View source for .25 ACP

{{short description|Pistol cartridge designed by John Moses Browning}}
{{Redirect|.25|other cartridges in this caliber|.25 caliber|other uses|1/4 (disambiguation)}}
{{Infobox firearm cartridge
|name=.25 ACP
|image=.25 ACP.jpg
|caption=.25 ACP cartridge with scale
|origin=[[United States]] and [[Belgium]]
|type=Pistol
|designer=[[John Browning]]
|design_date=1905
|production_date=1905–present
|case_type=Semi-rimmed, straight
|bullet=.2512
|land=.2429
|neck=.276
|base=.278
|rim_dia=.302
|rim_thick=.043
|case_length=.615
|length=.910
|rifling=1:16
|primer=Small pistol
|max_pressure=25000
|max_cup = 25,000<ref>Saami pressures. (n.d.). Retrieved May 3, 2023, from https://leverguns.com/articles/saami_pressures.htm</ref>
|bw1=22
|btype1=+P HP
|vel1=1750
|en1=150
|bw2=35
|btype2=JHP
|vel2=900
|en2=63
|bw3=45
|btype3=JHP
|vel3=815
|en3=66
|bw4=50
|btype4=FMJ
|vel4=760
|en4=65
|bw5=60
|btype5=Lead
|vel5=850
|en5=96
|test_barrel_length=2"
|balsrc= 
Buffalo Bore<ref>{{cite web | url=https://www.buffalobore.com/index.php?l=product_detail&p=605 | title=25 ACP Pistol & Handgun Ammunition }}</ref><br />
Ballistics 101<ref>{{cite web | url=http://www.ballistics101.com/25_acp.php | title=25 ACP Ballistics Chart &#124; Ballistics 101 }}</ref>
}}

The '''.25 ACP''' ([[Automatic Colt Pistol]]), also known as the '''.25 Auto''', '''.25 Automatic, 6.35mm Browning''', or '''6.35×16mmSR''' is a [[Rim (firearms)|semi-rimmed]], straight-walled [[Centerfire ammunition|centerfire]] [[pistol]] [[Cartridge (firearms)|cartridge]] introduced by [[John Browning|John Moses Browning]] in 1905 alongside the [[FN M1905|Fabrique Nationale M1905]] pistol.

==Design and history==
The .25 ACP was designed because .25-caliber was the smallest John Browning could go while still retaining a [[Centerfire ammunition|centerfire primer]] pocket, which would be more reliable for self-defense than a [[Rimfire ammunition|rimfire primer]]. As such, the .25 ACP allows for both a very compact lightweight semi-automatic [[pocket pistol]].<ref>{{Cite web|url=https://www.guns.com/news/2024/03/28/25-acp-auto-mouse-gun-caliber-bullet-browning-history/|title=Browning's .25 ACP: Mouse Gun History :: Guns.com}}</ref> The .25 ACP was hugely popular after its introduction, with many millions of small .25 ACP "[[Pocket pistol|mouse guns]]" being offered on the civilian market.

Following the [[Gun Control Act of 1968]], most foreign .25 pistols were too small to be imported; however, some domestic manufacturers continued to build guns in the caliber. The most common pocket pistols in the United States today are chambered in [[.22 LR]], [[.380 ACP]], and [[9x19mm Parabellum]].<ref>{{Cite web |title=All You Need To Know About the 25 ACP |url=https://gunmagwarehouse.com/blog/all-you-need-to-know-about-the-25-acp/ |access-date=2024-07-31}}</ref>

The cartridge is of semi-rimmed design meaning that the rim protrudes slightly beyond the diameter of the base of the cartridge so the cartridge can [[Headspace (firearms)|headspace]] on the rim.<ref name="wilson">*Wilson, R. K. ''Textbook of Automatic Pistols''. Plantersville, SC: Small Arms Technical Publishing Company, 1943. p. 258. {{ISBN|978-0-935632-89-7}}.</ref> This semi-rimmed design allows for it to be used in revolvers. Although rare, .25 ACP revolvers were produced in the early twentieth century by Belgian, French, and German gunmakers such as Adolph Frank and Decker.<ref>{{Cite book |last1=Hogg |first1=Ian |url= |title=Pistols of the World |last2=Walter |first2=John |date=2004-08-29 |publisher=[[David & Charles]] |isbn=0873494601 |language=en}}</ref> In the late twentieth century, [[Bowen Classic Arms]] produced a custom [[Smith & Wesson]] revolver in .25 ACP.<ref>Bowen, Hamilton. ''The Custom Revolver''. Privately printed, 2001. {{ISBN|978-0-9713366-0-5}}.</ref>

