OCW Load Development?

[StoneHorse]

So I have come across this website called Dan Newberry's Optimal Charge Weight Load Development or OCW for short. After reading through the website once, it seems to make a lot of sense. My question is, has anyone tried out Newberry's method of load development and does it work as stated?
Cheers.

http://www.ocwreloading.com/

 

[Pr589]

It works really well with some rifles and is hard to interpret with others. My experience is that it works best with relatively accurate rifles (~ 0.5 MOA shooters) and less so with rifles that group poorly. Tried it with an M1A at 300 yards but it was very hard to see meaningful patterns as the load increased. On the other hand, my target bolt action showed a regular vertical increase in POI with increasing powder loads until a nice little group started to form.

Longer ranges work better.

 

[StoneHorse]

It works really well with some rifles and is hard to interpret with others. My experience is that it works best with relatively accurate rifles (~ 0.5 MOA shooters) and less so with rifles that group poorly. Tried it with an M1A at 300 yards but it was very hard to see meaningful patterns as the load increased. On the other hand, my target bolt action showed a regular vertical increase in POI with increasing powder loads until a nice little group started to form.

Longer ranges work better.

Thanks for the reply. I was thinking it was geared more towards purpose built target rifles rather than hunting rigs. Not to say hunting rifles with sporter barrels couldn't benefit but probably less so.

 

[sure as shootin]

I've used it to develop hunting loads, as well as practice loads with all#my hunting rifles. I think the more you do it the better you get at interpreting the results. It's hard not to go with just the best grouping sometimes but it may not be the OCW. One thing that Dan Newberry mentions is if you're not capable of shooting MOA then it's not likely a good idea to use this process. He says to get more trigger time in before attempting it.

 

[StoneHorse]

if you're not capable of shooting MOA

I'm there but wondering if I'm able to improve on that with the rifles I have.

 

[Pr589]

I'm there but wondering if I'm able to improve on that with the rifles I have.

Can't hurt to try - OCW is very economical on components. The further out you go the easier it will likely be to see a pattern. I think this was why I wasn't having luck with my M1A since it groups reliably about 1.5 MOA at 100 yards. Given this, at 300 yards, a 4" to 5" pattern would be normal while moving up the load from start load to max would only increase velocity by a few hundred fps - resulting in a vertical dispersion of only 6" to 8". So the normal scatter of shots could easily mask any results from the load test.

My thinking is that to make sense of OCW results, you need to maximize the vertical dispersion of shots from the load test versus the "noise" from the group variation in a particular rifle. The best way to do this would be to test at longer ranges where the velocity changes due to load really start to vertically "string" your shots. If this is right, the reverse would be true as well - a tighter shooting rifle could OCW at shorter ranges.

 

[dusticles]

Thanks for the reply. I was thinking it was geared more towards purpose built target rifles rather than hunting rigs. Not to say hunting rifles with sporter barrels couldn't benefit but probably less so.

Every rifle could benefit from it. The main focus of OCW is to give the reloader the most consistent accuracy versus the most accurate group. If there is no difference in how your loosie goosie semi auto reacts to the different loadings, you have undoubtedly found your optimal charge weight right in the middle, tweak from there!

The benefit of testing hunting rounds this way is that you will end up with a load that is temperature stable and give your powder scale a little wiggle room.

I prefer to test this way so that I know I can rush 200 rounds of 260 in an evening and the .3 grain difference will still be a centered, 1/2 MOA group.

 

[notsorichguy]

I recently rebarreled my .243 AI.

I had 3 projectile choices and 2 powder choices.

I did an OCW test at 600y.
One projectile was out of the running after 10 rounds fired.
The other two projectiles showed good promise with both powders at 600. With at least 3 rounds impacting with-in 1.5" vertically and 3" L-to-R.

Shot a quick ladder at 200y to finalize a load.

All in 97 rounds fired (20 from break-in) and I have 2 .5 MOA loads accurate out to 600y (as far as I have tested).

I'm not sure I'd bother with the effort for a "hunting rifle" that won't get shot much past 3-400y.....

 

[xtremacanuck]

Thanks for posting this. I had never heard of this way of load testing. It was a good read, and something I will try for sure, as I have a box of 500 Matchkings my rifle seems to not like. Shooting the groups in this fashion and interpreting the results the way it indicates may start me down the right path.

It may take me a month or more (having a family will do that to a guy), but I'll make an effort to post my results.

 

[Baribal]

I use this method since years and my experience is that when it works, it often works for several rifles (of the same calber of course) and makes developing loads for multiple rifles much easier (faster),

 

[BCBRAD]

Ya, OCW does beget you a load that is 'variable' tolerant. These variables include but are not limited to charge weight, seating depths, ambient temperatures etc.

As others have mentioned OCW will get you a consistent load.

I use this concept in conjunction with a LabRadar and Quickload. The QL program demands accurate velocities to input.

Powder burn rate is dependent on pressure.

H-4350 has different burn characteristics at 50K compared to 60K. Maybe too fast or slow for the components used.

What your looking for in an accurate / tolerant load is one that has optimum burn rate and one that is on a barrel node.

The two a fore mentioned tools will get you there.

If it doesn't shoot then look at your platform before expending rounds with limited result.

 

[StoneHorse]

Informative responses, thanks. I'm going to the range today and put into practice what I have learned about OCW load development.

 

[RonR]

Tagged.

 

[StoneHorse]

Okay, after my range trip and interpreting the results, OCW works as advertised. Either that I lucked out on my bullet, OAL, case, powder, primer combination my first time out. I certainly will be experimenting much more with OCW load development. It was interesting seeing groups developing on the targets and the final results. The groping on the lower powder charges were meh and continued that way with increasing powder changes until, holy crap, I had two loads that shrank down to 0.58" . I didn't expect anything that dramatic.

This is a hunting rig with a sporter weight barrel folks, not a target rifle. After those two wonderful groupings, the next load up started to open up again. I didn't have any pressure signs with my top loads so I may have some room at or very near maximum loading in the book. Maybe I can get top velocity and accuracy. If anyone is interested in OCW load development, check out the link in the first post and read carefully, following instructions to the letter. Oh, take your time at the range.

One thing I already knew about my rifle, the difference in point of impact between a clean barrel and a fouled barrel is substantial. I need to fire five fouling shots before the barrel 'settles down'. Then wait for the barrel to cool down before shooting again. YMMV.

 

[Baribal]

Actually, even with a good jump, I most always have good results with the OCW theory. The OAL itself is part of the OCW and if you change your lenght and or powder load, you may end up with something that doeasn't work so well... Measuring average internal case volume helps a lot in the results constance (either with a case full of ball powder or with water (weight).