{"id":2973,"date":"2019-08-03T03:46:32","date_gmt":"2019-08-03T03:46:32","guid":{"rendered":"https:\/\/www.wideners.com\/blog\/?p=2973"},"modified":"2025-07-25T14:38:10","modified_gmt":"2025-07-25T14:38:10","slug":"what-is-fmj-ammo","status":"publish","type":"post","link":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/","title":{"rendered":"What Is FMJ Ammo?"},"content":{"rendered":"

By Guy J. Sagi<\/a><\/span><\/p>\n

Full metal jacket bullets have an outer shell made from one metal, with a softer interior core manufactured from another\u2014the latter typically being lead. FMJ is the firearm industry\u2019s shorthand for the design, although some militaries and enthusiasts refer to it as \u201cball.\u201d<\/span><\/p>\n

FMJ loads are full metal jacket ammo<\/a> and are most commonly used by shooters for range training or during competitions that require high-volume shooting. These rounds are not designed to expand on impact with a soft target, making them a poor choice for self-defense or hunting in most scenarios.\u00a0<\/span><\/p>\n

FMJ Bullet Design\u00a0<\/strong><\/h2>\n
\"a

The copper-coated FMJ bullet reduces barrel fouling and is cleaner to shoot than other non-coated ammo options.<\/p><\/div>\n

Lead was ideal for the spherical projectiles in early firearms, thanks to its relatively low melting point, abundance and energy-carrying mass. As gun designs improved\u2014bringing with them higher muzzle velocities, increased chamber pressures and a departure from single shots. The malleable metal\u2019s drawbacks in bullets also became obvious. It fouled barrels, deformed with eerie regularity on exit and even made chambering a second round from newfangled magazines a hit-and-miss affair.<\/span><\/p>\n

Swiss Col. Eduard Rubin discovered a solution in 1882 when the mechanical engineer tested a bullet with its lead core enveloped in copper\u2014the first FMJ. His experiments determined the tougher and higher-in-melting-point exterior minimized fouling and, thanks to copper\u2019s reduced willingness to bend unpredictably, improved cycling of fresh rounds into a firearm. In addition, the layer of slightly lighter material had little impact on the bullet\u2019s ability to retain energy downrange and the projectiles were not deforming.<\/span><\/p>\n

Modern FMJ Manufacturing<\/strong><\/h3>\n
\"a

An expanded view of FMJ pistol (top) and rifle (bottom) ammo, note the lead core visible on the 9mm bullet.<\/p><\/div>\n

It caught on fast and the design is probably the most common encountered at the range today. There\u2019s good reason, too. Advances in technology have made FMJ bullets more uniform and accurate than ever before.<\/span><\/p>\n

Modern manufacturing of an FMJ begins by shaping the material that will become the jacket into a uniform cup. Companies typically use copper although they continue to discover and harness a variety of advantages offered by other alloys.<\/span><\/p>\n

Core material\u2014usually swaged lead wire\u2014then goes into the cup and pressure applied to draw the jacket over it. This removes issues like air pockets or other performance-robbing inconsistencies at the same time. Lead lends itself extremely well to the process due to its ductility.<\/span><\/p>\n

The final steps are shaping, trimming and inspection. The manufacturing process leaves some core material visible at the base of the bullet, even after it\u2019s finished.<\/span><\/p>\n

FMJ Advantages<\/strong><\/h2>\n
\"a

FMJ rifle caliber bullets are known for their accuracy and reliability, even in adverse climate conditions.<\/p><\/div>\n

FMJs are inexpensive, a fact reflected in the price of factory ammo loaded with the bullet design. That makes them ideal for high-volume shooters, competitors and plinkers.<\/span><\/p>\n

They may be budget-friendly, but don\u2019t underestimate their long-distance performance. Even after you\u2019ve learned to adjust for the wind at 1,000 meters, most FMJs outperform the shooter. When you\u2019re ready to dial things up feel free to invest in loads with fine-tuned projectiles, but it\u2019s surprising how this routine firing line fodder is the preferred choice at major training academies.<\/span><\/p>\n

Cleanup is a breeze, too. If you\u2019re not fond of scrubbing bits of lead from the hidden recesses of your barrel, you\u2019ll appreciate FMJs. Thousands of gun owners owe thanks to Col. Rubin\u2014few know his name, although most appreciate his ingenuity.<\/span><\/p>\n

