12ga to 10mm Text 2

12ga to 10mm Shotgun Adapters

(9 customer reviews)


10mm Shotgun Adapters for 12 Gauge Shotguns

10mm Shotgun Adapters are Rifled with a 1:16 twist rate.

Available in 3 Lengths: 6″, 11″ and 18″


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12ga to10mm Shotgun Adapters

12ga to10mm Shotgun Adapters Allow a 12 gauge Break Action Shotgun to use 10mm Ammo.

Compatible with 12 gauge Break Action single and also double barrel shotgun.

Comes with multiple O-ring configurations.  As a result,  easily achieving a good fit for 12 gauge shotguns.
Rifle dimensions are .390″/.400″ with 6 grooves and .120″ wide with a 1:16 twist rate.
Black Oxide coating as a result provides notably better corrosion protection (for maximum corrosion protection keep a thin coat of oil on the insert)
I recommend to keep a coat of oil on the insert for more corrosion protection
Please Note:  Not all shotguns are the same!  While most shotgun are capable of handling high pressure rounds. However, some are not. Therefore only use these rounds in shotguns that are capable.  For example, a shotgun with a SB1 or Sb2 reciever.  I recommend on any shotgun to test the first shot in a vice while out of harms way in addition  always wear eye and ear protection.  After that if you see that the primer punctured in the round discontinue using this round and use the less powerful round. Such as a 38 Special instead of the 357 Mag These high pressure rounds include: 45-70 gov., 357 Mag, 327 Shotgun Adapters , 44 Mag Shotgun Adapters, 10mm, 40 S&W and 22 Hornet.  Please always be safe and aware. Thank you for reading.


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.


However, not all shotguns are capable of handling all of the shotgun adapters we offer. Low-pressure rounds work in any shotgun, whereas high-pressure rounds can cause problems in some shotguns. The problem is when the firing pin punctures the primer. This event causes the gases to escape and possibly damage the firing pin. All adapters chambered for high-pressure rounds have red text on the website, signifying that is is a high-pressure round. These adapters also include a pamphlet with more information about this concept. In addition These Shotgun Adapters also have a Low-Preasure round alternative.


12ga to 10mm Shotgun Adapters

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
The video below gives a brief demonstration of how they work.

We are working to make more adapters for more calibers, so you can sign up to be notified here. Thank you for your interest.

Additional information

Weight N/A
Dimensions N/A

6", 11", 18"

9 reviews for 12ga to 10mm Shotgun Adapters

  1. Dan

    I would truly love to give this a 5-star review, and I have no doubt that I would be as satisfied with the 10mm calibre adapters as I am with the 22LR, 22 WMR, 9mm, 357 Mag, 44 Mag, and rifle calibre ones that I already have. BUT, these 10mm adapters have been out of stock for more than. Year and a half. What gives? Such a popular calibre with great power increase in longer barrels, but you’re just not making them available. Super disappointing. Please make some. Thanks.

    • Chaszel (store manager)

      Good afternoon. We will try to make some next year, hopefully it will work out. Thank you for your support.


  2. Jonathan Futch (verified owner)

    The adapter looks great have not tested it yet should work fine though

  3. curtis edwards (verified owner)

    the entire process was timely and professional and the product is very good. the fit and finish is top notch.

  4. Charles B. (verified owner)

    I had a great experience. I would buy more products when they are available.

  5. Keith Bayless (verified owner)

    I love having multiple caliber adapters for my shotgun! They make my shotgun a lot more versatile which is what I like!

  6. Richard Ervin (verified owner)

    I’ve never been more pleased with a specialized product. The fit is perfect, even in my old model 51. Great rifling that I hope to use for a lifetime.

  7. Juan C (verified owner)

    Awesome adapter…..Just wish I could get one of their 30-30 adapters.

  8. Robert (verified owner)

  9. Michael Talley (verified owner)

    Hello. I just purchased this in 6 inch. Anyone else has had experience with this caliber drop a note please. I’ll be giving an update on my situation soon.

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