Requires a gunsmith
clockwise
The M4, like most US military rifles made in the past 70 years, uses a ring and post sight system. The front sight, a post, is placed on your target, being elevated or depressed to account for range, and centered in the circle of the rear ring sight. Do a Google search for FM m16 rifle, and find the Field Manual for the rifle- it shows illustrations of sight alignment and sight picture.
Aside from the obvious differences, such as the collapsible buttstock and shorter barrel (14.5 inches vs. 20 inches), there are some more subtle ones. The M4 has a higher Front Sight Base to compensate for the shorter sight distance, the M4 uses a different buffer and buffer spring than the M16, the M4 has an indentation in the barrel to accommodate the M203 grenade launcher mount developed for the M4 (government law enforcement M4s typically have a barrel without this indentation), and the M4 has a longer set of feed ramps which also extend into the lower receiver itself.
The M4 is the basic weapon system for the modern infantry soldier. It is usually equipped with a M68 red dot sight. A standard combat load for a soldier carrying an M4 is 400 rounds of ammunition. Are you serious? 400 rounds is not the STANDARD combat load. The M16A4 is the standard basic weapon but is being replaced by the M4. A red dot is definitely not the standard sight.
Next to Reading. Just off the M4
The M4 is basically a carbine version of the M16A2 rifle, and was developed both to reflect the development of the M16A2 over the previous M16A1, and to correct deficiencies which had been identified with the XM-177 (which was the carbine variant of the M16A1).General differences between the M4 and M16 include:M4 has a four position collapsible buttstock (vs. the fixed buttstock of the M16)The weight of the buffer is different in the M4 than the M16The M4 has shorter handguardsThe M4 has a shorter gas systemThe M4 has extended feed ramps cut into the upper receiver for ease of chambering rounds.The M4 has a 14.5 inch barrel, vs. the 20 inch barrel of the M16The M4 has an "F" marked front sight base, which is designed to compensate for the difference in sight radius between the M4 and M16The M4 has an indentation in the barrel profile to facilitate the mounting of an M203 grenade launcher.Some people often cite the removable carry handle of the M4 as one difference, but the first production run of M4 carbines had the same fixed carry handle as the M16A2 (I was actually issued one when I was in the FL National Guard).
Any rifle that has open sights is aimed the same way. Line up the target with the front sight while looking through the rear sight at the same time.
Looks to me to be an M4 with various ancilliaries, such as an optical sight and foregrip.
The M4 is an assault rifle based off it's popular cousins the M16 and AR 15 also assault rifles.
Springs are found in the following location on the M4, M16, and all AR15 pattern rifles:Buffer assemblyForward assistEjection port coverExtractorBuffer detentBolt catchHammerMagazine catchSafety selectorRear takedown/pivot pinTriggerDisconnectorOn most models, there is also a spring in the rear sight assembly, if so equipped.There is also a spring under the detente in the front sight assembly. And don't forget the magazine spring.
It all depends on the Daisy Scope rings that you have. The M4 has a removable front and rear sight. This will allow you to add a scope to the Weaver rail mount on the M4 if your scope rings are the weaver size. If not, then you need to purchase weaver scope rings for your scope.
You can buy a plastic m4 or you can buy a metal m4