BEGINNER'S RECIPE FOR CAST BULLET RIFLE ACCURACY
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- Last Post 02 January 2015
Joe,
Thanks for the article. I would appreciate your opinion on using new vs fired brass. When I start with virgin brass, I chamfer the mouths, full length size and fire them, then trim to length, ream primer pockets, neck turn, etc and start testing. I have never done any extensive testing to determine if virgin brass will shoot differently than fired, but it always “felt” better to eliminate one more variable.
In your example you said to start with 100 new brass and fired 270 test rounds, so obviously the majority of the testing was done with fired rounds. Assuming you are starting with fired brass from the same lot and not working with relatively low pressure loads, do you feel there is any advantage in starting with new brass.
Thanks again,
Jackpine
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"A bullet MUST slide into the fired case mouth with little resistance. If not, turn the case necks." This statement has little relevance to the entire bell curve of beginners that your recipe is stated to be for.
Brass and bullets selected correctly for a standard firearm will cover this and never require neck turning. More utility for beginners would be available with more importance applied toward selection of a basic firearm with standard chamber and reloading supplies that are simply correct.
Neck turning repels beginners and is unnecessary to be discussed with beginners that have standard firearms and correctly selected reloading components.
Gary
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Joe,
You have previously discussed neck turning, most specifically about one of your rifles that you posted modified chamber dimension specifics. You battled and self announced frustration of a long battle with neck turning to get that rifle to shoot better. We debated dies, loading methods and chamber dimension at the time.
It was an interesting account you shared with the readers but the entire subject is not relevant to beginners that have standard rifles and correctly selected loading components.
Gary
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Joe,
Thanks for the article. I would appreciate your opinion on using new vs fired brass. When I start with virgin brass, I chamfer the mouths, full length size and fire them, then trim to length, ream primer pockets, neck turn, etc and start testing. I have never done any extensive testing to determine if virgin brass will shoot differently than fired, but it always “felt” better to eliminate one more variable.
In your example you said to start with 100 new brass and fired 270 test rounds, so obviously the majority of the testing was done with fired rounds. Assuming you are starting with fired brass from the same lot and not working with relatively low pressure loads, do you feel there is any advantage in starting with new brass.
Thanks again,
Jackpine
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Joe,
You have previously discussed neck turning, most specifically about one of your rifles that you posted modified chamber dimension specifics. You battled and self announced frustration of a long battle with neck turning to get that rifle to shoot better. We debated dies, loading methods and chamber dimension at the time.
It was an interesting account you shared with the readers but the entire subject is not relevant to beginners that have standard rifles and correctly selected loading components.
Gary
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Being a new rifle bullet caster i clicked on this posting expecting at least a modicum of basic advice on the creation of bullet & gcs, difficulties common to newbies, etc. You can understand my dismay at what i found. I “lurked” here for a week and joined last night, and largely am impressed with the amount of experience here, however i will be much more selective of which posts i open.
