Author Topic: IDEAL CAST BULLET DIAMETER (Read 1059 times)

WL44 · « **on:** March 02, 2006, 09:45:22 PM »

OK, my 2nd ignorant question as promised.

I looked for a more appropriate Forum Category to post this, but this seemed as appropriate as any of the others.

My .44 Mag SBH slugs as follows:

*Cylinder throats .4323 (in fact Sierra's .4295 180grs drop right out the bottom of the cylinder if I drop them in the back and Hornady .430's too).

*Barrel .430

I've encoutered a few different views on ideal bullet size for the throat size, ranging from "not more than .0005" under" to "not less than 0.001" under".

I've also heard of problems with particularly WFN and SSK type designs where you risk ending up with a loaded round too large to chamber if you go close to throat diameter.

Mountain Molds seems to allow you to tailor the diameter from in front of the crimp ring, which may let me go with a .432 WFN, but a smaller diameter like .431 from in front of the crimp.

So what's the real deal on the appropriate bullet size?

Here in SA there's nothing over .431 cast (all Keith or variations thereof) available to purchase and I can't try out any other designs, so I'm cautious to import a mold, pay import duty and find that I can't chamber the loaded cartridges!

THanks again for any help.

Wim
(JHB, South Africa)

Lloyd Smale · « **Reply #1 on:** March 02, 2006, 10:43:25 PM »

its rare that a 44 ruger is out of spec that much Id first try sending it to ruger to see if they will replace the cylinder. IF not try .433 or even .4325 bullets. I dont know where you will be able to buy them one option i guess woud be to buy them unsized and size them yourself. If you didnt buy this gun new id guess someone was tampering with it. Like i said ive seen lots of 45s out of spec and a few 44s but never a 44 that big.

Steve P · « **Reply #2 on:** March 03, 2006, 06:17:57 AM »

Go load up some .431 bullets and see how they shoot. .001 over bore is standard sizing for cast.

Steve

Prof. Fuller Bullspit · « **Reply #3 on:** March 03, 2006, 08:06:09 AM »

Your measurements made me curious. I pulled the two .44 mag Rugers I have (one a Super Blackhawk the other a Vaquero) and measured the throats. Both are quite consistant at .429-.430. A 240 grain .429 lead bullet will not drop through any of the chambers.

I haven't done a lot of experimentation with this. All I know is that I have read that the ideal situation is to have the bullet about .001 larger than the chamber throat, and to have the chamber throat about .001 larger than the groove diameter of the bore.

I would also recommend contacting Ruger about the revolver if it shoots poorly. I realize this may not be an option given where you live.

If possible can you order some bullets of differet sizes to try? It would be nice to try a .433 bullet given your measurements.

No matter what mould you get be aware that you can adjust the size of a bullet somewhat by changing the lead alloy with "harder" (more antimony) bullets being larger than pure lead bullets cast from the same mould.

However, in my experience, softer bullets often result in less leading (at reasonable velocities) and are more likely to "bump up" to fit the larger size of your chamber throats and the swage down in the smaller diameter barrel.

For that reason, if I was not getting good accuracy with commercially cast .431 bullets I would experiment first with larger bullets, and if not able to do that, or if larger bullets didn't work I would try a standard mould (that cast .431 or so) and softer lead alloys.

Good luck!

WL44 · « **Reply #4 on:** March 05, 2006, 11:29:42 PM »

Thanks for the replies.

What's interesting is that to most of you think my SBH is quite out of spec, but in the successful internet searches that I've come up with there were Rugers (RH and BH) referred to out that needed .432's or .433's to shoot better.

For what it's worth, my BH is an early 80's model.

My understanding was around .0005" to .001" under throat and .001" over bore would be ideal, so yep somewhere between .431 and .432, but I'm wanting to order moulds and I need to get it at the "best" theoretical level up front.

"However, in my experience, softer bullets often result in less leading (at reasonable velocities) and are more likely to "bump up" to fit the larger size of your chamber throats and the swage down in the smaller diameter barrel. " Agreed, that is what I've seen recommended. Correct sizing takes care of most leading.

I may contact Ruger anyway, but won't be able to do anything if they agree that my pistol needs attending to. At least they can give me some pointers.

Thanks again for the replies.

Wim

MS Hitman · « **Reply #5 on:** March 06, 2006, 04:28:59 PM »

I am new to this discussion, so forgiv emy question, but are you having accuracy problems with your revolver? I have a SBH and it requires 0.432" on hard cast bullets to shoot tight groups. Softer bullets do expand to fill the grooves with out the magnum velocities. How do jacketed bullets perform for you?

To date, I've had no problems with any of the longer bullets such as the SSK fitting into a Ruger.

Lloyd Smale · « **Reply #6 on:** March 07, 2006, 12:05:54 AM »

if you didnt edit your post i must have read it wrong. 432 chambers arent all that big. and should acutually do well with bullets sized 432 to 433 Its just that most of my rugers are cut to run 430-431 bullets and they might shoot just fine out of yours too if you tried them

jhrosier · « **Reply #7 on:** March 08, 2006, 03:26:27 PM »

I'd go with a .431 mould. If it doesn't work out, you can always hand lap it bigger 1/2 thou at a time.

WL44 · « **Reply #8 on:** March 14, 2006, 09:15:27 PM »

Hi,

Sorry for the late reply; I was out of town for a week.

No edits to my post - .430 barrel, .432 (plus a teeny bit) throats.

I'm leaning towards .432 from all I've seen and from your replies. Thank you.

Accuracy is "so-so" but I expect (and think I can attain) better. Also that was generally with softer cast and pretty moderate velocities. The jackets that I've tried are so undersize that they are no better.

Jhrosier, the idea of lapping is a good one that I didn't even consider. Thanks.

Getting the mold bought and shipped will likely take a while, but I'll let you all know how it works out. I'll probably do a decent comparison with a few diameters and make a project out of recording the results.

Thanks for the replies and input.

Wim

leverfan · « **Reply #9 on:** March 15, 2006, 01:47:10 PM »

I had a Redhawk that had .433" or so throats. I found an old Lyman/Ideal mould on ebay that drops Keith bullets that just barely fit through the throats with a little finger pressure. This mould pre-dates the invention of the 44 mag, and, like some other older moulds I've tried, it drops large diameter bullets. The Redhawk is a good shooter with those fat Keith bullets(Wilbe Lead, another member here, has the gun now).

EdK · « **Reply #10 on:** March 28, 2006, 06:03:52 AM »

I also had a Redhawk with .433" throats.

It was circa 1992 manufacture.