My 270 WSM likes Retumbo

[el matador]

From the day I bought this gun I've never been able to get decent groups with 150 grain bullets. It did ok with 140s, and eventually I tossed in the towel and got a new barrel. So with the new Pac-Nor 3 groove installed I went about working up loads with 150 grain Nosler Ballistic Silvertips and couldn't get much better than MOA with a few different powders and seating depths. That is, until I tried Retumbo. The first group I shot was under 1/2 moa, and the second was just a hair bigger. I've shot a few more groups since then and it's consistently around 1/3 to 1/2 moa at 200 yards. 67.0-68.0 grains is where I'm finding success. I know these groups aren't stellar by some of your standards, but hopefully this info can help someone that's having trouble getting 150s to group.

 

[ekcaller]

El matador, do you have any idea on your fps. I'm also shooting Retumbo out of my 270 wsm , but I'm shooting 165 matrix.

 

[Radhimself]

My wsm shoots the fed premium 150's very well, but ive been handloading 160grn partitions over a 68.4grn charge of retumbo at max 2.865 OAL in reused Fed brass wih a 215 primer... 3180fps, very consistant and 3 rounds into a dime @ 100

Worked up a 110tsx load 66.6grns of IMR4350, 2.779oal 215 primer

This is out of a xbolt comp stalker that i stock stabilized and bedded... I love my .270

Im having issues finding a load for 140grn accubonds though, kinda wanna trym on a bear or a mulie and see what everyone is raving about

 

[el matador]

I haven't clocked any loads from the new barrel but I did a bunch of chronographing from the factory tube. I was always pretty close to the published Nosler data as far as max velocity, although I used a couple more grains of powder to get there. I think the factory chamber was on the large side though since my new chamber maxes out right where the published data does. I was using around 72 grains Magpro to push the 140 Accubonds right at 3200 fps. This is several grains over the published max. I tested the same powder in the new barrel and started getting sticky bolt lift around 69 grains. My buddy had a Tikka T3 Lite which liked the Magpro as well, then he traded that for a Kimber in the same caliber. Once again, Magpro was the ticket with groups right around 1/2 moa. Both of those guns shot the 150 SSTs quite well with Magpro, and maxed out around 3100 fps. 24" barrels on all the guns I've mentioned. My Rem 700, pillar bedded with the factory barrel, would shoot 1/2 MOA with perfect ammo and 140 accubonds, but I mean PERFECT ammo. Norma brass, neck sized, neck turned, weight sorted, and concentricity .002" or less. If I had .005" of runout I'd get fliers and would usually end up 1.0-1.5 MOA. I got tired of the thing being so picky so I had Pac-Nor put a new tube on her and now she's much happier!

I'll be interested to see what kind of velocity I get with Retumbo. The book says I should be around 2950 with 67.0 grains and 2990 with 68.0. If you're getting 3180 with 160 grain bullets you must have a longer barrel than 24". That or else I'm in for a very pleasant surprise when I chrono my 150s gun)

 

[ekcaller]

My 270 wsm is running a 28 inch 1/9 twist Benchmark barrel. retumbo has been the only powder I tried with the 165 Matrix. 68.5 grains launches it a little over 3000 fps, but the bolt on my Savge action was quite stiff, I think my action is also really tight.
I want to try RL 26 as soon as I can get my hands on sum.
Let us know your findings as I will be following your posts.