300wsm max charge?

[bosstom]

I am wanting to work up some loads for my 300wsm using 168VLD's over IMR4350, but all the load data I have found shows MAX charges that are very different. I have found MAX charges listed from 63-68.5gr. Walt from Berger sent me load data that shows IMR4350 starting at 60gr and a MAX of 63gr, is this the max I should use since im using the VLD's? I will start low and work up, but if the MAX is well over 63gr I would rather not have my test loads covering a range of 6-8gr.

 

[Tyler Kemp]

Just load one or two up at the lower weights, then as you get past 63 load one up at .5 grains of powder, when you see an ejector mark back the load off a grain.

 

[Buffalobob]

I find this to be incredible. You would rather trust strangers on the internet than a reputable bullet manufacturer?

 

[bosstom]

I find this to be incredible. You would rather trust strangers on the internet than a reputable bullet manufacturer?]


What is is so incredible, the lowest MAX charge that I have is 63gr and that is from Walt of Berger Bullets, the highest MAX charge is 68.5gr and is from a different bullet manufacturer. I have never seen such a broad powder range for a bullet. I alwas start low and work up looking for any pressure signs. Speer says that they use new ways of testing pressure and new published MAX loads maybe higher than those listed in the past, something about this dosent seem right to me.

 

[MontanaRifleman]

Max pressure in a particular cartridge will vary form rifle to rifle and load to load depending on a myriad of things. Bullet design, throat design. neck tension, seating depth, etc.

My approach is to start with a conservative starting load, work up 1 gr at a time, and when within 1 or 2 gr of probable max, I work up 1/2 gr at a time. I shoot 2 rounds at each level to look for consistancy. It has never failed me and it is a safe way to proceed.

Using H4350, I found *my* max loads (max meaning highest charge not showing excessive pressure signs) to be 66 gr for 180 E-T-ips seated about .050 off the lands and 65.5 for TTSX's seated at the same depth.

 

[britz]

There are many factors contributing to the actual chamber pressure. Case volume (slightly different from brand to brand and lot to lot), primers used, temperature, the actual chamber size, and most notably the bullet disign. A streemlined boat tail will take up more room in the casing than a blunt based hunting bullet. So with that said, you are always better off using data from the actual bullet manufacturer.

With that said, It is up to you to deside how far you want to push your load. There are USUALLY (I won't say always) warning signs of excessive pressure, but I'm not going to tell anyone to go beyond the max published data.

Earlier this winter I blew out a ejector spring on my savage 22-250 by being well within the loading data. However, due to all the little factors my chamber pressure really spiked prior to hitting the higher recomended load. I got lucky and I'm going to chalk that one up for a lesson learned. "note to self... be carefull".

 

[johnnyk]

That's why they call it "working" up a load. JohnnyK.