Picking a new bullet...how do you go through that process.

[fpgt72]

The rifle in question is a 243 Savage 99 made in the early 60's. It really liked a 107gr sierra that has been discontinued. I can not find the twist anywhere on the rifle. Google says the twist is 1:10 so it should not like heavy bullets.

When I first got the rifle I went and bought a box of several factory rounds in different weights. One of the pictures I have that I really like is my dog Willow not liking one of the boxes.

So down to one box left that I just busted open, now I need more. I went with a couple versions of bullet around the 107gr of the old Sierra that the rifle liked. I also have a 223 with a pretty fast twist so it should like heavy bullets, but it does not, anything over 70 grains will keyhole and just shoot like hell, give it good old 55's and I can bang steel at 100 all day. I don't understand. The other 223 with a 1:7 follows the rules.

So with the savage I just went to the range with the 4 or so boxes and put them on paper. It was real clear the rifle likes heavy bullets. How do you go about picking the right bullet, trial and error, or is there some other way. I have rifles that follow the rules and some that dont.

I was just wondering how you go through the process.

 

[LR1845]

Do you reload or are you shooting factory ammo?

 

[diggler1833]

Trial and error. I do try to match bullet length to twist rate, but sometimes (as you noted) you get surprised.

Since 99% of my shooting is done with reloads, I usually have supplies on hand to give everything a fair shot at accuracy. As I get older however - and my desire to tinker with loads diminishes - I'll usually look for combinations that shoot well right out of the gate before I start exploring with trying to make them shoot even better.

 

[brianf]

Berger bullet
Lapua brass

That’s the easy button, always has been always will

 

[fpgt72]

Do you reload or are you shooting factory ammo?

Reload

 

[fpgt72]

Berger bullet
Lapua brass

That’s the easy button, always has been always will

On the way is one box of berger, one hornady and one sierra, all right around 100 grains. As to brass I am using what I have and that is a mix mash. If I get hand sized groups at 100 I will be happy. Some of the lighter factory ammo would not hit paper.

 

[wv.citybilly]

I had a factory ammo that shot 1/2 MOA through my rifle. When I began reloading, trying to re-create the wheel, I started with the same bullet, brass, etc., as the ammo manufacturer, and achieved similar results.

However, after using the Berger Twist Rate Stability Calculator, I switched bullets, and the results spoke for themselves at 1/4 MOA.

Berger Twist Rate Calculator

 

[salks]

If you have a cleaning rod with with some kind of bearing in the handle you can measure twist rate with a tight fitting patch.