Swing bolt

Anything Fullbore rifle related, Hunting, Target, Match.

Moderator: dromia

Message
Author
User avatar
Pete
Past Supporter
Posts: 2654
Joined: Tue Sep 15, 2015 8:48 am
Home club or Range: NRA Bisley
Contact:

Re: Swing bolt

#11 Post by Pete »

Be careful!!! You need to make absolutely sure that the pin is fully seated in it's hole in the collar (make sure there's no crud underneath it...) and in line with the slot in the sleeve.......one of the reasons I switched to Belleville washers was because I nearly mashed up the whole thing trying to compress the ridiculous massive spring. I started to tighten the end cap, but it jammed, and it took me some time to figure out why. If the pin isn't in the correct place, tightening the cap will force the sleeve against the pin and mash the sleeve.
With Belleville washers, you can adjust the number of washers so that they're only compressed when the cap has around 3-4mm to go before being fully tightened. This makes it a doddle to get everything in alignment before the final tightening.
I've done the same thing with my CG-RPA 2000, which is essentially identical to the Swing, apart from the sear pin having a squared off top.

If you're really stuck, I could take mine apart with pictures, and post on here.....

Pete
"Tantum religio potuit suadere malorum" Lucretius
User avatar
shugie
Past Supporter
Posts: 1555
Joined: Sun Apr 29, 2012 3:42 pm
Home club or Range: Sperry at Bisley
Location: near Reading
Contact:

Re: Swing bolt

#12 Post by shugie »

I understand the logic of that spring, to give a very short lock time, but I had decocked the bolt before taking the cap off, and didn't get the sense that it was under much pressure, so was a bit puzzled about having to compress the spring to get the cap back on again. I'd been thinking about changing to Belville washers, now might be the time to do it. I think HPS do them.

Is there only the one spring, despite the picture having two?
Careful now/that sort of thing
User avatar
shugie
Past Supporter
Posts: 1555
Joined: Sun Apr 29, 2012 3:42 pm
Home club or Range: Sperry at Bisley
Location: near Reading
Contact:

Re: Swing bolt

#13 Post by shugie »

An update, the bolt is now back together again following Pete's useful instructions, I went with Belleville washers too, although not stainless, as I could not get the size I was after (14 by 7.2 by 0.5) but phosphated spring steel should suffice now that I can get into the bolt innards for cleaning and lubrication.

Certainly easier to get the bolt open, and I get the feeling the trigger pressure may be a bit lighter. Will see how it shoots tomorrow.
Careful now/that sort of thing
User avatar
Pete
Past Supporter
Posts: 2654
Joined: Tue Sep 15, 2015 8:48 am
Home club or Range: NRA Bisley
Contact:

Re: Swing bolt

#14 Post by Pete »

John Carmichael (previously of HPS-TR) gave me a handful of Bellville washers to try when I complained about the effort required to open the Swing bolt.
A further discussion with Robert Chombart about setting them up re-affirmed that Bellevilles were the way to go.
The Swing has been sold now, but I still use Bellevilles in my CG-RPA 2000.
The large spring shown in the Wiki pic was in the rifle when I bought it from Fultons. I replaced it with the smaller one in desperation.......and a few weeks later, with the Bellevilles.
With the firing pin protruding, I added washers until I could just feel the end cap touch the collar with 1/2 turn to go. This gave minimal compression of the stack with 100% strike reliability and ease of opening the bolt.
However, Swings were "hand made", so there may be an element of suck it and see.....whatever, I'm sure you'll find it better to use. What trigger does your have? I bought a Davies for mine.

Pete
"Tantum religio potuit suadere malorum" Lucretius
User avatar
shugie
Past Supporter
Posts: 1555
Joined: Sun Apr 29, 2012 3:42 pm
Home club or Range: Sperry at Bisley
Location: near Reading
Contact:

Re: Swing bolt

#15 Post by shugie »

I don't know what trigger it has, but I've always found it to work perfectly as long as I get my bit right. Not shot it yet due to change of plans, have some ammo cooking to do then will go and hire an electronic target for an hour.

When I bought it, I was told the barrel was quite new, and had only been used for light loads on a 100m range. I borescoped it when checking how the bolt worked with Bellevilles, and the rifling is very clean and sharp. I had a new Joe West stock put on it in 2018, and I think I shall be keeping it until such time as my shooting improves to the point that a new rifle is justified. The only gripe I have is that it only like 155gr bullets, anything heavier reduces the accuracy, no idea what the twist is though.
Careful now/that sort of thing
User avatar
Pete
Past Supporter
Posts: 2654
Joined: Tue Sep 15, 2015 8:48 am
Home club or Range: NRA Bisley
Contact:

Re: Swing bolt

#16 Post by Pete »

Easy to find the twist.......cut a circle out of a bit of card, draw a radius on it, push it on to a cleaning rod through the centre, stick a patch on the rod, shove it into the bore until the radial line is at 12 o'clock, (it will rotate as it moves up the bore)
Then mark the rod where it enters the receiver, shove the rod in until the pointer does one full rotation to 12 0'clock, make another mark on the rod level with the receiver, pull it all out and measure the distance between the two marks on the rod, which will be the distance travelled by the bullet during one rotation in the bore.......ie, the twist.
It will most likely be 13" (or 1:13), which is correct for 155 grain bullets. I had mine re-barrelled in 1:11 which made no difference whatsoever with 155 grain bullets, but reduced the group sizes with 175+ grainers.

Pete
"Tantum religio potuit suadere malorum" Lucretius
User avatar
shugie
Past Supporter
Posts: 1555
Joined: Sun Apr 29, 2012 3:42 pm
Home club or Range: Sperry at Bisley
Location: near Reading
Contact:

Re: Swing bolt

#17 Post by shugie »

I like that cunning plan. Will try it next time I'm cleaning.

I suspect you are correct that it's 1 in 13.
Careful now/that sort of thing
Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest