BSA Light Pattern

[Chippendale]

Has anybody on here stripped a 'BSA Light Pattern' rifle, I have acquired one for bell target shooting circa 1929/32 and it seems a bit harsh and and it could do with a less of a thump when shot. The trigger also needs to have a tad lighter pull.
Any advice or a diagram on how to strip and tune it would be very welcome.

Cheers

Melv

Chippendale (with clothes on)

[T 20]

I just take the trigger guard off then unscrew the action off the back block, Mel.

If it's a tight one, then I remove the stock and all the trigger assembly in order to get a lever in the back block.

Once I've got the back block off I remove the underlever and cocking arm to get the piston out --- you can just remove the cocking arm if the screws are loose.



All the best Mick

[edbear2]

Hi Melv,

Longer description here down a bit;

https://forum.vintageairgunsgallery....l-tips-faqs-2/

But as Micks says really, trigger guard off then just unscrew........you may need to pull the trigger back a bit to clear the cylinder at the start and also do it standing up with the muzzle on a bit of carpet or the like, there is normally not a load of preload on these, but standing gives the best control.


They normally unscrew really easily, as Mick says again, if tight don't force it as the stock is secured to the breech block by a long single screw only up the middle of the stock (access bung at rear) and if the stock is not tight you can do damage, so remove the trigger and sear and use something in the slot for leverage, or use a strap wrench on the block etc.

It's also easy to damage the stock bolt cover.......there should be a spring steel plate under it which pops it out once you have removed the two small screws, but often if not disturbed these covers can be tight , especially if the wood has swollen or debris / old polish is present.

Best way I have found if this happens is use a slightly bigger pair of screws that bite in the holes just a tad, and a bit of metal with two holes drilled in it to match, and a small slide hammer / pair of grips.

If you try and lever them out it causes damage and you also run the risk of breaking them.

Trigger weight is stamped on the stock underneath, and can't be changed unless a 3 hole block with the rear adjuster pair of screws from each side I recall.......but triggers and sears on two hole blocks on earlier guns respond well to stoning and pivots polished etc. and can be made very crisp.

ATB, ED

[Chippendale]

Hi Melv,

Longer description here down a bit;

https://forum.vintageairgunsgallery....l-tips-faqs-2/

But as Micks says really, trigger guard off then just unscrew........you may need to pull the trigger back a bit to clear the cylinder and also do it standing up with the muzzle on a bit of carpet or the like, there is normally not a load of preload on these, but standing gives the best control.

They normally unscrew really easily, as Mick says again, if tight don't force it as the stock is secured to the breech block by a long screw only up the middle of the stock (access bung at rear) and if the stock is not tight you can do damage, so remove the trigger and sear and use something in the slot for leverage, or use a strap wrench on the block etc.

It's also easy to damage the stock bolt cover.......there should be a spring steel plate under it which pops it out once you have removed the two small screws, but often if not distubed these covers can be tiget even so, especially if the wood has swollen or debris / old polish is present.

Best way I have found if this happens is use a slightly bigger pair of screws that bite in the holes just, and a bit of metal with two holes drilled in it to match, and a small slide hammer / pair of grips.

If you try and lever them out it causes damage and you also run the risk of breaking them.

Trigger weight is stamped on the stock underneath, and can't be changed unless a 3 hole block with the rear adjuster pair I recall.......but triggers and sears on two hole blocks on earlier guns respond well to stoning and pivots polished etc. and can be made very crisp.

ATB, ED

Thanks Ed & Mick,Will give it a go, the Vintage gun gallery is not letting me in, getting a 'time and date wrong' on computer.
Will try and see if the advice works for me, though when it comes to tinkering with air rifles, i have a Cadet Major and a Meteor in bits that iare waiting to be re-assembled. Oh and an HW 35 waiting to have the trigger block and safety fitted correctly

Thanks again

Melv

[Garvin]

Thanks Ed & Mick,Will give it a go, the Vintage gun gallery is not letting me in, getting a 'time and date wrong' on computer.
Will try and see if the advice works for me, though when it comes to tinkering with air rifles, i have a Cadet Major and a Meteor in bits that iare waiting to be re-assembled. Oh and an HW 35 waiting to have the trigger block and safety fitted correctly

Thanks again

Melv

As Ed says Melv, try technical tips section here:

https://forum.vintageairgunsgallery....bsa-resources/

[Chippendale]

As Ed says Melv, try technical tips section here:

https://forum.vintageairgunsgallery....bsa-resources/

As I have said in my previous post I can't access that, When I go into the clock it is set correctly, it automatically updates etc.

