OCW, Ladder Test, a Combination of the 2 or Something Else?

[HogsLife]

Curious as to what everyone’s preference is. I’ve always done OCW, but after listening to a lot of the comments regarding OCW and Ladder Testing consistency / repeatability, I may give Brian’s Litz’s method of finding max pressure then backing it down 1-1.5 gns and moving on with searing depth. By max pressure I mean “signs of pressure”

 

[nn8734]

I like to do an OCW when I’m not as familiar with the cartridge or components (I did a full OCW last for my 300 Norma, which was the first time I’ve loaded for that cartridge).

When I have some experience, I pick a couple charge weights close to where I expect pressure to be and start my testing with them via one five shot group per charge weight. Example: 5.56 nato /77smks and TAC usually yields best performance in ARs between 24.2-24.7g so I’d pick 24.3 and 24.6, measure MVs and look for pressure signs). I’d pick the highest charge with no pressure for further development.

 

[supercorndogs]

I like to run an OCW when its not a well known combo, or with something like Varget that varies a lot, from lot to lot. Usually if I can find quite a bit of load data, i will load up a smaller test around what someone else has determined is the node, and see where the POI changes are relative to the charge.

You can run a pretty decent OCW test with 30 rounds, and identify a couple areas that are probably the best areas to load in.

At the same time, a good rifle will shoot a decent load, pretty well.

 

[CK1.0]

Seating depth matters, everything else is a Rorschach test.

There’s no rule that says you have to run it up just below max either: it’s ok to trade some “ballistic potential“ for more barrel life and less recoil if you feel like it.

 

[HogsLife]

Seating depth matters, everything else is a Rorschach test.

There’s no rule that says you have to run it up just below max either: it’s ok to trade some “ballistic potential“ for more barrel life and less recoil if you feel like it.

What is this “more barrel life” you speak of?

 

[spife7980]

I do ocw only I do it at 500 yards so I went with the combo option.

 

[Wheres-Waldo]

I do a ladder test to find a target velocity... something within 10-20 FPS of the barrel it replaced.

After finding a charge I’ll dick around with seating depth for a bit, but as long as it’s less than 1/2 MOA, I’ll choose a depth that shoots well for the next .010 - .015 worth of jump and forget about load development until the next barrel.

 

[CK1.0]

What is this “more barrel life” you speak of?

Less pressure = less wear, simple as that. A "small 6" and a "big 6" shoot the same exact .243 projectiles down steel tubes in the same way, but the one that does it with less pressure lasts longer.

IMHO case-fill is usually the "X factor" though: some powders work fine with less case-fill, many don't. So sometimes it isn't as easy as just using less grains, sometimes it is. YMMV.