Play with Seating Depth or something else

[Pineman]

So I did a couple of ladder tests for my 270 WSM with the Federal TA 136g. I worked up the same load with Remington Brass and virgin ADG brass. Went to the range today and shot the 2 groups. The Remington brass grouped 1.983 with and ES of 11 and SD of 4. The virgin ADG brass load grouped 1.776 with and ES of 8 and SD of 3. My question : since the ES and SD are very good, do you think I need to play with seating depth or tweak the powder charge? With other handloads in 130,140 and 150 grain it consistently with shoot around 1/2 inch. This is one of my winter projects to find a load for the 136TA.
TIA

 

[Charlie-NY]

So I did a couple of ladder tests for my 270 WSM with the Federal TA 136g. I worked up the same load with Remington Brass and virgin ADG brass. Went to the range today and shot the 2 groups. The Remington brass grouped 1.983 with and ES of 11 and SD of 4. The virgin ADG brass load grouped 1.776 with and ES of 8 and SD of 3. My question : since the ES and SD are very good, do you think I need to play with seating depth or tweak the powder charge? With other handloads in 130,140 and 150 grain it consistently with shoot around 1/2 inch. This is one of my winter projects to find a load for the 136TA.
TIA

I'd work on seating depth changes in increments of .015" to see if groups shrink.

BTW - I think you're the first poster that I've ever seen list his group size down to the 1/1,000 of an inch.

 

[SJB358]

I’m with Charlie. With numbers like that, if the speeds acceptable then I’d change seating depths.

 

[Pineman]

Yes, I'm happy with the velocity. My Browning's like quite a bit of jump so would you try seating slightly shorter first or seat a group .015 shorter and 0.15 longer and try again?

 

[300WSM]

So I did a couple of ladder tests for my 270 WSM with the Federal TA 136g. I worked up the same load with Remington Brass and virgin ADG brass. Went to the range today and shot the 2 groups. The Remington brass grouped 1.983 with and ES of 11 and SD of 4. The virgin ADG brass load grouped 1.776 with and ES of 8 and SD of 3. My question : since the ES and SD are very good, do you think I need to play with seating depth or tweak the powder charge? With other handloads in 130,140 and 150 grain it consistently with shoot around 1/2 inch. This is one of my winter projects to find a load for the 136TA.
TIA

How far is your jump into the rifling now?

That size of a grouo
you need to work on both charge and depth

 

[SJB358]

I usually start close with plain old cup and core. Bonded or mono I start .050 off and work back typically.

 

[Pineman]

I'm currently about 0.070 jump. I was using Fed 215 and Fed 215 Match primers. I've had good luck in the past with Fed 210, WLRM and Rem 9.5M primers.
I might try a different primer along with different seating depths and compare to this baseline. This is part of the fun for me..

 

[SJB358]

If you’re getting a wide shot a primer change may help and tinkering with the charge. I’d also keep going further from the rifling just to see what happens.

 

[TackDriver284]

Have you ran 3 shot groups in .3 grain increments and see what the paper tells you? You should be able to find a node within those groups. What powder are you using in this test?

 

[Pineman]

TackDriver284
I'm using RL 17 as per Federals recommended powders. I found a good velocity node during my ladder test on 0.2 grain increments. The loads I worked up are with one of the nodes at the higher 0.2 grains. I haven't tried the lower 0.2 grain node yet.