User Panel
User Panel
User Panel
|
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?
|
|
|
|
MO, USA
|
Posted: 11/22/2016 7:30:23 AM EDT
[Last Edit: thorshammerblow]
[#1]
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.
|
|
|
|
Posted: 11/22/2016 10:22:57 AM EDT
[#2]
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.
|
|
|
|
TX, USA
|
Posted: 11/22/2016 2:14:22 PM EDT
[#3]
"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. |
|
|
|
Posted: 11/22/2016 3:16:15 PM EDT
[#4]
Quote HistoryOriginally 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. |
|
|
|
TX, USA
|
Posted: 11/22/2016 10:11:29 PM EDT
[#5]
Quote HistoryOriginally 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. Quote HistoryOriginally 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. |
|
|
|
Posted: 11/23/2016 1:02:33 AM EDT
[#6]
Quote HistoryOriginally Posted By MitchAlsup:
If you get 10 reload cycles on a set of brass, it is inside the sane envelope of pressure. Quote HistoryOriginally 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. |
|
|
|
|
Posted: 11/26/2016 10:45:49 AM EDT
[#7]
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. |
|
|
|
|
Posted: 12/8/2016 8:02:01 PM EDT
[#8]
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. 
|
|
|
|
|
Posted: 12/25/2016 1:39:57 PM EDT
[#9]
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.
|
|
|
|
CA, USA
|
Posted: 12/26/2016 12:00:12 PM EDT
[#10]
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. |
|
|
|
Posted: 12/27/2016 12:18:39 PM EDT
[#11]
Quote HistoryOriginally 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. So, how do you know? I like stories.... |
|
|
|
TX, USA
|
Posted: 2/8/2017 10:15:16 AM EDT
[#12]
Quote HistoryOriginally 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. 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. |
|
|
|
Posted: 2/8/2017 1:14:48 PM EDT
[Last Edit: popnfresh]
[#13]
Quote HistoryOriginally 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. 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. |
|
|
|
|
Posted: 2/9/2017 1:02:15 AM EDT
[#14]
Quote HistoryOriginally 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. 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. |
|
|
|
|
Posted: 3/1/2017 12:43:22 AM EDT
[Last Edit: Tranquility]
[#15]
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. |
|
|
|
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.
