300 RUM Re-Loadings

[Chilly Willy]

Here's the deal guys, I need help!

The load I've decided on is:
200 grain Accu Bond molly coated
Magnum primer
Retumbo powder
Remington Brass

I figure I'll start the mix at 86 grains and work up. Here's the big question, how far do I seat the bullet??? I've heard of free bore but is this what I want to do with a stock 700 BDL SS w 26" barrel?

 

[HoytemanPA]

Chilly Willy,
Mine too is a 700 bdl ss. I plinked around at 100 only briefly and then stretched it out to 4,6, and 820. A couple of those groups made me briefly contemplate selling my 222 and 22-250 for a good bench rest and lots more Retumbo. But with the hot barrel after 3 or 4 I came to my senses. At 820 groupings were in the 5 inch vertical range, horizontal pretty much wind dependent.

I'm one of the "ones with issues" loading to 94 gr with that ball. I see my sierra edition five has 95 gr max listed for 220 MKings. I also read somewhere it was a misprint and there are now corrections to put in the book. All I know is that in my gun I feel it is safe. I went to 96 during load testing and didn't find any signs. Accuracy went to pooh for me though. I would think moly would only add to the safety factor but I don't know, I never touch the stuff.

My current OAL is 3.696. I can't remember exactly where that is in relation to the rifling but I will check. That is where my first round is seated to. The rounds that see no action in the mag are seated to 3.665 to clear the mag well and scribbled on with magic marker to keep them seperated. These are for the back-up oh what the heck happened time to make some noise at close range shots anyway.
I'm happy to say those weren't needed this year. I took 2 whitetails this year with it, one at 375, and the other about 3 paces beyond a 771 lasered tree.
Good luck and if I were loading up to pound stuff inside of 300 yd, I would commence to seating them near 3.660 or such a matter and then find out just how much Retumbo it likes.
HPA

 

[Chilly Willy]

Thanks PA

 

[Brent]

Brian,
I'm getting about 3015 fps average at 50 deg F with that load, 26" BDLSS. That's the load I listed MV for at 3.660" OAL, but with no pressure data beside it. You can see the same load above that, seated on the lands, was 3082 fps at 62k psi.

The only ones I shot groups with were the ones I seated at 3.66" to fit in the mag. They were so accurate with that first load I never even changed a thing, or looked further. They shot as good or better than ANY load I'd ever fired from this rifle, and I've fired a boat load of ammo through this thing working up loads.

I'm pretty sure brass life will be pretty good at this level, but I'll go up and see how it shoots at about 3100 or so. I definitely will be looking for more speed, I can't expect any better accuracy from it, and I'll drop back down if I loose any.

CW,
As many guys that shoot 700's and this bullet combo, I know the vast majority don't seat 'em long and single feed them, and they all are getting super accuracy, so I'd say the shoot very well seated way off the lands and you should start at max length your mag allows and see how they shoot.