Editing Rifling (section)

== Recent developments ==
[[File:Polygonal vs normal rifling.svg|thumb|left|Conventional rifling (left) and [[polygonal rifling]] (right). Both types of rifling use a spiraling pattern]]
[[File:Hammer forged 6-right polygonal rifling pattern.png|thumb|The spiraling pattern (here with polygonal rifling) is shown]]

The grooves most commonly used in modern rifling have fairly sharp edges. More recently, [[polygonal rifling]], a throwback to the earliest types of rifling, has become popular, especially in [[handgun]]s. Polygonal barrels tend to have longer service lives because the reduction of the sharp edges of the land (the grooves are the spaces that are cut out, and the resulting ridges are called lands) reduces erosion of the barrel. Supporters of polygonal rifling also claim higher velocities and greater accuracy. Polygonal rifling is currently seen on pistols from [[Česká zbrojovka Uherský Brod|CZ]], [[Heckler & Koch]], [[Glock]], [[Tanfoglio]], and the [[Kahr Arms]] ([[Kahr P series|P series]] only), as well as the [[Desert Eagle]].

{{anchor|Extended range, full bore}}
[[File:ERFB 155-mm projectiles for the G6 howitzer.jpg|thumb]]
For field artillery pieces, the ''extended range, full bore'' (ERFB) concept developed in early 1970s by Dennis Hyatt Jenkins and Luis Palacio<ref>{{US-patent|3939773A}}, {{patent|GB|1405329A}}</ref> of [[Gerald Bull]]'s [[Space Research Corporation]] for the [[GC-45 howitzer]] replaces the [[bourrelet]] with small nubs, which both tightly fit into lands of the barrel.<ref>{{Cite web |title=155 mm HE ER FB-BB (OFd M3-DV) |author= |website=MSM GROUP |date= |access-date=29 July 2022 |url=https://www.msm.sk/en/what-we-do/defence/ammunition/artillery-ammo/155-mm-he-er-fb-bb-ofd-m3-dv/ |archive-date=15 July 2022 |archive-url=https://web.archive.org/web/20220715081144/https://www.msm.sk/en/what-we-do/defence/ammunition/artillery-ammo/155-mm-he-er-fb-bb-ofd-m3-dv/ |url-status=dead }}</ref><ref>{{Cite conference|url=https://asat.journals.ekb.eg/article_25665_987e8a5fd08bf4dd1b97a1fcd8a2c2fd.pdf |archive-url=https://web.archive.org/web/20190429105945/https://asat.journals.ekb.eg/article_25665_987e8a5fd08bf4dd1b97a1fcd8a2c2fd.pdf |archive-date=2019-04-29 |url-status=live|title=ASSESSMENT OF ERFB-BB PROJECTILE|first1=HASSAN|last1=YAKOUT|first2=MOHAMED S.|last2=ABDEL-KADER|publisher=MILITARY TECHNICAL COLLEGE|location=CAIRO, EGYPT|date=14–16 May 1991|conference=FOURTH ASAT CONFERENCE|id=MF-366}}</ref> Guns capable of firing these projectiles have achieved significant increases in range, but this is compensated with a significantly (3&ndash;4 times) decreased accuracy, due to which they were not adopted by NATO militaries.<ref>{{cite web | url=https://soapbox.manywords.press/2018/07/05/extended-range-full-bore-rounds | title=Extended Range, Full Bore Rounds | date=5 July 2018 }}</ref> Unlike a shell narrower than the gun's bore with a [[Sabot (firearms)|sabot]], ERFB shells use the full bore, permitting a larger payload. Examples include the South African [[G5 howitzer|G5]] and the German [[PzH 2000]]. ERFB may be combined with [[base bleed]].