Which is more accurate, fixed barrel underlever or break barrel ?

[secretagentmole]

Yet another interesting thread, young JB.

Going back many years, the fixed barrel was seen to be a definite advantage, due to sloppy breech lock up designs. However, in more recent times, many breech lock-ups were solidly engineered so this became a non-issue (take note, BSA). Although many plunger type designs have proven to be solid, reliable and durable, I still like the extra reassurance of manual barrel latches, like those on the HW35, 55, modern LGVs and others.

Such as the Westlake B2....

[TonyL]

Such as the Westlake B2....

Mmm, not quite what I had in mind.......

[Shed tuner]

now I come to think about it. ....I remember someone experimenting with solid lockup on a TX and remarking that the accuracy went to sh**.

Interesting, thanks....
Hmmmm just found this starter by one of our own BBS members .. also very interesting and supportive of the concept...

http://www.network54.com/Forum/45130...TX200+shooters

Time to play....

[Barryg]

For a true test, one needs the same gun,
)

The DIana under lever can be modified to a PS type lever for a experiment.

[hmangphilly]

It makes a lever long enough to make cocking relatively easy? The Prosport and Airsporter could be right sods to cock. Especially the box like arm on the Prosport...

sure .
no issue with the cocking arm being where it is on the hw / tx .

it's the fact that it's attached to, and therefore able to apply pressure to ,the barrel .

a lock up or detent which is not attached to the barrel would remove the potential for the cocking arm to affect barrel movement / flex

[Artfull-Bodger]

When I built my HW77FT one of the items on the list to scrutinise was the lock up, I considered a few alternatives and in the end came up with spring loaded top hat shaped button that has a key hole in the top, on the bottom of the air stripper there is a cap screw that projects downward by 4mm, when you press the button in the circular end of the key hole lines up with the cap screw which then allows the cap screw to locate in the button, on releasing the button the cap screw is captured in the key hole slot, it's very simple , totally secure and becomes second nature to operate after a few shots and applies no tension to the barrel.

[hmangphilly]

When I built my HW77FT one of the items on the list to scrutinise was the lock up, I considered a few alternatives and in the end came up with spring loaded top hat shaped button that has a key hole in the top, on the bottom of the air stripper there is a cap screw that projects downward by 4mm, when you press the button in the circular end of the key hole lines up with the cap screw which then allows the cap screw to locate in the button, on releasing the button the cap screw is captured in the key hole slot, it's very simple , totally secure and becomes second nature to operate after a few shots and applies no tension to the barrel.

got a pic Mr Bodger

sounds interesting .

[Artfull-Bodger]

I will take one this evening, can you upload on here or do you have to host?

[Shed tuner]

I will take one this evening, can you upload on here or do you have to host?

you have to host... if you've not got a suitable account already, feel free to email it to me to host..

Did you notice any difference in accuracy, or reduction in an y POI shofts ?

These days with strong magnets being so cheap and freely available, I'm going that route... but I like the sound of your "proper" engineering..

[Shed tuner]

Comparison of std ball bearing catch vs magnetic "zero tension" catch.


So I did a quick test, using my expensive custom multi aimpoint targets Top group was the std arrangement, bottom group was the magnetic catch.

http://i73.photobucket.com/albums/i2...de_groups.jpeg

BIG CAVEAT the weather isn't ideal - each 5 shot group took nearly 5 minutes to shoot, waiting for gaps in the wind, so I need to retest this one evening this week at my local club's indoor 20 yard range.. but it does look promising, heh ?

As an aside, the TX end button is just threaded in and loctited. Thread appears to be M12 x 1.25 (not the more ususal 1.75). So I just turned down a bolt to suit, milled some of it off flat for the magenet to sit, screwed it in, job done. Not pretty, but functional.

[Artfull-Bodger]

you have to host... if you've not got a suitable account already, feel free to email it to me to host..

Did you notice any difference in accuracy, or reduction in an y POI shofts ?

These days with strong magnets being so cheap and freely available, I'm going that route... but I like the sound of your "proper" engineering..

To be honest Jon, there are so many modifications on this rifle that narrowing it down to one item would be impossible, suffice to say it's without doubt the most accurate springer I own.

I have known ball catch underlevers to drop down on firing and others to put tension on the barrel due to tolerances in the cocking linkage, so when I designed this setup it was with putting no external forces on the barrel (other than it's free weight) and eliminating any vibrations it could impart.

I will e-mail you a couple of piccies this evening as the missus has the camera.

[Shed tuner]

To be honest Jon, there are so many modifications on this rifle that narrowing it down to one item would be impossible, suffice to say it's without doubt the most accurate springer I own.

hehe, I know the feeling Hence my planned accuracy test with only this variable changing. At the very least, if it's no worse, it just removes one more potential variable. It also makes rebarreling TXs really easy, as there no catch / shroud arrangent to worry about.

Be interesting to know what happens when I shoot steel cored prometheus through it - maybe they'll get electrically charged

I will e-mail you a couple of piccies this evening as the missus has the camera.

Cheers, will host and stick them up on this thread.

[TORNADOS7]

Both as accurate as each other, never had any issue with either as long as you buy good quality, the only time you'll have any issues is when you buy cheap, workmanship/poor machining tolerances are then to blame, other than that my '95k' was as accurate as my 'Webley Xocet' which is as accurate as my 'TX200hc' which is no more accurate than my 'Theoben Scirocco GP' was !...

[Shed tuner]

Both as accurate as each other, never had any issue with either as long as you buy good quality, the only time you'll have any issues is when you buy cheap, workmanship/poor machining tolerances are then to blame, other than that my '95k' was as accurate as my 'Webley Xocet' which is as accurate as my 'TX200hc' which is no more accurate than my 'Theoben Scirocco GP' was !...

What kind of accuracy are we talking ?
the above experimental groups were at 28 yards, and I think they are OK (well the magnetic catch one is), but should be bettered...

http://i73.photobucket.com/albums/i2...de_groups.jpeg

[TORNADOS7]

What kind of accuracy are we talking ?
the above experimental groups were at 28 yards, and I think they are OK (well the magnetic catch one is), but should be bettered...

http://i73.photobucket.com/albums/i2...de_groups.jpeg

Nice shootin matey, I'm talking ragged one holers that'll fit under a 5p although I will say I can't vouch for the 'Xocet' anymore as in a moment of madness I shortened the barrel, not quite sure what possessed me but there it is, anyway I've got a picture on my iPad of one of my 5 shot groups done with my 'TX' but I can't seem to get it to appear on this forum for some reason (something to do with this photo bucket thing) although I have posted it a few times over on the other forum, probably not as tight a group as yours but then you are using a .177 !...