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roarin 54
10-28-2012, 03:03 PM
I am in the process of sizing and lubing a batch of boolits I cast from a Lee 452-255-RF mould yesterday. I've settled on a load with this boolit on top of 8.5 grains of Unique. I'm getting 3.5'' to 4'' groups at 50 yards with no leading in my Bisley Blackhawk .45 Colt. I want to see if I can improve on this by culling over weight and under weight boolits. So far, the majority of my boolits weigh 262 grains plus or minus 2 tenths of a grain, with my culls being plus or minus 2 grains. My question is, just how close do I have to be to get the most accuracy out of a given boolit? It might seem to be a little nitpicky but I believe the more accurate I am at the bench and the more attention I pay to the little details, the more accurate I will be shooting at a deer from a field position.

HangFireW8
10-28-2012, 03:27 PM
The exact answer for your gun/ammo combo is easy enough to determine for yourself. Shoot a batch of optimal, and a batch of +/- 2 grains, alternating between batches (on different targets of course). Assuming there are no visible imperfections in the inferior batch, and good bench technique, I'm betting you'll find only a small but measurable difference.

To answer your question, I think the +/- 2/10 grain group is fine for your application, only small caliber rifle would benefit from much more culling than that. That means you can control that variable, and look for more accuracy elsewhere.

HF

runfiverun
10-28-2012, 05:18 PM
even a 2 grain swing is something lke 0.85% error.
so even 1% of 3"s is [ummm,hmm.. carry the one over]
it's really small.

any way i'd look elsewhere to shrink your groups.

roarin 54
10-28-2012, 05:36 PM
My gun would definitely benefit from a spring kit and polishing. I'm presently using the poor boy trigger job. I'm going to put a few more rounds through it before I resort to fire lapping, and I am considering reaming the chambers to make them uniform, they are not undersized as so many .45 colts are but they are slightly different and I'm sure that cant help accuracy any.

Stork
10-28-2012, 05:41 PM
any way i'd look elsewhere to shrink your groups.

+1.
At an earlier more anal time in my cast boolet journey, I separated a batch of H&G 68 flat base boolets, into 1 tenth of a grain groups. The bullets were all sorted and examined for base perfection.

I tested groups in a Ransom Rest with a proven load. (4.3 gr WST, .469 crimp, TZZ Match brass). I used several groups of my current 50 yard loads as a baseline. I also ran a baseline 30 shot test of picking 1 bullet from each group and loading then testing that batch.

What I found was that as long as the bullets were within 3 grains they still went into the same 1 1/2" group at 50 yards. I could not find that using bullets weighed to .1 grain decreased the group size.

I used a proven 1911 Bullseye pistol that had a very good Kart barrel installed and had proven itself in multiple tests.

Since that test I don't bother weighing anything "for my Bullseye pistols". As I don't cast anything for rifle, I can't speak for that corner of the casting table, however I'm told weighing bullets for longer range rifles definitely pays off.

If it makes you feel more confident about your loads, go for it.

FWIW

williamwaco
10-28-2012, 07:34 PM
So far, the majority of my boolits weigh 262 grains plus or minus 2 tenths of a grain,




You are already into the overkill zone.
Closer weights will not improve your groups.

See runfiverun for more


.

popper
10-29-2012, 11:28 AM
I will reiterate - you have to get a really high quality high $$$$$ scale to measure +- 0.2 gr difference!!!!. Your RCBS knife edge balance beam won't do it, especially after a year of use. Same comment for those claiming to measure powder to 0.1 gr. You're kidding yourself. Read the manufacturer's specs.

runfiverun
10-29-2012, 12:10 PM
you know some places don't weigh powder they use a volumetric measurement.
pretty cool if they would show a gas volume produced by a powder volume.
you could easily make changes based on bbl length and bore diameter [volume of the pipe]
assuming a constant pressure.

cbrick
10-29-2012, 09:10 PM
Pretty doubtful that group testing will show any benefit at 50 yards or under by weight sorting.

A better way to spend your time is to make sure that all bullet bases are perfect. The easiest way to do this is by inspecting them the moment you open the sprue plate & before you open the mold. An incomplete base will show up like a neon sign.

