Mould not dropping correct weight

[firewalkerd1]

The more I read the more confused I get. When purchasing a boolit mould how does one decide what weight to purchase? I am planning to cast .358 dia. 158gr RNFP 38 spl. I have read where a mould might drop + or - as much as 5 grs. difference. I would think this would have an effect in how much powder to charge. I understand the different lead chemistry causes the problem. How would you solve this problem or would you just take that it drops the correct 158 grs. and drop the correct powder charge for my load? This is for CAS and not paper punching as of yet. NEED HELP!!!!!

[mooman76]

You're reading into it too much! A few grains won't matter all that much. Consistancy is what you want. Every gun shoots a little different anyway and that's just another reason why you work up your loads and don't start at max. Load and shoot and have fun!

[45nut]

Agreed, don't get caught up in the minutiae when you are just looking for basically plinking loads. The 158gr RNFP has got to be one of the most forgiving projectiles to begin with and you aren't looking for something to reach out 500 yards for CAS.
The 38 spl you seek is a mild mannered critter, start at the bottom of the data charts, just make the rounds consistent.
Once you are working for target grade rifle ammo you can get into the sifting and grading, right now just remember you need to walk before you can run.

And Welcome aboard!

[shotman]

well most molds are very close to the weight listed if you use PURE lead. most dont, the more antimony the lighter the boolit. The powder is not real inportant for a 5to 10gr boolit weight change. Your gun is what you need to load for. I have a 220 sig and a colt gold cup the colt likes 5gr tite group and the sig liks 6gr with same 205gr boolit

[Bret4207]

As the other guys said, don't sweat it. Start low, work up to where you want it to be. Same thing as with ALL handloading. For CAS you'll be loading low powered pipsqueak loads anyways. Find a nice clean, cheap one that will at least penetrate the paper. What more do you need?

[Junior1942]

+ 5 to what the guys said.

[jhrosier]

All of my moulds cast lighter than the spec'd weight with the alloys that I usually use. I look at the spec'd weight as a general guideline and use loads for that weight, not the actual cast weight. This has never caused me any problem or loss of sleep. Other factors, such as as-cast hardness,seating depth, and diameter are likely to have a greater effect on the load than a one or two percent difference in weight. Working up a load from five to ten percent below maximum will give room for all of the real world variables to work their magic safely.

Jack

[montana_charlie]

well most molds are very close to the weight listed if you use PURE lead.

Lyman #2 alloy is the 'standard' used by Lyman when establishing parameters for all of their casting equipment. If they say a mould throws a 200 grain bullet, it means you can expect that weight IF you are using Lyman #2.

Unless he is just cutting a copy of someone else's design, each mould maker has some kind of alloy 'standard' in mind when estimating the weight of bullet that will be produced by a given mould. I once heard (but cannot verify) that Lee uses wheelweight alloy as their 'standard'.

In order to predict (with some accuracy) the weight of the bullet thrown by a particular mould, you must first know something about the maker...
CM

[Bob Krack]

I once heard (but cannot verify) that Lee uses wheelweight alloy as their 'standard'.

I spoke to Lee tech support and was actually able to speak to a machinist supervisor. He told me that their moulds were designed to cast within about 1-2% of documented casting weight and the alloy being used by Lee for testing and/or design purposes was 90% lead and 10% tin.

I assume with Lee being a site sponsor or supporter, we (someone here) has a line of communication with Lee? Ya know what? I would bet that a "Lee Tech Support" forum here with someone from Lee participating would save them some tech support expense in-house and would address an audience capable of supplying FAQs to reduce future Lee tech support questions. Kinda like "Dixie Slugs" answers many times to our questions.

Vic

[dwtim]

Unless there are shrink holes in the base or wrinkles (i.e. bad fill-out), I wouldn't worry about 5 grains. If each bullet I picked from the same lot was 10 grains difference from the last, then I would investigate, (barring obvious defects in one sample.) My mag shot alloy regularly drops oversize bullets that are 4 grains under. So I made faux WW alloy by mixing it with soft range scrap alloy. Those cast 8 grains over. So what? They just fine.

[docone31]

I used to be a grain counter.
Today, as long as it is close I am good.
If I have a load I am not sure of, I start with the powder charge with the next higher bullet weight.
I watch primer signs, action signs, tight bolt, mega flat primers, or craters that go into the firing pin guide.
I am in no way saying be a jerk with loading, but with lead especially, the weight spread has never been an issue with me. I get em a few grains high, low, and inbetween. I cannot tell the difference at the range.
The only time I ever got flat primers, or huge crater primers, was with jacketed. In my IMHSA days, I used compressed case loads. I saw flat primers, huge craters. On some reloads, the primers fell out of the pocket.
I have not experienced that with lead. I do not compress load lead either. Couldn't hit the berm with a compressed lead load anyway.

[missionary5155]

Lyman Specificly states their molds are designed to drop boolits of specific weight using their #2 mix. I forget what Lee says what mix their molds are "designed" to drop a marked weight at... 5 grains one way or the other (over 150 grains) just does not make a whole flip flop of difference. More important is matching boolit mix ( strength ) to velocity, desired effect on Target and boolit diameter to bore or cylinder diameter. That to me is where the real joy of casting comes alive and is beneficial.

[dukers65]

if i read this right if i got a lyman 41 mag mold 220 grs. and it drops 212
it is probably too much 50/50 solder mixed with the lead,correct,or should i be ok with the ones cast 212.

[zampilot]

Not that I have done much casting, yet, but 5 grns isnt too much for worry with that .358.
I do have some loaded BPCR ammo from a major 'house' who's 500 grn boolits actually weighed 450 or so when I pulled a couple apart........

[runfiverun]

rcbs uses the 10/90 mix and magma uses 2/6/92.
lyman the 5/5 and lee the 10/90 again.
we are using ww's or 1/3 or 1/4. hmmm ,no wonder we can't hit a given weight for a mold.
did we mention that lead/mold temp can,and does affect weight also.
and the humidity in the air.
heck, i would worry about weight variations, not what they weigh.
you are gonna load them the same. so if they are the same, you get the same results.

don't worry about it load and shoot.