Anybody tried Super heavies?

[Blancs3030]

Thank you hoot! What fps were you getting? With the 1:16 twist of the Ruger american it's gonna need to be near 1050 fps to try to keep it stable.

[Bmt85]

Running it through a calculator, a 1:20 twist should be able to stabilize those bullets at around 1000 FPS. A 1:16 shouldn’t have a problem at just about any velocity. Won’t know for sure until it’s actually tested, though.

[Rklenke]

All I have is my 1:24, so I'll post reports from that.

[Bmt85]

I was commenting on Blancs3030 comment on needing 1050fps with a 1:16.

For a 1:24, it looks like you're probably going to have to stay around 1050fps, temps at 50 or higher, and at least an elevation of 1000ft, to have a chance. Even then it might not be enough. If you could cast those bullets without a cavity, you'll have a better chance. That's assuming the bullet casts at 569gr with the hollowpoint, and around 600gr as a flat point.

But like I said in my other post, won't know for sure until it's actually tested.

[Hoot]

Thank you hoot! What fps were you getting? With the 1:16 twist of the Ruger american it's gonna need to be near 1050 fps to try to keep it stable.

First off, I mistyped the length and weight that I used in QuickLoad. It was early and the coffee had not taken affect yet. I did use 569gr and 1.43 length. For the 21gr of 1680, the velocity was predicted to be 1067, which where I live, is subsonic. Keep in mid that QuickLoad is only a model of what should happen. Not that it will end catastrophically but with oddball combinations of powder and bullets, it is less accurate, erring usually on the side of caution. Once you get some field results, it can be tuned to make more accurate predictions for future load changes.

Hoot

[Rklenke]

Sorry if I confused anyone, probably mostly myself injecting with a different bullet. I cast these today, they came out at 490 grains, 1.4 inches. They have a very narrow nose profile, so not much for the crimp to grab and I have to seat to 2.3. I don't have high expectations for this bullet, but we'll see where it goes. I seated a dummy round to see how it looks.

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[Bmt85]

Well, running it through a calculator, it will have an SG of 1.31 (marginal) at 70 degrees and 1000ft. However, that has a pretty long nose, so you might be able to get a little better. If you knock it down to 1.3" at 470gr, it should have an SG of 1.49 at 50 degrees and 1000ft. I like using the calculator, but it can only do so much. I've seen bullets with an SG of 1.2 fully stabilize, so who knows.

[Rklenke]

I went ahead and made up a single round to shoot when I get time. I went with 19 grains SWBO, which after much extrapolation, seemed like safe starting point. I still don't plan to have my face next to the rifle when I shoot, as this is new territory for me. I'll make a new thread when I have enough information on this load to do so.

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[Hoot]

Personally, I never would shoot less than three of a particular load, to allow for the barrel to foul and settle down. Your starting recipe is pretty low on case fill percentage. When I said 21gr of 1680, that was a starting load to establish a baseline. You give me your resultant velocities and I'll tune QuickLoad to nail it the second time and then going forward. With SWBO, you're on your won however, unless someone has worked up a QL file for it in one of the forums. I've gotten a few that way from other people's work.

Hoot

[Rklenke]

The single round is to see what ball park I'm in before I start loading three per group. I'll switch over to 1680 for the initial work up and go to SWBO afterward. I'll post results as I get them.