Ballistic double check .223

[el pres]

I just want to reassure that I'm on the right path in my thinking.

My main "match" rifle load is a 69gr bullet going 2900fps.

My secondary load, which I would like to use a bit more this year, is a

55gr bullet screaming at almost 3200fps.

Problem is the rifle is sighted in for the 69gr load. The 55gr load impacts 1.5"

lower at 100yd, I belive it's due to the fact that it is so much hotter and apexes

later on ?? So comparing some ballistic charts, my thinking is if I bring the

55gr down to 2950fps they should both have relatively the same balistics and

meet up at 100yds ??

Edited January 1, 2010 by P.Pres

[smokshwn]

Peter,

I don't have my charts right in front of me but if I remember correctly with my 55gr load at 3150 and my 69gr load at 2900 I was within .25"-.5" in 25 yd increments all the way to 400 then there started to be a little more separation growing to 4" at 500 and 10" at 600.

I played on Sierra for quite a while trying to find velocities that matched up well and that was about as good as it got. By the way I have actually shot these two to 600 and was able to get the hits very easily with them mixed in a mag.

Edited January 1, 2010 by smokshwn

[Graham Smith]

Since I have only dealt with pistol reloading up to this point, I've got a whole new set of things to learn when it comes to rifles. Could you suggest some reading to help get me up to speed on how to go about calculating loads?

[el pres]

Peter,

I don't have my charts right in front of me but if I remember correctly with my 55gr load at 3150 and my 69gr load at 2900

Craig,

I'm confused, thats where I was basicaly at 3200 but according to JBM and other available software

a 55 matches up to the 69 at around 3010, 3150 is just a little too hot ??

Edited January 1, 2010 by P.Pres

[AlamoShooter]

T think you are on the rite path, & I do about the same thing you are doing but at a bit slower FPS, out of Old School mind set I want to keep my loads belowe 3,200 so that the barrel last a bit longer.

and with a 1-8 twist my 69 bullets group better closer to 2800fps , Make sure you are useing the rite BC on the table and the rite Altitude you are shooting at.

I do all my groups at 200 yards and the combination of 2800 for the 69, and 3050 for the 55 group good and the tables are very close.

I use the 55 in practice at 400 & under and have had good target responce, I don't know that I can see the diffrenc in how the target responds to a hit.

even though the table says that the 69 has 35% more energy at 300 yards

at 400 yards the 69 holds 10mph wind 7" better than the 55 so if the wind is variable, I think the 69 makes for less guessing.

I find it very hard to 'feel' wind variation when I am -On the gun& in the scope- The only wind can get feedback on when I am shooting is slow fire or the wind that pushes me around.

Remember I most likey do not know nothing , most of my rifle shooting exsperiance is with rimfire and a high power scope dieled in for the longer STC targets at 90 yards

Even with my limited 3gun shooting it is very dishearting to be looking hard at a 200 yards target -make the shot- ---see the target bounce ------ amd not have a, ( HIT! ) called. But but _{but but}

Edited January 1, 2010 by AlamoShooter

[Dan Sierpina]

Jamie,

My experience has been, If I miss at 200.....I slapped the heck out of the trigger! Either that or my postition was way too wobbly.

Shooting rimfire at the little Diamonds for the STC makes 3 gun targets seem huge.

[Dan Sierpina]

Since I have only dealt with pistol reloading up to this point, I've got a whole new set of things to learn when it comes to rifles. Could you suggest some reading to help get me up to speed on how to go about calculating loads?

Do mean actual loads or the trajetory of said loads? JBM ballistics has a free program that lets you do all kinds of things ballistically to find differing loads, zeros, etc.

Here's the place to start.

http://www.jbmballistics.com/calculations/calculations.shtml

[AlamoShooter]

Thanks for that link, I wanted to download the "Al_Bal " to this new computer. That is the program I have been useing, it is a real supprise to find how much Altitude efects shots past 500 yards.

The Diamond & Star at 90 yards is not so hard ...untill nationals

It would be fun to have some scale upp-ed Biathalon style long range 3gun targets Like wtih a 10" to 12" center flash and a 48" blocker with the center hole in it. And an exsperianced spotter to call you in to the center Thats what I want