==Performance==
The .25 ACP is viewed by some, including ''[[Gun Digest]]'' magazine, to still be a relevant choice (with it being over a century old) for a personal defense handgun when compared to more modern subcompact handguns & cartridges due to its small size, low recoil, centerfire primer, effective penetration, and proven track record of being reliable.<ref name="gdcc">{{citation|title=Gun Digest Buyer's Guide to Concealed-Carry Handguns|author=Jerry Ahern|pages=19–20|isbn=978-1-4402-1383-0|publisher=Gun Digest Books|year=2010}}</ref><ref>{{Cite AV media |url=https://www.youtube.com/watch?v=rfycMCuuKxY |title=Lynn Thompson talks about the effectiveness of 25 ACP |date=2016-08-25 |last=Cold Steel |access-date=2024-07-31 |via=YouTube}}</ref><ref>{{Cite web |last=Borisenko |first=Adam |date=2021-08-10 |title=.25 ACP: The Best Cartridge For Really Little Guns |url=https://gundigest.com/gear-ammo/ammunition/25-acp-the-best-cartridge-for-really-little-guns |access-date=2024-07-31 |website=Gun Digest |language=en-US}}</ref><ref>{{Cite web |last=Esson |first=Roger |date=2023-03-17 |title=Is.25 ACP Any Good? |url=https://trueshotammo.com/academy/is-the-25-acp-any-good/ |access-date=2024-07-31 |website=True Shot Ammo |language=en-US}}</ref> However, more modern ammunition offered from manufacturers such as Buffalo Bore [[Bullet#Materials|hard cast]] [[lead]], [[Federal Premium Ammunition|Federal "Punch"]], and [[Hornady]] Critical Defense are designed to be closer to the cartridge's full potential. Some more powerful loadings of the .25 ACP can even get close to [[.32 ACP]] territory.<ref>{{Cite web |last=K |first=Zac |date=2024-06-17 |title=Federal Punch Self-Defense Ammo Has New .25 ACP Option |url=https://www.thefirearmblog.com/blog/federal-punch-self-defense-ammo-has-new-25-acp-option-44814382 |access-date=2024-07-31 |website=thefirearmblog.com |language=en}}</ref><ref>{{Cite web |title=Tested: Buffalo Bore 25 ACP 60 Grain Hard Cast Ammunition |url=https://gunmagwarehouse.com/blog/tested-buffalo-bore-25-acp-60-grain-hard-cast-ammunition/ |access-date=2024-07-31}}</ref><ref>{{Cite web |title=25 Auto 35 gr FTX® Critical Defense® |url=https://www.hornady.com/ammunition/handgun/25-auto-35-gr-ftx-critical-defense |access-date=2024-07-31 |website=Hornady Manufacturing, Inc |language=en}}</ref> 

The .25 is viewed by others as inadequate for personal defense. Self-defense instructor Greg Ellifritz conducted a study using statistics from almost 1,800 real-world shootings. Of the 68 people shot with a .25 ACP, 35% of them were not incapacitated. 25% of the hits were fatal, one-shot stop was 30%, and 49% were incapacitated by one shot. The .380 ACP, on the other hand, left 16% of people shot not incapacitated. This was a 30% increase from that of the .25 ACP. Ellifritz stated: "I would skip carrying the "mouse gun" .22s, .25s and .32s." However, he also pointed out that shot placement is more important than caliber (a common argument from .25 users) and concluded his review by stating: "caliber really isn't all that important."<ref>{{cite web | url=https://www.buckeyefirearms.org/alternate-look-handgun-stopping-power | title=An Alternate Look at Handgun Stopping Power &#124; Buckeye Firearms Association }}</ref> Other critics of the .25 ACP have pointed out that the round has trouble penetrating through bone and typically does not have enough energy to ensure the reliable expansion of hollow-point projectiles, and that even if the projectiles do expand, that results in a decrease of penetration.<ref>{{cite web | url=https://blog.cheaperthandirt.com/rise-fall-25-acp/ | title=Throwback Thursday: The Rise and Fall of the .25 ACP | date=13 April 2023 }}</ref><ref>{{Cite web|url=https://gunmagwarehouse.com/blog/ammo-test-hornady-critical-defense-25-acp/|title=Ammo Test: Hornady Critical Defense 25 ACP - The Mag Life}}</ref>

