Callibrating bullets, way to go?

[HDS]

Okay so I bought a mold last autumn as part of a group buy here. It was a 4-cavity mold that casts 245gr .44magnum bullets.

I actually haven't cast any bullet yets... Had no lead, since then I've acquired 100lbs of pure lead (any tips btw for good sources on tin/antimony?) and just now I bought a Lee Pro 4-20 melter. I also bought a bunch of cheap lead bullets so I had something to shoot while getting my lead casting in gear. I still have 400-ish bullets left from that, they're 225 gr .44-40 bullets actually in .431".

What I am wondering about is whats the best way to go to get these bullets to work best with my revolver (S&W 629) that I am gonna shoot it out of. It's got a bore thats barely .429" (gunsmith with a proper equipment checked it for me) and the cylinder throats are .4295" so they are on the small side and this mold drops them at .434" which is rather large. Which is the reason for this post.

I know that too much sizing down or up of a bullets diameter is not good, but it doesn't seem like it can be avoided here. I was considering having the revolvers chambers reamed out to maybe .431", that way the bullet won't have to reduce in size that much when I shoot it. I also figured that during callibration you could possibly get it down to .432" or so. So you see what I am doing here, spreading out the sizing down over many separate moments until it hits it's final swage down in the bore to .429". I have no idea if this is the way to go about it or not?

I know that you shouldn't callibrate a bullet down too much and I know that the cylinder chamber should not swage the bullet down to a diameter smaller than the bore and right now they are quite close to each other in size. I think increasing the size of the chambers is good since they're on the small side anyway. Still with this procedure the bullet will be reduced in sizes in several steps from the mold .434 -> .432 (callibration) -> .431 (cylinder) -> .429 (bore),

I'm wondering if all that reduction in size is good for accuracy in the end? Or is it like I imagine it is, that spreading it out over various steps like this can work?

I'm not sure I even make sense so thanks for reading!

[44man]

Okay so I bought a mold last autumn as part of a group buy here. It was a 4-cavity mold that casts 245gr .44magnum bullets.

I actually haven't cast any bullet yets... Had no lead, since then I've acquired 100lbs of pure lead (any tips btw for good sources on tin/antimony?) and just now I bought a Lee Pro 4-20 melter. I also bought a bunch of cheap lead bullets so I had something to shoot while getting my lead casting in gear. I still have 400-ish bullets left from that, they're 225 gr .44-40 bullets actually in .431".

What I am wondering about is whats the best way to go to get these bullets to work best with my revolver (S&W 629) that I am gonna shoot it out of. It's got a bore thats barely .429" (gunsmith with a proper equipment checked it for me) and the cylinder throats are .4295" so they are on the small side and this mold drops them at .434" which is rather large. Which is the reason for this post.

I know that too much sizing down or up of a bullets diameter is not good, but it doesn't seem like it can be avoided here. I was considering having the revolvers chambers reamed out to maybe .431", that way the bullet won't have to reduce in size that much when I shoot it. I also figured that during callibration you could possibly get it down to .432" or so. So you see what I am doing here, spreading out the sizing down over many separate moments until it hits it's final swage down in the bore to .429". I have no idea if this is the way to go about it or not?

I know that you shouldn't callibrate a bullet down too much and I know that the cylinder chamber should not swage the bullet down to a diameter smaller than the bore and right now they are quite close to each other in size. I think increasing the size of the chambers is good since they're on the small side anyway. Still with this procedure the bullet will be reduced in sizes in several steps from the mold .434 -> .432 (callibration) -> .431 (cylinder) -> .429 (bore),

I'm wondering if all that reduction in size is good for accuracy in the end? Or is it like I imagine it is, that spreading it out over various steps like this can work?

I'm not sure I even make sense so thanks for reading!
Many S&W guns run on the small side and .429" is common. You would still be OK with .430" boolits if rounds chamber and maybe even .431". The throats will size them and all you need to do is work loads so as not to raise pressures too much.
What you need to worry about is boolit damage either in the throats or in the sizer. You don't want to wipe out GG's so larger and deeper grooves would be better. You don't want to remove the crimp groove in the sizer either. Your consideration is the boolit design you start with. A Lee TL boolit can turn into a smooth sided boolit with too much sizing.
I would say you would do better with a mold that drops boolits at 430" to start with. Some will say GG full of lube will stay put when sized but that is not so. .434" might just be too large to start with.
Your gun will shoot great with .4295" boolits.
There is no sense opening the throats, it is right as is. Find a boolit that fits.

[Maven]

HDS, By "calibrating," do you mean sizing or optimum sizing diameter? If so, .44man is correct about .430" and maybe even .431" being correct for your S & W. As for sizing down from .434", it's not a problem if it's done concentrically. A bit of lubricant on the CB's will make the job easier, as you may suppose. Moreover, the Lee Precision press mounted sizing die .430", #90062) will make the task go quickly and can easily be opened to .431" if necessary.