Annoying stovepipes and many other \u201cjams\u201d can disappear, too. With lead\u2019s tendency to bend, dig and otherwise defy the purpose of a magazine\u2019s feed lips blanketed in copper, things get more reliable.<\/span><\/p>\n

FMJs are also better at containing lead when they hit a target. The metal\u2019s dust\/vapor is a major concern at some ranges, particularly indoor facilities. This style bullet is mandatory at some facilities, a rule that supplements the cutting-edge ventilation systems always in use.<\/span><\/p>\n

FMJ Disadvantages<\/strong><\/h2>\n
\"a

A comparison photo of 115gr FMJ 9mm ammo mixed with 115gr JHP 9mm ammo. Can you spot the differences?<\/p><\/div>\n

FMJ bullets are notorious for an unwillingness to expand at bullet impact. Terminal ballistics that make this style of bullet style not recommended for self-defense or hunting. They often pass completely through the target, whether it\u2019s a deer or felonious attacker, delivering minimal stopping power. With little loss of kinetic energy, they can keep going through most metal, walls or untargeted animals in the herd until friction and gravity finally grind things to a halt.<\/span><\/p>\n

There are better bullet designs for those who hunt, carry or are ready to defend their family and home. They\u2019re tailored to maximize energy delivered on the target to ethically take an animal or stop the assault, a task the FMJ doesn\u2019t perform well. The design of the jacketed hollow point or JHP as it is commonly referred to is a much better choice for hunting or self-defense situations.<\/span><\/p>\n

Plated vs FMJ<\/strong><\/h3>\n

A plated bullet is related to the FMJ, visually anyway. The resemblance is there, but the two are not identical. It also has an exterior metal shell, but the manufacturing process explains subtle differences.\u00a0\u00a0<\/span><\/p>\n

To create a plated bullet, manufacturers submerge the core in a solution rich in \u201cjacket\u201d material. The exterior coating collects after the introduction of an electrical charge, an electrochemical technique more often associated with the jewelry industry. The process results in complete coverage, including the base of a plated bullet. Manufacturers stuff the end of the bullet inside a loaded cartridge, so the average shooter who doesn\u2019t reload will never notice.<\/span><\/p>\n

CMJ vs FMJ<\/strong><\/h3>\n

Whether or not these coated metal jackets (CMJs) quite live up to the FMJ family\u2019s fame is a matter of discussion. Those with opinions on the subject often point out some of the finer differences between the two. A plated bullet\u2019s \u201cjacket\u201d material, for example, has not gone through the heavy machining process a pureblooded FMJ undergoes. Without that work-hardening, the former is theoretically more prone to nicks and bends. Those imperfections tend to hang up when traveling from a gun\u2019s magazine into the chamber.\u00a0<\/span><\/p>\n

Other often-cited factors include a typically higher price tag, a fact that reflects thicker coatings require a longer stay in the solution. Performance, particularly at long range, can also be a concern. The slightest change in a bullet\u2019s weight distribution\u2014even if it weighs the same\u2014can affect the point of impact. Shooters typically only notice the change when firing at great distances.<\/span><\/p>\n

FMJ-BT Ammo<\/strong><\/h4>\n
\"a

The boat-tail bullet design is known for its accuracy and is favored among long-distance shooters.<\/p><\/div>\n

There are many forces affecting a bullet as it travels downrange. Minimizing their impact increases accuracy, the primary reason long-distance shooters favor boat tail (BT) bullets. Many hunters, competitors, LEO and military marksmen prefer the boat tail bullet design for its precision accuracy.<\/span><\/p>\n

The design is simple and is visible at a bullet\u2019s base. The sides of boat tail bullet<\/a> end with a slight taper instead of the more traditional and abrupt 90-degree angle. The best way to visualize the concept is to think of a boat hull from an overhead view. The gentle inward bend at the stern is the BT design, hence the name. It reduces turbulence\u2014even friction\u2014as air passes over and behind a projectile during flight. That makes an FMJ-BT the best choice for anyone shooting at extreme range.\u00a0<\/span><\/p>\n

FMJ Ammo Legacy<\/strong><\/h2>\n
\"a

Although not a great choice for self-defense, the FMJ is a favorite option for those training or plinking at the range.<\/p><\/div>\n

