maximum bullet weight for a whisper

[Bulletsmith]

I was over in the shop playing tonight with the new punches and trying differant jackets for this new subsonic venture.By using a 1.4 inch long jacket and a 6 ogive,I found that a 270 grn bullet is possible,is this desirable????? Or is it way to heavy.The expansion factor will be high so that isn't a issue,just the weight.Please note that I have never shot or even seen a whisper.My encore barrel is still not finished so I have to reley on information from knowledgable shooters.
thanks for all input!!!!!!!!!

Bulletsmith

[dflicker]

I'd like to try weights up to 300 grains if they would fit into an AR magazine. Has anyone given any thought to a round nosed, tapered base bullet? I read in an article a few months ago that a "teardrop" shaped bullet would be the most ballistically efficient at subsonic velocities and I would like to try some to see if it is true. Does anyone have a link to the formulas for calculating BC when given bullet drop?


David

[pug]

Bulletsmith I was thinking about your bullet when I noticed the Greenhill twist calculator setting on my computer. Using a 1.9" bullet in the standard formula yeilded a required twist of 1:7. Most of us have a 1:8 I think for the 300 whisper. There are those who feel the formula does not fit subsonic bullets well and drop the twist constant to 130 which would yield a required twist of 1:6.5 for a 1.9" bullet. The formula assumes that for a given caliber a longer length means a heavier bullet but the ULDs really stretch that weight out and are believed to need a even faster twist. For what I have to work with now I would like to see them stay under maybe 1.625" in length but I am not sure about that. I guess only testing will tell.

[m21black]

240 SMK's work just fine wish I could find some older 250 SMK's though