地下軍火庫: iPhone Ballistic 軟體初體驗

最近開始籌畫挑戰遠程射擊，打起用隨身攜帶的iPhone進行彈道計算的主意．在AppStore上搜尋，發現彈道軟體有好幾個．看來使用iPhone的槍友有著一定數量．

Ballistic
iSnipe
KAC Bullet Fligh

Bulletflight名氣較大但是功能其實相差無幾，價格卻貴了一倍．iSnipe則是看似陽春了些．我決定買的是Jonathan Zdziarski(請別問我怎麼發音)所寫的Ballistic FTE．

進入Ballistic軟體，沒有什麼開頭畫面，迎頭就是參數輸入頁．預設值是.308 220gr彈頭，或許是程式設計者最愛用的彈頭．資料庫目前有超過1,500筆彈頭資料．我常用的Sierra和Hornady幾種.224彈頭都有，不需人工輸入．

歸零距離等參數也是必須．值得一提的是天候狀況除了人工輸入，也可以透過iPhone定位功能取得海拔高度，並從網路上讀取氣溫等資料．

輸入所有資料，按下Calculate Trajectory，幾秒鐘後就出現彈道表．

用JBM以同樣的參數計算，結果相當接近：

Trajectory (Simplified)
Input Data
Manufacturer:	Sierra	Description:	HPBT MatchKing™
Caliber:	0.224 in	Weight:	69.0 gr
Ballistic Coefficients:	0.317 [0-2200], 0.305 [2200-2800], 0.301 [2800-5000] G1

Muzzle Velocity:	2900.0 ft/s

Sight Height:	1.50 in	Line Of Sight Angle:	0.0 deg
Cant Angle:	0.0 deg

Wind Speed:	10.0 mph	Target Speed:	0.0 mph

Temperature:	59.0 °F	Pressure:	29.92 in Hg
Humidity:	0.0 %	Altitude:	0.0 ft

Std. Atmosphere at Altitude:	No	Pressure is Corrected:	Yes
Zero at Max. Point Blank Range:	No	Target Relative Drops:	Yes
Round Output to Whole Numbers:	No
Output Data
Elevation:	3.544 MOA	Windage:	0.000 MOA

Atmospheric Density:	0.07647 lb/ft³	Speed of Sound:	1116.5 ft/s

Maximum PBR:	329 yd	Maximum PBR Zero:	282 yd
Range of Maximum Height:	158 yd	Energy at Maximum PBR:	601.8 ft•lbs

Sectional Density:	0.196 lb/in²

Range	Drop	Drop	Windage	Windage	Velocity	Mach	Energy	Time	Lead	Lead
Calculated Table
(yd)	(in)	(MOA)	(in)	(MOA)	(ft/s)	(none)	(ft•lbs)	(s)	(in)	(MOA)
0	-1.5	***	0.0	***	2910.7	2.607	1297.8	0.000	0.0	***
50	-0.2	-0.3	0.3	0.5	2753.3	2.466	1161.2	0.053	0.0	0.0
100	-0.0	-0.0	1.0	1.0	2602.7	2.331	1037.7	0.109	0.0	0.0
150	-1.1	-0.7	2.4	1.5	2457.1	2.201	924.8	0.168	0.0	0.0
200	-3.7	-1.7	4.4	2.1	2316.2	2.075	821.8	0.231	0.0	0.0
250	-7.8	-3.0	7.1	2.7	2180.6	1.953	728.4	0.298	0.0	0.0
300	-13.8	-4.4	10.5	3.3	2053.6	1.839	646.0	0.369	0.0	0.0
350	-21.9	-6.0	14.7	4.0	1931.1	1.730	571.3	0.444	0.0	0.0
400	-32.3	-7.7	19.7	4.7	1813.4	1.624	503.7	0.524	0.0	0.0
450	-45.3	-9.6	25.7	5.5	1700.7	1.523	443.1	0.610	0.0	0.0
500	-61.4	-11.7	32.7	6.2	1593.7	1.427	389.1	0.701	0.0	0.0
550	-80.8	-14.0	40.7	7.1	1492.9	1.337	341.4	0.798	0.0	0.0
600	-104.2	-16.6	49.9	7.9	1399.2	1.253	299.9	0.902	0.0	0.0