I shoot revolver to 200 meters in competition, I don't weigh my bullets but any bullet with a base imperfection goes straight to the sprue pile. I don't care what the rest of the bullet looks like or what it weighs.

Rick

HangFireW8
10-29-2012, 10:14 PM
I will reiterate - you have to get a really high quality high $$$$$ scale to measure +- 0.2 gr difference!!!!. Your RCBS knife edge balance beam won't do it, especially after a year of use. Same comment for those claiming to measure powder to 0.1 gr. You're kidding yourself. Read the manufacturer's specs.

I just read my 5-0-5 instructions, it doesn't give an accuracy spec, but it does say it has agate bearings, steel pivots and a guaranteed sensitivity of 0.1 grains.

Assuming the edges aren't hammered, and the documentation is correct, that means one CAN sort boolits into groups spanning +/- 0.2 grains.

Measuring correctly to that accuracy is a different matter. I won't get into that.

The "year of use" comment I don't quite understand. A beam can get hammered the first time something gets dropped on it during the first week of use, or can last for years if properly cared for. I dismount and store the beam in a hardwood and plexiglass box I made for it. It isn't pretty but it keeps the beam clean and unhammered. I also inspect the knife edges (pivots) on regular occasions. It doesn't time-out after a year that way. I think giving advice to do the same might be more helpful than throwing about arbitrary time frames with no explanation.

Anyway I think it's pretty rude to just come in and blast someone's measurements like that. At the very least we can assume he's using his scales as optimally as possible, and reporting what the results are reading given the equipment he has. We can draw our own conclusions as to the actual meaning of those measurements. Since he's already way over the precision needed for accuracy for his gun and ammo combination, is it really necessary to blast his measurements?

HF

popper
10-29-2012, 11:45 PM
Anyway I think it's pretty rude to just come in and blast someone's measurements like that I do apologize if I was misunderstood. This is the 2nd recent post of OP trying to measure 0.1gr with a scale. The rbcs 505 web spec sheet states 0.2gr accuracy. Statistically, one needs precision at least 5x better than guaranteed accuracy (~3 sigma - 1 sigma is 30%+/-). My point is that you are wasting your time trying to measure the small amount as the equipment we use just isn't good enough. Short story - a co-worker was designing a chemo-chemical measuring system. Very accurate strain gauge system, < 0.1% if I remember correctly. His design kept getting bad measurements. The cause? Air vent 10' above his desk. Solution - build an enclosure around the measurement while the measurements were taking place. Your discussion of balance beam scales is very good, but they also get dirty, damaged during measurement, not just storage. I remember years ago trying to set the phono needle pressure to a very small weight, using an extremely high quality scale. Didn't work. However, you are correct, I shouldn't be so harsh.

HARRYMPOPE
10-30-2012, 12:09 AM
I did something similar to what "stork" said in a Remington 40X in 30 BR about 15 years ago.I weighed/visually sorted etc for the 1997 CBA Nationals.When i ran low of perfect bullets(bad wind and used to many sighters) i used my culls/sighters. that were "nearly" visually perfect but varied by a few grains here and there(RCBS 180SP).I shot better than ever and was in the top of the heap at the three 200 yard matches.when i got home ran the test again and saw no difference.(Groups were down to 1/2 MOA with unsorted/weight varied bullets) If the casting session is good and you are getting few to no visually flawed bullets its a waste of time to sort by weight(even 22 bullets).If you have to visually sort too many bullets than its probably an inconstant batch/session and they may not be worthy of match bullets.

cbrick
10-30-2012, 06:57 AM
Harry, that's been my experience also. I used to weigh all my bullets for long range revolver matches right up to the day when I woke up, smelled the coffee and realized what a silly waste of time it was. My scores never changed once I stopped weighing.

Many years ago when shooting silhouette in Orygun at the conclusion of the smallbore match they would have a turkey shoot to raise money for the club. Everyone would put in a couple of bucks and the winner split the money with the club. The smallbore turkeys were placed at 100 meters and whoever got the most won. The rage at the time was to weigh the loaded smallbore ammo for consistency so I spent two evenings weighing several boxes of ammo and came up with just enough that all weighed the same to shoot the match. For the turkey shoot the only ammo I had was the stuff that had weights all over the place. I lost in the match and won the turkey shoot.

Anyone ever weigh a box of J-word bullets. Try it if you think they are weight consistent, odds are that with consistent mold temp your cast bullets are more weight consistent.

Rick

HangFireW8
10-30-2012, 09:56 AM
Yes, decades of tests have shown us that uneven tips and slight weight variations didn't matter, even out to 1000 yards, but the condition of the bullet base means everything. The fact is two .22 rimfire cartridges or 2 Sierra Match bullets may weigh the same but have come off of different production machines.

But, there is a market to sell 22 ammo sorting gear and match bullet tip uniformers...

prs
10-30-2012, 10:21 AM
When testing for very fine variables, use only one cylinder of your wheel gun. Mark it and use it. Its odd, to me, that the Rooger would have different sized cylinder throats on same cylinder set. Are they milling all the chambers at once with 6 different bits? I have two stainless Ruger Bisleys in 45 Colt and a plow handled blued one. They were all uniform of throat, but all tight. I reamed them all with the same tool and all slug the same with a dead soft lead ball, .4525". Made a heck of a difference, but now my himan error is far greater than the guns' accuracy errors.

prs

roarin 54
10-30-2012, 06:55 PM
I have read awhile back that revolver cylinders are reamed with a gang reamer so that all six are done at once to increase production. to clarify some of the replies, most of my boolits weigh 262 give or take.2 grains the ones that I am culling are the ones weighing 260 and 264 grains anything in between I am keeping. To clarify my question, will a boolit 2.0 grains over or under weight affect handgun accuracy at 50 yards or more? I am using an RCBS 1010 scale and I can take a single boolit and weigh it repeatedly within a tenth of a grain. I have found keeping the pan clean with alcohol to keep oil from my fingers building up on it, keeping plastic away from the scale, and keeping it dust free go a long way toward maintaining repeatable accuracy.

popper
10-30-2012, 07:25 PM
That is ~ 1% weight. Ballistically, it would only increase drop so I would say no. Now where that weight difference is could make a difference. If it is due to a bad base, yes. On one side of the CB, maybe. Due to difference in lube groove fillout, probably not. You are doing what you can to maintain the scale - good. Acetone doesn't leave a film like alcohol.

cbrick
10-30-2012, 07:56 PM
roarin,

With more experience & time casting you will learn to get & maintain a consistent mold temp. A consistent mold temp goes a very long way to reducing the weight variation. The next time you cast keep the bullets seperated as you cast. Weighing them afterwards will show you that the very first bullets you cast are the lightest by a few grains. That's because even though you may have pre-heated the mold it's not yet at a consistent, even & proper temp. I do pre-heat my molds in a mold oven on a hot plate, even so I do not keep the first 10-12 pours regardless of how good they may look, they will be lighter. If you don't pre-heat it will be the same except several more pours will be needed to get the mold properly & evenly heated.

Try this and see if your weight variation decreases.

Rick

runfiverun
10-30-2012, 08:57 PM
roarin the answer is no.

i will stand by the answer that small bore boolits do need to be visually and weight sorted.
a 1-2% weight variation is not a big deal
4-5% is and those same 1-2 tenths of a grain is 5% of a 50 gr boolit.
even a small gas bubble/dross/slightly not square area, even near the center of a small boolit is near the edge.

HARRYMPOPE
10-30-2012, 09:56 PM
I have never weigh 22 bullets anymore and shoot very small groups.i think weight variation is not a problem in the small ones.I have shot visually wrinkled 22's at 2000 fps int sub MOA quite often.I have also shot perfect ones over 3" so go figure?There are unknown reasons 22's dont always group consistently well but i dont feel its bullet quality.

George

cbrick
10-31-2012, 09:26 AM
R5R,

Can't argue about weight variation in the tiny bullets but the OP's post is on 45 caliber 255 Gr bullets.

Any effect weight variation will/can have is a factor of the percentage of the whole. A 2.0 grain variation in a 255 grain bullet is a very small percentage of the whole and will have very small impact on accuracy and the shorter the range the less impact. A 0.5 grain variation is a much larger percentage of the whole in a 40 or 50 grain bullet and could effect accuracy more, and more so the longer the range.

Rick

Bluehawk
10-31-2012, 12:41 PM
I Shoot the same bullet with the same load in the same gun . I DO NOT weigh the bullets and have not for years now. I USED to shoot competition also and weighed them but then found it to be a waste of time MOSTLY Unless your 12 to 15 grains off .
I came upon a load a number of years ago with one of my 45/70s shooting the Speer J 400 grain FP bullet that ALWAYS shot under an inch off the bench at 100 yards . I was amazed at this and was consistent with the load always . One day I decided to weigh some of the bullets to see if I had bullets of more consistent weight to POSSIBLY make it even better . I was surprised to find Factory J bullets in that range having weight differences at some times 15 grains OR MORE different and after segregating some and then shooting some at random I got the SAME groupings . I weigh a select few out of any new batch of mix to make sure of any weight variants but other than that I do not weigh .
Id try the mix and see if a slightly harder bullet MIGHT lower the group size. MY same mold only throws a bullet of about 250 grains . AND my mix is NOT particularly hard . ALSO lube can be a factor also . Lots of things to try, BUT 8.5 grains of UNIQUE is a winner for me in 4 different 45 colt guns with that bullet weight range .

runfiverun
10-31-2012, 01:59 PM
R5R,

Can't argue about weight variation in the tiny bullets but the OP's post is on 45 caliber 255 Gr bullets.

Any effect weight variation will/can have is a factor of the percentage of the whole. A 2.0 grain variation in a 255 grain bullet is a very small percentage of the whole and will have very small impact on accuracy and the shorter the range the less impact. A 0.5 grain variation is a much larger percentage of the whole in a 40 or 50 grain bullet and could effect accuracy more, and more so the longer the range.

Rick

the longer the range and the higher the velocity.
then even how the gas check sits on the base matters more and more,and how the lube ejects from the boolit. etc.

50-100 yd revolver,or 1900 fps rifle loads don't matter a whole lot.
1-2% weight variation or a rounded base covered by a gas check won't show in the group either.
when i mentioned to look elsewhere for the op's accuracy i meant:
look at neck tension,ignition quality,throat consistency,trigger,and boolit hardness as load tuners.

45-70 Chevroner
11-01-2012, 12:30 PM
I think it was, (if my memory is correct) Bob Milick (probably spelled wrong) wrote an actical in Guns and Ammo magazine about 30 years ago I wish I had keep that magazing. He did some testing with weighing powder and using a powder measure, I think the measure he was using was an RCBS. He did the testing shooting a 223 of some sort. The test he did was repeated several times. He finally came to the conclusion that weighing powder did not gain any accuracy and as a mater of fact he wrote that the powder measure (dispenser) loads shot better than the weighed powder loads. IMHO I think the same is true of weighing pistol boolits. I have not weighed a pistol boolit except to determin the mean weight, so as to determin a starting load for that boolit weight.

felix
11-01-2012, 01:29 PM
Boolit weight matters only with suspect alloy. If the alloy is not correct for the casting conditions, then the air bubbles within the boolits will not be uniform. Weighing gives info about the distribution of the air bubbles, and that is about all that is necessary for target boolits. Yes, consistent powder volume is a better measure than powder weight as the same reasons for the weight distribution of the boolits. ... felix

mpmarty
11-04-2012, 03:26 PM
A man with one wristwatch knows what time it is. A man with two wristwatches is never sure.

1Shirt
11-09-2012, 01:56 PM
Being at best only a fair handgun shooter, I visually inspect, but do not weigh hand gun bullets. Rifle cast is a whole different world to me however. I weigh 22's, and 6mm's to exact weights. I weigh 6.5' & 7 MM's to within .01, and 30's &
8MM's to within .02. I stay with .02 from that point up cal wise for hunting and serious target work.

I use an electronic scale, and weigh by exact weight on a bell shaped curve. The ones at the top of the curve, and a couple on either side are shooters, and are put in seperate compartments of a plastic box by weight. Those outside that limit are either loaded for plinkers, or go back in the pot for remelt. I have found that over the years and by testing single vs. double cav molds, that there is usually a variance in multi cavs. This is particularly true with cavs over 2 and up to 6 cavs.

1Shirt!