BSA Light Pattern tinkering

[jirushi]

Hi,

A few days ago I received my first BSA Light Pattern, from a very kind gentleman on here.
I thought it would be a nice, compact gun for hours of plinking and target practice fun. I've had a Standard Pattern, but it was a bit long and heavy for me (must go to the gym more often, plans for 2022 ).

Although the gun shot well, I could see that the spring was dry, and the tap didn't say "click".
So I opened her up.

After having worked on a few slightly frustrating pumpers, this was a piece of cake!
So easy to disassemble. Only a small amount of preload on the spring.

I have soaked the piston seal in neatsfoot oil for about 24 hours. I'm not sure if it did anything, as power hasn't gone up or down. Luckily there still isn't any dieseling.
There is a small amount of moly grease on the spring and piston.
The part that makes the tap click, was stuck. It took about an hour to get it out, but it was worth the effort. I put a new spring in, and a ball bearing. She clicks again!

The trigger is nice. A tiny amount of creep, which I could probably remove by adjusting the trigger weight screw, but I think I'll leave it for now.
The weight is not too heavy, not too light.

Now the barrel. I have had an Improved Model D Light Model from 1916 with almost completely worn rifling.
So I was quite afraid to get the same problem.
On this Light Pattern, the rifling looks ok, but shallow. Apparently this is quite usual?
The only worry is that the rifling of the last 0,5 cm (quarter inch or so) looks more or less flat at the top of the barrel, but much better at the bottom.
Not sure how this has happened, and if it will affect accuracy.
I'm itchiing to test the gun, but must wait as I live in the city and can only shoot during some weekends.

Fingers crossed!

Now the velocity/power.
- About 167 m/s (548 ft/s) with 7.33 gr JSB. 4,9 ft/lbs
- About 153 m/s (502 ft/s) with 8.44 gr JSB. 4,7 ft/lbs

The gun shoots a little bit nicer with the lighter pellet, but it's a close call.
Will probably have to test a few more pellet weights and brands.

Any thoughts are appreciated. Is this ok power? Ideas on the rifling?

The search for a very nice example continues by the way

Many thanks,
Louis

[edbear2]

Hi Louis,

600 fps with the original lightish Wasp pellet (7.2 Gr or so) was the claimed power I believe, and what a good one seems to do, so yours sounds quite healthy they often like flat head match like Meisterkugeln /R10 or cheaper Hobby pellets, well worth running a few through and checking power and also how the gun "feels", ie. a smoother shot cycle as it can be notable when you find the one it likes.

The near muzzle issue could be a problem, you will only find out when you test for accuracy, at indoor / bell target ranges (5.5 meters) it should be pellet on pellet if rested, especially with match ammo.



ATB, Ed

[Josie & John]

Hi Louis,

That looks like a nice example of a c.1929 Standard No 1 with the so called 'Transitional' stock.

I'm not particularly technically minded, so can't comment on rifling but it generally does not wear out on old BSAs. It will last several lifetimes if lead pellets are used rather than nails, BBs or other inappropriate ammunition, albeit a lot of misuse would be needed to wear out a BSA!

The velocities you measured sound about right to me; brand new, these Standards shot at around 600 fps.

The piston washer looks a little worn but if the rifle fires smoothly, I would be inclined to treat it with oil, as you have done and leave it in place. Protek should be able to supply a replacement that fits if you need one.

Kind regards,

John

[jirushi]

Thank you very much Ed and John for your advice. Much appreciated.

@Ed, I will buy a tin of RWS Meisterkugeln. And I might be able to shoot indoors, "when the cat's away".
Pellet on pellet is the goal.
I have a feeling that holding the front with an open hand palm, works best.
A gentle "artillery" hold, as with most springers, I guess.

@John, I can't wait to receive your book (I think Dutch customs are having a good read, judging by the time it's spending there ).
I do like this gun, but most of the original finish has gone. Not a problem for me; as long as it's a good shooter.

Cheers, Louis

[harvey_s]

I've tested 3 pretty good shooting light patterns and they came out at 5.30, 5.51& 5.64 ft/lbs if that helps.

[Lakey]

The sear tumbler seems to be missing from the photo of the dismantled gun. Was it shy

Seriously, the trigger group might benefit from a light clean and relube. You have the three hole , trigger block with the internal adjustment. Loosen off the lock screw, then you can adjust the trigger. Dont make it too light though.

Nice rifle, hope it shoots as good as it looks.

Lakey

[DAVALI]

I recently brought back to life a BSA light where the muzzle end of the rifling had rusted away due to being stored vertically for some years in a damp shed by drilling the rust out until clean rifling was noted, I checked the rifling by pushing a pellet, after removing the loading tap, through using a length of heavy gauge strimmer line checking the rifling indents on the pellet this got the grouping from in excess of two inches at six yards down to less than half an inch.

Dave (the bodger).

[edbear2]

Thank you very much Ed and John for your advice. Much appreciated.

@Ed, I will buy a tin of RWS Meisterkugeln. And I might be able to shoot indoors, "when the cat's away".
Pellet on pellet is the goal.
I have a feeling that holding the front with an open hand palm, works best.
A gentle "artillery" hold, as with most springers, I guess.

@John, I can't wait to receive your book (I think Dutch customs are having a good read, judging by the time it's spending there ).
I do like this gun, but most of the original finish has gone. Not a problem for me; as long as it's a good shooter.

