BSA Scorpion pistol - technical info and history

[evert]

Is there any thread here on the forum for all things about the BSA Scorpion pistol? If there is, please tell me.
As a "new" Scorpion is about to turn up here soon, I am looking for all kinds of info on this gun, and as ususal, I have loads of questions!

Which features separate the different Mk's?

And what velocity can one expect in the different calibers?

What are the dimensions of the main spring?

Does anyone have experience with different springs?

I have of course read Jimmie Dee's excellent tutorial:
https://www.jimmiedeesairguns.com/gu...on-air-pistol/

[Shed tuner]

they will all make 6 fp. I prefer them a fraction under, as they can be tough to cock for an extended plinking session, and they shoot nicer that way.
.22 are much smoother - it's a 28mm comp tube, so that's to be expected.

[WILBA]

jimmy dee's strip down tutorial is outstanding. well done jimmy.

[TonyL]

jimmy dee's strip down tutorial is outstanding. well done jimmy.

Yep, very good. And it brought back many memories of working on mine.....about 39 years ago.

[evert]

they will all make 6 fp. I prefer them a fraction under, as they can be tough to cock for an extended plinking session, and they shoot nicer that way.
.22 are much smoother - it's a 28mm comp tube, so that's to be expected.

Do you have any spring recommendations?

[Shed tuner]

Do you have any spring recommendations?

the stock spring is plenty. With a properly fitting o-ring piston head, i.e. a slightly smaller one that stock, they make power easy.

[Josie & John]

You might want to consider taking the next three issues of Airgun World for a historical detailed study of the BSA Scorpion pistol.

There will also be a follow up on the Shadow Carbine.

John Milewski

[p.j.]

You might want to consider taking the next three issues of Airgun World for a historical detailed study of the BSA Scorpion pistol.

There will also be a follow up on the Shadow Carbine.

John Milewski

John's article should be compulsory reading for anyone with even a passing interest in the marque.
Inspired by part one, I have bought two pistols recently, early and late model, both in need of a service.

[TonyL]

You might want to consider taking the next three issues of Airgun World for a historical detailed study of the BSA Scorpion pistol.

There will also be a follow up on the Shadow Carbine.

John Milewski

Funnily enough I read your fine article a couple of hours ago. Very enjoyable and informative. Great info on the revised piston for the .22 giving shorter stroke and taming the power.

Eagerly awaiting the next instalments.

[evert]

Thanks for all the great info everyone!
It will be interesting to see what shape the spring is in.

You might want to consider taking the next three issues of Airgun World for a historical detailed study of the BSA Scorpion pistol.

There will also be a follow up on the Shadow Carbine.

John Milewski

The wife gave me a sbuscription for AGW for christmas, so I hope to get all the articles.

[piggy589]

the stock spring is plenty. With a properly fitting o-ring piston head, i.e. a slightly smaller one that stock, they make power easy.

The last one I stripped had the obligatory seized buffer and a mainspring like a dog's hind leg.
With the action vertical a few minutes with the hot air gun saw a smoking lump drop out.
A used airsporter spring was cut down to the same number of coils and the end refinished, together with a replacement washer kindly supplied by that man in north wales and an air con. O ring.
The end product produced a consistent 430fps plus with superdomes.

[p.j.]

The last one I stripped had the obligatory seized buffer and a mainspring like a dog's hind leg.
With the action vertical a few minutes with the hot air gun saw a smoking lump drop out.
A used airsporter spring was cut down to the same number of coils and the end refinished, together with a replacement washer kindly supplied by that man in north wales and an air con. O ring.
The end product produced a consistent 430fps plus with superdomes.

Yep, one of mine has the buffer washer issue, should be a bit of fun

[TonyL]

the stock spring is plenty. With a properly fitting o-ring piston head, i.e. a slightly smaller one that stock, they make power easy.

Do you use a Meteor 'O' ring, Jon? Or just a smaller one from your "stash"? Have you ever played with different piston heads on them.....ie the alloy head or an altogether different one and parachute seal?

[Mach 1.5]

I owned a Venom Tuned one back in the day. I wonder what happened to that? Mach 1.5

[Shed tuner]

Do you use a Meteor 'O' ring, Jon? Or just a smaller one from your "stash"? Have you ever played with different piston heads on them.....ie the alloy head or an altogether different one and parachute seal?

from the "stash" Yes, I've also fitted a diana 28mm seal - have to space it out though to maintain the same stroke, as the unique trigger arrangement makes it very difficult to play with the stroke, and have the main trigger sear sitting in the right place - i.e. the piston can't come too far forwards. Not sure it;s worth the effort to be honest - I guess it could be though if you have a poor cylinder that's not true enough to seal with an o-ring.

The two different strokes were actually different pistons, same heads. The longer stroke isn't really necesary, and just makes it hard to keep under the limit. With a weaker spring, it's more prone to bounce.