Bullet testing?

[TrxR]

I am going to be doing some testing on a rifle I will be using for my first year of F/TR and will be using 155gn for the first year.

Anyways I currently have 200 Lapua 155's and was wondering if a lot of 100 bullets would be enough for testing purposes?

I was thinking about buying 100 Sierra 2156's and 100 Berger 155.5's

Which bullet do you all find the least fussy?

What do you all think is 100 enough for testing purposes?

I am on a budget so I cant really buy a large quantity until I figure out what bullet I am going to use.

Thanks

 

[chkunz]

Excellent question! My recommendation is first to develop a detailed "Test Plan" with as much detail as possible. If you are testing bullets then everything else needs to be as consistent as you can make it so you have only one variable, the bullets. In the real world it is very difficult to keep it that pure but you should strive for it. If you are familiar with the "scientific method" that will help guide you, if not get someone who is familiar with the scientific method to review your Test Plan. Spend considerable time on the plan. Now, specifically to your question as to how many of each type of bullets do you need for a meaningful test? The discipline of statistical analysis will give you the answer and it depends on the variability of the data and the confidence level you are willing to accept for your answer. I started a thread that asked, "How do I choose load A vs load B" and most of the responses demonstrated that most folks do not understand what it takes to answer the question. Mother nature is a bitch. The short answer is that it will take more shooting than you will want to do but I can tell you that three five shot groups will not do it. Develop the test plan and post it here and get some review on that before you shoot the first bullet.

 

[deadwooddick]

2¢

Ya' find a load w/ 100. Get 100 of the same bullet and find they don't perform as did the first lot of 100. Ugh !

 

[TonyR]

Al three bullets should shoot well. Since you are on a budget, why not just start with the least expensive which is the Sierra 2156? From what I've seen, it is a mistake to try and find a good load by testing a lot of different bullets. It's been better for me to start with a bullet and powder that others have done well with and try to find a powder charge that works in your rifle by shooting some ladder tests. Varget works as well as anything in a 308 and most bullets like the 2156 like a little jump so maybe shoot a ladder in 0.3 grain increments with the bullets 0.010 inches off the lands and see if you can find a node. From there you can test different seating depths. The 308 cartridge guide on this website has some proven loads for the 308 for at least the Lapua and the Sierra:
http://www.accurateshooter.com/cartridge-guides/308win/
I believe that the Berger 155 mentioned in the guide is different than the 155.5. In any event, you should start out 10% below the powder charges mentioned in the guide and work up carefully in increments looking for pressure signs.

 

[TrxR]

I understand what you are saying about the different lots. But it is not possible for me to buy 1000 or even 500 of each . I might be able to pick up 200 of each . I will be using Varget for now as I have 8lbs of it. Im am wanting to see which bullet will be the more consistent in my rifle and be able to give me enough velocity to get out to 900 meters reliably. I will also be using Lapua brass and CCI BR2 primers. The barrel is a 1 in 12 at 28" long.

I do have a couple of guys that can help me setup a plan of attack.

Thanks