Factors that cause leading

[rcarter9578]

I am new to the forum and have been trying to learn as much about casting as possible before I start in the next week or so but I am mainly stuck on the topic of the type of alloy to use and also how important it is in preventing leading. I understand that a lot of factors come into play such as the BHN of the alloy, quality of the cast, sizing of the boolits, fit in the barrel and also the lubrication used. My question is based on the above factors which of them is most important vs least important in preventing leading. I know I cant just focus on one area and slack in the another and expect great results but I am just trying to avoid any damage to firearms before I send a boolit down the barrel. This will be for strictly recreational/weekend shooting. I am planning on casting 124gr 9MM, 208gr 300BLK and also 62gr .223. I am planning on powder coating all of them so that should serve as the lubricant. Any advice/information/links to other threads that I have missed is appreciated!

[MBTcustom]

Don't worry about leading. If you are getting leading, it means you managed to blatantly ignor the most common casting advice on this forum, and bought the wrong mold.
In order to prevent leading, you need an alloy that is almost anything other than pure lead, and you need to use a mold that casts at least .001 larger than the groove diameter of your rifle/handgun.
There is a lot of information here on how to determine the exact groove diameter of your barrel by "slugging" it.
The main thing you need to worry about is accuracy, and that's where getting the right alloy, lube, and powder comes heavily into play.

In the case of your 300BLK, use COWW+2% tin (ye old standby). Powder coating with the shake-n-bake method will get you where you want to be (research the correct powders for the job).
For propellant, try trailboss.

The .223 is going to be difficult. Getting PC bullets over 1800FPS is challenging, and getting ANY bullet with ANY lube to shoot fast enough to cycle the action is one of the rainbows many here chase after (some have even found a pot of copper coins at the end LOL!)
Just kidding! The fact is, it's possible, but very difficult to achieve reliable results.

Honestly, if you plan on doing PC, you can make no better decision than to post your questions in the PC section. The gents over there are at the top of their game with this exciting method of coating bullets.
Good luck!

[gloob]

For pistol bullets, I agree. You can use a very soft alloy without any problem. But for softer bullets, you have too keep an eye out for case swaging. For my softer alloys I need to use custom expanders to open up the case. I use plain wheel weights just fine.

For 223 bullets you probably want to go harder. I can push gas checked 50:50 wheel weights to lino just hard enough to cycle my gun and shoot accurately. But any much harder and the bullets melt/disintegrate.

[MtGun44]

Actually, BHN plays very little part at all in leading, yet you - like most new folks -
list it first. It is at best, third or fourth. Fit is #1 by a mile, followed by lube and
design.

For rifles, there may be more to the BHN issue, but for my normal loads in the
under 2000 fps range, air cooled wwts at about 10-12 BHN WITH A GAS CHECK
have been fine in everything I have tried.

[44man]

Actually, BHN plays very little part at all in leading, yet you - like most new folks -
list it first. It is at best, third or fourth. Fit is #1 by a mile, followed by lube and
design.

For rifles, there may be more to the BHN issue, but for my normal loads in the
under 2000 fps range, air cooled wwts at about 10-12 BHN WITH A GAS CHECK
have been fine in everything I have tried.
This is good advise! I hate the BHN numbers since too many alloys can have the same numbers.
I shoot hard boolits but I fit them. Hard will not lead your gun and many softer alloys also will not lead your gun.
The nine is a fairly high pressure round with fast powders that peak right quick so you need a tough enough boolit that will not skid rifling. Those alloys could fill a book.
My alloys are figured for accuracy only for all the shots I care to take and I can go 3 years without touching a bore.
Some need to clean after 20 shots so that means an alloy change and that might not mean a BHN change.

[popper]

Forget the PC, try the HiTek coating - real cost is about the same as are results. Whatever gives you ~3% Sb, WD if needed. I'd go for the Lee 155 unless you are planning on a can from a pistol length. You will have trouble cycling a carbine gas with the sub.

[Animal]

Actually, BHN plays very little part at all in leading, yet you - like most new folks -
list it first. It is at best, third or fourth. Fit is #1 by a mile, followed by lube and
design.

For rifles, there may be more to the BHN issue, but for my normal loads in the
under 2000 fps range, air cooled wwts at about 10-12 BHN WITH A GAS CHECK
have been fine in everything I have tried.

RCarter, take this advice, stick it in your back pocket and carry it everywhere you go. I just experienced some very nice before and after results with a mold I had lapped to fit my throats better. Undersized results gave me a mess of leading. The after results that provided properly fitting bullets left my barrel clean as a whistle. Many folks would have condemned my hard alloy as the problem. But it was not, the bullet just needed to be a smidge bigger.

[waksupi]

Hey, wadaminute! Another RCarter on the forum? Why didn't my mom tell me I was twins?

