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View Full Version : Cast boolits accuracy, seeking knowledge for holy grail of best performers



mike 30-06
02-12-2016, 12:02 AM
I have been doing some reading on the craft of casting boolits and stumbled upon some very interesting information in 10th chapter 2nd edition of Modern Reloading by Richard Lee.
The question that I have is: Have any of you come across this info and is any of it worth trying? What in your opinion is the biggest contributor to making most accurate cast rifle bullets? Any shared knowledge would be much appreciated.

Mike 30-06

dilly
02-12-2016, 12:22 AM
My book is out in the shop do I can't speak to the text right now.

The biggest contributor is consistency. How that is measured is up for debate.

I can say without too much controversy that perfect, sharp bases are important, and that bullets sorted by weight CAN shoot better under the right circumstances.

Do a search for consistency applied to get a write up that's really nifty on casting well.

vzerone
02-12-2016, 12:31 AM
I'll say knowing what to do. I only go along with consistency so far because one can consistently do the wrong things.

ukrifleman
02-12-2016, 07:10 AM
160602`Matching Bullet metal to Chamber Pressure`

First and foremost slug your bore, as bullet fit is probably the most important thing to get right. An undersized bullet will be less accurate and cause increased leading.

Matching alloy hardness to chamber pressure/velocity is important, particularly if you wish to push cast bullets 2000+fps.

Using Lee's data and BHN hardness tester kit takes a lot of the guess work out of cast bullet manufacture.

Cross referencing bullet strength against published pressure/velocity of any given powder charge, will enable you to have a much greater control over bullet performance.

A lot of people (me included) found it difficult to hold the Lee 20x microscope steady when checking the bullets for hardness.

Here is my no cost answer to the problem.

ukrifleman

44man
02-12-2016, 10:21 AM
Everything is worth testing but what you find is the most important. Everyone has something different that works and also what failed.

Char-Gar
02-12-2016, 12:02 PM
I have been doing some reading on the craft of casting boolits and stumbled upon some very interesting information in 10th chapter 2nd edition of Modern Reloading by Richard Lee.
The question that I have is: Have any of you come across this info and is any of it worth trying? What in your opinion is the biggest contributor to making most accurate cast rifle bullets? Any shared knowledge would be much appreciated.

Mike 30-06

Mike, if you will send me a PM with your email address, I will send you a primer on cast bullet accuracy in rifles I put together a couple of years ago. This is far easier than doing a very long post and disputing some of the misinformation that is common on this board.

Getting good to excellent cast bullet accuracy from rifles is not some kind of arcane science but comes from following basic principals. It really is pretty simple if you do it by the numbers and follow a linear path.

stu1ritter
02-13-2016, 08:03 AM
There is an excellent thread on this forum on bullet consistency and how to measure it and cast for it, and I'm pretty sure it is exactly what you are looking for. http://tinyurl.com/ztjzlcw

Stu

Char-Gar
02-13-2016, 01:28 PM
There is an excellent thread on this forum on bullet consistency and how to measure it and cast for it, and I'm pretty sure it is exactly what you are looking for. http://tinyurl.com/ztjzlcw

Stu

That is a very good post by Tim about how to cast good quality bullets. But it should be remembered that a perfect bullets might not shoot worth beans, if it is not a good fit for the barrel of the rifle, is cast from alloy incorrect for the pressure, uses the wrong type and/or amount of powder and is not a good design for the barrel.

Unfortunately there is no answer to the OP question, as there is no one "biggest" contributor to cast bullet accuracy. If a fellow wants the bullets to play follow the leader through the same hole, he must pay attention to several factor. They all work together.

mike 30-06
02-15-2016, 01:31 PM
Thank you all for your input. I am new to shooting, reloading and casting. I have only shot 500 bullets down range. Reloaded about 100 of them and have never cast a single boolit. This new hobby of mine is very involving and I love it. Thanks to all the people on this forum and the information they provide my learning curve is going to be steep. In a very short time I have learned that bullet fit is where I should start. l also should look at the aspect of accurate shooting with doing everything right. Accuracy will not be there if the single mistake takes place. I understand now that the parameters of everyone vary wildly. Everyone has different understanding of accuracy and what it is to them. To me it is constant improvement and the journey itself. The gun used, cartridge, barrel quality, twist rate, powder, primer, alloy type and hardness, lubricant selection, bullet design, quality of cast are only a fraction of the potential game changing variables. Due to many variables I should take a linear approach in testing to see what works.

