how much should a cast bullet weight vary

[delt167502]

I just bought a lee mold (457-340) cast about 100, size, ok .They look good, but the weight varys from 336 to 348gr. what should I expect as to the weight deviation. this seems like a lot .if anyone can help,thanks (cleaned & prepped the mold as required) casting ww that I melted and cleaned properly.

[Richard P]

  A 12 grain spread on weight is a lot.  Have you set them out and weighed to get the distribution ?  I'd expect not more thal 2 grains for most moulds; sometimes less.  Is it a two cavity and have you segregated bullets from each while casting ?  You can put a small punch mark (or a file mark) in the nose of one cavity so when you have cooled bullets you can identify and sort them.  Keep it small, just enough to feel it.
   W W in the past have run about 6% heavier than the nominal weight if the mould was regulated for linotype.  If that held true your bullet should weigh 20gr over nominal or about 360gr. Still, 12gr seems like too much variation.   If they are filled out and visibly good, see how they shoot ?     RP

[delt167502]

Yes i always seprate the cavities on a new mold ,they both seem to vary,about the same.

[bubba.50]

with soft lead and my lee drip-o-matic on high the bullets from my lee 340gr mold weigh 341gr +/- less than a grain. don't know if this is typical or not, just what mine does. good luck solving your mold problem and happy shootin' neighbor, bubba.

[Lloyd Smale]

that is a pretty big spread. You probably wont notice much differce at 25 yards but it may effect accuracy out at a 100. One suggestion to you is lee molds like being cast real hot. If your bullets arent frosted looking your probably casting to slow or with your pot turned down a bit to much. I cast a lee mold hot and fast enough that its just on the verge of smearing lead when opening the spruce plate.

[Graybeard]

Adding the two weights and dividing by two you get an average weight of 342 grains. Your high and low is then only 6 grains plus or minus from the average. That works out to plus and minus 1.75% from the mean average.

Anyone who thinks that's gonna be a big deal for anything other than long range target shooting is still kidding themselves about cast bullet shooting. Inside 100 yards it will not show up on the target at all.

I've been thru this before and done the on target testing with three batches. Batch one say were those that looked perfect and weights were plus or minus one half of one percent. Batch two looked very good but weights varied by even more than your 1.75% plus and minus. Batch three looked horrible and weights were all over the place.

Batch three actually outshot the other two by a small margin. It was then that my shooting partner and best friend Billy Doss said we weren't ever again gonna throw away a bullet after we cast it and he'd shoot any I didn't want. His scores never dropped as a result and he  still won hundreds of matches with them same as I did. When the two of us showed up at a match one of us almost always was the winner and as often as not the other took second place.

Now if you were shooting the NRA long range BPCR matches I'd say you'd want them a bit closer but for any shooting you are likely to do they will be fine. As you get more practice casting bullets and get your technique worked out the variance will go down but as it is at that bullet weight that's not bad, not bad at all. Let the naysayers waste their time remelting their bullets, you go shoot yours and then tell us what the groups look like.

[huntducks]

As far as shooting them it's not a problem.

Is this before sizing? if so one of the cavities is a wee bit bigger. I  have a few lee molds and a 6 cav. one is any where from -2 to + 10 in weight, I also have a H&G 10 Cav. 150gr WC mold and all 10 cavs are with in 2grs coming out of the mold you kind of get what you pay for but I still think lee molds are a great buy.

Just to throw this in I wish RCBS would make 4 cav. molds as the ones I have throw great looking bullets and are right there weight wise with both cavs.

[jhalcott]

 That variance in weight SOUNDS like inconsistent casting technique. Squeezing the handles to hard for one cast and not hard enough the next cast. Also the cadence of casting is important. Don't let the mold get to cold between fills. I've noticed that the first few bullets after I add ingots to the pot are a bit smaller/lighter than when the melt is at the correct temperature. A thermometer is REAL handy to know when the melt is right. Practice will improve your castings.

[HL]

From experience with .429 cast bullets and .459 cast bullets, I totally agree with GB's statement above.

I have taken bullets that cast 10grs different, and with .459 bullets, you could not see a difference in impact at 100yds, with all other things being same.

[Lloyd Smale]

problem is with a blanket statement like that is theres to many variables. I too have seen bullets with visable flaws shoot extreamly well. But then if a bullet has a void in it and its off center and thats where your 10 grains of weight differnce is comming from you groups are going to open up substantialy at a 100 yards. Ive notice differences in group sizes caused just by gas checks flying off at differnt ranges.

From experience with .429 cast bullets and .459 cast bullets, I totally agree with GB's statement above.

I have taken bullets that cast 10grs different, and with .459 bullets, you could not see a difference in impact at 100yds, with all other things being same.