[HDS]

By calibrating I refer to the sizing down (or up) of a bullet, like when you run the bullet through a lubrisizer.

As for the bullet mold, I really like that design and I would really like to keep it, if it was any old lee mold I'd probably consider getting another mold, but as it is I thought the revolvers chambers where on the small side for most commerical bullets even? What is the proper size difference between the bore and cylinder throat? .0005" or bigger?

I'm looking at a Lyman 4500 for a sizer btw. same reasoning as behind the molds there actually, been too much buying twice in my life, rather cry once. Which is kinda ironic given I am told I should sell this mold.

Here is the bullet mold in question that I got via the group buy:
http://castboolits.gunloads.com/showthread.php?t=64662

[Maven]

HDS, I wouldn't sell that mold, nor would I recommend buying a new Lyman 4500 lube sizer as there have been too many problems with them reported here, i.e., in the Casting Equipment section. A clean, used Lyman 450 or RCBS Lub-A-Matic would be my recommendation even if they lack a base heater (easily made from a pc. of aluminum & old elec. iron). Btw, I use the 450 more than my RCBS Lub-A-Matics, but all work well. The tendency of 450's to leak from the base can also be fixed with little time, effort, skill, or material purchase* on your part required.


*Tablet backing is used to form a gasket under the base of the lube-sizer and has been 100% effective. The whole job takes less than 15 mins. of your time.

[fredj338]

Whether you size the bullet or the cyl throats do, same thing. If you are going to run them @ 0.431", then opening the throats to 0.4305"-0.431" would make sense.

[MtGun44]

I'd just shoot some .430 or .431 diam boolits and see how they do.

Not a chance that I would have the throats reamed if it were mine, unless I had spent
a lot of effort and could not get it to shoot well. I would be surprised if your gun
has any problems at all.

Bill

[HDS]

It probably doesn't have any problems, I'm mostly curious as how to get these bullets I will be casting to work best in my gun. I was planning to make them the bread & butter for this gun, what it'll eat almost all the time from here on.

[Bret4207]

Do as Bill and Paul suggest- size your boolits ( the Lee system would be fine) and do not alter your gun. That would be the very, very last thing I'd do. If you barrel is truly about .429 GROOVE, not bore, diameter and your throats actually run .4295 then a .430-.431 boolit should work just fine. I agree .434 is a bit larger than I'd go to, but since you didn't measure your throats or barrel with the same equipment your smith did and if I understand correctly he didn't measure your cast boolits...the possibility that your measurements are inaccurate simply because of differing measuring instruments exists. If you can get your smith to measure the boolits to make sure things are standardized that would eliminate one potential variable.

An inexpensive Lee sizing kit and a little range time sounds like what you need. As far as that pure lead goes, if you can find wheel weights that would be about the cheapest way to enrich the alloy. If not, Rotometals and other advertisers here carry enrichment metals. Another option would be to purchase the cheapest commercial boolits you can find of any caliber that is advertised as HARD CAST. Most commercial casting concerns use an alloy much harder than needed to reduce denting in shipment and storage and to feed the consumers perceived notion that harder = better, a myth, a fallacy, a lie, pure misinformation based on advertising hype and a misunderstanding of what makes boolits work or fail. If you could lay your hands on a mess of rock hard boolits you could add them to your lure lead till you got an alloy that was workable, something approximating WW alloy to start with, or even mimicking 50.50 ww/pure. Another alternative would be trading your pure for someone else's WW alloy. Some of us have scads of WW but little pure. That might be the easier plan.

[HDS]

Do as Bill and Paul suggest- size your boolits ( the Lee system would be fine) and do not alter your gun. That would be the very, very last thing I'd do. If you barrel is truly about .429 GROOVE, not bore, diameter and your throats actually run .4295 then a .430-.431 boolit should work just fine.

Yes, I was just on my way to this thread to say that I might have confused people earlier with improper terminology. It's groove diameter I've been talking about on my gun, not bore diameter.


I agree .434 is a bit larger than I'd go to, but since you didn't measure your throats or barrel with the same equipment your smith did and if I understand correctly he didn't measure your cast boolits...

Well the measuring of a 5-groove slug requires a special kind of v-anvil micrometer that I did not have, so I slugged my revolver with a pure lead bullet and took it to the gunsmith who measured it for me. I measured the throats myself using an ordinary micrometer.