Mike 30-06

dilly
02-15-2016, 02:43 PM
It's astute of you to notice the many variables affecting accuracy.

It seems that most people have a story of something they did that greatly improved accuracy for them. I've seen posts where people have had accuracy issues resolved by solutions as varied as sizing bullets larger, primer pocket deburring, changing lubes, changing the powder charge a couple of grains, switching from magnum to standard (or vise versa) primers, using a different headstamp brass, weight sorting bullets, changing alloys, etc. In all of these scenarios someone was able to greatly improve accuracy by changing a variable, but the accuracy gains can't always be applied to shooting in general. In each case they were getting "everything right but..." and when the right variable changed things started going smoothly.

Sometimes it helps to ask "what's causing my inaccuracy?" It could very likely be different solutions for different rounds, different guns, different reloaders, different equipment, different air temperature, etc.

OS OK
02-15-2016, 07:37 PM
160602`matching bullet metal to chamber pressure`

first and foremost slug your bore, as bullet fit is probably the most important thing to get right. An undersized bullet will be less accurate and cause increased leading.

Matching alloy hardness to chamber pressure/velocity is important, particularly if you wish to push cast bullets 2000+fps.

Using lee's data and bhn hardness tester kit takes a lot of the guess work out of cast bullet manufacture.

Cross referencing bullet strength against published pressure/velocity of any given powder charge, will enable you to have a much greater control over bullet performance.

A lot of people (me included) found it difficult to hold the lee 20x microscope steady when checking the bullets for hardness.

Here is my no cost answer to the problem.

Ukrifleman

"s e x y​ …you found my answer to my shakey old paws! Thanksamillion!"

Wardo1974
02-15-2016, 09:59 PM
Hey Mike, greetings from Kingston. Reloading quality ammo, cast or not, depends on getting dozens of variables correct every single time when you're loading. It's not any single thing, it's a bunch of things you do the same way, correctly, every single time. Trouble spots I noticed on my own though:

1.) When looking at the bullet, if nothing else, the base has to be perfectly flat and clean. Flawed bases have much less chance of flying true, and a flat base can even overcome a dented, damaged nose, but not vice versa.

2.) I've found a huge difference in accuracy simply by not resizing my cases. Boolits tend to squash a bit as you seat them...if the cases have been full length resized, the brass is smaller and will squash the boolit even more, harming your accuracy. If the cases are going back into the gun they came out of, there's no need to size. Buy a Lee Universal decapper die which will allow you to deprime any case without resizing them.

3.) Use as little crimp as you can get away with for the same reason - it's gonna squash the boolit.

4.) Whenever possible, use the powder for your charge that will fill the case to complete capacity.

5.) When loading cast, if you can, get a reloading die set like Lyman "M" dies, or RCBS "cowboy" dies that flare the case necks for seating without shaving any lead. They also have expander balls that are larger than standard die sizes so the boolits don't get squashed, as I mentioned in the above points. If you don't have those, use a Lee Universal expander die which will flare any case neck. Or in a pinch, a taper punch can be used to tap into the case neck.

Just some ideas. Have fun!

leadman
02-15-2016, 10:13 PM
Wardo, you do not state what type of firearm you are reloading for but in some cases it can be dangerous to not size the case. A boolit getting pushed back in the case can increase pressures and cause problems. Sometimes a change of die or expander is needed as most die sets are set up for jacketed bullets and more neck tension than is needed for cast.
I use the Lyman M dies to open the case up for the boolit and provide enough neck tension so I do not have to crimp for most of my firearms. I would not substitute a crimp for proper neck tension.

guicksylver
02-15-2016, 11:44 PM
OK...mostly good information.
But first ypu can slug your bore if you wish ,BUT fitting the boolit to your THROAT is what you want. (Google"Fit is king").

