Brooks Creedmore

[RD4570]

I’ve got a Brooks Creedmore 45 cal. 560gr. Mould for bpcr. When I started casting with it the bullets are looking good and free of wrinkles. The issue is when I weigh them some are as heavy as 565gr. What would cause this? They all appear to be ok.

[Michael J. Spangler]

I’ve never cast with one of those Moulds but I’m guessing it weight variation due to some inconsistencies and maybe inclusions.
I hear there can be little pockets of air trapped inside when casting and this is why some people prefer swaged for consistencies.
That being said I would just sort by weight. I don’t think a 1% variation in weight is that bad.
How about some pics? I would love to see the bullets!

[Chill Wills]

Are you saying the Brooks Creedmoor mold is marked 560gr and you are getting 565gr bullets?
or
Your batch has a spread of 560 to 565grs?

[RCE1]

Are you using a dipper or bottom pouring? I always had better results with dipper casting heavy single cavity moulds like this.

[RD4570]

Yes it’s a 560gr and I’m getting anywhere from 560 to 565. Im using a Lyman dipper, im new at this so I’m guessing it’s something im doing.

[RD4570]

[RD4570]

I failed to mention I’m using a 30:1 lead/tin alloy

[Chill Wills]

Yes it’s a 560gr and I’m getting anywhere from 560 to 565. Im using a Lyman dipper, im new at this so I’m guessing it’s something im doing.

It is something you are doing, BUT, just keep at it and your bullets will get a lot better soon.
The heavy bullets you are getting are the ones that are more completely filled out and/or fewer voids. This assumes completely closed mold halves. By that logic, the lighter ones are the culls.

Sorting into groups based on weight is Okay, but understand that the light groups of bullets are not the best bullets.

Check to see if the mold halves are closed before each pour.
Mold blocks that don't close all the way each time can show fining on the part line and can be measured out of round with a micrometer. Tho these will be heaver than closed mold bullets, clearly they are culls. Put them back in the pot to be cast again.

As RCE1 mentioned, bottom pour V ladle pouring can make a big difference, especially when new to casting large BPCR bullets. Ladle pouring with the ladle in contact with the mold helps cast great bullets. This can be done with the bottom pour pot too, but may in some cases not be as easy.

[country gent]

Did you opt for the vented sprue plate? I would recommend opening the spout up to around .200 dia with a drill. This increases flow and smooths the surface in side the spout. Another trick that's helped me with consistency is to over pour the mould. Fill the ladle full fill cavity and continue pouring until ladle is empty allowing the excess to run back into the pot. Tis keeps the bullet hot longer and gives better fill and off gasing of the mould. Last is to flux the melt often to keep it blended as consistant as possible.

You can try pressure casting with the mould side ways insert ladle and turn upright together hold and then pour the excess. I use a simple pour into the hole from about 1/2" above the blocks. My bullets run very close and good. My Brooks mould is a adjustable nose pour Paper Patched cup base mould in 45 cal ( .442 dia.).

How do your bullets run as to size and roundness? Not fully closing the blocks every time can create weight variations and out of roundness.

Heres my procedure for casting these long heavy bullets:
My alloy is 20-1 and ran at 725*-750* in a propane fired pot of 100+ lbs
I preheat the moulds on the warming shelf while the lead is coming up to temp. Usually about 20 min. The night before I scrub the mould with dish soap and water then dry oil with 2 cycle oil sprue plate hinge pin block screws and handle hinges.
I place the ladle in the pot to "soak" for 10 mins bringing it up to temp. Let float on top of the melt for a couple minutes to remove and moisture condensation. Flux pot .
I hang the mould over the side of the pot and fill pouring a full ladle of lead into the cavity allowing the excess to run back into the pot. Set aside and fill second mould while 1sts sprue sets and bullet solidifies
break sprue on 1st mould and remove bullet. Refill.
I normally throw the first8-10 drops back into the pot as standard operating procedure.

The other tip is When your casting cast. Don't sort or inspect cast keep the cadence up

[RD4570]

I’m betting the mold didn’t completely close,would account for the heavier bullets.

[Deadeye Bly]

I've got 2 Brooks molds, a 40 and a 45, both the Creedmoor style. When they were new the pins would bind in the hole when the mold got hot and then not close all the way. Check if this is happening. Close the mold and see if you can see any light between the halves. It will eventually cure itself as the pins and holes wear. You could use one of the clamping sets of mold handles to alleviate the problem. I increased the diameter of the sprue hole on both my molds also.

[country gent]

Brooks web site also recommend a couple light taps on the side handle at the blocks to insure they are fully seated and closed. I also rest the blocks on a straight edge when closing them. The rolled edge on the paint roller pan I use works for me here but a piece of 3/4 X3/4 X 8" angle sitting V done on the casting bench works also.

[RD4570]

I've got 2 Brooks molds, a 40 and a 45, both the Creedmoor style. When they were new the pins would bind in the hole when the mold got hot and then not close all the way. Check if this is happening. Close the mold and see if you can see any light between the halves. It will eventually cure itself as the pins and holes wear. You could use one of the clamping sets of mold handles to alleviate the problem. I increased the diameter of the sprue hole on both my molds also.

How much did you open it up?

[Deadeye Bly]

I'll need to measure them and get back to you tomorrow.

[RD4570]

Found the issue- I casted 10 and made sure the mold was completely closed by tapping with a wooden mallet and that has taken care of that. Thanks

[Deadeye Bly]

The hole diameter in the sprue plates on my Brooks Molds is .155". I don't know what they were originally. I opened both of them up a little.

[RD4570]

The hole diameter in the sprue plates on my Brooks Molds is .155". I don't know what they were originally. I opened both of them up a little.

Thanks

[RD4570]

The hole diameter in the sprue plates on my Brooks Molds is .155". I don't know what they were originally. I opened both of them up a little.

Is that around a 5/32 drill bit?

[Chill Wills]

Yup. 0.156" The problem is you end up with a dull cutting sprue hole creating tear out.
If you are shooting pistol bullets and or not really needing the last bit of accuracy with rifle bullets, go for it.
Also, a dull cutter makes cutting the sprue harder - more work.

I know you don't have a lathe, but that is how I have done it in the past, and it makes a great job of it.
Maybe you know someone with lathe?
Chuck it up indexed and use the compound to cut in a larger hole. Really, shaving it larger is more the correct description, because you take off so little.