Thread: .243 load development part deux

Terribly fussy barrel isn't it

Originally Posted by gimp

Why are you measuring 2x 5rd groups instead of the total 10?

Does it make a difference? I plotted the 2 5 RND groups for each projectile as I was walking to the target after 5 rounds to see where I was at and allow the barrel to cool, so it seemed more accurate to plot each 5 individually.

And yes, it's fussy, like a former Italian/Sicilian GF, she was lethal if mishandled as well!

The 10rd group is slightly more representative of your actual precision

Are you satisfied with the performance of one of them?

So I should have shot each projectile in one 10 RND group rather than breaking to allow for barrel cooling etc?
Having just plotted the NBT as 1 ten RND group I can see that moves the MOA out to 1.2

I'm satisfied with the 95gr NBT over anything else and a whole different league compared to the SST/Win DS and I think it's good enough to go hunting with.
At the end of the session I re-zero'd my scope 4 clicks left and 6 clicks down but had no "relaible" ammo to check that with but I've a bof of NBT projectiles to load and will check re-zero then.

At the moment I feel I've got a load that me and rifle can shoot with reasonably reliable/predictable results, next is to get the new scope mounted and then see what I can do to tighten up my grouping further, which MAY include further tuning this load.

What are you seeing?

When I saw your list of components, I thought the ballistic tips with 2209 are going to shoot the best. This is my experience in my Sako as well. Both the 90 grain and 95 grain BT's are good bullets.

Oh I was once over lighly and missed the five shot measurements. 1.2 moa is very respectable; load that up and be satisfied.
I've only shot a handful of 10 shot groups, but shot them slowly and often with a break, to let skinny barrels and supressors cool. Seems a reasonable approach for a hunting rifle.

Originally Posted by Zedrex

So I should have shot each projectile in one 10 RND group rather than breaking to allow for barrel cooling etc?
Having just plotted the NBT as 1 ten RND group I can see that moves the MOA out to 1.2

I'm satisfied with the 95gr NBT over anything else and a whole different league compared to the SST/Win DS and I think it's good enough to go hunting with.
At the end of the session I re-zero'd my scope 4 clicks left and 6 clicks down but had no "relaible" ammo to check that with but I've a bof of NBT projectiles to load and will check re-zero then.

At the moment I feel I've got a load that me and rifle can shoot with reasonably reliable/predictable results, next is to get the new scope mounted and then see what I can do to tighten up my grouping further, which MAY include further tuning this load.

What are you seeing?

Gimp has a scientists gaze, it can be a bit more particular than some others of us, but believe me, load up some NBTs and enjoy you hunting!

Originally Posted by Dama dama

Oh I was once over lighly and missed the five shot measurements. 1.2 moa is very respectable; load that up and be satisfied.
I've only shot a handful of 10 shot groups, but shot them slowly and often with a break, to let skinny barrels and supressors cool. Seems a reasonable approach for a hunting rifle.

I think quite a bit depends on how much powder you are pouring down the tube. Anything up to 270 etc, say 60 grains of powder, just shoot them steadily for 10 shots, no pissing about but not a "mad minute" style either. If you can just put you hand on the barrel after you're finished it's not too hot (but be careful with suppressors, they get bloody hot, but shouldn't effect accuracy). A lot of the "hot barrel" thing has come about from the 3 shot groups approach, your sample size simply wasn't big enough. As I've said before, I've sold at least two nice rifles I thought "walked" but on reflection I think that was just their normal level of precision.

Yep, load development is the rabbit hole of all rabbit holes, for now I've a 100 NBT to load up and go hunting with.....and that was the aim all along. It's been a good introduction to reloading!

But you haven't tested 100grn nbt.....only 90-95grn......

I assumed he meant 100 95gr NBT...

Originally Posted by Tentman

I think quite a bit depends on how much powder you are pouring down the tube. Anything up to 270 etc, say 60 grains of powder, just shoot them steadily for 10 shots, no pissing about but not a "mad minute" style either. If you can just put you hand on the barrel after you're finished it's not too hot (but be careful with suppressors, they get bloody hot, but shouldn't effect accuracy). A lot of the "hot barrel" thing has come about from the 3 shot groups approach, your sample size simply wasn't big enough. As I've said before, I've sold at least two nice rifles I thought "walked" but on reflection I think that was just their normal level of precision.

Ok sounds fair. I know I've given up on projectiles way too soon, chased a zero all over the place and generally wasted ammo on 3 shot groups.

Originally Posted by Tentman

Gimp has a scientists gaze, it can be a bit more particular than some others of us, but believe me, load up some NBTs and enjoy you hunting!

That he may have and that ability to supply evidence based logic without getting emotional is why I found his input most useful and why I was willing to listen to what he had to say, when people start getting shirty I've a tendency to switch off and stop listening, I blame my parents

Originally Posted by Micky Duck

But you haven't tested 100grn nbt.....only 90-95grn......

Thats shorthand for you, I meant 100 x NBT 95gr

Oh thank fook for that!!! Lmfao.