20 Gauge to 45 ACP Shotgun Adapter

20 Gauge to 45 Caliber Shotgun Adapters

(2 customer reviews)


45 Caliber Shotgun Adapters for 20 Gauge Shotguns

Adapters come in 3 Lengths

2 3/4″, 11″ and 18″

All Adapters are Fully Rifled with a 1-12 Twist.

Select Length and Chamber below: 


20 Gauge to 45 Caliber Shotgun Adapters

45 Cal Shotgun Adapters Allow a 20 gauge Break Action Shotgun to also use 45 Caliber Ammo.

Compatible with 20 gauge Break Action single as well as double barrel shotguns
Rifle dimensions are .451″/.445″ with 6 lands and .145″ wide. With a 1:12 twist rate.
Black Oxide coating provides notably better corrosion protection (for maximum corrosion protection keep a thin coat of oil on the insert)
Comes with multiple O-rings.  As a result,  easily achieving a good fit for 20 gauge shotguns.

What are Shotgun Adapters?

Shotgun Adapters frequently called Chamber Reducers or Shotgun Barrel Inserts. Our shotgun adapters allow you to use other types of ammunition in a Break Action Shotgun. Including double barrel and over and under double barrels in addition to the popular single barrel break action. We offer several different versions to suit your preference in ammunition, as well as length. 12 and 20 Gauge shotgun adapters are our most popular adapters followed closely by the 410. 16 Gauge is something we plan on expanding in the future.


Most of our shotgun adapters come in different lengths to suit your needs. Some like the secure storage and portably of Shell length adapters. Whereas some are looking to get the most fps (feet per second) or accuracy out of their adapter. Black Oxide has become our standard finish. We can offer unfinished adapters during our production if you have requested one.

FPS (Feet Per Second)

As a general rule, the longer the adapter, the more FPS it produces. However, with low-pressure rounds such as the 45 colt, the fps difference is minimal. If you are interested, here is an excellent website that gives a good idea of fps per inch BBTI. All of our shotgun adapters are entirely made in the United States and are an affordable addition to your break action shotgun. Thank you for you interest in our Shotgun Adapters or Chamber Reducers.
We are working to make more adapters for more calibers, so you can sign up to be notified here. Thank you for your interest.

If you like our 45 Cal Shotgun Adapters, check out our other Shotgun Adapters

Additional information

Weight N/A
Dimensions N/A

2 3/4", 11", 18"


LC, LC/.410, ACP


Black Oxide, No Finish (Silver)

2 reviews for 20 Gauge to 45 Caliber Shotgun Adapters

  1. Johnny Ryals

    The adapter works. It is reasonably accurate. A 45 piston round is not loud and the extra barrel length of the 20 gauge quieten the sound even more.

  2. Marvin Schmid (verified owner)

    Verified reviewVerified review - view originalExternal link

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