Cheers

Melv

[Garvin]

As I have said in my previous post I can't access that, When I go into the clock it is set correctly, it automatically updates etc.

Cheers

Melv

Don't know why? Does it happen with other websites?

[TonyL]

Will try and see if the advice works for me, though when it comes to tinkering with air rifles, i have a Cadet Major and a Meteor in bits that iare waiting to be re-assembled. Oh and an HW 35 waiting to have the trigger block and safety fitted correctly

Thanks again

Melv

Hi Melv, hope you're keeping well. Did you ever get the right spring for the 35 safety? Seem to remember it was a "single-sided" one? Good luck with your various little on-going builds.

[Chippendale]

Hi Melv, hope you're keeping well. Did you ever get the right spring for the 35 safety? Seem to remember it was a "single-sided" one? Good luck with your various little on-going builds.

Aye up Tony, nice to hear from you, No I never got a spring to be honest and it is the single sided safety. Don't know or if you can recall, but when we were at Quigley Bottom you assembled the triger unit into the 35 and for some reason it either woudn't cock or it wouldn't shoot when cocked, i'm not sure which.
If you couldnt sort it I know I can't.
I have got the L Pattern apart and got the spring and piston out, the leather washer looks in real good nick, in the center of the washer there is a red hard washer wth a machine screw through it holding the leather washer to the piston. I think there is something amiss because the red hard washer is slightly proud of the leather washer and therefore must be hitting the bottom of the cylinder before the leather washer. This impact must be why the gun, when shot, is very harsh.
I dont know if its prudent to to try and grind or file the plastic washer below the surface of the leather one.

Edbear has given me a webbsite "Vintage guns' but for some reason I am unable to access this site or even join it.

I'm in a qaundry.

Stay safe my friend in these turbulant times

Cheers

Melv

[TonyL]

Hi Melv,

I seem to remember that a few people looked at your trigger / safety. Gun cocked and worked fine without the safety? I think we / they concluded that it may be simply down to fitting of the correct spring for the safety or that the "tab" on the trigger cage was interfering with proper operation of the safety?

Re the leather washer / insert. I haven't looked inside one. From an un-informed view I'd guess that the leather seal has impacted and compressed over the years. Maybe a treatment with neatsfoot oil may restore? If not, I'm guessing a new seal is required? I don't think I'd be wanting to grind the insert down.

[WebleyWombler]

I have got the L Pattern apart and got the spring and piston out, the leather washer looks in real good nick, in the center of the washer there is a red hard washer wth a machine screw through it holding the leather washer to the piston. I think there is something amiss because the red hard washer is slightly proud of the leather washer and therefore must be hitting the bottom of the cylinder before the leather washer. This impact must be why the gun, when shot, is very harsh.
I dont know if its prudent to to try and grind or file the plastic washer below the surface of the leather one.



Cheers

Melv

Leave the washer alone. It sounds right and the screw/hard fibre washer acts as a buffer. If you think the gun is too harsh, try using the heaviest or largest diameter pellet you can get hold of. Other than that the transfer port may need sleeving down.
Have you worked out whether there is trigger adjustment fitted( 3 hole trigger block) . I would expect so with your year rifle assuming you have that correct.

[Binners]

Hi Melv
I hope you are keeping well and get the rifle fettled. Just an idea, the Melbourne Armsfair is on 23rd October and some knowledgable folk attend there.

ATVB
Peter

[Chippendale]

Hi Melv
I hope you are keeping well and get the rifle fettled. Just an idea, the Melbourne Armsfair is on 23rd October and some knowledgable folk attend there.

ATVB
Peter

Cheers Pete, I am going to the Melbourne, hoping to meet up with Johnbaz. I’d not thought about taking this gun to the fair that’s a good idea.

Did that .177 with the lift up sight tha5 you had on your charity table when I was there last.

Cheers Melv

[Binners]

Cheers Pete, I am going to to Melbourne, hoping to meet up with Johnbaz. I’d not thought about taking this gun to the fair that’s a good idea.

Did that .177 with the lift up sight tha5 you had on your charity table when I was there last.

