Ammo differences when sighting in

[TucsonXD40sc]

I plan on sighting in my scope with 75grn hollowpoint ammo as that is what I hunt with mostly and have loaded for SD. But I was curious if there was a way other than just shooting to see how much different the point of impact would be between the 75grn hp and 55grn fmj since they are cheaper for plinking and I may use them for hogs here in Texas. Any thoughts are appreciated.

16" barrel 1/7 twist midlength gas.

[Dirty Rod]

There is no way to predict how ammo will shoot. You have to go shoot it. Even the same grain ammo from the same manufacturer will shoot differently. As an example, I use 168gr Black Hills Gold BTHP in my 700 and regularly shoot .5-1" groups. 168gr Black Hills Gold Amax shoots like crap out of the same rifle. 2-3" groups and lots of flyers.

[TucsonXD40sc]

Yeah, thats kinda what i figured. I know different ammo of different weight or manufacture will group differently. I just wasn't sure if there was a way to tell the difference between actual bullet weight and bullet drop at known distance. Not that I mind the range time, just curious.

[redyak3]

In my 6.8 hunting rig, I use 95gr Barnes TTSX when out for game. I have the rifle zeroed for that load, and it shoots under 1moa consistently. When at the range I shoot 90gr Speer TNT loads, much cheaper. I still get 1moa groups but at about 1" lower poi... go figure

[Alaskapopo]

Originally Posted by TucsonXD40sc

I plan on sighting in my scope with 75grn hollowpoint ammo as that is what I hunt with mostly and have loaded for SD. But I was curious if there was a way other than just shooting to see how much different the point of impact would be between the 75grn hp and 55grn fmj since they are cheaper for plinking and I may use them for hogs here in Texas. Any thoughts are appreciated.

16" barrel 1/7 twist midlength gas.

The 55 grain stuff will hit about 2 inches higher at 100 yards. At least it has for me in my guns.
Pat

[Fdxpilot]

Originally Posted by TucsonXD40sc

I plan on sighting in my scope with 75grn hollowpoint ammo as that is what I hunt with mostly and have loaded for SD. But I was curious if there was a way other than just shooting to see how much different the point of impact would be between the 75grn hp and 55grn fmj since they are cheaper for plinking and I may use them for hogs here in Texas. Any thoughts are appreciated.

16" barrel 1/7 twist midlength gas.

If you can find out the muzzle velocity and Ballistic Coeficient of the bullets you're shooting, any decent ballistics program can give you a rough idea. For instance, Winchester Q3131, which is their version of XM193, lists a muzzle velocity of 3270 fps and a BC of .267, while Hornaday 75gr BTHP is speced at 2790 fps and a BC of .395. Plug those numbers in and you should get some ideas of the different flight paths.

[TucsonXD40sc]

good info. thanks guys!