Aperture or Rearsights for Full Bore rifles and other things

[shugie]

I solved the stiff bolt problem on my mk4 by simply fitting a softer firing pin spring. The original spring is massive, and after suffering a sore bruised palm, I initially resorted using a short length of gas pipe.
Stripping the bolt and changing the spring is easy, but make sure you adjust the firing pin protrusion to no more than 1.6mm on reassembly.
Use of moly grease sparingly around the sear pin slot is also a good idea.

H/man

I do wonder about that spring, it does make a hell of a noise when you pull the trigger, and I've never once had a misfire. Might try the moly grease around the sear slot. Where did you get the softer spring though?

[R.G.C]

I solved the stiff bolt problem on my mk4 by simply fitting a softer firing pin spring. The original spring is massive, and after suffering a sore bruised palm, I initially resorted using a short length of gas pipe.
Stripping the bolt and changing the spring is easy, but make sure you adjust the firing pin protrusion to no more than 1.6mm on reassembly.
Use of moly grease sparingly around the sear pin slot is also a good idea.

H/man

Yes, I always compared this spring as a valve engine one..... Unnecessarily strong for a 6,35mm FP travel. Also reduce the diameter.
A some 12,5mm OD, 1,6mm wire, 70mm long spring would do it.

We have had quite a few transformed fpr Bellevilles as well.

One of the problem as well was the fact the cocking ramp was not a true helicoidal shape, but a simpla angular one, resulting in more effort at the start of the bolt lift... Once the bolt was rotated some 15°, lift become easier.
R.G.C
R.G.C

[shugie]

How easy is it to dismantle the mk. 5Swing bolt? I can see the disassembled bolt on the Swing thread on here, but I've learnt to be cautious dismantling things with big springs in.

[Dougan]

The stock is not as poor as I recall but low comb

You can make/have made a raised comb - I was having the same problem with my gallery rifle, so while waiting for a more permanent solution I strapped a piece of pipe insulation tubing to it with electrical tape...as it turns out it's perfect and I've left it as is...

...but if you're thinking of putting a SHED butt plate on it, Ovenpaa may not appreciate pipe lagging been used for a comb razz

I'd still recommend an adjustable front sight...once you've got the rifle zeroed, and a comfortable head position sorted; you only ever have to move the elevation of the rear sight 2.5 mins either way.

[Dougan]

Use of moly grease sparingly around the sear pin slot is also a good idea.

Ah, so that's what you call that hole - Is it right to put a little moly behind the front lugs too?

[Rickoshay]

sign92
OK, so lots to take in - some of which lost me in engineering but 'thank yall'.
More Qs
- Can the spring simply be shortened to reduce the cocking effort?

- Can't find butt plate on Shed Site, is it the same as the Dolphin butt plate?

- Further pointers on rear sights would be useful, so far Fulton's, RPA and EBay; is there a site that has a 'range' of FB sights?

- Eyepieces....seem to add another angle; what is recommended? (I have a stigmatism in my master eye)

- Link to stripping the SWING bolt, as unable to find it

- [spare for next random question...]

[R.G.C]

sign92
OK, so lots to take in - some of which lost me in engineering but 'thank yall'.
More Qs

Burst of questions. Replies under each:
- Can the spring simply be shortened to reduce the cocking effort?

NO. A spring had flats at each end to maintain it working in line and cutting it would mean one face not being square and the spring working twisty. Moreover, rates changes per mm cut would make the operation uncontrolleable unles you know exactly the spring dates.

- Can't find butt plate on Shed Site, is it the same as the Dolphin butt plate?

Think the SHED can help?

- Further pointers on rear sights would be useful, so far Fulton's, RPA and EBay; is there a site that has a 'range' of FB sights?

Centra Visiertechnik offers both. Available from Cantra UK I believe
http://www.centra-visier.de/abatoncms/p ... Frame.html

- Eyepieces....seem to add another angle; what is recommended? (I have a stigmatism in my master eye)
See above

- Link to stripping the SWING bolt, as unable to find it
Your firion pin rod is most likeli an aluminium one with a steel tip (a nonsense). If the case, be careful to not damage it witj the cross set screws. If the protrusion is correct, do not move the front collar and reach thespring by just removing the sear pin holder at rear.

To dismantle; remove the rear plug, move backwards the compression sleeve and you can then remove the cross sear pin and the FP comes out.

When refitting, the sear pin holder must be adjusted lenghtwise bu screwing/unscrewing it on the FP in order to maintain 0;1-0,2mm play between the sear pin and the bottom of the cocking ramp (when the FP front collar bears against the dry firing shoulder of the bolt. The set screw can the be tightened (gently to not damage the soft aluminium; a drop of Loctite in its hole is recommendable). To reinstall, place the FP unit, enter the compression sleeve, the sear pin well pushed in, and screw the rear plug, taking care it screw gently and tighten it.

I forgot: place the sear pin in its coched position of the ramp before tightening the rear plug.

Hope this help
R.G.C

- [spare for next random question...]

[Rickoshay]

This is great, thank you for the guidance.

For those of you that have sent me 'PM's unfortunatley I am not allowed to use that feature yet - so cannot read your messages.
Something to do with being 'recently joined'.

[shugie]

This is great, thank you for the guidance.

For those of you that have sent me 'PM's unfortunatley I am not allowed to use that feature yet - so cannot read your messages.
Something to do with being 'recently joined'.

I did try and send you a PM, I was going to offer to lend you my Swing TR sights, which I'm not currently using but don't want to sell. The rear sight has Swenson Engineering on it.

[BritBloke]

As far as sights do you can do alot worse than the RPA Tracker sights. Don't skimp on sights though they are a rather important part of the 'whole'! Any second hand sight would probably need to be refurbed or checked very carefully as wear will introduce 'backlash' which makes life very difficult for your windage changes! Similarly I would recommend an adjustable foresight (I use a Centra) to keep your head position as consistent as possible. It is quite an adjustment to go from 300 to 1000 on rearsight alone, you'll find yourself straining to obtain a decent and more importantly consistant sight picture. You can then start adding variable irises etc.