My dumb luck

[lordgroom]

I was test firing loads for .223 using IMR-4895. I had loads of three rounds each ranging from 23 grains to 26.5 grains (Listed in Ken Waters "Pet Loads" as very accurate) separated by .3 grains. I was shooting round robin with one minute in between shots to allow the barrel to cool. I was chasing down each piece of brass to inspect after every shot. Somewhere after the first round thru, the wind blew one of my sandwich bags off the shooting table. It was 24.8 grains. I discovered the bag on the ground after firing many more rounds. I clearly mixed rounds of different powder weights. How frustrating! Now I have to start all over again.

 

[Der Verge]

http://www.mtmcase-gard.com/products/rifle/rifl.html

Worth every penny of the $4.99 they cost.

 

[strat81]

The trouble with 3 shot groups:
http://www.ar15.com/forums/topic.html?b=3&f=118&t=279218&page=1

 

[snuffy]

You do mark each round with the powder weight, don't you? I use a sharpie to put like 26.5 on the case itself. Then line them up in an ammo box like the case guards.

Oh yeah, 3 shot groups won't tell you much, 5 is better, 10 is perfect.

 

[lordgroom]

Ok, I understand that statistically 10 shot groups are better. But 10 times 13 is 130. 130 minutes to test the rounds? Is that what you are suggesting?

Snuffy, I will mark them next time. My fault for not reading the little card in the bag and matching to the target. I assumed... yeah I know... That I was firing at the next in line.

How should I approach working up a load of .223 with 3 graduations of +.3 grains ranging from 23 to 26.6?

 

[Der Verge]

Start with 3 shot groups. Keep good records. Pick the best say, 3 loadings. Go home, load 10 of each, try again. Much less expensive this way.

 

[RustyFN]

I do like Snuffy. I color the primers with different color sharpies. I can drop them on the ground or they could get mixed up in a box and I can still tell what the powder charge is in each round.
Rusty

 

[Matt-J2]

Ok, I understand that statistically 10 shot groups are better. But 10 times 13 is 130. 130 minutes to test the rounds? Is that what you are suggesting?

Does it actually take a full minute for the barrel to cool?
And, I really don't know how this all works, but don't barrels group differently when they're hot? So if your normal firing will be done when the barrel is hot, why not test that way? Maybe these are dumb newbie questions, but since I are one, I'll post em up.

 

[lordgroom]

I was allowing the barrel to cool so progressive heating would be eliminated as a variable. The temp of the barrel would continue to rise with each shot and would be an added variable. I am fairly new to this also, this is something I read somewhere.