{"id":412299,"date":"2023-12-13T11:00:58","date_gmt":"2023-12-13T17:00:58","guid":{"rendered":"https:\/\/gunmagwarehouse.com\/blog\/?p=412299"},"modified":"2025-09-10T16:21:06","modified_gmt":"2025-09-10T21:21:06","slug":"ar-15-pin-and-weld-basic-questions-and-answers","status":"publish","type":"post","link":"https:\/\/gunmagwarehouse.com\/blog\/ar-15-pin-and-weld-basic-questions-and-answers\/","title":{"rendered":"AR-15 Pin and Weld: Basic Questions and Answers"},"content":{"rendered":"

We often hear the words “pin and weld” when it comes to the AR-15 platform. Below are a few questions and answers that revolve around the whys<\/em> of a pin and weld service and also some hows<\/em>.<\/em><\/p>\n

Why do I need pin and weld?<\/h2>\n

Without going into too much politics, Congress and the Bureau of Alcohol, Tobacco and Firearms have laws and regulations pertaining to the National Firearms Act. Within these laws and regulations is the U.S. Code defining a short barreled rifle (SBR):<\/p>\n

18 USC \u00a7 921(a)(8) short-barreled rifle<\/strong>
\n(8) The term \u201cshort-barreled rifle\u201d means a rifle having one or more barrels less than sixteen inches in length and any weapon made from a rifle (whether by alteration, modification, or otherwise) if such weapon, as modified, has an overall length of less than twenty-six inches.<\/em><\/p>\n

To legally own a NFA firearm such as an SBR, it must be registered. The registration involves a $200 dollar tax and submitting fingerprints. To get around this, there is a permanent modification that involves pinning and welding (i.e. pin and weld) a muzzle device<\/a> to the barrel. For example, a 14.5″ barrel with a 1.5″ muzzle device or a 13.7″ barrel with 2.3″ muzzle device can meet the 16″ minimum with a pin and weld.<\/p>\n

Shooters want a more maneuverable rifle and that means a shorter barrel. Companies have heard that and offer longer muzzle devices to reach the overall barrel length of 16 inches without using a 16 inch barrel plus a muzzle device.<\/p>\n

\"ar
This is a 13.7 inch ballistic advantage barrel with 2.3 inch Cobalt Kinetics RCB-KM Deadair Keymo device. This will be my 2-gun\/low-light match gun for close range PCSL type shooting matches. The overall barrel length is 16 inches due to the pinned and welded muzzle device.<\/figcaption><\/figure>\n

How is pin and weld completed?<\/h2>\n

Due to the ATF ruling, this a permanent modification to the firearm. It must be done correctly or it can be seen as not permanent. The process involves drilling a hole through the muzzle device and just barely into the barrel. A pin is then added into that hole and a tig welder welds over the pin so it cannot be removed.<\/p>\n

Who does pin and weld?<\/h2>\n

While pin and weld seems simple, it can be botched. A competent gunsmith should complete this modification due to having the correct tools and knowledge. For example, if your gunsmith says he is going to use a hand drill for the hole, leave. If he doesn’t have a tig welder or even a soldering gun, leave. If he is charging you 200 bucks, also leave.<\/p>\n

The fact someone will be drilling into your barrel should be enough to force you to seek someone competent. Go too far into the barrel and malfunctions can occur with the barrel ruined. Welding over the pin without the proper tools and it can look atrocious. Forget to place the pin and, well, the muzzle device can easily come off as normal (Yes, it has happened).<\/p>\n

As far as specific gunsmiths, it’s understandable if someone doesn’t want to mail their upper to a gunsmith and instead wants to seek a local gunsmith for the modification. However, I recommend having an open mind and looking online for good reviews first before being totally against mailing the upper assembly. Mailing the upper isn’t a difficult task and I’ve heard too many horror stories about random local gunsmiths.<\/p>\n

Some of my recommendations of specific gunsmiths and companies:<\/p>\n

Dwilson Manufacturing<\/strong>
\nPrice: $60.00<\/h4>\n