Starting seating depth

[beetroot]

I'm about to start load development for a new 6.5CM and have been scrolling through a lot of threads about the different loads guys are using.
One thing I've noticed is a pretty big proportion of guys loads are seated .020" off the lands regardless of bullet used and in some case regardless of cartridge.

I know that I'll need to do my own seating testing to find what works the best and I've read the article from PRBlog but it's very interesting that .020" seems to do so well for so many people.
I usually start the normal 0.010" off for my initial powder charge testing and will do lands testing afterwards but should I take a stab in the dark that 0.020" will also work well in my rifle and start from there?

Shooting: a Tikka CTR, 147gr ELDM, Lapua, H4350, BR4s if it matters.

 

[XLR308]

I am running .030" off in my 65CM with the 147eldm that is were I'm still above the neck shoulder junction with a COAL of 2.885" and no were near compressing powder with charge I'm using but very little air gap in the powder column.

 

[equilibrium]

What scope?

 

[Supersubes]

.020 is a good number. So is .030-.050. I’m no fan of jamming or loading right at the lands, so typically get no closer than .020. The load only gets more forgiving with a little jump.

 

[XLR308]

I'm using pretty much the same components as you.
Lapua brass
CCI-450
H-4350
147ELDM

I noticed from reading through some of threads with the same components that 41.4 grains of H4350 was a sweet spot for many and surprisingly that's were I ended up as well.
Running 2740fps from a 23" barrel.

 

[Gee Kay]

 

[AKMarty]

I don’t think it’s that .020” isn’t good, it’s that you don’t have to keep chasing the lands as the throat erodes. My rifle likes a spot at .020”. It also likes .070”-.100”.

Factory Tikka Tac A1 6.5cm w 147 ELD-M

 

[salks]

For me -.050 is the new -.020 from what I have read and experienced in my reloads. It is where I plan to start.

 

[acudaowner]

please write back with your results and good luck .

 

[rockchalk06]

I'm using pretty much the same components as you.
Lapua brass
CCI-450
H-4350
147ELDM

I noticed from reading through some of threads with the same components that 41.4 grains of H4350 was a sweet spot for many and surprisingly that's were I ended up as well.
Running 2740fps from a 23" barrel.

40.9 grains of H4350 is my sweet spot on everything 140 grain and 39.7 grains on everything 147 grain. All bullets loaded to mag length.

 

[beetroot]

.

I found my lands using the Wheeler Accuracy method.


Erik seats .020" off the bullet being jammed hard into the rifling to ensure he will be well off the lands, the above method more accurately finds where touch is so you can safely seat 0.010" off. I know that it doesn't really matter where you start from so long as you start somewhere and the whole chasing the lands is a different topic all together.

 

[beetroot]

I'm using pretty much the same components as you.
Lapua brass
CCI-450
H-4350
147ELDM

I noticed from reading through some of threads with the same components that 41.4 grains of H4350 was a sweet spot for many and surprisingly that's were I ended up as well.
Running 2740fps from a 23" barrel.

That's pretty good velocity, I'll be happy if I can get over 2700fps.
I'll start from 41.0 and go up to 43.0, based on other guys loads it seems that 41.5ish seems to be the magic number with H4350.

I think I'll go ahead and seat them to 0.020" as a starting point, then in lands testing will try 0.010".

 

[XLR308]

That's pretty good velocity, I'll be happy if I can get over 2700fps.
I'll start from 41.0 and go up to 43.0, based on other guys loads it seems that 41.5ish seems to be the magic number with H4350.

I think I'll go ahead and seat them to 0.020" as a starting point, then in lands testing will try 0.010".

It's a Bartlien 7.5" twist and has always seemed a bit fast to me.
I didn't bother to see were it topped out just ran a ladder pressure test initially shot a few groups above and below the node I identified and stayed with it.

 

[Supersubes]

That's pretty good velocity, I'll be happy if I can get over 2700fps.
I'll start from 41.0 and go up to 43.0, based on other guys loads it seems that 41.5ish seems to be the magic number with H4350.

I think I'll go ahead and seat them to 0.020" as a starting point, then in lands testing will try 0.010".

You’d be starting over Hornady’s max just below Hodgdon’s. Ive load developed about two dozen creeds and not one of them ended up above 41 gr with lapua and 147’s.

 

[salks]

please write back with your results and good luck .

Not bad. 142 SMK -.050 5shots. Got an ES10 SD5. I will try em at distance next see how they hold up.