I just cast over 200 Lyman 220gr. #311284 bullets. After visual inspection I still had 200 bullets left. I used a digital scale to sort the rest into piles from 211.0gr to 214.8 gr in .1 gr groups. Some groups had as little as 2 bullets and one had 42 bullets. My questions are. Should I shoot them in the .1gr groups or should I group into .3gr lots? How far can I go and still get a good group? Is 3.8 gr to much variation when casting 220gr bullets in a double mold?
Thank You
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I weigh almost all bullets I cast.
Every 2 cavity mold I've ever owned cast bullets of two different average weights. I mark the mold cavity with a tiny punch mark on the nose so I can tell the two cavities apart.Mark/no mark or front mark/rear mark. I mark cavities with a Lee decapping rod pointed end and a hammer. Less is better here.
30 caliber bullets from the same cavity will weigh +/-.3 grains. Ex: 205 gr. average, with weights varying from 204.7 gr to 205.3 gr. Variation greater than this tells you that there's something odd going on. With everything cooking right variation will be less, with most bullets +/- .2 or even .1 gr.
Does weight matter? With lots of bullets from the same cavity and variation of +/-.3 gr., I have never been able to reliably detect an accuracy difference between bullets sorted into .1 gr. sets and those mixed. Ex: Sorted sets of bullets weighing 204.7 or 204.8 or 204.9...or 205.3 vs. mixed bullets from the same cavity weighing 204.7 to 205.3 display no reliable detectable accuracy difference in rifles shooting <1” 5 shot 100 yard groups, averages of five groups. If your gun shoots, and you're happy with 2” 5 shot 100 yard five group average, weight doesn't matter if the bullest are inspected.
Why weigh? It lets me identify and re-melt the stragglers, the bullets outside the norm. Ex: With bullets from one cavity bullets weighing 205 gr. average and most +/-.3 gr., now and then there's a bullet weighing 204.2 gr. or 206.0 gr. Something is different with these, and I use these for sighters/warmups or put them back in the pot.
This is based on records of 24,628 cast and weighed bullets.
joe b.
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I agree completely with joe b. even though I haven't weighted nor keep records of 24,628 bullets, good grief! That's a lot of records. I'll say one thing though I'll keep most of my bullets that are outside the comfort zone and use then for practice shots, warm-up, and offhand practice it's always handy to have a excuse with standing up and shooting off your hind legs, when you get one of those wild ones it's easy to say “had to be a bad bullet, I couldn't have possibly slung one clear over there!"
Richard
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99 straight,
I'll agree with what the others have said but one thing not mentioned is that an almost 4 gr. spread for 200 gr. bullets is to much. This is not bad if your just starting but if you've been casting a while you need to look at your technique more to get that down to at least within a max. spread + or - 1/2 gr. for all but the obvious rejects.
Pete
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Thank you all. This is what I was looking for. I will work on my casting technique and smaller groups.
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the only way to tell is by shooting them.It will take more than a couple of 5 shot groups to really prove anything.I dont weigh bullets personally but do segregate cavities(sometimes)
George
"if it was easy we'd let women do it" don't tell my wife I said that!
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Like joe b., I weight all match bullets. And like him, I can't tell a differece in 0.3 grain spreads. But, since I alread have them in 0.1 grain groups, I load the 0.1's, then the 0.2's just because it it just as easy as not. I need about 10% of my bullets for foulers and sighters. So the bottom 5% in weight become foulers and the the top 5% become sighters. The 90% in the middle goes on the targets.
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I doubt in non BR type 30 calibers .5g would be noticeable on the target.
"if it was easy we'd let women do it" don't tell my wife I said that!
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Maybe this is another way to say it.
Some visually perfect bullets are outliers, weigh a lot more or less than the average. We think that these will affect accuracy. The only way to identify these strangers is to weigh all the lot of bullets. Weighing them all is the only way to find the average and id the strangers.
joe b.
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Heavy bullets won't cause a problem. It's the underweight ones that “bite” you.
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99 Straight never really got an answer to his question.
"How far can I go and still get a good group? Is 3.8 gr to much variation when casting 220gr bullets in a double mold?"
I think that is probably because nobody knows. At least I have never heard of a good test that pinned this down or even one that came close. Joe's system makes sense and he answered the question about sorting them into 0,1 grain groups. Pete's remark that with good casting the weights should be closer than 4 grains for a 220 grain bullet is true. But what weight variation really makes a difference and at what level of accuracy?
I used to weight bullets. It removed one worry and maybe that is a good enough reason. But I am lazy and would use the culls for practice instead of melting them and they seemed to shoot as well as the ones of uniform weight. Then I tested the lightest and heaviest mixed together against the “good” ones and the culls seemed to shoot better about half the time. I should go back and do more of this because it doesn't seen reasonable but in the meantime I don't weigh bullets.
