Drum vent hole?

[Kansas Jake]

I finally took my new to me 32 Traditions out to the range on Saturday to do some sighting in. I ended up spending most of the time help another couple with a old inherited 45 CVA/Jukar.

Anyway, I did manage to shoot the 32 at 50 yards as the range only had enough RSO's for the longer range. I really didn't get a chance to see where it was shooting as the sights need some work on this gun. I had not noticed before but the drum has a vent hole about 1/31 in diameter at about the 1:00 position on top of the drum next to the barrel. Have others used this and what is the purpose? It looks to have been made this way. Let me know what you know. Is there an advantage to the vent hole?

Secondarily, when I was cleaning it I had a plastic jag get stuck and pull out at the bottom of the barrel and pull out of the cleaning rod. I know this is not uncommon for some of these rifles to be rough there. Fortunately I was able to get it out by pulling the nipple and stuffing a few grains of powder in the drum and firing the gun. I took about 6 tries to get the patch and jag out completely after it started to move. I was lucky as it was a wet patch.

 

[Billnpatti]

No idea on the vent hole. :idunno: Never seen anything like it. But ther patch and jag getting hung at the bottom of the bore sounds like the breach area has been allowed to rust from poor cleaning. If it is rusty down there, you can try to polish it to remove the rust by wrapping some steel wool around an undersized bore brush and using it to scrub out the rust. There is an electrolysis method of removing rust from your bore. I think it is on You Tube. Just go to You Tube and enter "electrolytic rust removal". I think that will show you how to do it. It is a simple, cheap and effective way to remove rust from anything metal. But before doing that, I'd try getting it out with steel wool soaked in a good oil. Motor oil will work just fine for this application. Just be sure to thoroughly clean your bore and re-oil it with a good gun oil when you are finished removing the rust.

Wish I had some idea about the vent hole :hmm: but I got nothing. :idunno:

 

[necchi]

the drum has a vent hole about 1/31 in diameter at about the 1:00 position on top of the drum next to the barrel.

Nope, that doesn't sound right,, Can you post a picture?

 

[crockett]

In the back of the Dixie Gun Works catalog is an explanation on these vent holes. I didn't think any manufacturer used them. On rare occasion a cap will get blown back or ignition seems problematic and (according to DGW)the problem is solved with a vent hole. I myself have never dealt with any, just noting what was in the catalog. Maybe the small 32 caliber for some reason requires one.

 

[ZUG]

This is a vent hole that was sometimes done to prevent excess pressure from blowing back the hammer and for a "safety vent" done by an individual back in the 60's - 70's maybe later also. It was thought to be a good idea at the time. Maybe yes - maybe no - it's been around for a while but not very popular with most of the "crowd" so you don't see it much :v .

 

[hawkeye2]

"a plastic jag get stuck"
I think you will find that plastic was the issue and not a problem with the bore. The plastic jags and slotted patch holders that come with cleaning kits do not last. I will use them in any barrel that is open at both ends but they have a very short life and should never go into a barrel that is closed at one end. I have had them break off at the rod end leaving a piece in the end of the cleaning rod and had the threads pull right off them.

The idea behind drilling a vent hole in the drum was somewhat like the idea for vented nipples. it supposedly allowed some of the pressure ahead of the flame front to dissipate giving better ignition. I have never seen a vented drum or bolster or known anyone who has done it but it won't hurt a thing and would be less noticeable than firing a flintlock.

 

[Grenadier1758]

That vent was thought to serve a couple of purposes.

One as a safety relief vent to prevent blow back of the hammer. The real solution to that is get a nipple with the proper sized smaller holes.

Two it was believed with a tightly patched ball the flame from the firing of the cap was held back by the back pressure from the tightly patched load. The vent allowed the flame to get deeper into the powder charge before it was stopped. Considering how few of us practice the drilling of the drum, its probably not a real solution that is better than a Hot Shot nipple with a vent in the cone or one of the other nipple designed for use in a traditional gun using Pyrodex as the powder.

That vent is not really any form of a hazard any more than the touch hole on a flintlock rifle. It is drilled to direct the jet of gas away from the shooter and away from any next to the shooter on the firing line.

 

[Kansas Jake]

I was vaguely familiar with the concept years ago, but had never seen it in practice. The hole is angle up and forward and doesn't seen to present any problem. I was more curious if anyone was using it today. I can't tell if the hole was in the drum or added later by the owner. When I first shot it I was getting some hang fires and then realized I had grabbed some really old RWS caps.

The plastic cleaning jag was all I had around that fit other than a small brass bore brush. It wasn't one of the slotted jags, but a regular style. The bore seems to be smooth all the way down without and catches or rough spots so, I'm looking forward to getting the thing dialed in.

I'll try to get some pictures up of the drum hole.

 

[nhmoose]

I bet rain will mess with that vent hole, old idea yes good one no.

 

[jethro224]

The vent hole is not factory installed. Others have pretty well covered the idea behind it.

The hang-up at the breech is a factory problem with these rifles. The problem is that the patent breech chamber is very slightly larger than the rifled bore. When you push a patched jag all the way to the bottom it goes past the rifling and hangs up on the ridge created by the powder chamber in the breech. It can be a real bear to get the patched jag out. You can pull as hard as you can and it won't budge until you get it to line up exact center again by pure dumb luck.

There are a couple ways to avoid the hang-ups. One is to find a long jag with more rings than normal jags. These won't drop past the ridge. These are scarce!
The other way is to use a patch over a .22 or .25 caliber brush instead of a jag. This works but you still take the chance that the brush might break off down in the bore.

 

[Grizzly Adams]

I remember reading somewhere that very early percussion guns had a vent hole, as it was thought that the more airtight seal provided by that design would contain too much of the charge's pressure and thus needed a place for the extra gases to escape.

 

[ohio ramrod]

I have a gun that was "vented" in the early 70's as per recommendation in the Die catalog. It shoots no worse/no better than my other guns. :idunno: :idunno:

 

[Kansas Jake]

That seemed to be the case here after I started using decent caps. I'm probably not going to mess with changing anything at this point. If I end up carrying it in a a drizzle, I'll just put a little grease over the hole.

 

[Zonie]

The second muzzleloading rifle I had was a CVA Frontier percussion style. This was back in the '70's.

It often had misfires although I was using real black powder and I read the suggestion to add a vent in the Dixie Gunworks catalog.
I figured it couldn't hurt and it might help.

With this in mind, I drilled a 1/16" hole in the drum, pointed upward and forward.

It did seem to solve the misfire problem for the gun and I never had a problem that was caused by it.

If your gun has one of these vents added to the drum, don't worry about it. Just make sure the thumb or fingers on the supporting hand are not in line with the vent. It does release a lot of powder gas and flame when the gun fires.

 

[ohio ramrod]

For hunting I put some beeswax over the vent hole. This is good for the first shot! And carry some with me for any later shots. :idunno: :idunno:

 

[mr.flintlock]

Back in the mid 1970s I read about this in Dixie Gun Works Catalog. If I remember correctly, it was to reduce the back pressure from the blast of the cap so the flame entering the drum would have less resistance reaching the powder. I was new to muzzleloading at the time and vented an old CVA Kentucky Rifle that I had built from a kit. I couldn't really tell any difference in the performance of the rifle. Before I vented it, when I pulled the trigger the rifle went bang. After I vented the drum, when I pulled the trigger the rifle went bang. I was still beginning to learn about shooting these rifles! and it sounded like a good idea. I have always been prone to experiment. I put several deer in the freezer with that old rifle before buying a CVA Big Bore Mountain Rifle kit.