Sprue plate

Brad

Benevolent Overlord and site owner
Staff member
A year or more go there was a discussion about Al sprue plates. I have had a 12x12 pice of 1/4” 7075 waiting to be used for a sprue plate but had no good way to evenly space holes, etc. , that is no longer an issue.

Got it rough sawn, cleaned up the sides, measured and marked holes. All drilled, and done except for a little thinning with the flycutter. The sprue holes aren’t sharp enough yet but the flycutter will take care of that.
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Brad

Benevolent Overlord and site owner
Staff member
I do have a couple questions. I used a .147 hole as that is what I got when I measured the holes in the existing plate.
Any reason to not go a little bigger and get lead in the cavity faster?
Any reason not to relieve the bottom of the plate on the edges? Think of Veral’s formed plates and how little contact the plate has with the mould surface.
 

Pistolero

Well-Known Member
I like LBT sprue plates. You want to leave a rim to align the plate, and of course the base
of the bullet.
Looks good. Did you just use a countersink on the holes?

Bill
 

Brad

Benevolent Overlord and site owner
Staff member
I don’t have a countersink with the angle I wanted so I used a much larger bit.

I don’t own any LBT moulds but it makes sense. Easy enough to mill away a small amount between the edge of plate and the sprue holes.
 

Rick

Moderator
Staff member
Any reason to not go a little bigger and get lead in the cavity faster?

I don't know the answer to that but I do know how to find out. Pretty simple now to make a couple of different size holes in different plates and experiment. Could be quite informative regardless which may turn out to work better, or even no real difference.
 

Brad

Benevolent Overlord and site owner
Staff member
That makes perfect sense Rick. I just need to find the 3 hours it takes to make each one.
A bandsaw would make it easier. The Sawzall does a fine job but damn is it vibrating me to death.
 

fiver

Well-Known Member
I have a couple of sprue plates with larger than normal holes.
they tend to leave a bump if your timing is off even a little, and they seem to pour better on the short fat bullets.
 

Rick

Moderator
Staff member
Boy I tell ya, all that whining about not having a mill and now he's whining about spending time using it. :eek::confused::rolleyes:
 

fiver

Well-Known Member
now he needs a band saw.jeez
one of these days he is gonna have all these tools and his wife is gonna expect him to be out there using them instead of dickin around in the gun room all the time.
 

Brad

Benevolent Overlord and site owner
Staff member
My gun room is feeling a bit neglected these days. I did load 200 rounds of 45 ACP today.
 

RicinYakima

High Steppes of Eastern Washington
Hole sizes: unless you like to run cool alloy, bigger is not better. A smaller hole cuts easier if your timing is off if you cut with your thumb. It doesn't matter at all if you use a mallet and hit down at a 45 degree angle. FWIW Been there and done that experiment.
 

Brad

Benevolent Overlord and site owner
Staff member
Thank you Ric. Had not thought of the extra effort required to cut the thicker sprue.
I love it when someone saves me from myself with wisdom they earned the hard way.
 

RicinYakima

High Steppes of Eastern Washington
Brad, you are always welcome. Having been at this casting thing since 1961, the school of hard knocks is an effective teacher. :)
 
F

freebullet

Guest
Nice work, Brad! You've been busy as a beaver with the new toy.

If you need some items rough cut I have a plasma cutter. Would leave rough edges you'd need to mill, but it zips through metal like butter.
 

Brad

Benevolent Overlord and site owner
Staff member
Got a few bullets cast today. Sprue cuts fine, bases fill out very well.
Only issue is the lack of draft on the spru holes. The sprue doesn’t like to come out of the countersunk holes. That is a simple fix.
 

fiver

Well-Known Member
it's that little tunnel you got at the bottom.
just re-cut a different [wider] angle right there where they start, or fly cut the bottom of the plate again.
Ben put up a post a while back about how he done it on one of his plates.
 

JSH

Active Member
Do you guys ever sleep;)?

Brad, I got a Milwaukee porta band summer before last. It was an estate auction, brand new in the box never used. It came with four boxes of three blades. Basically got the saw and a box of blades free. There was also a vise made for it, can be used on table top or add pipe legs, made from cast. Vise is like a pipe vise with the chain, no provision to cut angles. I have an idea in my head when I find a worn out miter saw for cheap.

But as to your bandsaw. I was peruseing around the other day and ran across a build for making a small band saw using a porta band. Dang if I recall where it was. The guy was either from Europe or Australia.
 

Ian

Notorious member
it's that little tunnel you got at the bottom

Yep. Gotta have a sharp edge there, the shear force from cutting actually pushes the sprue up out of the well, like primary extraction on a rifle.