How much does a bullets accuracy vary with powder load?

[Prios]

Hi all,

I'm a soon to be reloader, but haven't done it before... Just writing to get my head around the best process for working out what loads are accuracy in my rifle...

Obviously I will buy a few different projectile brands and weights etc. but how quickly and how much load testing do I need to do before deciding if a bullet it no good for my rifle and giving up on it.

I mean If I buy bullets A, B and C and do a starting load for each, if A shooters 3" groups, and B shoots 2" groups and C shoots 1" groups... Is there any point doing further load testing with bullets A and B? Does accuracy change slightly with different loads? Or can it change a lot, making further load testing worthwhile.

Cheers.

[Prios]

Forgot to say, this will be for reloading .308 win and I'm looking at bullets weights from 130gr to 160gr or so...

Thanks again.

[Norton]

A bullets accuracy will vary greatly with the powder load.

Shooting a single load won't tell you anything about it's potential accuracy, you need to do proper load testing with a range of powder weights to find out how well it can work for your rifle.

[Vati]

I mean If I buy bullets A, B and C and do a starting load for each, if A shooters 3" groups, and B shoots 2" groups and C shoots 1" groups... Is there any point doing further load testing with bullets A and B?

Definitely, yes.

Groups can easily vary a couple of inchs between powder loads.

You'd be extremely lucky if you fluked it and landed on your optimal load the first time round.

If you're going to reload for accuracy do proper load testing starting at minimum powder load for your projectile and work your way up.

[Lorgar]

Obviously I will buy a few different projectile brands and weights etc. but how quickly and how much load testing do I need to do before deciding if a bullet it no good for my rifle and giving up on it.

IMO do .5gr interval loads from starting to max power load.

e.g. with a 140gr bullet and ADI 2208 powder the starting load is 44 gr, max load is 47gr according to their load data.

You would do loads of 44, 44.5, 45, 45.5, 46, 46.5 and 47 grains of powder. (The number of loads to test for other bullet/powder combinations will vary, but you'll probably be looking at testing 8-9 loads max.)

Shoot a 5 shot group with each and find out what is your most accurate.

Once you have your most accurate load from the above options, do 2-3 more loads in .1gr differences on either side of that to fine tune it.

[Lorgar]

I mean If I buy bullets A, B and C and do a starting load for each, if A shooters 3" groups, and B shoots 2" groups and C shoots 1" groups... Is there any point doing further load testing with bullets A and B?

Yes.

I recently did some load testing in my .308 with 150gr Hornady SST's with 2208 powder...

The loads with 46.5gr of powder shot a 0.61" group, the loads with 47gr powder shot a 3" group.

Both 5 shot groups, both shot by me, same day, same weather, same shooting position etc. etc.

A little change in powder load can make a big difference obviously...

[Hercl]

You would do loads of 44, 44.5, 45, 45.5, 46, 46.5 and 47 grains of powder. (The number of loads to test for other bullet/powder combinations will vary, but you'll probably be looking at testing 8-9 loads max.)

Spent most of the last 2 days doing this for half a dozen new bullet types I'm trying out.

I was so over it by the end of the two sessions I was almost put off shooting them, lol.

Almost