QB78 breech seal mod

[iconoclast]

I've obtained some of the 1/4" OD poly tubing that everyone talks about.
The breech seal method described places the tube between the Exhaust Valve Body (0410) and the Breech (1200).
The tube fits through the Tube (0100) hole and directly contacts the Exhaust Valve Body (0410).
I was thinking, why not have the poly tube go from the Exhaust Valve Body (0410) to the Barrel (2500) instead?
In other words, I'm thinking of drilling the Breech (0100) hole to 1/4" allowing the tube to pass through the breech to directly contact the Barrel (2500).
At first I thought this would apply too much side pressure on the Barrel O-rings, but then I realized that the Set Screw (2800) is on the opposite side, so this shouldn't be a problem.
With the breech seal going from the  Exhaust Valve Body (0410) to the Barrel (2500) this reduces or eliminates the need for the Barrel O-rings seal.
Is this a good plan?
Is there a downside to doing it this way?

[ribbonstone]

One reason not to is becasue it would make dissassembly more difficult. As it is,. can remove the barrel while leaving the breech in place (and have to in order to uncover the breech screw).  Loock the barrel and breech together and it will make sliding the barrel forward to get at the breech screw a lot harder.  Don't think here is anything to be gained by setting the seal against the barrel, but if you've the urge to do it, don't see where it would hurt (other than making takeing it apart and putting it togeterh a bit harder).

If you just replace the transfer seal, have not had one of the poly seals leak or burst one me.  You'll lose it in dissassembly if not careful, but they do not seem to wear out.  If it doesn't leak, then it's done it's job....and they don't leak.

[iconoclast]

Thanks for the reply.
I just didn't think about the breech screw hidden by the barrel.
I'm glad I asked the question to you experts before I did anything.
What seemed like a good idea would actually cause me more problems.
Thanks again.