New .44 caliber Brooks mold.

[Distant Thunder]

Kurt,

Yea, those are the scary things I worried about with a cupped base and why I wanted this mold to have a flat base.

I’ve done some measuring of the base on these bullets and the cup is only .055” deep. The flat around the cup is .060” wide so the cup is about .314” diameter.

I’ll look around in front of my shack tomorrow and see if I can find some of the wads. They should be easy to tell apart from any shot with my other bullets which all have flat bases. There should be some evidence of the cup.

Later this winter if we have enough, and I won’t be disappointed if we don’t, I’ll see if I can shoot some bullets into snowbanks and recover them in the spring.

I’m pretty sure I’ll end up using the flat base, but the mold came with the cupped screw and while Steve did make a flat screw for me it will require a little fitting and I don’t have the means to do that just yet. Later this winter I should have my lathe set up and running.

For now I’m having fun shooting the bullet with the cupped base and it’s working fairly well. There is NO way it is necessary for this bullet, flat base would be best probably.

[Distant Thunder]

I believe a picture would answer a lot of questions. You can see the cup is not real deep and has a wide flat skirt. That is probably why it's working for me.

[Kurt]

Jim,

From looking at your target your doing it right, it's working for you.

These photo's I posted are bullets a friend send me from down south to see why he was getting to many dirt diggers and he instructed me how to load them and use the components he send me with the cup .50 cal bullets.
The problem I saw that caused what I seen on the bullets were a couple things I myself have done.
Bullet to soft,
Wads to flexible,
Nor enough support between the bullet base in the cup between it and the wad.
I went through this myself with the bullets for the .40-70 and .45-120/3-1/4.
If you look at this cropped bullet picture, look at the skirt rim. Those rims were .072" wide and they ended up as a sharp edge from the wads getting pushed into the cup from lack of support of a twisted tail holding the wad from flexing into the cup.
I had read some of the old books why the Sharps rifle company used the twisted tail and why the the cup base in the first place. What they said the cup was supposed to push the hard cast bullet bases out like a mini ball to seal the gas.
I cant remember who wrote that book but I read it in the Library of Congress collections.

[J.B.]

Now another term to add.. I knew about hollow base.. learnt about cup base and now there's 'dish based'. I keep saying I've got to get out more. The BACo nose pour I've been using is running deeper at .123" deep with walls/ skirt at .045. I'd love to recover some bullets but thats not an option where I shoot and snow banks are as common as rocking horse **** around here. 80F degrees and heading for 88 F on the weekend. Yep..summer has arrived in New South Wales. It only goes up from here. So far I've stuck to veg. fibre wads and have been happy with them. A little nervous about trying ldpe for fear of losing some cases to separations. I gather its not common...but then neither is 44/77 brass. .060 is my usual 'go to' thickness and some of my best results on paper in years past was with 2 x .030 card wards. Cut with a .447 punch through BACo. Commercial wads seem to be at .446. Of course this could all be down to my not developing my flinch to the scintillating standard it sits at now. :-(

Gavin.

[Distant Thunder]

I looked for some LDPE wads that had been fired with this cupped base design. I found 2, not easy to find in the grass and leaves. I also picked up two that were fired under flat base bullets. It's not going to be easy to see in the picture, but on the flat base wads yoy can see a faint impression of the fold over of the patch and the bare spot left in the middle of the base.

If you zoom in on the two wads to the right those are two that were fired under cupped base bullets. The impression left by the cup is visible and is the rim of the skirt and the rifling marks on the edge. I looked at my patch remnants and there is no evidence of any blow by or gas cutting, no burnt patches. Also, at the time the wad left the bullet base the skirt seems to have been undamaged.

Yesterday I cast 100 bullets from this mold at 1.350" long. They weigh 475 grains. I'll start my load development with these bullets and where the targets lead me. I am starting 1.350" long because I read somewhere that a 1-17 twist really likes that length, so we shall see.