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Opening bolt faces

Posted: Sun Sep 03, 2017 7:41 am
by Ovenpaa
A recent job was to open the bolt face of a .223 Tikka T3 to suit the 308 cartridge, the T3 is always a nice bolt to machine and I use a stubby solid carbide micro boring bar so no chatter. This one clocked in with no discernible movement on a 0,01mm lever dial indicator so I was happy. It is one of those jobs where it takes as long to clock the job in as do the machining and I used a .308 Go-Gauge to confirm the fit. Probably the hardest part was fitting the extractor back in place as they either go in first time or you faff around for ages. Luckily having a second pair of hands in the form of the Viking makes life easier. I am always surprised at how many bolts we receive for such work as it is not a particularly difficult job, it just needs some care.
T3-bolt-face.jpg

Re: Opening bolt faces

Posted: Sun Sep 03, 2017 9:00 am
by WelshShooter
Looks very shiny and smooth! goodjob

Re: Opening bolt faces

Posted: Sun Sep 03, 2017 9:23 am
by flamoudi
That's all new learning to me. Very interesting....

Could my Barnard S action bolt be converted to take a 6.5 lapua? That done I rebarrel and save a fortune mebe?

Be kind if I got it wrong I'm no machinist or gunsmith.

Re: Opening bolt faces

Posted: Sun Sep 03, 2017 10:06 am
by Ovenpaa
flamoudi wrote:That's all new learning to me. Very interesting....

Could my Barnard S action bolt be converted to take a 6.5 lapua? That done I rebarrel and save a fortune mebe?

Be kind if I got it wrong I'm no machinist or gunsmith.
is it a .223 bolt face? If so yes it is easily done, if it is a .308 bolt face it is already capable of accepting the 6,5x47 Lapua cartridge :)

..and yes it would save a lot of money as you are not investing in a new bolt or rifle action.

Re: Opening bolt faces

Posted: Sun Sep 03, 2017 12:24 pm
by Alpha1
Interesting this kinda stuff facinates me. Would I attempt it myself. I wouldnt dare.

Re: Opening bolt faces

Posted: Sun Sep 03, 2017 1:03 pm
by Ovenpaa
Dave, this is with exactly the same solid carbide cutters as I sent up to you :)

Re: Opening bolt faces

Posted: Sun Sep 03, 2017 3:34 pm
by Alpha1
Ah I get it. I was actually using the ones you gave me over the weekend. They work a treat.

Question for you how would you go about milling a square hole in the end of a piece of 20mm aluminium round bar 10mm width and about 12mm deep. I might also need to do it in a piece of 20mm stainless. I have searched youtube and can not find any thing that helps. I don't want to rush into it in case I get it wrong I need to do 35 of them. wallhead

Re: Opening bolt faces

Posted: Sun Sep 03, 2017 3:52 pm
by Ovenpaa
Square hole? Do you mean without radius's in the corners?

Re: Opening bolt faces

Posted: Sun Sep 03, 2017 6:09 pm
by Alpha1
They can have radius's in the corners but they need to be tight they are going to be sitting on a valve stem. They need to be a snug fit. The other end of the job has an indicator on it to show the valves position.When the valve turns it moves the spindle and indicates the valve position. The drawing was wrong we had 35 of them made at £10 each.

Re: Opening bolt faces

Posted: Sun Sep 03, 2017 6:56 pm
by Ovenpaa
Dave, I would need to see a drawing to better understand the job. I assume you will need to make a fixture, then drill a pilot and square it off, then move to a smaller slot mill to finish it off however that is a wild guess without knowing more about the job.