As for alloy amd hardness, that is determined by the velocity you are trying to achieve, unless you are going for over 1800 fps in most rifles,the alloy is pretty much your choice.
I can show you bug holes at 100 yds using the same boolit with a bhn of 12 and 15 or better.
IMO most shoot best at 1450-1650 fps.
Fire from cases, neck size only.,.002-.003 neck tension.
I like others like to weight sort my boolits, but there are others who don't and achieve the same results.
Seating depth can account for better tesults, most say the boolit should slightly engrave the rufling,my seem to work better slightly off.
Use enough tin to get fill out of the boolit when casting.
Ask what "good" means when one says it works good for me.
My expectations for my scoped and stock 03'S and a3's are 5/8 to 3/4 " 5 shot groups at 100 yds.,ditto for my iron sighted ones.
Ya I know that's not 10 rounds,but when you do four in a row it's twenty and no fluke.
Have fun, it's not rocket science, we all learn by our mistakes and ask questions,sometimes the answers are rediculosely simple.

trfourtune
02-16-2016, 12:34 AM
Knowledge.
Might want to get all the info/books you can get before any investment. Lyman cast bullet handbook, jacketed performance with cast bullets (Veral Smith LBT Molds), from ingot to target:a cast bullet guide for hand gunners, just to name a few.
Then, you need a the best mold that drops bullets that fits the exact gun you plan to make bullets for, which means bullet fit and design. After that, there are many factors, but the starting point is the right mold IMHO.

noisewaterphd
02-16-2016, 12:52 AM
Mike, if you will send me a PM with your email address, I will send you a primer on cast bullet accuracy in rifles I put together a couple of years ago. This is far easier than doing a very long post and disputing some of the misinformation that is common on this board.

Getting good to excellent cast bullet accuracy from rifles is not some kind of arcane science but comes from following basic principals. It really is pretty simple if you do it by the numbers and follow a linear path.

I'd be interested in checking that out myself. I've been casting for sometime, but only recently taking a serious interest in doing so for rifles.

I have done a lot of reading and testing already, but the more the merrier!

Wardo1974
02-16-2016, 08:12 AM
Wardo, you do not state what type of firearm you are reloading for but in some cases it can be dangerous to not size the case. A boolit getting pushed back in the case can increase pressures and cause problems. Sometimes a change of die or expander is needed as most die sets are set up for jacketed bullets and more neck tension than is needed for cast.
I use the Lyman M dies to open the case up for the boolit and provide enough neck tension so I do not have to crimp for most of my firearms. I would not substitute a crimp for proper neck tension.

I don't size cases for all my lever guns. Just because I didn't resize doesn't mean the boolits are dropping into the powder - I can't let them do that anyway because they have to work through the magazine. But even without sizing, the boolits are still held in the necks with a certain amount of tension. These are model 1894s, an 1886, 1892s. There's no danger, and in fact in many manuals and expert testimonials, the path to best accuracy is through the use of unsized cases.

The lightest crimp I can get away with in the groove means the rest of the boolit diameter has the best chance to impact the rifling.

Perhaps I should note I do this because I'm using very soft alloys for hunting expansion...it's not uncommon for me to seat a boolit in a sized case and have it swaged down by .003 or .004 inches. Maybe it's less of an issue with harder ones. But this method has worked wonderfully for me and I'm going to keep doing it.

HangFireW8
02-16-2016, 12:56 PM
A really big contributor to cast boolit accuracy is proper neck fit and seating.

Consistent neck tension (a.k.a. bullet pull) is critical.

Concentric seating is critical as well. Crooked seating will start the boolit crooked in the barrel, it will wobble more in flight and open up groups.

If you don't have a cartridge runout gage, get one. I have and recommend the RCBS Case Master, but there are other good ones.

robg
02-16-2016, 02:26 PM
Keep to reasonable speeds ,I use fcd with a heavy crimp ,seems to help consistency

leadman
02-16-2016, 09:41 PM
Wardo 1974, you must be using boolits that are large enough to fill the entire neck area and allowing the case to expand very little to release the boolit. Obviously you are getting away with it but someone else shooting higher pressure loads may not. I always like a boolit that is smaller than the inside of a fired case so the case needs to be resized.

blikseme300
02-16-2016, 11:12 PM
Most of my rifle cast reloading is for hunting from lever action rifles and Marlin's are my preference. As pointed out soft alloys can be sized down by the case when seating and my preferred method is to size annealed cases using dies modified to size down the necks minimally so as the ensure good neck tension but not size down the CB's. For me, the combination of annealed case necks and minimal sizing of the right design CB and proper powder load improved accuracy a lot. Many factors need to come together before good accuracy and good terminal performance come together. Soft alloys can be shot accurately at higher than expected velocities with good accuracy if effort is put into putting together good ammo. Loading good quality ammo is not as as easy as a paint-by-numbers portrait that too many folks want or demand. Effort and understanding is required but pixie dust does not exist that magically makes a singular recipe work for everybody.