Although the basic concept of the FMJ remains the same, advances in technology have fine-tuned the design to levels unimaginable by Col. Rubin and his development team at the Swiss Federal Ammunition Factory and Research Center\u2014then considered among the world\u2019s foremost in ballistics research. There\u2019s no doubt they\u2019d marvel at the modern material and manufacturing but appreciate the fact it all remains true to the primary goal, one they accomplished more than 100 years ago.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

By Guy J. Sagi Full metal jacket bullets have an outer shell made from one metal, with a softer interior core manufactured from another\u2014the latter typically being lead. FMJ is the firearm industry\u2019s shorthand for the design, although some militaries and enthusiasts refer to it as \u201cball.\u201d FMJ loads are full metal jacket ammo and […]<\/p>\n","protected":false},"author":7,"featured_media":3061,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[48],"tags":[447,443,444,3106,3104,3105,448,209,3107,519,445,231,446,449],"class_list":["post-2973","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ammo","tag-cmj","tag-fmj","tag-fmj-ammo","tag-fmj-bullets","tag-fmj-handgun-ammo","tag-fmj-rifle-ammo","tag-fmj-bt","tag-full-metal-jacket","tag-full-metal-jacket-ammo","tag-handgun-ammo","tag-jhp","tag-pistol-ammo","tag-plated","tag-rifle-ammo"],"yoast_head":"\nWhat Is FMJ Ammo? - Wideners Shooting, Hunting & Gun Blog<\/title>\n<meta name=\"description\" content=\"Learn about the full metal jacket bullet in this article as we explain FMJ ammo and look at the design and history of this popular bullet type.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"What Is FMJ Ammo? - Wideners Shooting, Hunting & Gun Blog\" \/>\n<meta property=\"og:description\" content=\"Learn about the full metal jacket bullet in this article as we explain FMJ ammo and look at the design and history of this popular bullet type.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/\" \/>\n<meta property=\"og:site_name\" content=\"Wideners Shooting, Hunting & Gun Blog\" \/>\n<meta property=\"article:published_time\" content=\"2019-08-03T03:46:32+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-07-25T14:38:10+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/BSS0579.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1024\" \/>\n\t<meta property=\"og:image:height\" content=\"683\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Guy Sagi\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Guy Sagi\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"8 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/\",\"url\":\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/\",\"name\":\"What Is FMJ Ammo? - Wideners Shooting, Hunting & Gun Blog\",\"isPartOf\":{\"@id\":\"https:\/\/www.wideners.com\/blog\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/BSS0579.jpg\",\"datePublished\":\"2019-08-03T03:46:32+00:00\",\"dateModified\":\"2025-07-25T14:38:10+00:00\",\"author\":{\"@id\":\"https:\/\/www.wideners.com\/blog\/#\/schema\/person\/02c3c8a4ca5dfe01956690f834228062\"},\"description\":\"Learn about the full metal jacket bullet in this article as we explain FMJ ammo and look at the design and history of this popular bullet type.\",\"breadcrumb\":{\"@id\":\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#primaryimage\",\"url\":\"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/BSS0579.jpg\",\"contentUrl\":\"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/BSS0579.jpg\",\"width\":1024,\"height\":683,\"caption\":\"a photo of 45 acp fmj ammo\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.wideners.com\/blog\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"What Is FMJ Ammo?\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.wideners.com\/blog\/#website\",\"url\":\"https:\/\/www.wideners.com\/blog\/\",\"name\":\"Wideners Shooting, Hunting & Gun Blog\",\"description\":\"Tips for shooting, self-defense, hunting and more\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.wideners.com\/blog\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.wideners.com\/blog\/#\/schema\/person\/02c3c8a4ca5dfe01956690f834228062\",\"name\":\"Guy Sagi\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.wideners.com\/blog\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/guy-1-96x96.jpg\",\"contentUrl\":\"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/guy-1-96x96.jpg\",\"caption\":\"Guy Sagi\"},\"description\":\"Guy J. Sagi\u2019s byline and photography have appeared in many major outdoor publications, from periodicals specializing in firearms, to hunting, off-roading, fishing and more. For a decade he served as editor-in-chief of Safari Club International\u2019s monthly Safari Times. He later joined NRA Publications, where he started as executive editor for three of the organization\u2019s publications before assuming the editor-in-chief role at Shooting Illustrated\u2014then the NRA\u2019s only newsstand publication. Sagi resigned the position after more than 10 years, due to family reasons, but his work continues to appear on a variety of outlets, both on the web and in print. For a look at more of his work visit his website.