Newbie with 54 Cal Great Plains Mould

[mveit]

Hi guys,
I'm a newbie to making boolits, and I just made my first cast.
I'm using a Lyman Plains Mould, which is a conical with solid base.
Bullet # : 548657
Grain: 450gr
Single Cavity # : 2654657
I've made about 150 bullets as a trial run.
I have some questions about the weight's I am getting, and also the size of boolit.

Boolit Weight Question
The Mould claims that it makes a 450g boolit.
My boolits are coming out with 90% 437-439g, and about 10% 440g. (I'm tossing back anything below 436, just a few are 435 & 434)
I do see that my bullets are shinnier, and not as dark as the bullets I have purchased, so I guess that it is not 100% lead. The fingernail test seems to indicate they are about the same hardness though.
Could non-pure lead be 10g lighter on a 450g boolit?


Boolit Size Question
The Hornady 425g boolits that I bought are .550 at the top bullet ridge and go smaller below that, something like .547, .545 and .540
My boolits that I made are .539 at the top and .535 at the base.
When I put them in my T/C Renegade they slip down in fairly easily compared to my purchased Honoday 425g Great Plains Boolits.

Did I just not pay enough attention when I purchased my mould? (Newbie mistake?)
Will it matter that the boolits I am making are .539 max diameter, will they engage the rifling properly? (I shot 10 last Saturday and they seemed to be fairly good at 100 yards. Not really any difference that I can tell between my loose fitting boolits .539" (438g) vs Hornady .550" (425g).

I sort of rather have a tighter fitting bullet, does it engage the rifling more?
Will my boolit stay tight after hunting 5 days?
Should I buy a new mould?
Should I care?

Thanks!

mveit (newbie - Idaho)

[stubert]

When you light off a load of black, the boolit will shorten and fatten to seal the bore. Your weight issue sounds like you have some tin mixed it. What does it melt at?

[mooman76]

Moulds rarely match up exactly what the grains come out to and there are other variables too like purity of lead. 10 grains off isn't hat bad for a 450 gr mould and they fact that the diameter is smaller could be part of it.
It should fit tighter but only shooting it will tell how it works. If you purchased it new you may be able to return it for another mould. Lyman has been famous lately for having undersized bullet moulds.

[mveit]

I am not sure the temp it melts at.
I'm using an infared thermometer and it is only getting the surface temp, which
is in the 343 F range, so it is clearly is not telling me the real temp of the lead.

I'll contact Midland and see what they say, maybe I'll call Lyman directly too.
Thanks

Mike

[mveit]

Ok looked up the Lyman Plains bullet mould specs and it should be a .548 dia boolit.

I measured three boolits and found:
Top ring: .541 (.541, .541, .541-542)
2nd ring: .539 (.5405, .539, .539 )
3rd ring: .539 (.538, .539, .541)
Base: .535 (.532, .535, .5355)

I also mic'd the base of the mould, (it's hard to do), and I get .534 to .537
depending on how good/bad I run my micrometer.

Lyman said the base should be at least 0.538, and one spec I read said .548 dia.
So, they offered for me to ship them the mould and they would re-size it.
Or, I think I can return it to MidwayUSA for replacement.
Lyman said about 2 weeks turn around.

When I measure my boolits, I see the diameter perpendicular to the mould halves mating surface as being like 2-3/1000 smaller, and the diameter where the moulds come together as being longer. I figured this is just due to the minor extra protrusion where the moulds come together. Normal variation?

So the question is, what should I do?
Replace it, or have it reworked?

[Maven]

"Could non-pure lead be 10g lighter on a 450g boolit?"

mveit, The answer to the above is yes. (Don't ask how I know this!) As for Lyman's offer to resize the mould and bring it up to their own specifications, I'd certainly do it as there's no guarantee that Midway USA's replacement would be better.

[mooman76]

I'd go for the resize from Lyman also. Like Maven said, no guarantee it will be better and probably not. Lyman makes a cherry to cut the moulds . As they cut more moulds, the cherry wears down and is smaller. If they use it too long the result is undersized moulds.
On your thermometer, it won't read right because the lead melt reflects the light beam. You need to float something lik a piece of steel in the lead to help get the right temp.

[mveit]

Ok, thanks for the tips.
Kinda cool, floating steel... I'll try that.

I'll send the mould into Lyman for a re-size.

Before I send the mould off, I'm going to melt down a little pure lead, and see how much pure lead weighs.

I'll also clean out the mould real well, I'm a tad concerned that the spray on non-stick stuff I have sprayed on the mould is affecting the bullet diameter.

Thanks folks!

Mike

[mveit]

Hi all,

Ok, I've learned some things and I think that my mould *might* be ok and it could be operator error. (Newbie error I'm guessing)

I inspected my 238g boolits and thought it was curious that the edges of the rings seemed to not be very sharp, almost rounded off, and the bullet diameter was not large enough. So, I tried a few things that seemed to help my boolits have sharper edges, and also have more mass. Here is what I did:
1) Increased the temperature of my lead, from 7 to 9 on my Lee Pro Pot.
2) Used a hot plate to keep my steel mould hotter if I dilly dallied between boolits.
3) Increased the flow rate on my spout as to fill the mould with a bit more pressure.

Results: (Note 54 cal boolit, Lyman Plains mould with 450g Flat Base bullet)
BEFORE: Typical weight 238g, top ring dia ~= .541, bottom ring dia ~= .535
(Weight variation 236-241, most are 238)

AFTER: Typical weight 245, top ring dia ~= .546, botton ring dia ~= .538
(Weight variation 243-245, most are 245)


As I mentioned earlier, I suspect that my lead is not pure lead, so that might account for some of the boolit being 5g light.

The main thing I am a tad concerned about now is still how tight the boolit is in my rifle. (T/C Renegade 54 cal) Here is what I am currently noticing.
1) My boolits are about 2/1000 wider along the mould mating line.
Is that the expected, or necessary to facilitate releasing the boolit?
Is this within spec?

2) I loaded a couple boolits and noticed that the rifling is not really engaged on one side of the narrower diameter. 3 sides are engaging. Is this good enough?

3) If I measure along the mould mating line I am getting pretty close to Lymans
stated diameter of .538 at the base. (I get .537) and at the top I get .548 along the mould mating line diameter, and more like .545-.546 perpendicular to the mating line.

Is this close enough, and should I just move on and get on with life?
Could using pure lead make it possibly shrink less?

I'm thinking about trying to increase the heat up to 900 F to see if that might even get me closer to 450g, and a wider diameter. If my mould is hotter, will it produce a slightly larger boolit?

Any more thoughts from you guys who are not tired of my myopic observations?
Should I really send this mould back to Lymans, I'm thinking they will tell me that it is in spec, and close enough.

mveit - Boise

[mveit]

Ok I found an expansion for Steel.
6.4" x 10 -6 per Degree F.

Then is this correct... for a steel mould.
Expansion in thousandths of an inch per 100 Deg F. == 0.64
Thus if I increase my lead by 100 F, could I get 0.64 thousandths wider boolits?

Maybe also try to use a hot plate to keep the mould hotter when I idle for a bit moving boolits out of my drop zone.