10mm Hardcast COAL

[Terrapin]

Can someone pull a quick overall length measurement on a 10mm Double Tap or Underwood hardcast lead load. I’m reloading some hardcast bulllets and having some feeding issues with “book” overall length. I’m wondering if I don’t need to be shorter to get the angle right due to the truncated cone shape of the bullet. Thanks




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[Huntinaz]

You talking about the 220gr version?
Underwood Pulldows

 

[wayno945]

Keep seating them deeper. You're starting with a less than max powder charge, right?

 

[Huntinaz]

I agree if you are at “book” oal for that bullet then you can seat them a little deeper Especially if not at max charge but that may not be the issue if you’re at recommend length. Have you plunk tested them?

 

[Terrapin]

Yes, I’m starting pretty close to min... not a bunch of faith in cast bullets. I am attempting to run 180 grain bullets. I would prefer 200+ grain bullets, but shelves are a little picked bare at the moment.

I plunk tested them. My issue is making the transition out of the magazine into the bore. I’m good on all the pertinent dimensions, just a bit concerned about seating them substantially deeper.


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[Huntinaz]

You should be fine seating a little deeper

 

[Huntinaz]

What bullet are you using?

 

[Terrapin]

What bullet are you using?

It’s a local company. Kootenai Ammo Works. No other data available on-line. It’s a powder coated 180 grain truncated cone with a giant meplate. Probably good for deep penetration, maybe not too conducive to smooth feeding.


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[thinhorn_AK]

You want a caliper measure of a cartridge?

 

[Terrapin]

You want a caliper measure of a cartridge?

Yes, I’m curious how much shorter than spec they are going. Book calls out 1.260. The JHP factory loads I have laying around are ~.050” shorter than that. I’m wondering if they go shorter on the flat pointed hardcasts to help them feed.


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[thinhorn_AK]

Yes, I’m curious how much shorter than spec they are going. Book calls out 1.260. The JHP factory loads I have laying around are ~.050” shorter than that. I’m wondering if they go shorter on the flat pointed hardcasts to help them feed.


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ok hold on a minute I’ll drag my lazy ass off the couch and measure a 200 and a 220 for you.

 

[thinhorn_AK]

Yes, I’m curious how much shorter than spec they are going. Book calls out 1.260. The JHP factory loads I have laying around are ~.050” shorter than that. I’m wondering if they go shorter on the flat pointed hardcasts to help them feed.


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the hsm bear loads are 200g and the Underwood is 220g.

 

[Huntinaz]

You should be fine at 1.25”

start at min and work up assuming it feeds. If it doesn’t feed at 1.25” then that’s not the problem

 

[5MilesBack]

My 200gr Underwood are 1.245".

 

[Jesse Jaymes]

I tired them in an XDm 10 and a Kimber 10....sucked in both. AA#9. Did NOT have feeding issues tho. Good Luck

 

[Terrapin]

Just to follow up. I messed around with them for another evening, finally gave up getting them to feed and switched back to Nosler 180 JHP. They feed and shoot exceptionally well. I’ll just buy Double Tap or Underwood for woods carry.


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[thinhorn_AK]

Just to follow up. I messed around with them for another evening, finally gave up getting them to feed and switched back to Nosler 180 JHP. They feed and shoot exceptionally well. I’ll just buy Double Tap or Underwood for woods carry.


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that’s what I do, I keep a few mags of hard cast around and several boxes on the shelf but I don’t load them.

 

[Myronman3]

measure your bullet outside diameter....and give them a turn while you are measuring. some bullets are out or round, even though you can’t see it. there is also something called “bullet springback” that you get with cast bullets...which the alloy used has a lot to do with. i ran into these issues while casting bullets for my freedoms arms years ago. they would load, function and fire perfectly in the rugers, but it was a no go with the freedom arms.
the cartridge OAL shouldnt change from what the book says. it’s my guess that you are dealing with bullets that are a smidge too big. i love cast bullets; but there is a learning curve. and with a smaller local company, there is a good chance that’s your issue.
another thing to do is measure the diameter of a loaded case where the bullet is seated.

 

[doverpack12]

I’m loading montana bullet works 200 hardcast hitek coated bullets. They are a really good shape and meplat diameter. Even wider meplat than Double Tap or Beartooth bullets. Just shot 30 or so yesterday at increasing powder increments. Found a nice load with long shot at just over 1200 fps. I’m seating deep, you will find searching 10mm hardcast loading information that deep seating isn’t out of line. I’m at 1.240” COAL any longer and once in awhile a bullet would be touching when dropped in chamber and wiggled with my finger. Should jiggle around freely in a glock 20. Was loading a 0.401 sized bullet and upped that to a 0.402 sized bullet and accuracy increased immediately.