Recommendations or steps on load development for a 300 RUM

[dave300]

Kinda stuck on this one, sorry in advance for the maybe obvious answer

I am have a brand new Sedero II in 300 RUM that I am helping a friend out with and it is unfired.

Can anyone help me with advice on simplest way, if at all, to do load development/ladder testing along with barrel break in, or should I just get rounds thru it to break it in and then do load development afterwards. This will also give me FF brass to begin bumping the shoulder back with the 1X fired brass.
Thoughts?

We will be using new Remington brass, Fed 215GM primers, Retumbo and 230 Grain Berger Hybrids.

Thank you, Dave

 

[redneckbmxer24]

I always do an initial cleaning and put at least 20 rounds through a barrel to help smooth out the roughest parts of the throat. Every time I've started with a new barrel without doing this I've had to go back and do it again. I'd buy a box or two of factory stuff and run through it for sure.

Make sure you have a brake on that beast too, RUM's with 230's thump. I burned the barrel out last year running one of mine with them and no brake and it wasn't fun. It had a 30" straight contour barrel in a McMillan A3 heavy fill, weight with scope about 19.5lbs. It was uncomfortable, I couldn't imagine running the same load in a rifle that will probably weight 5-6lbs less setup without a brake.

 

[LoanHarvey]

For your load development, read the sticky's about load development by TresMon. They are excellent!

 

[dave300]

Redneck, yes it has a brake, and yep it thumps you, I cheat and get it on a lead sled for break in and then man up afterwards and go at it on a bipod. Think Ill just build some minimal loads and go thru my normal breakin and to avoid "having to do it all over again". Just hoped someone had an idea. Pretty much knew the answer

LoanHarvey, thanks and yes I agree they are extremly helpful, it starts at having FF brass and a gun already broke in to which I dont have for this specific gun. Thanks