300 RUM development?

[Slickrick0999]

I finally got to shoot my new 300 RUM today. I fired 6 rounds and cleaned between each. These were loaded with 88 grains of H1000 and Berger 215 hybrids. Now i'm ready to start tuning.
So, what should I load? How many rounds of what increments in charge weight?
I appreciate everyone's support on this site, i'm use to shooting 308s and this is all new to me.
Thanks!

 

[Snootch]

I finally got to shoot my new 300 RUM today. I fired 6 rounds and cleaned between each. These were loaded with 88 grains of H1000 and Berger 215 hybrids. Now i'm ready to start tuning.
So, what should I load? How many rounds of what increments in charge weight?
I appreciate everyone's support on this site, i'm use to shooting 308s and this is all new to me.
Thanks!

I usually go in .5gr 3 shot groups until I get a working group and fine tune from there. If I have time to go shoot over 300, I'll do a ladder test. I just started breaking in my 300 rum barrel myself. I'll be doing load development for 225 eld-match soon. Good luck

 

[tbrice23]

I finally got to shoot my new 300 RUM today. I fired 6 rounds and cleaned between each. These were loaded with 88 grains of H1000 and Berger 215 hybrids. Now i'm ready to start tuning.
So, what should I load? How many rounds of what increments in charge weight?
I appreciate everyone's support on this site, i'm use to shooting 308s and this is all new to me.
Thanks!

Just finishing a 300 RUM. I may have to go back to TN for barrel break in, too cold here... the solvent will freeze in the bore!
Is yours a 10 twist? I did a twist rate calculator for 400' ( worst case scenario) which is Savannah and the 215s weren't stable. So I decided to shoot the 200.20X Hybrids.

 

[Slickrick0999]

Just finishing a 300 RUM. I may have to go back to TN for barrel break in, too cold here... the solvent will freeze in the bore!
Is yours a 10 twist? I did a twist rate calculator for 400' ( worst case scenario) which is Savannah and the 215s weren't stable. So I decided to shoot the 200.20X Hybrids.

Mine is a factory remington long range and 10 twist

 

[tbrice23]

Mine too. Bedded the stock yesterday, the barreled action is getting threaded for a brake now.

 

[tbrice23]

I think it turned out pretty good.

 

[tbrice23]

Next thing to do is install the Timney trigger and install the Wyatt's mag box as soon as it gets back from muzzle threading.

 

[tbrice23]

I'll probably do .7gr increments of Retumbo, 3 shot groups. When I think I've struck gold I'll load 5 or 6 round group to verify.

 

[Slickrick0999]

I've got mine threaded with a MB&M 5 port beast brake.
Threw in an old Shillen trigger that is doing really well.
Haven't bedded it.
I thought about the Wyatts mag deal but i'm loading them pretty long and just shooting steel with it so may stick to single loading.

 

[tbrice23]

Did you have any pressure sighs with 88 gr of H1000?

 

[jpd676]

When I did my load development (300 RUM in r700 LR) I ended up gaining over 100fps within the first 100 rounds. Just keep that in mind. I usually do .5 gr increases, three shots of each charge to look for an area to focus in on.

 

[Slickrick0999]

Did you have any pressure sighs with 88 gr of H1000?

None yet

 

[trebark]

For the 300RUM where your loading in the 90grain range, I will differ from the pack here and recommend you make 1grain changes from load to load. 1grain is just slightly more than a 1% change. Your go-to powders are going to be Retumbo, H1000 and RL26.

https://www.longrangehunting.com/threads/my-300rum-by-mcr.70809/

 

[Slickrick0999]

For the 300RUM where your loading in the 90grain range, I will differ from the pack here and recommend you make 1grain changes from load to load. 1grain is just slightly more than a 1% change. Your go-to powders are going to be Retumbo, H1000 and RL26.

https://www.longrangehunting.com/threads/my-300rum-by-mcr.70809/

Your advice follows exactly what a friend of mine here locally says. He suggested 88, 89, 90 grain loads for 3 shot groups and possibly have 90.5 or 91 ready if pressure is not seen earlier.
I just worry about "missing a node" by these larger jumps. This is the first time I've had access to a chrono for load development.
I am using H1000 powder as well.
Thanks