More On Chamber Inserts

Dear Bruce,

What comments can you share on the various companion tubes/inserts type products currently on the market. As you know these products range from expensive(full length) to the newer much less expensive(3-4 inches in length) sets? If obtaining true subgage performance, i. e. pattern/distance relationships from an existing 12 ga O/U is the goal of the buyer, is the cost of these product directly proportional to reach this desired end.

I’m sure, like all questions regarding shotgun performance, these are loaded with the typical ambiguities such as shot weights, powder charges, shot hardness, bore diameter/choke characteristics, atmosphereical conditions, mood, etc. Do you believe it possible for the enthusiast/ consumer to make a rational choice in selecting a sub gauge conversion product from ” jump city ” or will it be like all other shotgun equipment pursuits, where we try to recoup our mistakes at 70% losses on the internet?


Dear Gary,

I’ve commented on chamber inserts before, but it is helpful to compare them to full length and mid length tubes.

It really all depends on what you mean by “true subgauge performance”. The only thing that give true subgauge performance is a true subgauge gun.

There are two considerations here. The first is ballistics and the second one is handling. Full length tube sets (Briley, Kolar, etc.) work perfectly ballistically, but they add 10~16 ounces of noseweight. American-style skeet shooters have learned to live with this. Sporting and field shooters require better balanced guns. If the weight penalty isn’t a problem for you, then full length tubes are definitely the way to go for the best ballistics. Everything else is a compromise in ballistics vs weight.

So, the question becomes how to get subgauge performance without the weight penalty. The shorter the subgauge tube, the less the weight penalty. It’s really that simple. Unfortunately, the shorter the tube, the less reliable the ballistics.

Chamber inserts like Little Skeeters or Chambermates are all the rage now, but they sure aren’t new. I remember playing with plastic chamber inserts back in the ’70s. Webley and Scott produced a set of 6″ .410 steel chamber inserts under their own brand name at about that time too. I’m sure that there were many examples of chamber inserts before that too. For a while Savage produced a 10″ (or so) short tube called a “Four Tenner”. Browning made sets of 16″ all-aluminum “Supertubes” for their Superposed shooters. Everything has been tried, long and short.

On the short tube/chamber insert side, the problem has always been what happens to the subgauge load when it exits into the 12 gauge barrel. Briley will make short tubes for anyone who asks, but they feel that the movement of the gas around the shot load that occurs when the ejecta exits the short tube and enters the carrier barrel does something to degrade the pattern. They say that they get their most consistent patterns from full length tubes. What I haven’t been able to figure out is just what the consistency difference really is over a long test string.

I’ve tested the Little Skeeters chamber inserts and they worked well in 12>20 and 12>28, but not in 12>410. Little Skeeter has recently redesigned their 12>410 insert to one that is now about 5″ long. I have a set, but have yet to test them. I understand that Chambermates ran into exactly the same problem with the 410s and are also lengthening their tube. Did I mention that the Webley & Scott 410 chamber insert from the ’70s was about 5″ long? It seems that everyone has to relearn the lesson.

When I say that my Little Skeeters worked “well”, I mean that they patterned normally according to the choke that was in the 12 gauge barrel. My tests were not exhaustive by any means. I shot a bunch of skeet with them and also quite a few quail and chukars. Hunting is a poor test because it is so random, but the birds seemed to go down about the same way that they would have from a standard subgauge gun.

The Little Skeeters were dirty and inconvenient to use. But they are cheap at about $40/pair. It wouldn’t cost you much to try a set and form you own opinion. As to how well they really work on exhaustive patterning tests that would include some method of measuring shot string, I can’t say. I’ll leave that up to you. My take is that they are sort of like a poodle that can walk on its hind legs. Everyone comments simply on the fact that the dog can do it, not on how well he does it. If you buy the Little Skeeters just for fun, you won’t be disappointed. They are a nice gadget and LS is selling a ton of them.

Bottom line: Right now I wouldn’t commit a lot of capital to chamber inserts. If weight is a factor, try a set of Little Skeeters in 12>28 and see what you think. They don’t cost much. If you like the concept and feel that the performance is what you want, Chambermates would be worth a look. If not, then you are only out $40 for the Little Skeeters.

Best regards,

Bruce Buck
The Technoid writing for Shotgun Report, LLC
(Often in error. Never in doubt.)

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1 Response to More On Chamber Inserts

  1. Jay Bute says:

    I second that: About ten years ago I did substantive pattern testing of Briley 20 ga. Side Kicks in my Browning XS Sporter, 30″ and got good patterns more or less true to choke (Cyl, SK, IC, Mod) depending on the shell. Promo loads patterned looser than Win AA’s. I used them extensively for practice since 7/8 oz., 12 ga., 1200 fps loads were high priced specialty items and 7/8 oz. 20 ga. promo loads were about as cheap as reloading.


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