Cheers Melv

JB will sort you out mate, yes the early light with the No22 sight sold on my charity table.

[Lakey]

Here is a short guide to dismantling a B.S.A underlever air rifle to inspect or replace the mainspring and piston head. It is the way I would do it.

All the main points are included but some people might tackle the task in a slightly different order. This is offered as a basic guide only and I recommend that you experiment and adopt the way that suits you best, but please remember to keep safety in mind at all times.

Before I start here are a few words of caution about tools.

When attempting to take one of these guns apart I would recommend the use of a gun maker’s turn screw, engineer’s drivers or other parallel bladed screwdriver. The gun screws on these guns have straight slots cut into their heads which are not suited to carpenter's/general screwdrivers which have a tapered blade.

If these unsuitable tools are used, damage can easily be done to the finish of the screw heads themselves which is difficult to remedy. Irreparable damage occurs because the tapered blade always wants to lever itself out of the slot when any pressure is applied to tighten the screw in question. If proper engineer's screwdrivers cannot be obtained, ordinary screwdrivers can be adapted by grinding the blade profile into a parallel blade.



How to dismantle a pre WW2 B.S.A Underlever Air rifle

Probably the main reason for dismantling the gun would be for regular service and in order to change the spring/piston washer. So I will describe this easy task first.

First, make sure the gun is not cocked and/or loaded.

Remove the trigger guard. This is done by removing the two or three (depending on the exact model of gun) screws holding the trigger guard in place and pulling the trigger guard free from the gun.

Next you need to unscrew the stock/trigger block from the cylinder. (On certain early guns such as some ‘H’ The Lincoln models, there may be a fourth screw holding the trigger block in place. You will see this on top of the compression cylinder just ahead of the trigger block. It also needs to be removed if present)

At this point it is advisable to have the end of the gun barrel placed against the floor (on a suitable pad to protect the muzzle crown). Using this technique you can lean on the stock continuously as you unscrew the trigger block and use your body weight to control the mainspring tension. (Some people prefer to clamp the cylinder in a soft jawed vice to leave both hands free to release the trigger bock).

You will need to pull the trigger back a little as you start to unscrew the trigger block away from the cylinder, but only for the first few turns, after which you can release the trigger. As you get near the end of the thread brace yourself to contain the sudden spring tension as the trigger block separates from the cylinder.

Once you have removed the trigger block/stock combination, you can gain access to the mainspring and piston. The spring guide on these guns forms part of the trigger block, so there is no need to worry about this being a separate component. Once the mainspring is removed, you can then go on to remove the piston.

In order to remove the piston from the compression cylinder, you first have to remove the short auxiliary cocking lever, just behind the larger hand cocking lever. This is done by unscrewing the auxiliary cocking lever pivot screw (and keeper screw if present), pulling the front of the lever down and disengaging the rear end from the cocking slot.

Once this has been achieved, a small screwdriver can be put gently through the cocking slot to push the piston back towards the rear of the compression cylinder eventually to emerge at the end of the tube.

At this point you can also remove the primary hand cocking lever by removing the pivot screw and lock screw (or round pin if a later model). After disengaging the front catch the cocking lever, you should be able to remove it from its recess below the breech.

If you want to remove the wooden stock from the trigger block, you need to either remove the metal butt plate by removing two screws at top and bottom (early models) or to remove the small oval wooden plug on the base of the stock (later models).

(If a later model, the oval plug will be secured with two dome headed wood screws and beneath the wooden plug there should be a curved spring steel washer, which pushes on the wooden oval making it easier to release. If the wooden oval is jammed in the hole, proceed very carefully and do not try to lever the wooden oval out, as they snap across the grain very easily and replacements are hard to find and even harder to replicate successfully.)

Once you gain access to the area behind the butt plate/wooden oval you will see a long hole with the head of a slotted bolt at the end. To remove the bolt you will need either a long, large flat blade screwdriver, or a flat bar bit attached to a brace or pair of mole grips (the large screwdriver is easiest!).

Once the bolt is loosened fully the stock should slide easily off the trigger block, but pay attention to the metal locating peg in the trigger block (this is often rusted or badly corroded)

Re-assembly is the reverse of the dismantling procedure.

I have not mentioned dismantling of the loading tap, as this part of the gun shows many variations and I will explain the different sorts of loading tap types in another post.

Lakey