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shootzem222: First, If you are looking for CB information this is the place to find it. Glad you found the forum After reading your post, I think I know what you mean but don't let one experience discourage you. There are many knowledgeable long time cast bullet casters and shooters here, some who I know personally, that are more than willing to answer any questions that you may have. We all started somewhere. So, I would suggest, search the archives for info. And if you don't find what you are looking for, tell us what you have and where you want to go with cast. Then start a new topic with your questions and take what works for you. This game is not rocket science. Is the 222 in your forum name significant? One of my all time favorites. R. Dupraz
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Shootzem222; If you are casting good bullets ( no wrinkles and all the edges of the casting filled out, and they all weigh about the same +- .3grns) Then I would say to fit the bullet to the throat of the chamber. That is the quickest and most useful advice I can give to attain useful cast bullet accuracy. If the bullet fits the throat it will be well aligned to the rifling and enter the bore in a straight manner. A little more information on what you have been doing and what problems you are having would be helpful. I am certain sure that the membership here will be glad to help you . We always welcome another cast bullet addict into the fold. Brodie
B.E.Brickey
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Goodsteel,
Thank you for taking the time to post your very complete procedure for developing a successful cast bullet load. You have packed a lot of good information into a very concise package. I have done every one of the things except one that you suggest at one time or and have learned something from each. The exception is the one shot of each load “ladder test” which as you recognized in your (Edit to add) revision requires a group at each load level to make any sense. For the hard core cast bullet shooter trying to achieve accuracy of less than 1 MOA (for averages of several consecutive groups -- not one show group) or trying to break the .5 MOA CB barrier I believe almost all the procedures you suggest are worth doing and a couple of them haven't appeared on this forum, at least recently. However, very good CB accuracy of 1.5 to 2.0 MOA can usually be achieved with a good factory bolt action rifle with much less work than you suggest. Joe Brennan specified a recipe for doing exactly that for a 30 caliber rifle when he started this thread. His experience matches my own that good (but not record breaking) CB accuracy is easier than sometimes suggested -- IF a few critical things are right. (Joe's recipe and his report of using it to achieve good accuracy from a factory rifle have mysteriously disappeared and I hope that Joe will repost the recipe and his results.) Your tutorial is an excellent addition to the thread but I worry that to the non hard-core or beginning CB shooter it may appear intimidating and discourage an interest in our hobby. It calls for many steps and procedures that are not necessary to achieve excellent and satisfying results with cast bullets for most shooters even though the more rigorous procedures may be needed for those dedicated individuals trying for extreme accuracy and/or extreme velocity. John
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Your fixation on bore and groove measurements just isn't necessary unless you have a chamber that is not standard. Standard chambers will have a throat area larger in diameter than barrel groove diameter and bullets at throat diameter will be sized by the barrel upon firing. Un-ubed bullets sized to a sliding fit in the chamber throat is a good fit that the barrel will size and barrel bore and groove measurements are not productive and not needed at all to project a correct bullet diameter. A chamber throat casting or your pounding a slug method to the throat is all that is needed or helpful.
The sliding fit of a bare un-lubed bullet to the throat makes lube type and lube application last in importance for accuracy and leading. A simple, light tumble lube is sufficient and will not be outperformed by any lube that is stylish or traditional. The better the fit is, the less important lube is. Alloy ultimate tensile strength (expressed in psi ) as Brinell hardness selected at 10% below the ballistic pressure of your load in psi as promoted by Lee is a reasonable and successful method I use and recommend, but this is for plain based not gas checked bullets. Hunting loads with gas check bullets in Lyman #2 alloy can be accurate beyond the 10% Lee recommends but you have to determine how far beyond the 10% you can go and maintain accuracy that you need for hunting.
The sliding fit with the largest diameter bullet that will chamber in the throat is simplified for me by custom honing Lee Lube and Size push through bullet sizing dies with a simple slotted wood dowel with emery cloth and oil and spun in an electric drill to enlarge the bullet sizing die hole a little at a time till sized bullets are at throat diameter. Presto , oingo biongo, that is it for bullet size.
There is no reason to slug a bore unless your groove diameter is larger than your chamber throat diameter. A rifle with that unlikely condition will never be a good shooter with any kind of bullet at all as the bullets will wobble down the loose bore and shoot all over the place.
Getting beginners to understand this does not spit in the face of tradition it only emphasizes the basics beginners should understand to start using cast bullets.
Your pounding method to get a throat measurement sounds effective but perhaps I am misunderstanding something about it as it does not sound simple compared to a chamber casting that only centers on the throat. I would appreciate a video to convince me your pound method is simple and easy. I would certainly change if it is simpler and easier and just as accurate to get a throat measurement.
Gary
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Gary wrote: “There is no reason to slug a bore unless your groove diameter is larger than your chamber throat diameter. A rifle with that unlikely condition will never be a good shooter with any kind of bullet at all as the bullets will wobble down the loose bore and shoot all over the place.
Your pounding method to get a throat measurement sounds effective but perhaps I am misunderstanding something about it as it does not sound simple compared to a chamber casting that only centers on the throat. I would appreciate a video to convince me your pound method is simple and easy. I would certainly change if it is simpler and easier and just as accurate to get a throat measurement."