\",\"url\":\"https:\/\/www.wideners.com\/blog\/author\/guy\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"What Is FMJ Ammo? - Wideners Shooting, Hunting & Gun Blog","description":"Learn about the full metal jacket bullet in this article as we explain FMJ ammo and look at the design and history of this popular bullet type.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/","og_locale":"en_US","og_type":"article","og_title":"What Is FMJ Ammo? - Wideners Shooting, Hunting & Gun Blog","og_description":"Learn about the full metal jacket bullet in this article as we explain FMJ ammo and look at the design and history of this popular bullet type.","og_url":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/","og_site_name":"Wideners Shooting, Hunting & Gun Blog","article_published_time":"2019-08-03T03:46:32+00:00","article_modified_time":"2025-07-25T14:38:10+00:00","og_image":[{"width":1024,"height":683,"url":"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/BSS0579.jpg","type":"image\/jpeg"}],"author":"Guy Sagi","twitter_misc":{"Written by":"Guy Sagi","Est. reading time":"8 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/","url":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/","name":"What Is FMJ Ammo? - Wideners Shooting, Hunting & Gun Blog","isPartOf":{"@id":"https:\/\/www.wideners.com\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#primaryimage"},"image":{"@id":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#primaryimage"},"thumbnailUrl":"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/BSS0579.jpg","datePublished":"2019-08-03T03:46:32+00:00","dateModified":"2025-07-25T14:38:10+00:00","author":{"@id":"https:\/\/www.wideners.com\/blog\/#\/schema\/person\/02c3c8a4ca5dfe01956690f834228062"},"description":"Learn about the full metal jacket bullet in this article as we explain FMJ ammo and look at the design and history of this popular bullet type.","breadcrumb":{"@id":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#primaryimage","url":"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/BSS0579.jpg","contentUrl":"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/BSS0579.jpg","width":1024,"height":683,"caption":"a photo of 45 acp fmj ammo"},{"@type":"BreadcrumbList","@id":"https:\/\/www.wideners.com\/blog\/what-is-fmj-ammo\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.wideners.com\/blog\/"},{"@type":"ListItem","position":2,"name":"What Is FMJ Ammo?"}]},{"@type":"WebSite","@id":"https:\/\/www.wideners.com\/blog\/#website","url":"https:\/\/www.wideners.com\/blog\/","name":"Wideners Shooting, Hunting & Gun Blog","description":"Tips for shooting, self-defense, hunting and more","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.wideners.com\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/www.wideners.com\/blog\/#\/schema\/person\/02c3c8a4ca5dfe01956690f834228062","name":"Guy Sagi","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.wideners.com\/blog\/#\/schema\/person\/image\/","url":"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/guy-1-96x96.jpg","contentUrl":"https:\/\/www.wideners.com\/blog\/wp-content\/uploads\/guy-1-96x96.jpg","caption":"Guy Sagi"},"description":"Guy J. Sagi\u2019s byline and photography have appeared in many major outdoor publications, from periodicals specializing in firearms, to hunting, off-roading, fishing and more. For a decade he served as editor-in-chief of Safari Club International\u2019s monthly Safari Times. He later joined NRA Publications, where he started as executive editor for three of the organization\u2019s publications before assuming the editor-in-chief role at Shooting Illustrated\u2014then the NRA\u2019s only newsstand publication. Sagi resigned the position after more than 10 years, due to family reasons, but his work continues to appear on a variety of outlets, both on the web and in print. For a look at more of his work visit his website.","url":"https:\/\/www.wideners.com\/blog\/author\/guy\/"}]}},"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/posts\/2973","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/comments?post=2973"}],"version-history":[{"count":29,"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/posts\/2973\/revisions"}],"predecessor-version":[{"id":17983,"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/posts\/2973\/revisions\/17983"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/media\/3061"}],"wp:attachment":[{"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/media?parent=2973"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/categories?post=2973"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wideners.com\/blog\/wp-json\/wp\/v2\/tags?post=2973"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}