BSA Light Pattern tinkering

[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!

[Shed tuner]

you'll need to take the gun apart, and look down the barrel from the cylinder end and work the tap ( a light source at the muzzle makes it easier), to determine where the properly aligned position is. It would normally be "full closed" but maybe something got bent or damaged.

[Lakey]

The ball bearing isnt correct, an is probably the reason why the tap isnt indexing properly. The original spring used was quite powerful, and drove a wedge shaped plug. Here is a link to a pattern part. The spring will be there as well if you search.

https://www.airgunspares.com/catalog...category/1066/

Lakey

[jirushi]

Cheers Shed tuner and Lakey.
I installed a different spring and ball bearing in the tap click mechanism yesterday, and now it works problem free.
A much more positive click; a stronger, longer spring, that fits exactly in the hole, and a larger ball bearing.
The tap has to be closed 100% for good alignment (which makes sense!).

Another piece of good news is that the RWS Meisterkugeln have arrived and they have brought the power up to 5.4 ft/lbs;
180 m/s; 590 ft/s.
Less vibrations; smoother.

Thank you Ed for the advice!

Will do a thorough accuracy test during the weekend.

[jirushi]

Third group at 8 meters indoors, 5 shots with the Meisterkugeln.
I have been told that this might not say a lot about the barrel, but the first impression is good.