Gary,
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Of course since this thread is about a recipe for beginner cast bullet shooters we could always go back to the old outdated method of sizing a couple thousandths over groove diameter, trimming the brass to maximum spec., and using something along the lines of 11 grains of Unique, 16 grs of 2400, or 20 grs of 4198. Worked for a lot of years for a lot of people to get them started and doesn't require much work. Once they get their feet wet and find out if they like the game or not then they can get into all the other stuff.
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The Chamber Cast Alloy I use is from RotoMetals:
The temperature chart for dimensional change is easy to use and the instructions are easy:
Description 
Sold by the ingot. Ingot weighs approximately 1 pound.
Rotometals Chamber Alloy (158-190) is the best known material from which to make a casting of the chamber and throat of a firearm to determine caliber or check the dimensions. It melts at a temperature just above M & M's, so all you need is a propane torch and a bullet casting ladle. It can also be used to make a cast of a dovetail slot or any other hard to measure area. Also, it is great for removing the front half of a case from the chamber, in the event of case head separation; and lots of folks cast a small portion of the barrel to determine bore diameter. For best results, measure the casting one hour after casting. Contains 42.5% Bismuth, 8.5% cadmium, 37.7% lead, 11.3% Tin
Technical Information
Basic Instructions
<>Plug the bore immediately ahead of the throat of the chamber using a small cleaning patch.
<>Pour the alloy directly into the chamber until full and allow Melting Point to cool, it will turn a shiny silver color. As soon as it has cooled enough that it is no longer a liquid (and doesn't present a burn hazard), remove it from the chamber. Take care not to overfill the chamber as the alloy will then run into the locking lug area, making removal extremely difficult.
<*>During the first 30 minutes of cooling cerrosafe shrinks. At the end of one hour it should be “exactly” chamber size.
Notes <>Melts between 158 and 190 degrees Fahrenheit <>Should be melted in a clean iron ladle without direct flame on the product. <>The chamber being cast should be cleaned thoroughly and a thin coat of oil or graphite applied. <>Reusable
Contraction expansion factor versus time, measured in inch per inch compared to cold mold dimensions. Test Bar x 10 <>2 minutes - .0004" <>6 minutes - .0007" <>30 minutes - .0009" <>1 hour + .0000" <>2 hours + .0016" <>5 hours + .0018" <>7 hours + .0019" <>10 hours + .0019" <>24 hours + .0022" <>96 hours + .0025" <>200 hours + .0025" <>500 hours + .0025" I record on a slip of paper the measurement at 1hour and then again a week later and keep the notes with the slug in an envelope noting date and rifle. If you have done this several times, you can easily verify the metal does dimensionally what the maker says it does for $15.99 a pound. The product is re-usable also and one pound is easily a lifetime supply for one shooter. It is just my preference to use this product and I find it very easy to follow the instructions.
Gary
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I prefer and use the pound cast. All one needs is the ctg case, lead and rod. In fact I've flled the case to the neck with #12 shot, and used a length of lead wire sinker for the pound. No heat, muss or fuss. It's simple, quick and the dimensions never change.
Match Director
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Gary,
Happy New Year!
Given a supply of 311284 and 314284's of varying band and nose diameters: 309-314 and 299-304 respectively (pretty much any combo of the above), what procedure would you use to determine the best fit without the chamber cast? The 30 calibers are an M1, M1903A3, M1917 (5 groove), K31. There is also a M39 Finn Mosin. All Mil-Surplus, no commercial barrels. I have LEE 309, 311 and 314 sizers.
Dave
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If you are not going to measure your chamber throats with a chamber or pound cast, all you can do is guess and try the sizers you have, then ink the bullets and look at them after chambering dummy loads. Look for the one that slides in and marks the ink but chambers easily. I suggest you also get .310", .312” and 313” sizer dies added to what you have, then you have 30 caliber covered. Don't lube the bullets for these test dummy rounds, lube hides bullet ft.
Gary.
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I apologize. You're right, it's altogether too complicated a procedure, and results can be had following the advice given.
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