Replacing that awful BSA breech pin with a bolt?

[evert]

Yes, I'd always wondered about the possibility of the scenario you describe on your rescue Mercury, evert. I guess the solution would be to employ shims as well as the bolt to keep those jaws parallel?

Either shims, or squeezing the forks AND then expanding them slightly in front.
I've done the expand/squeeze combination with great success on a couple Supersports, but you have to be careful.
What you want to achieve is better contact all the way along the breech block.

[greenwayjames]

Its also worth thinking about why the breech jaws have a tendency to open after often little use. By breaking the barrel and pulling it down as vertically as possible there is less likelihood of barrel wobble especially with the BSA positive vertical lock up.
IMHO when the jaws are spread it is because the barrel is continually pulled down at an angle to cock the rifle as most folk do.
See for yourself by putting a few shots through your breakbarrel

[TonyL]

Absolutely. Agree. But then employing an arrangement that demands such attention to correct technique to avoid issues is a huge risk. Especially when, as others have said, many less prolific "budget" rifles have a more sturdy arrangement.

[TonyL]

Either shims, or squeezing the forks AND then expanding them slightly in front.
I've done the expand/squeeze combination with great success on a couple Supersports, but you have to be careful.
What you want to achieve is better contact all the way along the breech block.

Yes, I think shims are the route I'd be taking. Much less faff.

[evert]

Yes, I think shims are the route I'd be taking. Much less faff.

But shims will reduce the length of the breech/fork contact area. on a well fit meteor/Supersport, the breech block contacts the forks all along its length.

Plus, on a BSA, the pin is out of center of the barrel block. The barrel is brazed or sweated on, so the breech block does not have the height to provide full contact area for the shim.. so almost half the shim will not have contact with the breech block.

[TonyL]

But shims will reduce the length of the breech/fork contact area. on a well fit meteor/Supersport, the breech block contacts the forks all along its length.

Plus, on a BSA, the pin is out of center of the barrel block. The barrel is brazed or sweated on, so the breech block does not have the height to provide full contact area for the shim.. so almost half the shim will not have contact with the breech block.

Understood. And highlighting even more shortcomings with the arrangement. The more you think about it, BSA's arrangement was far removed from the ideal.

Even those Wobblies had a fuller, more substantial, proper breech block.

[look no hands]

Understood. And highlighting even more shortcomings with the arrangement. The more you think about it, BSA's arrangement was far removed from the ideal.

Even those Wobblies had a fuller, more substantial, proper breech block.

Something I've always found a bit annoying and strange as well.

[evert]

Even those Wobblies had a fuller, more substantial, proper breech block.

The Superpsort is better than the Vulcan in fork/breechblock fit.
The Vulcan block has short contact area with the forks, as the block does not cover the rear part of the barrel.

[evert]

I'll stick my head out again and claim that the Xocet, with its bolt, is worse than the Vulcan with its pin.

[TonyL]

The Superpsort is better than the Vulcan in fork/breechblock fit.
The Vulcan block has short contact area with the forks, as the block does not cover the rear part of the barrel.

Can't argue with any of that.

HW and Co must find this a very strange situation.

[greenwayjames]

Absolutely. Agree. But then employing an arrangement that demands such attention to correct technique to avoid issues is a huge risk. Especially when, as others have said, many less prolific "budget" rifles have a more sturdy arrangement.

True but the BSA has the advantage of a superior vertical lock up.

[Hsing-ee]

True but the BSA has the advantage of a superior vertical lock up.

This is true, it is massive, locks well and is yet easy to unlatch. A Baikal 38 I had used a supposedly solid manual breech latch and yes a breech bolt, but had verticle lock up which was approximate at best.

[TonyL]

True but the BSA has the advantage of a superior vertical lock up.

Accepted.

Did (some of) the Theoben rifles employ a very similar latch? I don't have much first hand experience of them, having not owned one. But, from ones I've tried, they seem to have a very solid lock-up. Plus their hex-headed bolts look heavy duty and up the job but, again, I haven't stripped one so know not of the exact design details?.......

[evert]

Accepted.

Did (some of) the Theoben rifles employ a very similar latch? I don't have much first hand experience of them, having not owned one. But, from ones I've tried, they seem to have a very solid lock-up. Plus their hex-headed bolts look heavy duty and up the job but, again, I haven't stripped one so know not of the exact design details?.......

Thats the only thing I really miss after selling the Evolution, they took the Supersport/Meteor lockup system and maxed it out.
The threads on the locking bolt were too coarse for easy fine adjustment, but except for that, it is a great system.

[evert]

I'll stick my head out again and claim that the Xocet, with its bolt, is worse than the Vulcan with its pin.

Noone wants to challenge my preposterous claim??