Re: 700 sps tactical holdovers
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: djthemac</div><div class="ubbcode-body">howdy guys!
I am a noob to the long range game, and I just picked up my first rifle. It is a Remington 700 sps tactical 20" in 308, and I can't wait to take it to the range to try out. </div></div>
http://bulletin.accurateshooter.com/2011/05/gear-review-field-density-altitude-compensator/
I used this Monday with my Remington tactical 308. I am impressed!
My 175smk load is right at 2550 +/- a couple feet per second. Federal's FGGM 175smk load should be very close to this velocity as well in the tactical. I knew the temp was in the 80's and my range altitude is a few feet short of 1000'. I applied the temp and altitude and came up with a DA of 2000'. Slid the card to +2k and started pulling the trigger. I shot from 500y to 1000y, at this velocity my load was subsonic at 975y. My impacts were a 1/4 minute low at 5&6 hundred, dead nuts on at 7-9 and 1000 was 1/4 minute high. That is much better than my preprinted tables I usually take with me!
JBM ballistics is a good online calculator as well, but I can’t take that in the field with me...
My drops monday were:
500= 3.7 mil or 12.25 moa
600= 5.0 mil or 16.75 moa
700= 6.4 mil or 22.0 moa
800= 8.0 mil or 27.5 moa
900= 9.9 mil or 34.0 moa
1000=12.0 mil or 41.25 moa
That should get you close but will not be right on for you as I am sure your altitude is higher than mine, you will likely be using a little less. Weather conditions will also effect your out come from these numbers.
I was shooting at 75-80 degrees at ~960asl, BP was around 29.65 (corrected pressure) and I had a low pressure system coming in towards the end of my shooting which may have been a reason for my higher impacts at 1000.
http://www.wunderground.com
and
http://www.wunderground.com/history/
are good sources for current and historical weather data, FWIW
I set a personal best record (for this particular rifle anyway) at 600, my vertical was under 3" and horizontal was ~4" for 4 shots... and at 1000 I had three land inside 6" with two more opening the overall group size to 11"
308's rock!
Also, if you have the factory rifle I assume you have it in the original stock. That stock has a tendency to touch the barrel when a bipod is employed and leads to stringing of groups once you get out about 200-300 yards. You have two options if it touches, 1-new stock or 2-hogging out the offending area.
I had a pss stock that I dropped mine into and a DIY skim bedding job with devcon steel. That stopped the group stringing and decreased my overall size plus made it much more consistent. It went from a ¾" grouper at 100 to a "I can't believe I'm shooting this tight with a factory rifle" sized group...