wv109323
02-16-2016, 11:28 PM
Post Number 12 is +++ especially point 1.
I will add to Point 2.
Most die manufacturers cater to those loading jacketed bullets. A jacketed bullet can withstand a lot more neck tension before distorting the bullet's diameter. So neck sizing dies are many times .004" below nominal diameters for that bore size. An example would be 9MM, the neck sizing could be .355-.004 or .351. Now your pistol may have a .3565 bore and you need a .3575 or .358 cast boolit. Putting a .358" bullet into a .351 hole will resize all but the hardest of cast bullets. End results is you are shooting a .355 bullet down a .3565 bore. Your bullets are keyholing on the target.
The above dimensions are exactly my situation with a Dillon neck sizer and a CZ 75B omega pistol.

Char-Gar
02-17-2016, 11:57 AM
I guess it is a pet peeve of mine, but when discussing cast bullet accuracy, folks want to throw the sink at folks who ask simple questions. The results are often confusing about what is mandatory and what is not, when it comes to the issue. There are so many points, sub-points, and sub-sub-points that the new fellow gets confused trying to triage the information. The end results is that folks throw up their hands and think there are no rules/principals just random experimentation with endless variable to try and find something that works.

How to get a rifle to shoot cast bullets, as well as it does with jacketed bullets, is knowledge that has been known for many years. There are a few considerations that can be counted on the fingers of one hand, well with maybe one or two on the other hand, that if followed will lead to success 99% of the time.

While the process is admittedly more complex than that used with jacketed bullets, it still is fairly simple and completely understandable by anybody that got through 6th grade. I guess it is human nature to make things more difficult and esoteric than they are.

The Cast Bullet Association by way of it's matches, solved all of the mystery years ago. These are the guys who are going head to head shooting for the smaller group or the biggest score. They learned what works and why many many years ago.

Folks seem to forget there are people who know how this is done. They seem to prefer to go on an internet board and play musical chairs, with the blind leading the blind. Most of the information is not bad or wrong, it is just partial and not placed in context of the whole. Confusion and frustration is the result.

Oh well, I have put up this same post in one for or another, many times over the years with very little success of changing the tone and tenor of this board. But..I muddle on!

jlchucker
02-17-2016, 12:09 PM
This has been an informative topic, with everyone chiming in with good information. After reading the discussions, I'd like to summarize all of it by saying, when a new person starts casting, then trying different loads, and shooting various firearms, it should be standard practice to set up a noteKbook, gun by gun, and load by load, with results, for everything. There's lots of variables involved, and what boolit will vary with each load and in each gun you load for. It's worth it to keep them all straight. What gun, what boolit, what powder, and what group you ended up with--good ones and bad ones. It can be satisfying, challenging, sometimes frustrating, but never to be taken for granted. It never ends.

Char-Gar
02-17-2016, 12:47 PM
This has been an informative topic, with everyone chiming in with good information. After reading the discussions, I'd like to summarize all of it by saying, when a new person starts casting, then trying different loads, and shooting various firearms, it should be standard practice to set up a noteKbook, gun by gun, and load by load, with results, for everything. There's lots of variables involved, and what boolit will vary with each load and in each gun you load for. It's worth it to keep them all straight. What gun, what boolit, what powder, and what group you ended up with--good ones and bad ones. It can be satisfying, challenging, sometimes frustrating, but never to be taken for granted. It never ends.

Just a couple of points;

1. You are very correct about keeping good records. I have a complete record of every round I have reloaded, complete with range notes from 1959 until the present. This information is invaluable to me.

2. A journey that never ends, is one that has no destination. If a fellow has no where in particular to go, then it doesn't matter which road he takes. As for shooting cast bullets in rifles, there is a definite end, unless one just likes to wander.

Wardo1974
02-17-2016, 06:16 PM
Just a couple of points;

1. You are very correct about keeping good records. I have a complete record of every round I have reloaded, complete with range notes from 1959 until the present. This information is invaluable to me.

2. A journey that never ends, is one that has no destination. If a fellow has no where in particular to go, then it doesn't matter which road he takes. As for shooting cast bullets in rifles, there is a definite end, unless one just likes to wander.

Charles, thanks for your sending me your informative cast boolit reloading mini-manual you've written. It was enjoyable and informative!