Interesting development..... Shrinkage?

[redbird1976]

The wife swiped the tv remote from me tonight; so I've been sitting here mic'ing the bullets that I casted last week. I've noticed something interesting. All of my sized and lubed bullets are measuring .400. They are nice and round, though. This is of interest to me because out of the mold they were .401-.403. They were sized within 24 hours of casting. I can't remember if I bothered to measure any of them after I sized them. More than likely, I took it for granted that my RCBS .401 sizing die was sizing them to the proper diameter. But it raises the question: Has the curing process resulting in the diameter of the sized bullets shrinking?

Regardless, I've been firing .400 diameter cast bullets through a barrel that slugs .401[smilie=b:. Another side note,that probably answers a lot of my previous questions,
I recovered some of my fired slugs from my range. They all exhibit the same condition: 1. little or no rifling marks showing
2. from nose to tail there are finely spaced spiral grooves that appear to be burned into the bullet (although it could be abrasion from the soil) consistent with a right hand twist.
3. .390 diameter.

Any thoughts?

[knifemaker]

I have found that a lot of the sizing dies are running a wee bit undersize then what they are supposed to be. I would try sizing some and measure right after sizing to see if your die is .400 instead of the stated .401.

[sagacious]

Aside from initial thermal cooling from the molten state, I'm not aware of any process that would decrease the diam of your bullets. Sounds like your sizing die is in need of some fixin'.

I agree with your assessment that the fine grooves on your .390" recovered slugs were made by grit in the soil. Sometimes it's enough to wipe-out even deep rifling grooves. You might set up a large box of sawdust for shooting at-- you'll be able to recover your slugs with less deformation, and very often one can learn valuable insights from recovered bullets. Good luck.

[Dannix]

through a barrel that slugs .401
I'm new to all this, but why aren't you trying .402 or .403 sized boolits?

If you need a bigger boolit then what your mold is dropping, try reading up on beageling (http://castboolits.gunloads.com/showthread.php?t=26930&highlight=beageling). You could look at your alloy as well, but that's beyond my current scope of knowledge.

HTH

[fryboy]

a 40 cal mold is one of my newer ones, when i was waiting for it i noted one thing ,if a person wants a sizing die above .401 they will either have to make it or buy a custom ...


umm u didnt state if they were leading or not lolz and some alloys do shrink ..look at cerrosafe for an example - there is a time frame to get the size from it ,several of the low melt alloys have different shrinkage ( even some a wee bit later )

[docone31]

You might need to flap wheel your sizeing die a bit.

[redbird1976]

They were leading severely. I've fired a couple hundred rounds over the past couple of days. Different charges, different powders, different OAL-- same results severe leading. The leading was worse with bullseye. The result is i've spent about four hours, in total, to get the barrel clean

[redbird1976]

I'm new to all this, but why aren't you trying .402 or .403 sized boolits?

If you need a bigger boolit then what your mold is dropping, try reading up on beageling (http://castboolits.gunloads.com/showthread.php?t=26930&highlight=beageling). You could look at your alloy as well, but that's beyond my current scope of knowledge.

HTH

The bullets dropped from the mould at .401-.403.

[Dannix]

What kind of mold? Just curious.

I know one uncommon reason to shoot an under-sized boolit, but otherwise, if I understand correctly being new to this, you want to bootlits ~.002 OVER bore. .400 through .401, cerebus parabis, is essentially asking for leading from what I've read. :???:

Take a look at beagling, if need be, and lap that sizer. :D

That uncommon reason? +P loads. From what I understand, .400 through .401 for 10mm+P loads could work, at least in moderation. +P is NOT recommended for reloading, fyi.

[redbird1976]

The mould is a lee six cavity mould.

[257 Shooter]

Redbird, Shoot some as cast and see if that will stop the leading. Pan Lube or use Alox.

