338LM load work up plan, what say ye?

[Sonic Crack]

Making plans for load development of 338LM, 300SMK, Laupa brass, Retumbo, CCI mag primers. I know to start with the bullet in the lands and work up slow but, The available reamers free bore puts the COAL at around 3.783". Im going to run 338 CIP mags and do not want the COAL longer that 3.760" for feeding reliability.

So the plan is to ether run a ladder test with bullets in the lands at 3.783"ish single feeding them, find my rifles max load and pick a node to run. Then seat bullets to mag length 3.760" and see how she runs? or

Just get a reamer ordered with .020-.030" shorter free bore and go from there?

My concerns are
1, Should I be worried about jumping the SMK's .020-.030"? not sure if they like that much jump or not
2, I will be running a high end node, worried about throat erosion and jump going even further and not being able to seat the bullet out further

 

[thefitter]

I would always design the reamer for what you want exactly. Why cut corners and sacrifice? Are you in a such hurry to build this?

I know waiting for reamers sucks...I'm waiting for 2 right now (16 weeks), but it's worth it to me.

On my reamers I always set the max COAL available within my mag to be full jammed. That way I can back off from the lands as needed to develop the load.

Just my opinion. No expert, just some guy that's lucky to get 2 hours of shooting in a weekend.

 

[ChrisGarrett]

Making plans for load development of 338LM, 300SMK, Laupa brass, Retumbo, CCI mag primers. I know to start with the bullet in the lands and work up slow but, The available reamers free bore puts the COAL at around 3.783". Im going to run 338 CIP mags and do not want the COAL longer that 3.760" for feeding reliability.

You really don't start load development jammed into the lands, especially since the SMKs can stand a jump and even like it. Start with your powder charge first, say .030" off the lands and once you get your high and low nodes dialed in, you fine tune your seating depth and I'd do this with a few bullets, not just the SMKs, before etching things in stone.

So the plan is to ether run a ladder test with bullets in the lands at 3.783"ish single feeding them, find my rifles max load and pick a node to run. Then seat bullets to mag length 3.760" and see how she runs? or

Just get a reamer ordered with .020-.030" shorter free bore and go from there?

My concerns are
1, Should I be worried about jumping the SMK's .020-.030"? not sure if they like that much jump or not
2, I will be running a high end node, worried about throat erosion and jump going even further and not being able to seat the bullet out further

Chris.....

 

[Sonic Crack]

Chris.....

You have it backwards sir, Its never a good idea to find max load with a jumped bullet then jam it. I will find a High end node with the bullet jammed and if that node does not shoot to my liking with a jammed bullet then ill play around with jump. That is the safe way to do it

 

[jkonzal]

I run .040 jump with 300 SMK's. As Chris said, they like to jump!

 

[ChrisGarrett]

You have it backwards sir, Its never a good idea to find max load with a jumped bullet then jam it. I will find a High end node with the bullet jammed and if that node does not shoot to my liking with a jammed bullet then ill play around with jump. That is the safe way to do it

I realize that, that's why I said don't jam the lands first and work on your nodes, say .030" off, since SMKs like a jump.

Jamming the lands first isn't the way to go traditionally, but if you have to start out jamming the lands for whatever reason, than that's the way you have to go.

Start low and work up, but that's not the 'normal' way to go about load development, was my point.

Chris

 

[cecchino76]

I load mine .060" from the land , and I have the best results ,
I even tryed .020" - .040" , but my rifle ( savage 110 BA) likes the sierra 300 with .060"