Is Dan Newberry still hanging out on this site, or would anybody else who has used his OCW method care to comment??

I have been attracted to the OCW load development method, sounds promising and sensible to me - to the point that it is worth trying out at least once. Assume you have done your OCW push-ups for one cartridge/powder/bullet/case/primer combination. How much is that OCW test going to tell you about the possible "sweet spot" (my term, can't remember what the proper technical term is?) if you switch from bullet A to bullet B - assuming you keep every other parameter constant, in particular bullet weight??

On his website, Dan points out how he can use the OCW test, and expect to find much the same sweet spot if he changes cases and primers - a function of having a pressure "resistent" load. But what if he kept everything (powder, case, primer) the same, and went from one 55grs bullet to another (for .223 Rem load development, say)??

And what if one was to hop from 55grs to 60 grs, say?? Obviously, one has to be aware of pressure issues. I.e. the load that produced safe pressures with bullet A may no longer be safe with bullet B, even if bullet weight stayed constant.
- mike

mho,

I have used the OCW Method to develop several loads for different rifles. I have found this method to work well for putting me in close to where I need to do the final tweaking.

It has also been my experience that the component that has the most dramatic affect on accuracy is the bullet.

Switching bullets in one of my rifles (a Ruger .22-250) makes little difference, although there is an optimum combination. So with that data point, I would say your switching to a same weight bullet would make little difference.

Well�.

Along comes a Mdl 70 in .300WinMag. Now this rifle shoots OK not great. 180gr Sierra and Nosler bullets can be made to shoot almost the same at about 1 �� at 100yds. Put a 180gr Hornady bullets in it and you can�t hit an 8 � x 11 sheet of paper consistently at 100 yds from the bench. Don�t know why, it just happens that way. It is so bad that I thought I got a bad batch of bullets. New box different lot # same results.

All of my other rifles fit between these two, most are at the redo end of the scale. I have found as a general rule that when I switch bullets it is best to rework the OCW process to find what shoots best.

Best of luck and Kind regards
Carl

I had a similar experience. When I use similar powders it doesn't change much. When I did my load for my Swedes Dan predicted that I would use XX.Xgr (can't remember right now) for a 139gr bullet. I ended up liking about /2 gr more in each gun, but I was using 140gr bullets. Made a little difference I guess. I haven't tried a powder with a much different burn rate, why would I?

Also, I can change between Nosler and Sierra in any Swede and not change anything, but when I load a Hornady 140gr there is no saying where it will hit.

These loads are very resilient to various cases also. I shot 3 different brands of cases and never had a change in POI.

If your looking to ask Dan a question he is on Snipers Hide forum as Green 778 same as it was over here. Hope this helps

Thanks for the input guys, much appreciated. Maybe I can dig up Dan at Snipers Hide as well?? Thanks for the pointer.
- mike

Just in case anybody else might be interested in this subject, I actually managed to locate Dan Newberry over on Sniper's Hide - as suggested above. Dan was kind enough to provide the following answer:

Quote:

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You should be able to go from one bullet to another so long as they are of the same weight--or at least very close. LTR's experience with the 175 SMK and the 178 AMAX is one example, and another is the .243 win using 58 VMAX's or 60 grain Sierra HP's--same 39.8 grain 3031 charge does the trick.

The key will be bearing surface. So long as the bullets have equal bearing surfaces (about the same amount of jacket touching the lands) and equal weights then you'll be likely to find that the OCW is the same.

One possible foiler would be engraving resistance--or the hardness of the jacket. With some bullets you might find that a harder surface will cause more pressure which will alter barrel time. This really shouldn't be enough of a factor to worry about, but it could explain why the recipe is "liking" one bullet better than the other (for instance you'll see some folks mention that their rifle shoots 168 grain Nosler J4's better than 168 SMK's or vice versa).

This all said,

Work up from starting charges every time you change bullets or brass case types--there's too much at stake here to do otherwise. Back at least half way down if you're going to change primers. I'm sure that was your intention; it's just that many inexperienced lurkers here might decide to skip the work up and end up having problems...

Dan

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- mike