stability Question

[Wayne S]

Is there a way to figure the lowest speed that a bullet will remain stable ?
given the BBl twist, the BC and OAL of the bullet ?
example;
RCBS 165 Sil bullet has a BC of .286

BBL has a 1-12 twist

with the .286 BC it will loose 370 FPS at 200 yds

If it starts out the muzzle at 1300 fps, at 200 Yds it's going 930 FPS

Will this bullet still be stable at 200 yds ??

[mooman76]

There are some formulas to tell you what twist is optimum for your particular bullet but even it isn't 100% correct. None that I know of to predict for exact speeds you are using. The only real way to tell is run some test loads. You might want to try the ladder method for this one.

[Wayne S]

[QUOTE= The only real way to tell is run some test loads. You might want to try the ladder method for this one.[/QUOTE]
[smilie=b:Damn, another reason I must go to the range, after all this is for your pistol ,sugarbabe
"ladder method" ?? you mean start at a point, and work down :p

[carpetman]

You are asking a question about stability on this forum? What an oxymoron.

[joeb33050]

792.4 fps. Just an opinion.
joe b.

[Wayne Smith]

Make sure it exits the barrel!!

[mooman76]

[smilie=b:Damn, another reason I must go to the range, after all this is for your pistol ,sugarbabe
"ladder method" ?? you mean start at a point, and work down :p

Yes. Usually it's done the opposite, working up but load a couple each with various amounts of powder starting at a certain point and drop a half a grain or so working down until you get where you want . Set your point of aim the same for all or it will degrade the test and it will show where the bullet starts to destablize as the pattern opens up.

[NSP64]

Wayne S, google 'bullet stability calculator' go to NFA website it is by peter cronhelm and you can download his free pdf format calculator. You input boolit weight, length, barrel twist. Fun to play with.

[runfiverun]

i do know that the greenhill says that a 10 twist is optimum for that boolit.[ha,ha]
and that it is still stable at 225 at 2100 fps [muzzle] but starts to lose stability after that.
but with a slightly slower[1900] start the stability [accuracy] was better at 200.
just some info to ponder...
1300 might not be enough in the 12 twist but 1500 might be.

[JIMinPHX]

There are a whole bunch of formulas that will help you predict what is theoretically possible, but in reality, things like the precision of your boolit base & the crown of your muzzle can throw all that right out the window.

[TexRebel]

if you study Hatchers work on Bullet performance , he did cover bullet stability also