different ammo, but since your dialed in load is 178gr at 2700 fps (quite hot BTW) it is possible.
3-4 inches is very typical. under 1 inch is very untypical. |
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Originally Posted By MitchAlsup:
"a foot" is a bit on the high side for different ammo, but since your dialed in load is 178gr at 2700 fps (quite hot BTW) it is possible. 3-4 inches is very typical. under 1 inch is very untypical. View Quote I know my load is hot, I'm going to back it off a little, but this load is capable of Half moa or better, so I don't want to tinker with it too much. |
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"The beauty of the Second Amendment is that it will not be needed until they try to take it." - Thomas Jefferson
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Originally Posted By LeadRX:
I know my load is hot, I'm going to back it off a little, but this load is capable of Half moa or better, so I don't want to tinker with it too much. View Quote View All Quotes View All Quotes Originally Posted By LeadRX:
Originally Posted By MitchAlsup:
"a foot" is a bit on the high side for different ammo, but since your dialed in load is 178gr at 2700 fps (quite hot BTW) it is possible. 3-4 inches is very typical. under 1 inch is very untypical. I know my load is hot, I'm going to back it off a little, but this load is capable of Half moa or better, so I don't want to tinker with it too much. If you get 10 reload cycles on a set of brass, it is inside the sane envelope of pressure. |
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Originally Posted By MitchAlsup:
If you get 10 reload cycles on a set of brass, it is inside the sane envelope of pressure. View Quote View All Quotes View All Quotes Originally Posted By MitchAlsup:
Originally Posted By LeadRX:
Originally Posted By MitchAlsup:
"a foot" is a bit on the high side for different ammo, but since your dialed in load is 178gr at 2700 fps (quite hot BTW) it is possible. 3-4 inches is very typical. under 1 inch is very untypical. I know my load is hot, I'm going to back it off a little, but this load is capable of Half moa or better, so I don't want to tinker with it too much. If you get 10 reload cycles on a set of brass, it is inside the sane envelope of pressure. I'm on my 5th and the only thing I'm noticing is that primers are seating in the casings quite easily, but they aren't falling out. |
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"The beauty of the Second Amendment is that it will not be needed until they try to take it." - Thomas Jefferson
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It's not always reliant just on bullet weight either. My m1 is zeroed at 200 with both m2 ball and 165 grain power points. The m1 load from hornady with the Amax shoots a foot to the10 o'clock into a 12" group.
I've never seen such a big difference. My hog hunter might be an inch or 2 between 150s and 165s. |
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"If you cant do something smart, do something right"
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You guys need to stop using a chronograph in determining the optimum load for your rifles.
Do a ladder test using different charge weights. Do several until you narrow your charge weight down to about 1/10th of a grain. Then work on the jam/jump of your pill seating depth. Every individual rifle has it's own unique barrel harmonics and matching your load to those specific harmonics is the key to accuracy. Measuring how fast the projectile is moving should be an afterthought. |
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CRUZ 2016: Fucking the stupid out of America. Didn't work. Stupid had a head start.
You can't teach Democracy to people that still shit in their hands and believe in sharia law. - EasTexan |
I recently re-zeroed for my hunting load, which is the same primer and powder as my regular shooting kid, just with a 168 a-max rather than hpbt. Same charge weight, primer, and approximately same length to ogive, the hpbt shoots two tenths lower at 100 than the a-max, with pretty much the same group size.
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Primer pockets loosening = You're running your pressures too high. Just loose primer pockets isn't the big issue for you. What you're going to get is case head separations. When you do, take a 20ga brush on a pistol rod and run it up from the chamber end till the brush enters the rifling, then jerk it backwards. That'll pull out the rest of the case for you. Then you can pull down every single round you've got left and pull 1 grain of charge weight out of each.
Running your loads that hot is hard on the gun, brass and the shooter. You're going to have something bad happen. Ask me how I know. |
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Originally Posted By ballisticxlr:
Primer pockets loosening = You're running your pressures too high. Just loose primer pockets isn't the big issue for you. What you're going to get is case head separations. When you do, take a 20ga brush on a pistol rod and run it up from the chamber end till the brush enters the rifling, then jerk it backwards. That'll pull out the rest of the case for you. Then you can pull down every single round you've got left and pull 1 grain of charge weight out of each. Running your loads that hot is hard on the gun, brass and the shooter. You're going to have something bad happen. Ask me how I know. View Quote So, how do you know? I like stories.... |
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Originally Posted By pcsutton:
You guys need to stop using a chronograph in determining the optimum load for your rifles. Do a ladder test using different charge weights. Do several until you narrow your charge weight down to about 1/10th of a grain. Then work on the jam/jump of your pill seating depth. Every individual rifle has it's own unique barrel harmonics and matching your load to those specific harmonics is the key to accuracy. Measuring how fast the projectile is moving should be an afterthought. View Quote More consistent velocity is more important than absolute accuracy for long range shooting. A ladder test only shows what charge range is giving more stable velocity and results in smaller velocity differences. If you play with jump and get better accuracy by .1 or .2 inches, but increase velocity SD by 5 or 6 fps, you are not doing yourself any favors. If you are giving up 20fps total velocity or more too, you are extra worse off. |
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Originally Posted By pcsutton:
You guys need to stop using a chronograph in determining the optimum load for your rifles. Do a ladder test using different charge weights. Do several until you narrow your charge weight down to about 1/10th of a grain. Then work on the jam/jump of your pill seating depth. Every individual rifle has it's own unique barrel harmonics and matching your load to those specific harmonics is the key to accuracy. Measuring how fast the projectile is moving should be an afterthought. View Quote Takes about 20-30 rounds total. If it is under an inch for a 10 shot group then it is plenty good, making it 1/2" will help very little at long range. I have done this method with several different loads in 3 rifles, it has worked great. I am all done fucking around with trying to get tiny groups with every load, it doesn't pay off on the far end. |
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MOA ALL DAY- 169 Arfcom rifles confirmed
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Originally Posted By pcsutton:
You guys need to stop using a chronograph in determining the optimum load for your rifles. Do a ladder test using different charge weights. Do several until you narrow your charge weight down to about 1/10th of a grain. Then work on the jam/jump of your pill seating depth. Every individual rifle has it's own unique barrel harmonics and matching your load to those specific harmonics is the key to accuracy. Measuring how fast the projectile is moving should be an afterthought. View Quote Actually I developed this load with a ladder test, I loaded up about 50 rounds starting at 40 grains flat of H4895. I increased my load by .2 grains in batches of 5 rounds each. Many of the loads shot at or just a little over 1MOA, but when I sent these three down range in a row and they all went through the same hole .418 across, I decided that that load was the one. The next day I met up with a buddy who had a magneto speed chrono and clocked them. |
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"The beauty of the Second Amendment is that it will not be needed until they try to take it." - Thomas Jefferson
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I got about an 8" POI shift from different lots of 6.5 Creedmoor Hornady ELD-M ammo. I usually handload so I wasn't expecting that much of a difference.
I am going to get a Magnetospeed chronograph so if I switch lots or reloading components I can get data really easily. I don't trust my optical chrono for that. I should add that's an 8" POI shift at 700 meters. |
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