View source for .221 Remington Fireball

{{Short description|Pistol and rifle cartridge}}
{{Infobox firearm cartridge
| name = .221 Remington Fireball
| image = 221fireball.png | image_size = 100px
| caption = 
| origin = [[United States]]
| type = [[Pistol]] / [[Rifle]]
<!-- Service history -->
| service = 
| used_by = 
| wars = 
<!-- Production history -->
| designer = [[Remington Arms Company|Remington]] / Wayne Leek
| design_date = 
| manufacturer = Remington
| production_date = 1963
| number = 
| variants = 
<!-- Specifications -->
| is_SI_specs = 
| parent = [[.222 Remington]]
| case_type = Rimless, bottleneck
| bullet = .224
| neck = .253
| shoulder = .361
| base = .376
| rim_dia = .378
| rim_thick = .045
| case_length = 1.400
| length = 1.830
| rifling = 1-{{cvt|12|in}}
| primer = Small rifle
| max_cup = 52,000
<!-- Ballistic performance -->
| is_SI_ballistics = 
|bwround=
| bw1 = 45
| btype1 = SP – Pistol
| vel1 = 2947
| en1 = 868
| bw2 = 50
| btype2 = SX – Pistol
| vel2 = 2813
| en2 = 879
| bw3 = 55
| btype3 = SBT – Pistol
| vel3 = 2700
| en3 = 891
| bw4 = 45
| btype4 = SP – Rifle
| vel4 = 3203
| en4 = 1025
| bw5 = 55
| btype5 = SBT – Rifle
| vel5 = 2950
| en5 = 1063
| test_barrel_length = {{cvt|14|in}}, {{cvt|24|in}}
| balsrc = Accurate Powder<ref name="accurate">[https://web.archive.org/web/20081120154743/http://www.accuratepowder.com/data/PerCaliber2Guide/Handgun/Standarddata/22Cal(5.56mm)/221%20Remington%20Fireball%20T-C%20data%20page%2048.pdf Pistol reload data at Accurate Powder]</ref>
}}

The '''.221 Remington Fireball''' (5.7x35mm), often simply referred to as '''.221 Fireball''', is a [[Centerfire ammunition|centerfire]] [[Cartridge (firearms)|cartridge]] developed by [[Remington Arms Company]] in 1963 as a special round for use in their experimental [[single-shot]] [[bolt-action]] [[pistol]], the [[Remington XP-100|XP-100]].<ref name="chuck_sub">[http://www.chuckhawks.com/subscribers/rifle_cartridge_page/221fireball.htm The .221 Remington Fireball (subscription req)]</ref> It is a shortened version of the [[.222 Remington]] and is popular for varmint and small predator hunting, as well as among target shooters. The .221 Fireball is used in both pistols & rifles.

== History ==
In the early 1960s Remington was working on an experimental bolt-action pistol based on their [[Remington Model 600|Model 600 action]]. The goal was a highly accurate pistol that would be well suited for competition. After working with the .222 Remington they determined that it contained more powder capacity than was necessary to work efficiently in the shorter barrels of pistols. While rifle barrels commonly range in length from {{convert|14.5|to|26|in|cm|abbr=on}}, pistol barrels are typically much shorter, ranging from {{convert|2|to|12|in|cm|abbr=on}} although occasionally up to {{convert|16|in|cm|abbr=on}} for some competition barrels. As a result, Remington decided to develop a shorter version of the .222 Remington cartridge, optimized for use in the XP-100.{{Cn|date=March 2025}}

While production of XP-100 pistols chambered in .221 Fireball was eventually canceled after 1985,<ref name="rem1">Remington Arms [http://www.remington.com/products/archived/centerfire/long-range-pistol/model-xp-100.aspx "Remington Model XP-100"] {{Webarchive|url=https://web.archive.org/web/20121016163702/http://remington.com/products/archived/centerfire/long-range-pistol/model-xp-100.aspx |date=2012-10-16 }}.</ref> [[Thompson Center Arms]] produced various [[single-shot]] pistols chambered for the .221 Fireball as part of their Contender and Encore models. Rifles chambered for the .221 Fireball include the Remington 700 and the Ceska zbrojovka CZ 527.{{Cn|date=March 2025}}

== Performance ==
Despite its smaller size, the .221 Fireball is capable of velocities nearly equal to that of the .222 Remington largely due to its higher [[Sporting Arms and Ammunition Manufacturers' Institute|SAAMI]] pressure. The maximum SAAMI pressure level for the .221 Fireball is 52,000 C.U.P. as compared to 46,000 C.U.P. for the .222 Remington. The purpose of the increased pressure was to allow it to perform more effectively in the shorter barrel of the XP-100.

The .221 Fireball produces the highest velocity of any commercial pistol cartridge.<ref name="chuck_free">{{cite web|url=https://www.chuckhawks.com/221fireball.htm |title=The .221 Fireball by Chuck Hawks |publisher=Chuckhawks.com |access-date=2013-12-25}}</ref>

== Offshoots ==
The .221 Fireball has been used by [[Wildcat cartridge|wildcatters]] to create a small efficient .17 caliber cartridge. The most common is the [[.17 Mach IV]] which is essentially the .221 necked down to the smaller caliber. This cartridge is reported to have a very flat trajectory and to be relatively quiet with low recoil. It has been so popular as a wildcat that in 2007 Remington legitimized it by introducing their version only slightly different from the Mach IV and calling it the [[.17 Remington Fireball]].<ref>{{cite web|url=http://www.accuratereloading.com/17mkiv.html |title=17 Mach IV at Accurate Reloading |publisher=Accuratereloading.com |date=2000-06-30 |access-date=2013-12-25}}</ref>  A .20 caliber version is also gaining popularity called the [[.20 VarTarg]] (VT), "vartarg" being the combination of the words "'''var'''mint" and "'''targ'''et". The .221 Fireball has also been used as the base for the [[.300 Whisper]], sometimes referred to as the .300/.221 or .300 Fireball. It is also the basis for other cartridges in J.D. Jones' Whisper family including the 6&nbsp;mm Whisper, which has been adopted by [[Knight's Armament Corporation]] for their [[Knight's Armament Company PDW]] as the 6×35mm PDW.{{Cn|date=March 2025}}

== Gallery ==

<gallery>
File:221 Remington Fireball.PNG|L-R: 40 gr Hornady V-Max, 55 gr Sierra BlitzKing, .221 Remington Fireball, .22 LR Remington Golden Bullet
File:17fireballand221fireball.png|[[.17 Remington Fireball]] next to its parent case, the .221 Remington Fireball.
</gallery>

== See also ==
* [[.22 Remington Jet]]
* [[.22 Spitfire]], a similar .22 caliber centerfire cartridge
* [[5 mm caliber]]
* [[List of rifle cartridges]]
* [[Table of handgun and rifle cartridges]]

== References ==
{{reflist|30em|}}

{{Intermediate cartridges}}
{{Remington Cartridges Firearms}}
{{Carbine cartridges}}
{{222remderivatives}}

[[Category:Pistol and rifle cartridges|221 Remington Fireball]]
[[Category:Remington Arms cartridges]]
[[Category:Dual-purpose handgun/rifle cartridges]]