300 Blk PDW Zero
Posted: Mon Aug 12, 2019 6:44 pm
Before you comment, please spare me the question of "why?"... There is good reason for what I'm about to state and ask...
I am building a 300blk pistol. 10.5" Faxon barrel and superlative adjustable block is really all that matters for my question lol.
The purpose of this build is strictly a home defense sub gun. I am going to be using 194gr Lehigh Maximum Expansion rounds only. I ran ballistic data matched to the specs of that round, and after playing with numbers I came to the conclusion of zeroing at 20 yards.
Ballistic data as follows @ 20 yd zero:
(FPS)(Ft. Lbs)(Traj)(MOA)
0 Yards = 1000, 431, -2.6", 0
25 yards = 992, 424, +0.4", -1.5,
50 yards = 984, 417, +1.2", -2.2,
75 Yards = 977, 411, -0.3", 0.4
100 yards = 969, 405, -4", 3.9
With this data, I can easily operate in and around 0 to 100 yards within a spread of less than 4". The likelihood of my using this past 10 yards is extremely unlikely, but at least I'll know what it can do. I actually like a 15 yard zero better with this round since it has a tighter overall spread, but the trajectory between 25 and 75 yards isn't as tight as with a 20 yard zero.
My question is this... How can I zero this thing at 20 from a 25 yard range? I've seen zeroing 50 yards at 25, 36 at 25, 100 at 50, etc. Just wondering if there's math behind it that I can use to zero 20 from 25. It's kinda dumb - I already know!
Also, with an adjustable gas block, does the setting(s) of the block affect the ballistic data? What about the suppressor?
Thank you
I am building a 300blk pistol. 10.5" Faxon barrel and superlative adjustable block is really all that matters for my question lol.
The purpose of this build is strictly a home defense sub gun. I am going to be using 194gr Lehigh Maximum Expansion rounds only. I ran ballistic data matched to the specs of that round, and after playing with numbers I came to the conclusion of zeroing at 20 yards.
Ballistic data as follows @ 20 yd zero:
(FPS)(Ft. Lbs)(Traj)(MOA)
0 Yards = 1000, 431, -2.6", 0
25 yards = 992, 424, +0.4", -1.5,
50 yards = 984, 417, +1.2", -2.2,
75 Yards = 977, 411, -0.3", 0.4
100 yards = 969, 405, -4", 3.9
With this data, I can easily operate in and around 0 to 100 yards within a spread of less than 4". The likelihood of my using this past 10 yards is extremely unlikely, but at least I'll know what it can do. I actually like a 15 yard zero better with this round since it has a tighter overall spread, but the trajectory between 25 and 75 yards isn't as tight as with a 20 yard zero.
My question is this... How can I zero this thing at 20 from a 25 yard range? I've seen zeroing 50 yards at 25, 36 at 25, 100 at 50, etc. Just wondering if there's math behind it that I can use to zero 20 from 25. It's kinda dumb - I already know!
Also, with an adjustable gas block, does the setting(s) of the block affect the ballistic data? What about the suppressor?
Thank you