[Doggonekid]

I will agree with the #1 answer is the mold. Fit the boolit to the gun. Most of the time I buy a mold from RCBS and a sizer die and every thing works out great. Sometimes it takes a lot of research to get that perfect fit. Sometimes you half to order a custom mold and custom sizer die to get the results you want. Next I would say is the reloading. You need to find the right load for you and your gun. I am still in the testing stage about PC. So far it seems to work well I just have not shot enough boolits to sure. There are no answers from this fourm that would be better than your own experience. Load and shoot often and keep good records and targets.

[rcarter9578]

So boolit to barrel sizing should be number one concern. If I am understanding everything correctly I will have to slug the barrel that I am intending on using and then ensure that my boolit is +.001 compared to the groove diameter. Lets say I am still planning on using PC (since this is what I am most knowledgeable with right now). I am under the impression that PC will add approximately +.002 to bullet diameter. (Once I start casting and adding PC I will measure so ensure this is accurate.) So with a barrel diameter of .358, I will need a cast boolit with a diameter of .357 and then once the PC is applied I will be sitting at .359 which would get me to my +.001. Am I on somewhat of the right theology or am I just making stuff up?

Should I start with casting 9MM for a Glock 19 or 300BLK subsonic used in an AR with a 7.5 barrel and pistol length gas system? I have read that 9MM can be a bit difficult.

[Wayne Smith]

Generally I agree with the above but one major point is missed. Especially with rifles, fit the throat and you will be more likely to achieve accuracy and not have leading. If you fit the bore but not the throat the boolit can enter the barrel crooked. If you fit the throat you will fit the bore and the boolit enters the bore straight.

[cajun shooter]

Rcarter9578, My advise is for you to go to the sticky section and download the "FREE BOOK" that is known as "FRON INGOT TO TARGET" written by Glen Fryxell and Robert Applegate. It's about 170 pages long and will answer all of the questions that you will need the answers for. I have been casting since 1970 and I still go to it for reference. I printed my pages out and put them in a 3 ring binder so they would be at arms reach at all times.
These two men could of easily published this book for sell and made a lot of money but they chose to release it here to the members of Cast Boolits. It's a treasure of information and should be mandatory
reading for all new casters.
In the hobby of casting just like all other endeavors they have more than one way to reach an end result. The problem with posting questions on any forum is that you have no idea who you are listening to. It could be a person who just started themselves and feel they now know enough to post an answer and become one of the old members or it could be a very knowledgeable person with a low posting count but is one of the best at the game of turning lead into a perfect bullet for his guns.
Take time to download the book, it will be a very wise move. Good Luck David

[44man]

I have not gone to PC because I don't know it it will wipe off a boolit like many TL's do, right at the start or whether it is retained the whole trip down the bore. Never seen recovered boolits shown yet. Does it toughen a soft boolit? It is what it is, a coat of paint.
I still believe in 2 to 3 GG's on my boolits.

[rcarter9578]

Thanks for the reference Cajun shooter! Just downloaded it and will get knocked out in the next day or two!

[edctexas]

You are starting with two tough cookies, a GLock with polygonal rifling and a gas operated gun. The boolit fit in the GLock is the most important thing, but it is not a simple measurement of a barrel cast because the lands and grooves are not as defined as normal rifling. The PC or Hi-Tek coating is good because you maybe able to make the boolit thicker with the coating to "make it" fit. I am getting OK results in H&K poly bores (9mm and 40S&W). I still have some trouble with the RN shape so I have switched to something more like a SWC.

In a gas operated gun, the PC or Hi-Tek is a good choice as it seems to leave little **** in my AR-10. That is on all the bolt carrier parts! Slightly less gunk than with normal rounds. In most rifles, the fit is to the chamber and leade area of the weapon. There are several nice threads showing this recently on the site. Basically the boolit size is set by the diameter directly in front of the case end and where the leade to the rifling starts. If the boolit is close to this diameter, then it is directed straight into the rifling. It should go straight out the muzzle to the target. To get any speed, you'll probably need a gas check on the boolit base. BUT!! the 300BLK is often shot subsonic! If you start with sub loads, you should not need GCs. I use GCs on my AR-10 with loads in the 1600-1800 FPS range.

Ed C

[MtGun44]

Wayne is right - but the fit to the barrel is all that is required TO PREVENT LEADING.
May be inaccurate as all get out. Fit the throat for ACCURACY.

Groove diam +.001 seems to work for pistols, some of the time, but as a general
rule for rifles, I stick to at least .002 bigger or even .003, and this is where the
.002 (or even .001 oversized) may not lead, but may not shoot as accurately as
.003 ---- with the standard caveat that ALL GUNS ARE A THING UNTO THEMSELVES
and your gun may well like something different than my ostensibly identical
gun.

9mms seem to do better with .002 or .003 over groove diam, where .45 ACPs seem
to do well with .001 over or even some with only .0005 over. Revolvers should
be fit to the throat (front of cyl) rather than the groove diam. . . . . and throat
should be at or greater than groove diam.

Read "From Ingot to Target" by Glen Fryxell -- well worth it.