why is berger load data always so much lower than everyone else.

[rotts4u]

Tonight I was loading for a 338 Lapua with a 250 grain bullet and Hodgdon shows 98grains max for the 250 grain bullet while the berger manual shows only 90.0 for their 250 grain bullet. I find similar differences in nearly every caliber I look up data for.

I usually exceed the berger data but in this case 8 grains is a LOT of difference. Of course the Hodgdon data was for a 250 hornady bullet which could account for some of the difference. I loaded up to 96.6g and stopped. I have shot 95 before with no issues on the berger 250g OTM.

Do you usually look at 2-3 manuals and decide where to stop?

[FW Conch]

Sierra can also be counted on to be on the low end. ?

[Westcliffe01]

Because the data in the Berger manual is based on software simulation and not actual load test data ?

I am guessing that SOME of the loads had experience to back it up, but I too found huge differences compared to Hodgdon load data. Hornady handbook was also conservative, then you look at their published data for 6.5 Creedmoor - wow. Quite the contradiction.

[KRP]

Max loads for my rifles with my components are just that...for my rifles and components. I check 2-3 sources for a place to start.

[Hotolds442]

Thank a lawyer for low max charge weights published by the manufacturers. They're working hard to prevent you from any litigation issues.

[the Ranger]

could be that the long slippery shape of the Bergers extends further into the case = less powder space = higher pressure?

[mikein]

I look at 2-3 manuals and 2-3 software programs for initial loading guidance. As I work my way up in powder charge weight, I let my rifles and the cartridge cases tell me if I'm approaching the real stop point for my particular rifle and load. Hard to eject cases; pancaked primers; hammered heads; as soon as any of these symptoms begin to present themselves, I back off a couple of tenths and declare that a "max load" for the rig. Then I load some more of them up at that reduced charge and test them again; one at a time, carefully examining each spent case for any pressure signs.

[yobuck]

i usualy refer to one manual for a starting point load.
i will then load 1 round with a near max charge. i then load 1 more round with 1 gr increases.
when the bolt starts telling me to stop, i stop. i then back up about 1 gr and start my testing
backwards from there. i know the max charge with very few rounds which is what im looking for.
i do that with each powder. with wildcat cartridges there is no published data. this is your only
viable option. if it works for wildcats, why not factory chamberings?
its a good idea to shoot over your chronagraph while doing this.
a few years back i had a large 338 built. i was instructed to start at 132 gr h50bmg w/a 300gr.
shoot over the chronagraph 1 round at a time with 1 gr increases till i got to 32 to 3250 range.
then look around for accuracy with seating depth and small powder increases/decreases.
pretty much same scenario used by mikein.