另一款完全相同的鏡子，只是MOA和MRAD不一樣，明顯可以看出MRAD更遠更密，其實MRAD更像公制米，MOA更像英制尺，MRAD更適合北約軍隊通用，MRAD是milli-radian，更符合圓周率的數學物理標準，MOA是民間打獵傳統，minute of angle，360度的60分之一，比較arbitrary沒什麼數學物理意義。
At close-range, you have a Personal Defense Weapon (PDW). These are your Uzis and TP7s and MP5s, or even your pistol brace kits. Their purpose is close-ranged defense, so compactness is king. They are usually foldable/collapsible, and are usually chambered in 9mm or .45 (though 300 blackout has started to overtake the role due to their shorter barrels).
A little bit more capable but less compact, you have your Short-Barreled Rifle (SBR). These are your MK-18s and M4s (10.3″ and 14.5″ barrels, respectively), very normal military-grade rifles designed for close-range combat, but capable of medium-ranged engagement. To suit this distance, they’re usually going to have a red dot sight, or even just iron sights. This style will also include your Honey Badgers and other 300 Blackout-chambered rifles.
A General Purpose Rifle (GPR) is likely going to have a 14.5″ – 16″ barrel, and designed for engaging at slightly further distances. This is likely going to have some kind of Low-Powered Variable Optic (LPVO) or a roll-over magnifier or ACOG, giving the shooter magnified sights usually from 1x to 3x/4x/6x power vision. It’s not as compact or maneuverable as an SBR, but it works well out to 400y or so.
Then, the SPR (Special Purpose Receiver/Rifle). The SPR has a magnified optic, from 1x-8x LPVO on the low end to 4x-16x FFP scope on the high end (most sit around 2.5x-10x). It has a bipod for more stable shooting at longer distances. It is the least compact AR-15 platform, with free floating barrel length of 18” to 20”, has the most capable at range, shooting standard ammunition accurately out to 600y, and more expensive, heavier rounds like 77gr mk262 out to 800y.
Beyond these, we have the AR-10 or HK417 or SCARH as DMR (Designated Marksman Rifle). The AR-10 functions similarly to the AR-15s, but is chambered in .308 or a similar, larger cartridge. They have a heavier frame, bigger magazines, and (significantly) heavier and more expensive ammunition than AR-15. A good .308 can reach out to around 1100y, but to take advantage of that range usually requires more serious optics — something more in the 5-25x or 6-36x scopes with MRAD MIL reticles.
Finally, bolt action rifle is another story, sniper teams usually use bolt action rifles and don’t work with Marine or Army squads. It is not semi-automatic at all. Its mechanical simplicity makes it both reliable and extremely accurate (potentially), since fewer moving parts means fewer points of motion or failure. Bolt-Action Rifles are usually chambered in more hunting-capable (bigger) cartridges, from .308 up to 300 Winchester Magnum with 10-60x scopes and can engage in enemy miles away.
What is the Typical Distance Range You Kill Big Game At?
Just interested on people’s theoretical max distance vs distance they’ve killed an animal. With my 308 my max distance is 400 yards and I’ve killed an oryx at 425 because the conditions were right and I felt super steady. I’m not big into long range but somewhat proficient at shooting to 500-600 yards. My personal cap is 400yds. Anything past 600-700 on a living animal is unethical. Too many uncontrollable variables at those distances. Huge difference between shooting targets vs a living animal at 700yds.
引用維基百科：
After using the HK417 as a stopgap designated marksman rifle under the G27 designation, the civilian MR308 was used to develop the G28, a designated marksman rifle for the German Bundeswehr (Federal Army) deployment to the War in Afghanistan. The semi-automatic G28 is chambered for 7.62×51mm NATO and has a factory warrantied accuracy of 45 mm dispersion at 100 meters (0.45 mil or 1.5 moa) when fired with 10 rounds using OTM/HPBT/Sierra Match King ammunition. There are two different versions of the G28: G28 E2 (Standard) with a Schmidt & Bender 3–20×50 PM II (modified to Bundeswehr requirements) and the G28 E3 (Patrol) with Schmidt & Bender 1–8×24 PM II. The M110A1 SDMR is a Squad Designated Marksman Rifle (SDMR) being issued to US Army infantry squads to replace the M14 EBR. In March 2018, the Army announced that a version of the G28E-110 would be issued to infantry squads as the service's standard SDMR. While undergoing evaluation by PEO Soldier, it was designated as M110E1. Issuing a 7.62×51mm NATO SDMR is meant to increase individual squads' ability to engage distant threats and defeat enemy body armor that standard 5.56×45mm NATO rounds cannot penetrate. The M14 EBR was previously issued for this role, but because it was based on an operational needs statement they had to be turned in by units at the end of a combat deployment. The SDMR model will also fire M80A1 Enhanced Performance Rounds or XM1158 Advanced Armor Piercing Rounds rather than sniper rounds. The marksman version is fitted with a simpler SIG TANGO6 1-6×24 telescopic sight to make quick adjustments between 0–600 m (0–656 yd) and features a red horseshoe dot for fast aiming and an illuminated Extended Range Bullet Drop Compensation (BDC) illuminated front focal plane reticle. Early testing began with several U.S. Army combat units receiving the first M110A1 SDMRs in fall 2018. Fielding to all close combat squads is expected to be completed in late 2023.
