Tweet
I'm a little hazy on the nitch the 123gr SST is suposed to fill. True SSTs are fine accurate hunting bullets, but will making them 4gr lighter then the 129gr make them shoot flater? Will there be less recoil? Will better powders be available in this weight class? Can any of you guys with balisitic programs run the numbers (assuming same shape and length and BC as A Max) and show me just how much velocity/energy increase I could expect, and what change in point blank range I could get?
-
-
my guess would be more reliable expansion at lower velocities ast the 129 is designed to preform at 260 velocities and the grendel starts a a lower velocity so a softer bullet design ie thinner jacket is needed
also here is a pretty nice free online balistics program
Last edited by mongoosesnipe; 10-13-2012, 02:52 AM.Punctuation is for the weak.... -
The 129gr SST is really meant for the 6.5 Swede and .260 Remington, or cartridges with much larger case capacity and longer overall length. It takes up way too much room in the Grendel case, intruding well below the neck-shoulder junction, so is a bit finicky to load for with many of us so far.
The 123gr SST sounds like it is purpose-built for the Grendel, so it will allow more case capacity, without sacrificing BC. Performance difference in trajectory is minimal.
129gr SST, 2350fps, 200yd zero, 2.7" scope height
123gr SST, 2550fps, 200yd zero, 2.7" scope heightCode:Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2350 1582 -2.70 0.0000 0.00 50 2263 1467 0.66 0.0650 -0.22 100 2178 1359 2.32 0.1326 -0.88 150 2094 1257 2.15 0.2028 -2.00 200 2013 1161 0.00 0.2759 -3.63 250 1933 1071 -4.30 0.3519 -5.78 300 1856 987 -10.92 0.4311 -8.48 350 1781 908 -20.06 0.5136 -11.78 400 1707 835 -31.95 0.5996 -15.69
Code:Range Velocity Energy Trajectory TOF Drift (yards) (fps) (ft-lb) (inches) (sec) (inches) 0 2550 1776 -2.70 0.0000 0.00 50 2463 1657 0.23 0.0598 -0.18 100 2378 1545 1.73 0.1218 -0.74 150 2295 1438 1.69 0.1860 -1.69 200 2213 1338 -0.00 0.2526 -3.05 250 2133 1243 -3.46 0.3216 -4.85 300 2055 1153 -8.84 0.3932 -7.11 350 1978 1069 -16.27 0.4676 -9.85 400 1903 989 -25.92 0.5449 -13.11Comment
-
Thank you for being the first to ask this as it was the first thing that went through my mind when I read about it a week or so ago, but I was too timid to ask. I'm guessing the ogive is somehow not as similar between the 123 Amax and the 129 SST, whereas more similar with the 123 SST. I just tried it and you can hide a 6gr of lead sliver under your index fingernail. In QL, lightening a 129 SST Over a load of BLC-2 by 6gr, accounts for ~25fps, all else being equal. I too am looking for a quick education from the masters.
Hoot
EDIT: Looks like the slow typer gets taught a lesson from LRRPF52Comment
-
Not so sure they represent the company today. See post #56 (http://www.65grendel.com/forum/showt...ll=1#post44500).Comment
-
To understand this well, you have to go back to the Hornady 120 A-Max, which was designed for the 260, 6.5 X55 and similar cartridges. The ogive worked fine for those but conflicted with the throat of the Grendel chamber. Hornady redesigned the 120 into the 123 grain A-Max specifically for the Grendel. It is one of the most forgiving bullet designs out there for use in the Grendel. The Sierra 120 grain Match King is similar in this respect. It can be jumped a wide range of distances and still provide excellent accuracy.
So, if Hornady did a similar redesign of the 129 SST and we believe they did the goals would have two major objectives, an ogive that plays well with the Grendel throat at mag length seating, 2.250" and expands well at lower Grendel Velocities while still holding together well enough to provide deep penetration.
If they in fact did this then it should be a real winning design for hunters using the 6.5 Grendel. If you are only shooting paper you don't need this bullet, you already have the 123 A-Max which is about as good as it gets. At least that's how I see this issue.
BobComment
Comment