I've never measured my own cast bullets, primarly becayse I've not cast a single bullet in my life yet :p

I bought the mold I have because castboolit users recommended it to me as a good mold for my purposes, compared to the Lee molds I was looking at. By that time I did not know what size I actually had on my revolver so yeah that was a dumb move of me, but I didn't want be left out of the group buy on this very impressive mould.


the possibility that your measurements are inaccurate simply because of differing measuring instruments exists. If you can get your smith to measure the boolits to make sure things are standardized that would eliminate one potential variable.

Thats certainly possible, though I've checked the throats multiple times using more than one tool. If there's an error somewhere it likely lies in the V-anvil micrometer and thats an expensive tool I cannot afford to get, and the gunsmith himself only has access to it sporadically via a machinist colleague.

[HDS]

Oh and as for the bullets, I do have 400-ish bullets of these .431" lead bullets, they are not pure lead. Wheel weights was one of the things I looked into but it's not looking good in my part of Finland, none of the tire shops wants to part with theirs. They reuse all their leads, cast new weights, because an EU law prohibits buying new lead weights, and the replacement weights of other metals just aren't as good.

[Wayne Smith]

I would find the alloy Rotometals sells that has the highest tin/antimony percentage available. This minimizes your shipping costs. Figure how much of this to add to your pure to get the hardness you want. Unless you have a local source for alloyed metal - then go there and do much the same thing.

For sizing consider your costs. The Lee setup will size and seat gas checks, but not lube. You will have to pan lube. A Lyman or RCBS or Saeco lubesizer will do both, but I have no idea how available they are to you.

[HDS]

Well, while I am at it, shot 50 rounds using a 225gr .431" bullet and vihtavuori n32c powder last night, looked at the gun in detail today and found little leading in the bore.

Forcing cone has some buildup like this on both sides, normal?
http://i.imgur.com/QrKR4.jpg

On closer look I am seeing some lead shavings in the cylinder throats too, not all of them either. Not sure what that indicates.
http://i.imgur.com/MynMS.jpg

[44man]

Not really, there should be no lead anywhere. Lead in the throats and cone means the boolits are slumping and there will even be lead escaping the gap.

[HDS]

I thought the crimp was kinda weak on this batch, could that account for this? Letting the bullets move too much from recoil or some such?

[Maven]

HDS, What kind of accuracy did you get? If only so-so, the crimp may be a contributing factor, the leading less so. Do those CB's slip through the cylinder throats with a bit of resistance? Have you tried pushing 1 or 2 through each throat and measuring (with a micrometer) their diameters for uniformity? As to the crimp, is all of your brass the same length? If not, trim it to make it so. Btw, Brian Pearce, in the current issue of "Handloader" magazine, says that a little leading in the forcing cone isn't a major concern. (I know .44man disagrees with this.) Ideally perhaps there should be none, but I get some in my Ruger SBH and accuracy is excellent. Barrel leading, well, that's a different story....

[HDS]

The CB will not push through the throat even with a lot of force. Accuracy was only so so as well, though its hard for me to say as I need more range time in order to reduce that error-factor.

I will measure each throat and check for consistency.

[44man]

The CB will not push through the throat even with a lot of force. Accuracy was only so so as well, though its hard for me to say as I need more range time in order to reduce that error-factor.

I will measure each throat and check for consistency.
Crimp will not change a thing. It is alloy hardness. Soft boolits slump and deform. The boolit is trying to get out of the gap. Point of least resistance.

[44magLeo]

Your as cast diameter will be different depending on the alloy. In my Lyman #46 it has a table. In this table is the 429421 boolit. In pure lead it has a .4296 diameter, WW it is .4303, Lyman #2 .4310, in lino .4314.
If sized with a .429 sizer the diameters are lead .4286, WW .4287, #2 .4290, Lino .4294.
You won't know for sure just what your boolits will be until you cast some. I would get some cast and see what they measure.
I would get Lee's .430 sizer kit. Size a few and see how the shoot. The kit won't cost much. Cheaper than a Lyman or RCBS. This will tell you a lot about what works.
When you find what works then you can spend the money for a different sizing system.
Also the boolit weight will vary on the alloy, lead will be the heaviest at 256 grs, WW 252, #2 245, Lino 238.
IMHO the boolit your mold will make is about all you need.
I have been at it for 33 years and use that boolit in ACWW and 8.5 grs Unique for a light load. In WCWW over 21 grs 2400 as a heavy load. can serve you well. Both very accurate, 1/2 inch at 25 yds of a good rest. Head shooting the small game is easy to 50-75 yds. Don't hurt the meat. The heavy load will take most any animal you care to point it at.

[44magLeo]

On the leading if it's a new or not shot much the chambers and forcing cone and barrel can be a bit rough. A few hundred J-words will smooth things up, or have your gun smith polish it up some.

[HDS]

Yeah its very new, only a few hundred CBs through it and a hundred more commercial ones. The new batch I tested, with a much better crimp now that working properly showed no leading in the throats atleast