Editing Colt Canada C7 and C8 (section)

== Design details ==
Diemaco changed the trapdoor in the buttstock to allow easier access to a small storage compartment inside the stock, and a {{convert|0.5|in|mm|order=flip|abbr=on}} spacer is available to adjust stock length and length of pull to user preference. For the furniture Diemaco chose ''Fiberlite'' nylon-reinforced polymer suitable for [[CBRN defense|CRBN decontamination]] and cold weather use at {{convert|-68|°C|°F}}. The carrying handle and rear sight assembly on top of the Diemaco C7 receiver features the most noticeable external difference between American M16A2s and C7s.
Diemaco C7s use a modified [[M16 rifle#Sights|pre-M16A2 style two aperture L-type flip rear and front post iron sight line]] featuring two combat settings. An approximately {{convert|0.070|in|mm|abbr=on}} diameter [[Iron sights#Aperture sights|aperture rear sight]] is used for normal firing situations for target distances up to {{convert|400|m|yd|abbr=on}}. A second larger approximately {{convert|0.200|in|mm|abbr=on}} diameter aperture battle sight is used as a [[Iron sights#Ghost ring|ghost ring]] for short range quick target engagement and during limited visibility.<ref name="Operator’s Manual: C7 family of com"/><ref name="Maintenance Instructions: C7 family"/>

The wing guards protected front sight was changed to a slimmer tapered round post of approximately {{convert|0.050|in|mm|abbr=on}} diameter. C7 iron sights are normally zeroed with the normal use rear aperture sight at {{convert|300|m|yd|abbr=on}} with [[SS109]]/[[M855]]/C77 ammunition. The rear sight can be zeroed for windage in 2.8&nbsp;cm or 0.28&nbsp;[[Milliradian|mrad]] increments at 100&nbsp;m, when used with a {{convert|502|mm|in|abbr=on}} rifle length sight radius. Elevation adjusting can be zeroed in 3.5&nbsp;cm or 0.35&nbsp;mrad increments at 100&nbsp;m.<ref name="Operator’s Manual: C7 family of com">{{cite web|url= http://www.coltcanada.com/techpubs.htm |archive-url= https://web.archive.org/web/20110708175626/http://www.coltcanada.com/techpubs.htm |url-status= dead |archive-date= 2011-07-08 |title=Operator's Manual: C7 family of combat weapons}}</ref><ref name="Maintenance Instructions: C7 family">{{cite web|url= http://www.coltcanada.com/techpubs.htm |archive-url= https://web.archive.org/web/20110708175626/http://www.coltcanada.com/techpubs.htm |url-status= dead |archive-date= 2011-07-08 |title=Maintenance Instructions: C7 family of combat weapons}}</ref>
Not so apparent is Diemaco's use of 1 in {{convert|7|in|mm|0|order=flip|abbr=on}} [[Rifling|rifling twist]] hammer-forged [[Chrome plating#Hard|chrome-lined]] barrel and chamber units with a slightly reducing bore diameter over the length of the rifling to increase longevity and accuracy.<ref name=TFB1>{{cite web |url=https://www.thefirearmblog.com/blog/2014/09/30/canadian-c7-different-m16 |title=Differences Between Canadian C7 and US M16 |date=30 September 2014 |pages= |access-date=28 December 2021}}</ref><ref>{{cite web|url=https://gatdaily.com/hammer-forged-barrels-made-2/|title=How are Hammer Forged Barrels Made? And Why?|website=gatdaily.com|date=4 September 2017|access-date=15 January 2022|archive-date=15 January 2022|archive-url=https://web.archive.org/web/20220115142905/https://gatdaily.com/hammer-forged-barrels-made-2/|url-status=dead}}</ref>

These features were introduced as the Canadians originally wished to use a heavy barrel profile instead of the M16A2 profile. Diemaco developed a different mounting system from Colt for the [[M203 grenade launcher#Variants|Canadian M203 grenade launcher variant]] for the C7 rifle family and the bolt and bolt carrier were produced from stronger materials. Diemaco optimized the rifle for using [[5.56×45mm NATO]] C77 cartridge L109 ball and the C78 cartridge longer L110 tracer projectiles by using a redesigned buffer assembly, thus making the [[M4 carbine|M4-style]] extended feed ramps later introduced in the Colt M4 carbine unnecessary. The Canadian military initially ordered polymer [[STANAG magazine|STANAG compliant magazines]] for their C7s. As the prototypes failed the Canadian military trials, the C7 was introduced with aluminum STANAG compliant magazines.<ref>{{Cite web|url=http://smallarmssolutions.com/1/post/2018/03/diemacocolt-canada-c7-the-canadian-connection-eh-part-1.html|title=Diemaco/Colt Canada C7 - The Canadian Connection, Eh! Part 1|website=Small Arms Solutions, LLC}}</ref><ref>{{Cite web|url=https://calibremag.ca/colt-canada-worth-the-wait/|title=COLT CANADA: WORTH THE WAIT?|date=September 14, 2014}}</ref> The C7 has a cyclic rate of fire of around 700–900 rounds per minute (RPM).<ref>{{Cite web|url=https://www.militarytoday.com/firearms/c7.htm|title=Colt Canada C7 Assault Rifle &#124; MilitaryToday.com|website=www.militarytoday.com}}</ref>