6.5 creedmoor lapua brass water capacity

[group therapy]

hello all. my question is I have a 6.5 creedmoor that I shoot 600 meter br with and have been using hornady brass. I am trying lapua brass out and the water capacity for the lapua brass is 2 grains less than the hornady brass. any insight out there what that might equate to, as far a powder reduction, because of the reduced case capacity. my current load shoots really well (4 shot groups in the 3/4" range) and I am just trying to reduce the experimentation(is that a word ?) I may otherwise have to do. thanks in advance. bryant.

 

[brantfredrickson]

I'm getting 52.55 grains H2O in fired 6.5 creedmoor Lapua brass. QuickLoad gives 53.5 for Hornady brass. I suspose it varies from chamber to chamber. New lapua brass case head to shoulder is about .006" shorter than my chamber. It takes about two firings to bring it to my chamber size.

 

[mauser284]

No you can not take empirical measurements and extrapolate some linear carry over that can be used to shortcut the load ladder process.

 

[MislMan]

Wife and I both shoot 6.5 Creedmoor. She uses Lapua brass and I use Hornady brass. We both shoot 140 gr. Hornady ELD-M bullets using H4350 powder. Her powder load is 40.2 gr. And my powder load is 41.4 gr. Her average muzzle velocity is 2712 fps and mine is 2703 fps. We’re both seated @ 0.025 of the lands (jump) and our chambers are within 0.002” in length on our Kreiger barrels (both shooting RPR’s). This is for our barrels and may not be safe in your rifle. This might give you and idea of how far to adjust your loads and work up.

Corrected to 0.025” from lands.

 

[Laurie]

The smaller capacity Lapua case dictates a lower charge all else being equal, but things aren't equal here as Lapua is small primer with a 0.059" dia. flash-hole whilst Hornady is large primer and 0.079" flash-hole. Where everything else remains the same (as in Lapua standard 308 Win v small primer 'Palma' 308 Win), the use of SP brass usually dictates a 0.5-1.5gn charge increase to obtain equivalent MVs to large primer loads, the amount depending on the make / grade of powder.

So, it's very difficult to predict what actual results these two factors working against each other will produce in combination. I'd suggest taking your Hornady brass load and reducing it by 1-1.5gn and working back up. The good news is that the Lapua case will take pressures that expand primer pockets in Hornady in a couple or three firings in its stride, so if your starting point turns out to be warmer than you expect / want, you won't be scrapping any cases.

 

[Rdlningcltchdmpr]

hello all. my question is I have a 6.5 creedmoor that I shoot 600 meter br with and have been using hornady brass. I am trying lapua brass out and the water capacity for the lapua brass is 2 grains less than the hornady brass. any insight out there what that might equate to, as far a powder reduction, because of the reduced case capacity. my current load shoots really well (4 shot groups in the 3/4" range) and I am just trying to reduce the experimentation(is that a word ?) I may otherwise have to do. thanks in advance. bryant.

3/4" at what yardage ?

 

[Rdlningcltchdmpr]

Wife and I both shoot 6.5 Creedmoor. She uses Lapua brass and I use Hornady brass. We both shoot 140 gr. Hornady ELD-M bullets using H4350 powder. Her powder load is 40.2 gr. And my powder load is 41.4 gr. Her average muzzle velocity is 2712 fps and mine is 2703 fps. We’re both seated @ 0.25 of the lands (jump) and our chambers are within 0.002” in length on our Kreiger barrels (both shooting RPR’s). This is for our barrels and may not be safe in your rifle. This might give you and idea of how far to adjust your loads and work up.

Did you mean .025"

 

[MislMan]

Did you mean .025"

Yes .... oops. Corrected my post.

 

[LVLAaron]

3/4" at what yardage ?

6.5 Creedmoor, so, 1000 yards.

 

[group therapy]

3/4" at what yardage ?

654 yards. Our range is 600 meters hence the weird yardage. Still haven’t got 5 in there LOL!!!!!!

 

[grovey]

6.5 Creedmoor, so, 1000 yards.

I think those yards are measured like peter inches. From the A**hole.

 

[Rdlningcltchdmpr]

I think those yards are measured like peter inches. From the A**hole.

Maybe from the middle of the back.