Anyone have a bullet calculator

[peter nap]

I know they exist, but haven't found a calculator to determine the length of a bullet that will stabilize in a certain twist. I always use the..."That' about right" method.:(

I'm trying to deign a .733 bullet that will stabilize in a 1:35 barrel. I want the longest possible with a very wide meplat (almost wadcutter) and turned out of solid brass.\
Velocity will be around 1450 fps.

[thx997303]

Looks like 2.3" will be your magic boolit length for the 1:35 twist barrel according to the twist calculator contained in Wiljen's Reloader's Reference.

[Wayne Smith]

For future reference go to the Mountian Molds site, design your boolit and it will tell you the twist that it fits best. Nice feature.

[peter nap]

Thanks Guys!

[thx997303]

Though I am not an expert on this, It would seem you may want the option of having a little range in your boolit and twist rate.

What I mean is, things vary, and the 1:35 will most likely stabilize that 2.3" boolit (the calculator says so) but it seems to me, that having the boolit slightly shorter may give you a margin of error.

For example, a 2.2" boolit will stabilize with a 1:36 twist. I would imagine this boolit would give you the margin of error I am talking about.

Though, as I said, I am not an expert. Perhaps someone else may chime in on this?

[peter nap]

Though I am not an expert on this, It would seem you may want the option of having a little range in your boolit and twist rate.

What I mean is, things vary, and the 1:35 will most likely stabilize that 2.3" boolit (the calculator says so) but it seems to me, that having the boolit slightly shorter may give you a margin of error.

For example, a 2.2" boolit will stabilize with a 1:36 twist. I would imagine this boolit would give you the margin of error I am talking about.

Though, as I said, I am not an expert. Perhaps someone else may chime in on this?

That's a good point and I had thought of it. The reason for going as long as possible, is that I can always make them shorter. Making them longer is the hard part.

I'm making some assumptions that probably aren't true. One is that after I get the brass shooting right, I can make a push through mold for lead and just adjust the velocity for the weight change. I may be setting myself up for another reality check.:mrgreen:

[Tom Myers]

Try this caliber/length/velocity/twist calculator

http://www.uslink.net/~tom1/twistrate.htm

Hope this helps.
Respectfuly,
Tom Myers



I know they exist, but haven't found a calculator to determine the length of a bullet that will stabilize in a certain twist. I always use the..."That' about right" method.:(

I'm trying to deign a .733 bullet that will stabilize in a 1:35 barrel. I want the longest possible with a very wide meplat (almost wadcutter) and turned out of solid brass.\
Velocity will be around 1450 fps.

[peter nap]

Try this caliber/length/velocity/twist calculator

http://www.uslink.net/~tom1/twistrate.htm

Hope this helps.
Respectfuly,
Tom Myers

Thanks Tom!
That's great. I sat there and played with velocity drops and think I can come up with a good compromise right off. Should save a pound of RE17 for testing.

[Bradley]

I know they exist, but haven't found a calculator to determine the length of a bullet that will stabilize in a certain twist. I always use the..."That' about right" method.:(

I'm trying to deign a .733 bullet that will stabilize in a 1:35 barrel. I want the longest possible with a very wide meplat (almost wadcutter) and turned out of solid brass.\
Velocity will be around 1450 fps.

Try a search on "Greenhill Formula"