Can't find the answer I need

[tjndaltx]

I'm sure the answer to my question is on this site but the site is so comprehensive I just didn't know where to look.

I've been around for awhile but never really sunk my teeth into casting boolits. Well, I'm getting ready to do that and I have a question.

I've purchased several molds from Lee, RCBS and Lyman and obviously want to use them. The only problem is I cannot find load data for any of them. I have the Lyman Reloading manual and the Lee Modern Reloading Second Edition but I can't find the load for my molds anywhere. So how do you know where to start to make up a load?

Can you use jacketed load data for a cast boolit (reducing the amount of powder by maybe 10%?)? Is that safe?

Can you use load data that is just close to the dimensions of your mold? For instance using 160 grain data for a 165 grain mold? or the reverse?

I would assume it is unsafe to substitute powders so don't intend to do that.

I would appreciate some answers to the questions above if you don't mind.

Thank you.

tjndaltx

[PS Paul]

I can answer two of your questions. First, substituting a boolit that is a bit LIGHTER (160 gr. for 165 gr., as you posted) is normally just fine. Substituting a HEAVIER boolit (170 gr. for 160 gr. data) is generally NOT alright and can be dangerous if you are loading at or near maximum.

Substituting powders is generally NOT alright and can be lethal, in some cases. There are recent changes to some powders with mergers/acquisitions of companies. H110 is now equivalent to 296 and 231 is now equivalent to HP38 are just two examples. naturally, using caution is always recommended.....

On the subject of using jacketed data for cast boolits: Although I often do it, there are some who think it is not prudent. A good rule of thumb, as you mentioned, is a 10% DECREASE in the powder charge when substituting a cast boolit for a jacketed bullet. I would just bet there are some on this forum who do substitute jacketed for cast data, but there are probably some who would flame me for posting such a thing, so I MUST post a disclaimer along with this: this is MY opinion and YOUR safety is up to YOU. In doubt, always refer to manufacturer's updated manuals when reloading ANY cartridges.

So when doing this, it depends on the alloy, the boolit design and the relative "burning speed" of the powder being used. As an example, I find it safe to sub a cast boolit with a light charge of fast-burning powder with slow to moderate target-type loads.

When loading heavy, slow-burning charges of powder with heavy jacketed bullets, I do not immediately presume I can substitute the same charge with the same cast boolit. THIS is when it becomes more tricky...... If I am shooting a cast boolit with a GAS CHECK, I substitute the cast for jacketed in heavy loads with an "ever-so-slight" reduction in powder as a starting point. It becomes tricky when using powders like H110 or 296 which REQUIRE full or near-full case capacity with the powder. So to use data interchangeably and safely, you cannot download these types of powders too much.

I hope this makes some sense? I have reloaded and cast for nearly 30 years and in my youth, with STRONG REVOLVERS, I commonly and frequently substituted heavy cast boolits for jacketed bullets in heavy magnum-type loads grain for grain! As I have learned more with age and experience, I am very careful about working up to full-house loads, but the appeal of shooting TONS of full-house loads is nowhere near what it was in my teens and twenties.

Paul

[tjndaltx]

Excellent answer. Thank you very much.

[41 mag fan]

Paul answered that one very well. I'll substitute jacketed data for lead, but as with Paul, take this on your own risk.
I don't reduce my loads, but I do start at the minimum, and work up. I'll go 1 gr at a time, looking for pressure signs.
Using lead PB, depending on caliber and powder, I'll normally stay to with 1/2 to 3/4 of what the manual lists as max loading.
With a GC I will go to within 1 or 2 gr of max load, but am very vigilante on looking for pressure signs or anything out of the ordinary.
I see or find anything that's not right or just doesn't sit right with me, I'll back off a couple of grains if possible.

[PS Paul]

As an add-on to this, very recently I had an experience with a 150 gr. RCBS Keith-type SWC I cast and used in .357 mag. I loaded it on top of a mag primer and a charge of Accurate #9. I loaded above the normal starting load (I don't use #9 a lot.....), but was two grains below maximum from my data source.

It was a cool day and recoil/flash/bang were not out of the ordinary, but case extraction was sticky and I took that as an immediate sign of higher-than-normal pressure, considering most all my cases otherwise drop right out with little or no sticking in my Security Six. I do not use that same combination any longer and according to the data, this was not a max load? Odd, but just goes to show that every load/gun combination is a law unto itself.

[Three-Fifty-Seven]

. have!

[hanover67]

You might try the powder manufacturer's websites for info. They list many load combinations for different weight bullets. Barring that, you might try buying old loading manuals on Ebay, for example Lyman #43 published in 1964. You didn't mention what caliber or bullet weights your molds use, or what kind of gun you use, but most common calibers are listed somewhere. When I started reloading in 1983 I also started building a library of reloading manuals and information. Now that I am also casting I've expanded that to casting books and information. i don't load anything exotic and I've had no trouble finding more than enough data to stay safe and produce accurate loads. Finally, Cast Boolits members are a great source of help. Just ask.