[delt167502]

thanks everyone.I loaded 10 rds with a weight variance of + - 1gr.using H 4198 they 1n a 2in. group at 100yd. then I loaded loaded 10 rds. with a weight variance of 10gr.using the same load 9 of the 10 into a 2'' group with 1 flyer. the flyer was the last rd.  By that time I was becoming gun shy,Ithink it was me not the rd,     thanks again.  may your groups be small,and the game be dead.

[Tommyt]

Well this is a good Post for me
 I am New to Casting and have one lee mold for 357 and one for my 45 colt
I cast about 300 45's and they varied 1 to 10 grain the 357 was only a few 1 to 5 grns off
 I loaded all the 45's and shot half of them with no Problem and about 300 of
the 357 fired same thing all went where I pointed I didn't notice any felt recoil or anything else
with the 45's but I had that weight difference on my mind every time I squeezed the trigger
 But why this post is good for me is,Yes I am all over the Place with Heat in my mold and pot
I am using a Turkey fryer and a cast Iron Pot and Ladle
The other day I ordered a Lee Production Pot Four Furnace in hopes that it will
keep me in Rhythm settle the weight Drifting

Tommyt

[jsh]

Interesting thread.
I expect no less from a CB than i would from a FLGC. Maybe I set my standards a bit high, though why would anyone settle for less. I think most all folks that are into casting still look for clover leaf to one hole groups.
The above mentioned spread leaves out a lot of details. I for one suspect temp and casting speed to be irregular. A good friend of mine has been casting for a fair amount of time and just can't seem to get into a rythem. His 535 Postell 45's were spread all over the place like a 20 grain spread. I fired up his pot, got the mold heated up tossed the first 5-8 throws out as culls, then went at it. He commented that I was going way faster than he did. I cast about 300 for him and we weighed a dozen or so and they were within my acceptable range.
This particular gent and another friend of mine are both leftys. They have both had issues with inconsistant fill, i think due to the fact that thay are switching hands to cut the sprue, then switching back to pour. it is a hard habit to break, ut they are both casting right handed other than one of them had a sprue plate and a mold modified for their left hand. Sounds goofy I know. But, they were setting the blocks down inbetween switching hands, then possibly not getting a consistant grip on the handles when pouring. It just threw a couple of more variables into the wash.
jeff

[ND Sharpshooter]

I don't understand how being left handed causes your buddies to do things the way they do.  I'm a lefty with limited use of my right hand and have no trouble at all with casting up consistant cb's.  Hold the mould in the left hand and run everything else with the right.  My limited ability with my right hand led me to use bottom pour pots because I cannot hold either mould or dipper in my right.  If your buddies are not using bottom pour pots, perhaps they should consider doing so.  I have 4 different bottom pourers and all of them work well. 

[454Puma]

I think the max I have ever gotten was +/-2 gr on varrance on all my molds and I cast for 6 diferent calibers all Lee mold 2 cavities!     I agree good consistant handle pressure makes alot of difference. 

[jsh]

I don't understand how being left handed causes your buddies to do things the way they do.  I'm a lefty with limited use of my right hand and have no trouble at all with casting up consistant cb's.  Hold the mould in the left hand and run everything else with the right.  My limited ability with my right hand led me to use bottom pour pots because I cannot hold either mould or dipper in my right.  If your buddies are not using bottom pour pots, perhaps they should consider doing so.  I have 4 different bottom pourers and all of them work well. 

They are (were) holding the mold with their right hand. Then switching to the left in order to use the right to cut the sprue. I have seen one of them twist his wrist and whack the sprue plate, with the mold upside down. He was dropping sprues and bullets into the same pile. Then he had to sort the mess out.
One of them had a mold or two modified for the sprue plate to swing from the opposite side.
 They are both using bottom pour pots.
All of the molds I have, I consider to be right handed. They are designed to be held in the left hand and a lot of the motions to come from the right hand. Or at least that is the way I do it.
I hold the mold in the left hand, slip under the pot, pour, cool the sprue for a second. Cut the sprue and drop it into one pile and the bullets into whatever, water or a pile for air cooled. Actually takes me longer to type it than it does to do it.

As to weights and back on subject.
A consistant rythem and temp seems to help a lot for me.
I run my pot down to about half or there abouts when I add more alloy. It takes less time to get the pot back up to casting temp. I also have my ingots setting on an old hot plat so they are not room temp and "kill" the pot even more. Even this way I wait at least 10 minutes or more for the pot to reheat.
No my molds don't cool off enough to bother much, as I set them on the hot plate. It will keep them right at about 300ish when covered with and old loaf pan. I have heard some say this will warp a mold. I have been doing this for about 4 years with a variety of molds with no ill effects. It is a lot different than sticking a torch to it or dunking in the pot, neither of which I do.
Even after setting on the hot plate, I still throw 4-6 times to get the mold back up to temp, I consider all of these to be culls.
I may have a few or a lot more steps than some, but, it works for me. Proof is on the paper and targets.
jeff