Review of the Colt AR-15 SP1 – Originally Manufactured 53 Years Ago

Ian from Forgotten Weapons takes a look at the original AR-15 and contrasts it to the original M-16 and our modern AR-15s. While the majority of the M-16/AR-15’s features haven’t changed, it’s very interesting to see what details have changed.

When you think about what technology was available in 1964, particularly in computing, and ponder how much has changed – and then contrast it to firearms technology and how much hasn’t changed… it’s kinda weird. It almost doesn’t make sense. But it goes to show how advanced the AR-15 was for its time, and also how advanced the AK-47 was – having been released in 1949.

Ian from Forgotten Weapons takes a look at the original AR-15 and contrasts it to the original M-16 and our modern AR-15s.

While the majority of the M-16/AR-15’s features haven’t changed, it’s very interesting to see what details have changed. These details are why the original M-16s were frowned upon, and the AR-15 and M4 still has a reputation among some people as being unreliable. When in reality, the original M-16s did have some issues, those issues have since been resolved by decades of refinement.

More info about the AR-15 SP1 in the video

Notable changes between the AR-15 SP1 and modern AR-15s

Most obvious, the original AR-15s included a carry handle rear sight built into the upper receiver, a rifle length buffer, and the fixed post front sight. Most modern AR-15s are modeled after the M4 variant, which features a flat top upper receiver with a picatinny rail for optics, a carbine length buffer for a collapsible stock, and a free float barrel for improved accuracy.

Very interestingly, the very first AR-15 SP1s did not include a forward assist, but was added later in production. There is definitely quite a lot of controversy around the AR-15’s forward assist. Though not all M16s and AR-15 SP1s had forward assists, all bolt carrier groups (BCG) did have the cuts for a forward assist.

M-16s and the AR-15 SP1 did not include a chrome lined BCG during its early days.

The original AR-15s, did not have a ridge around the mag release, causing accidental bumps to drop the mag. The mag release is now protected by a raised edge of various designs.

The M-16’s first buffer is an interesting design. It did not feature the standard weighted buffer we are familiar with. When ammunition changed powders, the M-16 began to have reliability issues, resulting in the new weighted buffer we have now. This is another source of the fables of the AR-15 being unreliable.

The first versions of the bird cage flash hider had slots all around the muzzle device, while the modern A2 Bird Cage flash hider only has slots on the top, to reduce the dust signature.

The original AR-15s featured a 20 inch barrel with a 1:12 twist. most AR-15s these days have a 16 inch barrel and a 1:7 twist, although 1:8 and 1:9 twists are common.

Early M-16s and AR-15 SP1s were chambered in .223 Rem, while modern M4s are chambered in 5.56 Nato, and civilian AR-15s are chambered in .223 Rem, 5.56 Nato, .223 Wylde, and others. All of those variants are generally the same and don’t really have issues due to modern machining.

What is a Curio and Relic License?

The Curio and Relic license allows gun collectors to purchase old firearms without undergoing a background check, because they already went through one to obtain the license. This is intended to help gun collectors obtain old firearms at lower costs. While the license costs $30 for three years, it works as such an easy excuse to buy more firearms, that having the license gets expensive really quick.

Criteria for a firearm to be a “Curio and Relic”

  1. Firearms which were manufactured at least 50 years prior to the current date, but not including replicas of such firearms;
  2. Firearms which are certified by the curator of a municipal, State, or Federal museum which exhibits firearms to be curios or relics of museum interest; and
  3. Any other firearms which derive a substantial part of their monetary value from the fact that they are novel, rare, bizarre, or because of their association with some historical figure, period, or event.

Obtain a Curio and Relic License

The original AR-15 is officially a “Curio and Relic.” So weird.

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Brian Purkiss
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Brian Purkiss is a firearms instructor, competitive shooter, proponent for individual liberty and Second Amendment rights, and a web developer. He enjoys competing in and organizing Run and Gun Competitions, as well as shooting in USPSA, Outlaw matches, and 3 Gun.

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