Bullet weight?does gascxheck/lube count?

Sorry if this is a stupid question. I just bought some cast boolits from a commercial source. The vendor says the mold he used lists bullets as "264gr but once lube and gas checks aare added they are 275 gr" When I look up load data for these boolits should I be looking up losds for 264gr or 275gr or?

I note that in this forum some people note bullet weight with gas check. Is there some accepted format for referring to boolit weight? as cast?> as cast+gas check?as cast +lube and gas check?

thanks!

I would look for loads with weight stated at 275 grain to 300 grains. Load data for heavier boolits is safe for lighter boolits. No so the other way around. Most refer to "as cast" as no check or lube. But honestly, 265 grains to 275 grains, the percentage of weight is only 3.5%. As long as you're not going for top end loads I think you'll find the powder charges to be extremely similar.

Technically speaking, the entire weight is what you are pushing down the barrel so that is the weight you should consider your bullet to have. But if you take this too literally it will drive you crazy because you will always end up with oddball bullet weights that are never going to appear in loading manuals. The way to handle that is to select loads for the closest bullet that is heavier unless your cast bullet is just barely heavier than a standard weight that is in the load manuals. You will also have some room for error as long as you aren't trying for maximum pressure loads.

My understanding is the weight listed for a mold is how much the boolit weighs when dropped
and using a specific alloy like Lyman #2.

For example:
I shoot a 405FP in my .45-70, but with my alloy and lube it's more like 425gr.
If you're not loading right up to the edge of safety,
those few percent extra weight is not that big of a concern.

I think you need to install gas checks, lube and weigh a sample. I usually do this with 5-10 and use the average to develop loads for that lot of bullets. I've always experienced a slight variation in cast bullet weights from what is listed depending on alloy, type of lube and gas check material. The higher the lead content in the alloy, the heavier the bullet will be (not a factor in your case with commercial cast bullets). Bullets lubed with Lee Liquid Alox will weigh less than when lubed with heavier wax lube that completely fills the grease grooves, and there's a miniscule weight difference between copper, aluminum and zinc gas checks.

Lyman provides the following in their mold descriptions: "Variations between listed nominal weights and actual as-cast weights have absolutely no effect on accuracy." Sometimes Lyman/Ideal used to note the "as cast" weights were applicable for a specific alloy, usually Lyman #2.

As for your question, I don't believe there is a reliable accepted and precisely accurate standard you can use across all cast bullet or mold manufacturers. Most will probably list the "nominal" as cast weight as the bullets come out of the molds, without lube or checks. Usually there is only a few grains difference that doesn't matter much. Sometimes it could make a difference in load development, depending on the naked versus lubed and checked bullet weights. In your case, 11 grains is a significant variation, if the manufacturer is correct. The largest variations I've experienced is the RCBS 45-405 FN that went up to nearly 420 gr, or molds from one now defunct mold maker that ran more than 30 grains heavier than listed.

Before you begin load development, you need to establish an accurate average "as loaded" bullet weight and look for published (and pressure tested, if available) load data as close to your as loaded weights will be. For me, a few grains (<5 or so) under or over is close enough to start load development with less than maximum listed loads. When in doubt, go with starting load data for listed bullet weights heavier than what you're going to load.

Quote:

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Originally Posted by 35 Rem

Technically speaking, the entire weight is what you are pushing down the barrel so that is the weight you should consider your bullet to have. But if you take this too literally it will drive you crazy because you will always end up with oddball bullet weights that are never going to appear in loading manuals. The way to handle that is to select loads for the closest bullet that is heavier unless your cast bullet is just barely heavier than a standard weight that is in the load manuals. You will also have some room for error as long as you aren't trying for maximum pressure loads.

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Thanks for the good advice. I tend to never push toward max loads in all my reloading . With the shortage of primers I am trying to restrain myself for trying so many loads in load development so I scour information sources for first hand experiences in reload data (I compare individuals recommended loads and published data and never exceed or even approach max published loads). I am surprised by how much personal experience loads are max or over max.I like my eyes, fingers and firearms , so I ignore the swashbucklers:-D

Some things can't be "exact" ... the boolit alloy will affect weight , lubing and gas check will affect weight ....
You have to use data for what you have data for ... I use the data in the Lyman Cast Bullet Handbooks and RCBS Cast Bullet Handbook for a bullet the design I'm using reguardless of what it weighs after I've cast , sized , lubricated and gas checked it ...
If I can't find data on a particular design , I will weigh it as cast and find the nearest match and use that data ...
My rule #1 is never exceed book Maximum Loads ... I start low and work up slowly
...and never forget rule #1 .
Gary

I have always taken an average of my final boolit configuration weights...then load for that weight. If it weighs more with a GC or lube or PC...it's part of the final weight of the boolit. Load for that number.

redhawk

More often than not there is no advertised data for the exact cast Bullets we load. That is not a problem if we stick to basics. Weigh what you are loading. Regardless of what numbers are on a mold, the bullet weighs what the scale says. Find data for a bullet that is similar in design and weighs the same or is slightly heavier. Changing alloy from what a mold is cut for alters the weight. Altering the weight alters pressure. More or less bearing surface alters pressure. So stick to the basics and you will be fine. Start low and work up watching for pressure signs and looking for accuracy. The start low and work up part is the most important of the basics I referred to.. Scouring others loads is a real crap shoot! Every firearm is rule unto itself. Doing your own thing working up the best load for the components you have is the way, if you want to have loads that shoot good.
Willie

I use the value associated with the mold.

look at the heavier weigth for the powder charges
check, lube and boolit should be considered

I consider the weights listed by the mold mfg to be an estimate. Change in alloy, casting temp, mold temp all affect the final bullet weight.

If a bullet design includes a gas check heel then the mfg suggested weight is with a gas check. If you use a gas check and lube then the 'projectile' weight includes both of those. If you use wads then those are also part of the projectile weight for the purpose of determining chamber pressure.