09 December 2003, 13:22
ByronSizer Die Choice
O.K., I'm sorta new to the casting my own bullet realm and I came up with an interesting question. Now I know that it seems the conventional wisdom has said to size your bullets .001" larger then the bore. The question I have is, with fast moving 2000+ fps rifle bullets that are linotype or heat treated WW and GC does this still apply?
I have not seen or read anything about it explicitly and have read through Veral Smith's book at least once cover to cover. The reason I bring this up is that aren't the linotype or heat treated bullets as hard as condom bullets? And if so, why size them larger then one?
I'm getting ready to order a die for my Star and at $40 or so dollars a pop I'd like to have a better chance at being right with the first one, instead of the second or third. I've got a Lachmiller 311 169 PT that I'm going to start with. Pure lead slugs are running B/T 168.+ gr and 170.0 gr, bare. One of the rifles I am going to try them in has a Palma Match chamber. I'd like to hit 2500 fps or more if possible. The die and lube are two of my last shopping items.
What are your thoughts and experiences here?
Thanks,
(corrected spelling in Veral's name)
[ 12-09-2003, 05:19: Message edited by: Byron ]09 December 2003, 14:10
<ben.>Byron: In my opinion I would buy the largest die
for your star. For example a 310 or 311. Use it for lubing and gas checking your bullets. You can also gas check with the Lee. Then buy a $12 push thru Lee die. Say a 309. They also have 308. If you want a 310 they are not hard to enlarge. Also I beleive for $25 they will make any size you want. Jacketed bullets a heck of a lot harder then the hardest lead. ben.
09 December 2003, 18:26
mountaingunByron,
Good question, thanks for asking.
Actually, conventional wisdom is shifting from "groove diameter" to "throat diameter". If the bullet is a sloppy fit in the throat, it is less likely to be delivered straight into the rifling, and may also experience some gas cutting while it is in the throat.
In a perfect world, the throat diameter is the same as the groove diameter or maybe 0.001" larger.
If the throat is a few thou larger than groove diameter, size to fit the throat, allowing a little clearance for easy chambering.
If the throat is more than a few thou larger than the groove diameter, as many mass produced guns are, I am not sure what is best -- perhaps a new barrel.
10 December 2003, 00:55
OldfellerSome old military Mauser rifle throats were intended to chamber a round literally coated in mud (trench warfare). They were cut large for this reason.
The throats are big. Very big. Much bigger than +.001" over bore diameter.
We have made up special bullets to fit some of these mil-surps that filled up their throats completely and have had good success shooting bullets that get swaged down .004"-.006" by the weapon's own throat during intitial or first movement of the bullets. They do get good initial alignment and they have lube grooves that are deep enough to do the job.
The technically best answer is "measure and fit your bullet to the throat itself for a rifle, fit your bullet to your cylinder throats areas on your revolvers" when shooting lead bullets.
Oldfeller
10 December 2003, 02:22
LeftoverdjOn a slight tangent, to get 2500 fps, lube choice is gonna be REAL important. The now obsolete Bullet Master would do it, but I've been out of the game for a few years and don't know which of the current crop will.
10 December 2003, 04:45
ByronI guess it's a good thing I like to tinker because there is diffinetly more to cast bullets then meets the eye.
O.K., here is some info on the bullet (all measurement are approx. - bare):
Spitzer nose
Overall Length 1.050"
Nose Dia. .297" - .299", length .525"
Crimp/Lube groove .050", depth .018"
Drive band .140" wide, dia. .311"
another lube grove
another drive band
Gas Check Shank dia. .280", length .160"
These measurement were taken with digital caliper, so take them for what they are.
I will update with chamber/throat dimensions when I get to work because that is where my drawing is at.
Of the lubes that came with the sizer, Lyman IDEAL - ?, RCBS - Rifle Bullet Lubricant, and Javelina - The Alox 2138F - Beeswax, I guess I could start with the RCBS. But based on what I have read on this site maybe I should see about getting some of Felix's or LBT lube.
Later,
[ 12-09-2003, 20:12: Message edited by: Byron ]10 December 2003, 05:14
starmetalAladin,
This group was fired with the Lyman 314299 sized .310 in my CZ 550 30-06 with WRA brass over 30 grs of 844 surplus powder with kapok tuff filler. It's ten shots. There was no care taken in casting, I didn't cull out by weight, I didn't orient in the sizing process, and they were water quenched at casting. I sized them after they were hardness treated and lubed with Javelina. The only experimentation I tried with it so far was to shoot the bullets unsized as the dropped from the mould and accuracy was down alittle bit. I was surprised my CZ shot like this as I have mentioned before SO FAR it hasn't shot condoms like thise YET. I wish I had someplace to try them at 600 yds like you have.
Joe
