Differences in velocity

[DizzyJ]

Maybe I'm blaming the Magnetospeed for something that doesn't exist then. The groups I was laying down while testing were way larger than I typically see, even during load development. The chrono is new so I've just started playing with it. Just makes sense in my head that it would cause additional whip from a lightweight hunting barrel profile.. Further testing will decide that. I'm going to take the load that gave me the best es and SD and test it w/o the chrono to see if they're any different.

Also, when playing with oacl, how big or small of changes should I be making? .005, 010? Not really sure what incriments to make my adjustments in.

I did make a device for my ar10 that attaches it to the mlok rail to get it off the barrel although that's because it shifted once and I shot the tip of it. Oops.

I generally go .005" difference when testing seating depth. Not necessarily right or wrong, but I have seen differences in that small of an increment that I may have missed had I gone .010" per step.

 

[Grimm]

I generally go .005" difference when testing seating depth. Not necessarily right or wrong, but I have seen differences in that small of an increment that I may have missed had I gone .010" per step.

Thanks for the advice!

 

[BigGame]

For hunting loads I usually test seating depth in advance of a charge test in increments of 0.010. I use the best one during my charge testing. Then I may go back and test 0.005 or smaller increments with my chosen charge.

DizzyJ's comment that 0.010 increments could skip over a good node is a risk.

 

[oremike]

I tend to load to "good enough". For my for my cheap Savage package rifle 30-06 I Picked the Hornady 180gr RN and seated it to the magazine length. It was convenient that that put the cantilure in the right place to act as a crimp groove. I then picked W-760 powder because I've had good luck with it in other heavy bullet 30-06 loads. After a couple trips to the range I had this rifles load shoot a tight 1" group at 100 yds shot off a bench. Honestly a chronograph is a newish tool for me. For 30 years or so a "good enough" load was good enough for me.

 

[Spitpatch]

"Seating the bullets deeper MAY increase pressure or it MAY decrease it. Depends on how close to, or possibly "jammed" the bullet was to begin with. If the bullet was touching, close to touching or jammed, then setting the bullets deeper will probably lessen the pressure. And of course vice versa."

There is the proper re-phrasing. Setting aside any engagement of the bullet with the rifling, deeper seating increases pressure by reducing combustion chamber volume. Pressure is reduced by shallower seating until the point where the bullet engages or is very close to engaging rifling: pressures at that point increase and can be erratic and unpredictable, particularly with a "top-end" load.

 

[No_Regerts]

One thing about loading long is I've found the magazine length sets the OAL rather than the distance off the lands. I load to hunt so want to use the magazine rather that target shooting as a single shot.

Or buy a rifle without a neutered magazine box.