Issues with the large quads

All
I have not been able to get the quads that I have installed in the Strasbourg to fire hard enough to penetrate more than half-way into the foam.
It appears that the quads that are set up to fire the 1/4" rounds are fine. But when firing the 7/32" ball, there is too much blow-by at the riser-tube if the cannon is not sleeved all the way into the lower piece of the magazine.
Perhaps some of the big-gun folks can explain this better than I can.
But the long and short of it is that I can get the cannon to fire the 1/4" rounds just fine. But the 7/32" rounds are going to be a problem with the cannons that I currently have installed. And it seems that there are quite a few of these cannons around.
I have been speaking with Dustin, and he mentioned swapping me cannons with his big-gun Richelieu cannons. Which will almost certainly solve my problems in this case. So we may do that so that I can get the Strasbourg finished.
But that would leave us with a set of quad cannons that would only fire 1/4" rounds, and there are not a lot of ships out there that will need them.
So I am wondering if we may need to consider allowing ships with quad turrets with calibers smaller than 15" to fire the larger ball, although perhaps at the slower rate of fire, so that the Dunkerques, KGVs and Normandies can be built.
I am not sure if there are any other boats that would be affected.
From what I am hearing..
The triple and twin cannons do not have this problem as the ball valve ports enough volume to support two or three barrels.
Four barrels as well. As long as the riser tube is sleeved at the lower part of the cannon.
Thoughts please.
Mikey

 

By the way.
I did try to sleeve my cannons with brass inserts. But then I had feed problems.
A machinist.. I am not.
So it may be that someone out there could fix my cannons to solve the problem.
Mikey

 

Froggyfrenchman, can you provide a little more information on the cannons you're using? I initially though you were using Big Gun cannons, but some of your later comments suggested a different design. If that is the case, then I'd need to know more before I can help.

If you are using the classic "indiana" style Big Gun cannons, here are a few things I can think of that may help.

1) sleeve the risers all the way down into the breech, then re-drill the feed ramps. I have seen some 1/4" cannons that, when loaded with 7/32", have too much room in the breech area and almost fit two balls in. When fired, a lot of air blows past while the 1st ball pushes the 2nd out of the way, because of how far it needs to go. In worst-case scenario, the balls simply jam and all you get is a puff of air. If this is the case, then sleeve down the risers using tight-tolerance brass, and run the sleeve all the way down so it blocks off the feed ramp. Then take a 7/32" drill bit (or whatever fits) and run it down the feed ramps, to open up the path again. I did this just yesterday with a .177" twin cannon, and it worked like a charm.

2) does the buna-ball valve have enough airflow to handle a quad? If you've got a Strike Models/BDE cannon base, then yes you do. If not, then I don't know. But a cannon with insufficient airflow for the given number of barrels will suffer a lot more when you reduce your ball bearing size than a cannon with sufficient airflow will. If you don't have enough airflow, you'll need a different valve with better flow.

3) how is the alignment of the barrels over the risers? Last year I had poor alignment on the front gun of my VU. When I fired, the balls going up the riser would slam into the bottom of the barrels, losing a lot of their energy in the process. Over time this dented and severely deformed the bottoms of the barrels. Half the time, the balls would simply hit the barrels and drop back down, so that nothing came out the barrels but a puff. Extremely frustrating when you've got an opponent trapped against shore and nothing from your barrels except hot air.

 

The cannons are Indiana style.
Probably made by Jason.
I have made sure that the adjustment screw is adjusted right.
Mikey

 

Have you tried sleeving the barrels themselves? Even something as simple as a brass tube stuffed down the business end of the barrels can help quite a bit. You'll just have to be careful about dents, afterwards. I have also seen a few people cut off their original loose-tolerance barrels just after the bend, and stick tight-tolerance brass in its place, held on with clear plastic tubing.

 

The problem, unfortunately, is that there is no proper ID brake line. 1/4" line is too small, suitable only for a .177" bb. 5/16" is the closest, since it starts out as a true 1/4" ID and can still pass 7/32" rounds even after it is bent. The problem is that it still has a lot of blow-by before and after the bend. It is common to insert a thin-wall brass tube to reduce the bore of the riser (before the bend) and the straight (after the bend), but this makes the soft steel barrel susceptible to jamming from dents. This is probably the best option, since the only other option I can think of to improve performance is a higher-flow valve and larger accumulator.

 

it is the opinion of myself and all under my command that the issue with the quads should remain unsolved as all ships with functional quad mounts that were actual built always had mechanical problems with them, they never worked quite right on the real ships, so it is only fair that they dont work in scale LOL!!! (besides i like german and most had duals, so quads not working makes it more of an even playing field for me LOL..again)

 

I was able to obtain a set of quads from Dustin that has the riser tubes that will allow my Strasbourg to fire the smaller rounds.
So I didn't actually fix the problem.
I had already obtained the smaller I.D. barrels, which helped some, but not enough to penetrate the thicker armor.
So construction will be resuming shortly.
Mikey