I don't believe those ballistics from a G29 for one second.
Why not? The original Norma 10mm loadings propelled a 200grn bullet at 1200fps from a 5" barrel. 100fps velocity loss with a 200grn bullet is pretty believable since heavier bullets tend to lose less velocity from short barrels than lighter ones (a 158grn .357 Magnum will usually "lose" 100-150fps from a 2" barrel as opposed to a 4" and one will typically see similar velocity losses with 230grn .45 ACP's is an Officer's Model as opposed to a Government Model 1911). Add to this that Glock's polygonal rifling typically gives higher velocities than standard cut rifling and I find Double Tap's claim of 200grn @ 1100fps from a G29 (which has a barrel only 0.82" shorter than a G20) entirely believable.
Smith, and Wesson, and Me. -H. Callahan
Well waddaya know, one buwwet weft! -E. Fudd
All bad precedents begin as justifiable measures. -J. Caesar