Cheers, Louis

Hi Louis, also it is woth trying a light hold under the trigger guard / behind the cocking slot are so you can use a proper target stance, they often shoot well like this too!

ATB, ED

[Shed tuner]

I recently brought back to life a BSA light where the muzzle end of the rifling had rusted away due to being stored vertically for some years in a damp shed by drilling the rust out until clean rifling was noted, I checked the rifling by pushing a pellet, after removing the loading tap, through using a length of heavy gauge strimmer line checking the rifling indents on the pellet this got the grouping from in excess of two inches at six yards down to less than half an inch.

Dave (the bodger).

well, you had nothing to lose, and got a great improvement, so I'd say that's a good job. Sometime there's nothing else for it if the rust has really taken hold, rather than getting brutal. Counterboring with a slightly larger drill, and then putting a flat end mill down there to make the crown at the end of the counterbore flatter (rather than the 60 degress at the end of a std twist drill) would be a simple improvement on this, but it sounds like your accuracy isn't too bad already.

Rgds - JB

[Josie & John]

Hi Louis, also it is woth trying a light hold under the trigger guard / behind the cocking slot are so you can use a proper target stance, they often shoot well like this too!

ATB, ED

Excellent advice. I do this and literally rest the BSA on my supporting hand with no pressure applied.

John

[edbear2]

well, you had nothing to lose, and got a great improvement, so I'd say that's a good job. Sometime there's nothing else for it if the rust has really taken hold, rather than getting brutal. Counterboring with a slightly larger drill, and then putting a flat end mill down there to make the crown at the end of the counterbore flatter (rather than the 60 degress at the end of a std twist drill) would be a simple improvement on this, but it sounds like your accuracy isn't too bad already.

Rgds - JB

It's a funny one, the marks on Louis' gun seem to be in the grooves not lands, I wonder if he has given it a brush. as you say a counterbore would give a slight Mercury / Airsporter effect of a larger hole for a few mm depth but I don't like sharp crowns, so would go with fine grinding paste on a ball bearing welded to a rod and some lapping, followed by a really good rinse out personally, that is how I have done a couple of damaged ones in the past with good results.

ATB, Ed

[jirushi]

Thank you harvey_s, Lakey, Dave, Ed and JB.

@harvey s, my Light might exceed 5 ft/lbs with the 7.0 gr RWS Meisterkugeln that I will receive tomorrow.
With JSB, 7.33 gr gave more power than 8.44 gr.
But of course, accuracy and shooting behaviour will be more important than power.

@Lakey, I should have removed the sear tumbler for the "exploded parts photo". I was lazy; it moves smoothly, so I thought I'd leave it there.
But it will be best to disassemble and clean it, and then give it some fresh oil. Also adjusting the trigger a tad lighter might be possible. Will have to be careful though.

@Ed, that technique sounds good; holding the trigger guard / behind the cocking slot.

The marks near the muzzle... I have to make a confession here. I used my veterinary dentist hook to gently "feel" the rifling. It's something I do with dog's and cat's teeth to feel for cavities. I tried to apply as little pressure as possible, but the hard steel of the tool must have scratched the relatively soft rifling.
This was a stupid mistake. Very silly of me, never to be repeated.
Never put steel in a barrel...

@Dave, I might have to follow your example, if my gun groups badly. I would ask fellow bbs member and gunsmith frakor if he could help me with this
He suggested that the worn rifling at the top of the barrel might be from cleaning in the past with a steel rod.

[Shed tuner]

It's a funny one, the marks on Louis' gun seem to be in the grooves not lands, I wonder if he has given it a brush. as you say a counterbore would give a slight Mercury / Airsporter effect of a larger hole for a few mm depth but I don't like sharp crowns, so would go with fine grinding paste on a ball bearing welded to a rod and some lapping, followed by a really good rinse out personally, that is how I have done a couple of damaged ones in the past with good results.

ATB, Ed

good idea on welding a BB to a rod - I use the ball/paste method myself, but was thinking it would be tricky to get the ball down in the counterbore... doh

[jirushi]

While Sarah was horseriding, I did some indoor shooting yesterday evening.
8 meters.
Sitting in a chair, elbow of right arm resting on right knee.
I think 8 meters is not enough to say anything about the barrel?
But the first group looks ok. With JSB 7.33 gr.
The front sight turned out to be slightly more left than center. I adjusted this with a hammer and now the gun shoots straight.
Gamo 7.2 gr flatheads grouped a bit tighter, and right on target, but I don't have a photo of that.

Yes, it's a bit late to still have a Christmas decoration. I like it though

[jirushi]

There was one shot where the pellet didn't leave the barrel.
Hopefully this hasn't caused any internal issues (I don't think so).
The pellet was still in the tap, and it looks like the flat head got stuck.
This must be because I didn't close the tap properly.
The ball bearing I'm using for the "click" mechanism, might not be correct.
It clicks, but not when the tap is 100% closed. There is a 2 mm gap. See photos.

I think I should actually close the tap 100% in order for the pellet to be aligned with the barrel?

Tap not 100% closed, this is exactly where it clicks:



Now 100% closed:



Ps. I think that some of you will think: I thought the finish on that gun was better!
Yes, it has a grainy surface. Luckily, no deep pitting!