? About OCW test

[dustinoif3]

I've been reading into ladder tests and OCW tests. I can see why a round robin test works well but the question I have is how many targets do you set up and how many rounds do I load? Lets say I have 10 different charges at .3gr increments so do I load 3 of each charge weight for a total of 30? I may be getting both tests mixed together in my head. Any help would be appreciated.

 

[roggom]

Few things: what are you shooting, what are your goals. Which bullet, powder, case.

10 loads x.3 is fine, but you will probably find two accuracy nodes in your spread about a grain apart. If you will be shooting close distance, there is no need to hit the highest node, as you will just reduce case life.

For instance, many guys shoot 308, and a 178 amax over some varget. There are two poplular nodes around 44.4 and 43.5. At 44.4 you will get decent groups, a bit more velocity and downrange energy. The trade-off is case life. If shooting 500, then focus toward the lower node. There is no need to run the whole gambit of loads if you will choose the lower anyway.

So back to your original question.. I use a common sighting target and shoot 5 rounds of each in a round robin, this is because sometimes I pull a shot and its easier to x that one out and still get a good group from 4 shots, than 2. If you plan to shoot all 10 loads, do five and then give your rifle a rest (cool down).


Also if you cleaned your rifle beforehand, have enough rounds to foul the barrel first.

 

[dustinoif3]

Few things: what are you shooting, what are your goals. Which bullet, powder, case.

10 loads x.3 is fine, but you will probably find two accuracy nodes in your spread about a grain apart. If you will be shooting close distance, there is no need to hit the highest node, as you will just reduce case life.

For instance, many guys shoot 308, and a 178 amax over some varget. There are two poplular nodes around 44.4 and 43.5. At 44.4 you will get decent groups, a bit more velocity and downrange energy. The trade-off is case life. If shooting 500, then focus toward the lower node. There is no need to run the whole gambit of loads if you will choose the lower anyway.

So back to your original question.. I use a common sighting target and shoot 5 rounds of each in a round robin, this is because sometimes I pull a shot and its easier to x that one out and still get a good group from 4 shots, than 2. If you plan to shoot all 10 loads, do five and then give your rifle a rest (cool down).


Also if you cleaned your rifle beforehand, have enough rounds to foul the barrel first.

My goal is to have a load that is consistently sub-moa at any given range? Could be a pipe dream. My usual load development is 5 rounds of a given charge from low to high till I obtain the tightest group at 100y. The last couple days I've been reading both the ladder and ocw methods. Both have good points and the science behind it makes me want to try one of them. I do have access to 300y yards so I think I'll try the ladder then bounce my original recipe against it.

My current components are:
168gr amax
Cfe 223
Black hills match brass
Cci primers

Rifle
Sps tactical currently in the shop getting a McMillan A5 installed hopefully in the next two days, glass bedded and trigger job.

Im using my down time to try some new things. Also to keep me on the bench loading instead of crying myself to sleep every night because the rifle has been down for two weeks. Hahaha

 

[shoot4fun]

Here is how I usually do it. I look at professionally posted load data for the cartridge/bullet/powder combo I want. Let's say it is 25 grains. I will back off that by 2% and then 4% and then over that by 2% and 4%. You should have five sets of loads and load three of each. Load some foulers and a few to confirm POA. Then conduct your test per Newberry's instructions. I take a cardboard IDPA target and place 2" round dots on it for my test loads, foulers and sighters. You should see a node. Redo the test within that node but with tighter variations than the original 2%. Once you see a satisfactory node then test for best accuracy by using varying seating depths.

 

[Bob 964]

Just follow Dan Newberry's instructions.

http://optimalchargeweight.embarqspace.com/#/ocw-instructions/4529817134

 

[dustinoif3]

Thanks for the input guys. After reading your posts and reading newberrys instructions I believe it's making more sense