Max Load 30-06 IMR4350 Sierra 180 SPBT

Just came up from my reloading room and I noticed something that caught my attention. I was loading .30-06 180 grain Sierra Spitzer Boat Tail bullet with IMR 4350. According to my latest Sierra manual max load tops out at 53 grains. This seemed a bit light to me. I checked my previous Sierra manual and they were publishing a max load of 56 grains. I checked my current Hornady, Nosler, and Speer manuals and they were all publishing a similar max load. I wonder why Sierra moved their max recommended load down? Would you feel comfortable loading Sierra bullets upwards to 56 grains checking for pressure signs along the way?

Sierra was listing what was max with their barrel, their lot# of components, meant to be a guide only.

53 grains is light. I've used more with 180 grain bullets in several rifles.

This is a comparison between the 4th and 6th Sierra editions.

I don't know if you can read my writing. Sometimes, I can't read my writing. I just compiled all the load data I have on hand for 180 grain bullets. Sierra 6th edition of maximum load of 52.9 grains definitely looks out of place when compared to everyone else's data.

As I said, Sierra was stating what their test barrel's pressure was, their lot# of powder, etc. Sierra's data indicates that their equipment spiked pressures early in the load development or their lot# of powder was a super hot lot#. Sierra's data May or may not apply to your barrel and components.

I am using a very hot load of H4350 with 180 Nosler Ballistic tips in Winchester brass and WLR primers, the most accurate load for that barrel. I always want to know what is the max load for my barrel, then back off 2.5g and work up carefully.