doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com question for those familiar with 24 gauge guns

I just tried 20 gauge snap caps in my 24 gauge gun - they won't enter the chamber at all.

I also tried 28 gauge snap caps and they dropped in and the rims, while loose, were held by the rim cuts of the chamber. I'm pretty sure if a 28 gauge round has the same rim size as A-Zoom snap caps they would fire.

You just found what I found when I fired a 28ga shell in a 24ga, FlyChamps--by accident in my case.

Okay, adding answers to some questions here...

Top of bore measures .680, which is basically right between the 20 and 24! My 20 gauge snap cap measures exactly .680 as well. Measuring the rim diameter "A" on the recommended chart is difficult as they walls are not straight but radiused.

I'm taking the kind old colonel up on his offer to send me a couple of spent 24 bore to see how these fit.

I'll try to get some photos on line, but likely not until this weekend. Thanks to All!

Joe, hoping that it is a true 24 and not the world's first documented 22 gauge. Gil

If you can not measure A you should be able to measure B. If your "top of bore" means C then it sounds like you have a 20 with tight chambers unless the shell rim is poorly cut. A 20 gauge chamber should taper from .698 (measurement B) down to .685 (Measurement C), bore should be .615 which is measurement F. A 24 gauge has a bore of .579 which is much tighter than .680.

http://www.ballisticproducts.com/24-gauge-hulls/products/79/

https://www.grafs.com/retail/catalog/category/categoryId/415

http://www.gunbroker.com/All/BI.aspx?Keywords=24ga

OR come to Amarillo
and we will shoot my ammo

I will measure my 24 later this evening and post what I find.

Joe, PM me your address

Tested my 24ga.

Like Fly hamps the chamber will not let a 20 hull in at all. Also tested 3 different sets of snap caps and none would make it past the rim recess into the chamber.

The rim recess measured .727, the top of the interior of the chamber measured .694.

If you can get a 20 gauge snap almost all the way into the chamber i suspect it may be a 20 with a very tightly cut chamber, similar to the difference between two of my 16s one of which will only let a fired all brass shell into the chamber to the last 1/8 of inch or so

I took a picture of my tight 16ga barrel to illustrate my point about chamber difference making I t not possible to fully chamber at shell.



The actual amount of shell length that would not chamber is .57 not the 1/8 I earlier describe. The difference between the two RMC brass shells in diameters at the point .57 is the difference of .0025 (.7350 & .7325)

The gun with the wider chamber is a Belgian Gun from the 1920, the narrower gun is a Purdey from 1898 (I also have a German 16 BLNE with narrow chambers similar to the Purdey.

I will see if I can dig out my Belgian 20 gauges tomorrow in order to measure their chambers rim recess and top of chamber.

If would really be good if you could either take a picture of the barrel flats or tell us what the stampings are.

Possibilities are:

1. You have a 20 gauge gun with tight chambers and slightly smaller bore for shooting fibre wads from thin walled brass shells (similar to the 13 bore 12 gauge guns)
(are measuring the muzzle or the bore, if muzzle you may be getting a way off number because you have a tight choke?)(also how accurate is you measuring tool, you may not be accurate on the .680)

2. You have a 24 ga gun with oversized bores and chamber ?

3. You have a custom gun of a very odd gauge like 22 etc.?

If you have very tight chambers with an undersized bore your best course is to cast the chamber and have RMC make you shells.

Before you know the answer you really need to post the barrel flat and barrel stamps and you really need someone with a proper bore gauge to measure the chamber, forcing cone, bore, and choke.