[Bret4207]

Do as suggested and try some as cast. Like someone else mentioned, measure them right out of the sizer too. Dies have been mismarked before. If they drop .402ish then I'd get a .402ish sizer.

[prs]

Liquid allox the unsized pills and let your barrel do the real sizing. That could be the easy and best solution.

But, maybe you are like me and have some need to use traditional lube (in my case its my choice of using black powder). I used 6 banger that drops right at .454 to 455 for .45 Colt (LC). My Lyman sizer die is right at .454 and just kisses these when lubing. When I cast with another mold with modern .452 Colt dimensions, that also drop true to size, AND that oversized .454 Lyman die still lubes them just fine and does no sizing at, of course.

prs

[Springfield]

Star dies are availale in any size. Plus Lathesmith makes them for the Star also.

[montana_charlie]

More than likely, I took it for granted that my RCBS .401 sizing die was sizing them to the proper diameter. But it raises the question: Has the curing process resulting in the diameter of the sized bullets shrinking?
RCBS dies have the same outside dimensions as Lyman, so I presume the interiors are sized to the same criteria.
With Lyman, you can expect the I.D. to be smaller than the size marked on the lip of the die. A Lyman 401 die (for example) is meant to produce a .401" diameter in a sized bullet...if it was cast in Lyman #2 alloy.
A 'soft' bullet passed through the die will come out smaller because it won't 'springback' like the #2 is expected to.

My Lyman 458 die sizes (soft alloy) to .457" and my 459 sizes to .458".
The 460 die Buckshot made for me actually sizes to .460".
CM

[redbird1976]

RCBS dies have the same outside dimensions as Lyman, so I presume the interiors are sized to the same criteria.
With Lyman, you can expect the I.D. to be smaller than the size marked on the lip of the die. A Lyman 401 die (for example) is meant to produce a .401" diameter in a sized bullet...if it was cast in Lyman #2 alloy.
A 'soft' bullet passed through the die will come out smaller because it won't 'springback' like the #2 is expected to.

My Lyman 458 die sizes (soft alloy) to .457" and my 459 sizes to .458".
The 460 die Buckshot made for me actually sizes to .460".
CM

Interesting, that may explain the discrepancy.

[redbird1976]

I managed to find one of my unsized bullets in my reject bin that meaured .402. I hand lubed it and loaded it up over 4.5 grains of bullseye. It left very little leading in the bore. I was able to clean it out with four or five passes of a dry nylon brush. The only place it leaded was within the first 1/2inch of the rifling. I know one round isn't a conclusive test, but this has been better than my previous results. The bore looked more like what I'm used to seeing in my .45acp or 9mm.

[Bret4207]

Redbird, get some 4/0 steel wool and wrap a little on that brush. Your lead will disappear rapidly.

[257 Shooter]

Way to go. Now you know that your barrel likes a .402 boolit and a .403 may be even better. If you are handy enlarge your sizing die. If not send Buckshot or Lathsmith a PM to discuss their services.

[redbird1976]

Redbird, get some 4/0 steel wool and wrap a little on that brush. Your lead will disappear rapidly.

Thanks for the tip. I'll pick some up the next time I'm at Walmart or Lowes.

[redbird1976]

I bought some lead free solder at Lowe's tonight. How do I treat it in terms of alloying my metal. I couldn't find anywhere on it where it mentioned the constituent metal.

[HangFireW8]

I bought some lead free solder at Lowe's tonight. How do I treat it in terms of alloying my metal. I couldn't find anywhere on it where it mentioned the constituent metal.

What I have is 95% tin 5% Antimony.

Try typing in the exact manufacturer and brand name and the word MSDS into Google and see what comes up.

-HF

[sagacious]

I bought some lead free solder at Lowe's tonight. How do I treat it in terms of alloying my metal. I couldn't find anywhere on it where it mentioned the constituent metal.
Treat hardware-store lead-free solder is as if it were pure tin. You should not expect any alloying problems.