John
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"99 Straight never really got an answer to his question"
I said shoot them and find out.i agree with John's answer.Weighing bullet makes you feel better,but not necessarily shoot better groups. if you have a good casting procedure and are not visually culling too many as casting my feeling is unweighed will shoot SUB MOA in capable rifles no problem.They do in my rifles anyhow.
George
"if it was easy we'd let women do it" don't tell my wife I said that!
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I cast up another 200, 220gr. Lyman bullets this time keeping them seperate from each cavity. They are different bullets. One averages 212.5gr. and the other is 213.5gr. The 213.5 is .001 larger in the nose. The 212.5 group was within .9gr in weight and the 213.5 was .8 gr different. I put them into .1gr. groups and shot them. Both bullets will go under 1 inch in my 30-06 Rem 40XB 21 gr. SR 4759. I made up 10 of each group and shot them at the same target alternating each shot. I got 2 groups about 1 and a half inch apart but that opened up the total group to 3 inches. Now I can work on powder and seating depth.
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Your 40XB is a very nice tester for cast 30-06 loads and better than any i could think of.Your accuraccy is much better than most get in a 30-06 cast rifle.I am jealous a bit.I had an early Savage “Tactical” in 30-06 that was a pretty solid MOA gun.It was the most accurate 30-06 i ever owned sometimes shooting way under 3/4"(never with witnesses of course!!)
Glad you were able to see a difference and have a baseline for load development.
George
"if it was easy we'd let women do it" don't tell my wife I said that!
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File this under “I told you so". I just happened to have 28 cases and 28 bullets in a .1 group so I put them together to work on my trigger pull and rifle hold. I was in a hurry so insted of hand lubing and Lee sizing I used my Lyman sizer. What a mistake. 3 inch groups. I took 18 unfired back home to find out what I did wrong. After a lot of measuring and head scratching I measured case run out and there it was. Bullets sized in the Lyman had .010 to.015 run out at the neck. I have all 3 Lyman sizers. The 45, 450 and the 4500.I tried them all and the same neck run out. .010 to .015. Went back to the Lee and got .001 run out. Groups went back under 1 inch. Now I am back working on 1/2 inch groups. I tried to measure if the bullet was being bent in the Lyman but I don't think so. I think they are sized off center but I can't seem to measure that with just the bullet.
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Push through sizers always seem to work better, at least for the sizing portion anyway. That's why the Star is so popular. I've bent rifle bullets in Lyman sizers before. Also, I never could get excited about sizing a bullet by it's unsupported nose, then pushing it back up in the opposite direction to remove it. Also, many “in & out” sizers have some degree of alignment problems between the die and the nose punch.
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Gentlemen,
I recall a past article that mentioned that weighing your bullets for uniformity is only the first step in casting “match grade” projectiles (after of course checking for obvious casting defects) and that they should be measured for uniform diameter as well. Part of the reason for doing this is that bullets having the same weights but different diameters could contain voids in the larger ones that would pass the weight culling but still be potential flyers. This is mostly of concern to our BR and long range folks but is interesting none the less.
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I recently bought a new mold for the RCBS 180FP bullet. The mold drops a really nice bullet with almost no culls. Although I had purchased the mold to produce hunting bullets I decided to try them in a rifle I use primarily for competition. Now to the point. I did not have a proper nose punch so I used one designed for a .358 Keith style bullet. This allowed the bullets to move slightly and possibly center better in the Lyman sizing die.
The result of this (or was it?) was some of the better groups I have shot with this rifle. I don't believe that this bullet is particularly well known for it benchrest potential. So did I get lucky with two 10 shot groups or did my lack of a proper nose punch actually result in more concentric bullets?
I am going to lube the next batch in a .312 die with the same oversize nose punch. I can then size them lightly with a Lee .311 push through die. I am very interested to see the results. This thread has me wondering if I have been shooting “damaged” bullets for years.
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So far all of my best groups have been with the Lee .311 sizing die. I tried to just seat the gas checks with the Lyman and then size in the Lee but groups opened up. I have tried both hand lubing and Lee lub before sizing with no difference in group size. Something about that Lee sizer just works. Case neck runout using the Lyman sizer is always .005 to.011. With the Lee, under .001.
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"I recall a past article that mentioned that weighing your bullets for uniformity is only the first step in casting “match grade” projectiles (after of course checking for obvious casting defects) and that they should be measured for uniform diameter as well."
This may be good advice or it may be a waste of time. I don't think we know. This is the type of advice in articles that has certainly been given and repeated down through generations of shooters. The question is; is it based on anything more than just sounding reasonable? I'm not sure of this one but several of our sacred rules are just old myths that sound good. We need more solid and well planned experimentation if we are going to get cast bullet shooting out of the mode of being based on opinions and sacred rules posing as facts.
CBA's members have done a lot of this but there is more to do.
John
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John Carlson
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linoww
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Bud Hyett
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drone
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beltfed
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Lucky1
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RicinYakima
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MP1886
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mashburn
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Aaron
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