I have mentioned in a number of articles how the 90 grain Sierra Match King .224 bullet designed in 2005 was prone to mid-air blow ups due to jacket issues. I talked about this most recently in my December 2016 article, “Gain Twist Barrels For Palma.” Those of us who write frequently for American Gunsmith sometimes find our articles “in the pipeline” for awhile from the time they’re written until they are published. Changes can take place in that interim. This was the case with Sierra’s 90 grain bullet.
Sierra’s original 90 grain bullet remained on dealer shelves for nearly a decade in its original flawed condition. However, it was recently redesigned. I have been testing the newly redesigned Sierra with Berger 90 grain Match Boat Tail and Sierra’s new bullet appears to be blow-up proof. I have torture tested it and have experienced no failures and am obtaining speeds of 2,800 fps in 30” and 32” Palma barrels with stellar results. I also have customers using it and they like it. Accuracy is comparable to the Berger and the ballistic coefficient of the new Sierra is higher than any other 90 grain AR-15 bullet on the market.
I’d like to formally update the record and apologize to Sierra for statements that were correct when written but out of date regarding the new bullet when published in my December 2016 article. Readers should be careful when purchasing Sierra 90s to be certain they are getting the new bullet. I would be leery of any boxes of 90 grain SMKs that have been on dealer shelves for much longer than a year as they may be of the old design. If the dealer will permit you to open the box, the new bullet is factory pointed (which helps attain the high ballistic coefficient) and the older bullet has an open hollow point.
Thanks for your understanding and look for a full article on the new bullet in the near future.
– Joe Carlos