Midway Dogtown RPM Limits

[darkker]

So I ordered the 500 pack jumbo case of .223" 55Gr SP Dogtowns from Midway.
I started loading and found a load that seemed to group well. The Chrono shows that it is flying at about 3350FPS. So I went out with a box to do my final sighting in this morning.
When what did I spy with my little eye??? Lead vapor following the bullets!! I re-Chrono'd and the velocity was the same.
I called Midway to ask what the RPM limit was, and the answer was the published "Keep them under 4000" So I asked him with what twist barrel, Since my FP has a 1-9 twist.
He had no answer, but gave me a Sierra tech number. Said they were "Familiar with our products" Which I think means they make them for them. In any case, I think that the Dogtowns are essentially the Blitz's, NOT BLITZKINGS. IF that is so, they have a rough RPM limit of around 240,000. This means that I'd have to slow to about 3000FPS.
Anyone else have a similar experience, or know about what the Rotational limit is??

[dcloco]

Vapor trail is just moisture in the air.

I push the 55's above 3600 with a 1:9 twist 223 AI. I fireformed a few through "super duece" - a 1:8 twist 222 mag ai.

Suppose, if boredom sets in, I could see how fast or when they explode from my 22/6mm AI with a 1:8 twist. That should push them past the 4200/4300 mark.

Do know, at 223 AI velocities....36xx, these bullet come apart rather nicely as they pass through a prairie dog.

[Uncle Jack]

What do the targets look like? If the bullets were starting to vaporize there would most likely be those little "comet tails" around the holes.

uj

[darkker]

Sorry no targets. Was shooting at some steel targets at a range. But you could see a Grey "aura" around them, the whole way to the target. I had 5 rounds that were Hornady SP's and they didn't do it, so I don't think that it is a condensation issue.

[Eric in NC]

Only times I have seen bullets come apart from excessive rotation they just made a "puff" and didn't reach the target. Never seen them leave a trail (other than condensation/vapor as was said).

[Bad Water Bill]

+1

[Uncle Jack]

Well, this is what it looks like:

http://www.thehighroad.org/attachment.php?attachmentid=5098&d=1059792338

uj

[darkker]

So I talked with a gentleman named Wade, from Sierra a moment ago.
Here is what he told me. The .223" 55Gr SP Dogtowns should have a RPM ceiling of about 260,000RPM. Of course depending upon bore smoothness, etc...