However, urban legends about .25 ACP's inadequacy (such as claims that the .25-caliber bullet will bounce off a skull or be stopped by thicker clothing materials)<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=rfycMCuuKxY |title=Is .25 ACP Literally the Worst Self-Defense Cartridge? |date=2018-10-30 |last=Lucky Gunner Ammo |access-date=2024-08-03 |via=YouTube}}</ref> are inconsistent with the cartridge's historically proven track record. The reputation of the .25 ACP has long suffered from the cartridge only being offered in low-capacity pocket pistols with {{convert|2|in|abbr=on}} barrels. This short barrel length limits the velocity and energy that a .25 ACP offers and contributes to the popular belief that the .25 ACP is less powerful than the [[.22 Long Rifle]]. The .22 LR is a rifle cartridge and, as such, is typically tested in rifle-length barrels, which is why the .22 LR appears to be more powerful than the .25 ACP. In an {{convert|18|in|abbr=on}} barrel, a .25 ACP performs similarly to a .22 LR being fired from a {{convert|2|in|abbr=on}} barrel, with a {{convert|50|gr|abbr=on}} projectile traveling at about {{convert|1,000|ft/s|abbr=on}} and producing in excess of {{convert|100|ftlbf|abbr=on}} of energy, while .22 LR gets such energy with twice the velocity from a {{convert|2|in|abbr=on}} barrel pocket pistol. <ref>{{Cite web |title=BBTI - Ballistics by the Inch :: .25 Auto Results |url=http://ballisticsbytheinch.com/25auto.html |access-date=2024-07-31 |website=ballisticsbytheinch.com}}</ref><ref>{{cite web | last=Baker | first=Chris | title=Pocket Pistol Caliber Ballistic Gel Tests | website=LuckyGunner.com Labs | date=2020-01-17 | url=https://www.luckygunner.com/labs/pocket-pistol-caliber-gel-test-results/}}</ref> Comparing the .25 ACP to the .22 LR fails to take into account a few things, namely that the .22 LR is far more popular and has had decades more of development. The .22 LR largely replaced the .25 ACP as a pocket pistol cartridge, but in addition received development for hunting purposes. As such, there are far more defensive loads for the .22 LR than the .25 ACP. That being said, most .25 loadings are still very comparable in performance to the .22 LR in short-barreled pocket pistols.<ref>{{Cite web |last=Brandon |date=2021-11-17 |title=22LR vs 25 ACP - Pocket Pistol Caliber Comparison |url=https://www.ammunitiontogo.com/lodge/22lr-vs-25-acp/ |access-date=2024-07-31 |website=The Lodge at AmmoToGo.com |language=en-US}}</ref><ref>{{Cite web |title=.25 ACP & .22LR: Comparing Pocket Pistol Calibers For Concealed Carry |url=https://nightgalaxy.com/blog/post/25-acp-22lr-comparing-pocket-pistol-calibers-for-concealed-carry |access-date=2024-07-31 |website=nightgalaxy.com |language=en}}</ref> 

<gallery widths="200px" heights="160px">
File:Browning 6,35 (6971783925).jpg|[[FN 1905]]/6
File:25 Caliber Jacketed Hollow Point.jpg|Modern jacketed hollow point loads for 6.35mm/.25 cal.
File:Walther's Patent Mod 9-103.jpg|The [[Walther Model 9]] pistol uses 6.35mm
File:Bauer .25 Auto pistol.jpg|[[Bauer Automatic|Bauer .25 Auto pocket pistol]]
File:Raven_MP-25_Chrome_with_faux_mother_of_pearl_grips.jpg|[[Raven Arms#MP-25|Raven MP-25]] .25 ACP chrome with faux mother of pearl grips and push up safety
File:Colt Vest Pocket.JPG|[[Colt Model 1908 Vest Pocket]] used .25 ACP
</gallery>

==See also==
* {{annotated link|6 mm caliber}}
* [[Table of handgun and rifle cartridges]]

==References==
{{reflist}}

==External links==
{{Commons category}}
* [http://www.ballisticsbytheinch.com/25auto.html Ballistics By The Inch .25ACP results.]
* [https://www.luckygunner.com/labs/pocket-pistol-caliber-gel-test-results/]
{{John Browning}}
{{Colt's Manufacturing Company}}

{{DEFAULTSORT:25 ACP}}
[[Category:.25 ACP firearms| ]]
[[Category:Colt cartridges]]
[[Category:Pistol and rifle cartridges|25 ACP]]