F T/R Competition Advice for my forst f comp

[Deltagunner00]

I am going to try my first f comp on April 1st. Today i had my 308 zeroed at 100. Moved out to 300 and moved it up 8 clicks or 2 mil. After shooting a little more i was dead on at 4 mil (16)clicks.

If this is going to be a 600 yard comp what can i expect to adjust by to get on paper at 600 yards?

 

[BigtimeAub]

Re: Advice for my forst f comp

nm

 

[phillietimothy]

Re: Advice for my forst f comp

I think you mean to be saying "moa" instead of "mil". At 300 yards, 2 mils would be 21.6"; 4 mils would be 43.2". 2 moa at 300 yards would be 5.73"; 4 moa would be 11.46". With a 100 yard zero, 155gr Sierra drops about 11" at 300 yards.

I believe your scope adjusts in 1/4 clicks based on your post. You can easily substitute "mils" for "moa". 1 mil is equal to 3.438 moa.

Scopes with mil adjustments will adjust in .10 mil increments.

Assuming you are using 155gr bullets at 2950fps, the drop at 600 yards is approximately 77" or 12 moa or 3.6 mils.

If you are using 175gr bullets at 2600fps, the drop at 600 yards is approximately 108" or 17 moa or 5 mils.

This should get you on paper. YMMV.

 

[XTR]

Re: Advice for my forst f comp

Shooting 175 SMKs at 2780 my 600 yard elevation is about 13 1/2 MOA, with 185 Bergers at 2740 it's about 13 1/8 MOA. Your mileage may vary with DA and MV.

 

[gstaylorg]

Re: Advice for my forst f comp

Ideally, you'd like to know the muzzle velocity of the load you plan to use. If you don't have access to a chronograph, you can do at least a couple different things to get an estimate:

1) Based on the length of your rifle barrel, subtract (or add) 25 fps per inch of barrel length to the muzzle velocity value given for a standard 24" test barrel that is on the ammo box. Plug that number into the JBM ballistic calculator (link below) with the appropriate projectile (pulldown menu) and atmospheric conditions. Although subject to many possible sources of error, this approach should at least get you in the neighborhood.

2) Do the same (above) exercise at JBM except that you will vary the muzzle velocity until you find predicted drops that match (or are as close as you can get) to the drop you determined at 300 yd. The more drops you have determined at various distances, the better the estimate you will get using this approach.

Neither of these approaches is even close to being as definitive as having your actual muzzle velocity and drop data, but hopefully you can make a reasonable estimate that will allow you to get on the target. As long as you're on the paper, the scoring markers will allow you to make adjustments toward the X-ring. Good luck and let us know how it goes.


http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.1.cgi

 

[Deltagunner00]

Re: Advice for my forst f comp

Thank you guys for the info and yes, I did mean MOA istead of MIL. My mistake there.

I am using 178 Amax's over 43g of Varget. This is out of my 26" CBI barrel.

 

[gstaylorg]

Re: Advice for my forst f comp

Ok, because it's not a factory load, forget option 1. Running the 178 A-Max through JBM with 1000 ft altitude, 60 degrees, 70% humidity, and 2" optic height, the estimate for your MV appears to be somewhere around 2760-2770 fps to give a drop at 300 yd of 4.0 MOA. You can play around with the numbers and see what you come up with. That MV with 178 AMax's would give you a drop at 600 yd of around 13.8-13.9 MOA.

Obviously, the shorter the distance, the smaller the drop you use for this type of reverse MV estimation (4.0 MOA @ 300 yd in your case). As such, short range data is inherently less accurate and will give a less reliable estimate of MV. However, even if the predicted drop using those MV values is in error by 1.0-2.0 MOA, that would only be between 6" to 12" off at 600 yd. Without taking windage into consideration, that should still easily put you in the black and you can use your sighters to get dialed further in from there. If your sighters are off the paper, it's that much more difficult to dial in for score. Anyhow, hope that helps and good luck in the competition.

 

[wadebrown]

Re: Advice for my forst f comp

Since this is your first match pay close attention to the order in which you shoot, score and do pit, if you have questions about where you should be ask them early. When in the pits work hard to pull, score and patch your target accurately and fast, give the pit service that you would like to get. Fast pit service gives the shooter the most time to shoot in the wind condition they like.

Lastly, have fun and enjoy your first competition, treat it as a learning experience.

wade

 

[BOL556]

Re: Advice for my forst f comp

If you have a driod or Iphone download an called shooter. Load in all the info and chart it. Go out before you go to the shoot and to confirm what its throwing out. Your biggest problem during the shoot will be judging the wind. I will be doing a 1000 yard FTR on suday and that is what I did today was hitting a 9"wx14"h steel at 800 yards. Get match grade ammo as well.

 

[XTR]

Re: Advice for my forst f comp

F class matches typically have unlimited sighters. Don't worry about the elevation. Put on 13.5 MOA from 100 and it will put you on paper, from there you can follow the spotter to the center. Wind will be another issue.

The advice above about good pit service is great. You will appreciate it when you get it, so give it too.

 

[wadebrown]

Re: Advice for my forst f comp

Usually only LR F-class matches have unlimited sighters. LR being 800, 900, and 1,000 yards. Midrange usually only allow 2 sighters.

wade

 

[gstaylorg]

Re: Advice for my forst f comp

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wwbrown</div><div class="ubbcode-body">Usually only LR F-class matches have unlimited sighters. LR being 800, 900, and 1,000 yards. Midrange usually only allow 2 sighters.

wade </div></div>

Apparently, it must depend to some extent on the event and whom sponsors it. The midrange comps here in San Diego at Camp Pendleton (300/500/600 or 3x600) have unlimited sighters in the first match, but only two sighters in each of the two matches thereafter. The midrange comps at ENGC in Omaha were two sighters only in all three matches.

 

[XTR]

Re: Advice for my forst f comp

If it's a full bore match you get unlimited on the first round at the first distance then 2 at the following on distances. (long range 800-unlimited, 900-2 and 1000-2), if it is a standard NRA high power course be it long or mid range you get unlimited sighters.