308 ladder test imr 4064 178 hpbt

[Goobie270]

I'm planning on doing a ladder test with my 308 178 hornady match 178gn hpbt, gold metal small rifle primers, lapua pulma cases, and imr 4064 powder. I'd like to know where to start and stop for my loads, just so I don't have a bunch of bullets to pull left over, they will be in 0.2 grain increments.

What's everyone's loads for accuracy using this powder/billet combinations. Thanks.

 

[RAT807]

Ladder test are normally .5 grain increments for larger cases and .3 for small cases. Looking at the Lyman 49th edition manual, starting load for 174gr, IMR4064, and an OAL of 2.780", is 39.5 gr and 44.3 gr max, PSI listed at 61,100. IF, your OAL is longer, using a bolt gun with 63k PSI, you can, maybe go higher with powder charge. Lyman is using Rem. Brass (no idea on how thick or thin), Rem. 9 1/2 primer. So, I would start at 40grs and load in increments of .5 up to 43.5, then drop back to .3gr increments up to 45 grains. After 43.5, 43.8, 44.1, 44.4, 44.7, 45. I have a bolt gun and normally load longer than most books list, and max PSI is 63k... Watch for pressure signs with the .3 gr loads, marks on case head, hard bolt lift, etc.
I don't load for 308 so can't be more specific. But if you see signs of over pressure, don't shoot the higher charged cases.

 

[Capt RB]

Around 42 it is going to come together. You may want to try the 168 and 175tmks while your at it

 

[game4lunch]

Just an FYI . . . when using Lapua brass you need to reduce the load amount because the brass dimensions are thicker than most other brass. Winchester, Hornady, etc. I didn't with my .308's and expanded the primer pockets so much they wouldn't properly hold the primer. The pressures were that much greater. Blew many primers out at the range. I did a water test to determine the load difference between brass manufacturers. The Lapua held 1.5 gr less water so I reduce all Lapua loads by 1.5gr.