No4 Bolthead for .223 Work in Progress

Hi Guys,

For ages I've wanted to make a No4 in .223. I hadn't really decided on the nature of the bolthead modification I wanted to use, but after see a few here and there I have come to a decision to go for a plunger type ejector with a modified original or quite possibly a newly fabricated extractor, with a brazed or silver soldered ring to retain the base. I will put this ring on a shoulder for more surface area. I have machined this ring from a piece of clapped out No4 barrel.

I am not sure if I will bush the firing pin hole, but I think I will as the non bushed examples seem prone to blown primers and bad primer cratering. Anyway we'll see about that bit of it.

This bolthead has been DP'd for some reason, so it's my prototype, I am not sure whether I'll use this one in anger at all, as the barrel would have to be chambered to suit the individual bolthead, and I'd prefer to use a non-DP'd one for a shooter.

How are you going to attach the ring on the boltface? Welding, yes but what technique to keep the temper?

I'll try silver soldering it first.

Tom,

When I made mine I made it a shrink fit and was pressed on and pinned, but was for .30 M1 carbine.

I had some mixed progress tonight. Mostly good.

I silver soldered on the ring, as if I bush the firing pin hole I'll tap and thread in the bush and lock tight it.

Then I setup to drill for the ejector. I went too deep and came out the back...Derrrrr!! Oh well I suppose that's what this one is for...sort of. Then chucked a bit of drill rod in the hole for the pics. I had to start the hole with a carbide end mill until I got through the case hardening, than went to a HSS drill bit.

Next I'll sort out the spring and the pin retention, I'm thinking a radial grub screw, but unsure. Any suggestions???

And then the extractor.

I'm feeling pretty confident it will work (the next one anyway). Looking forward to building the rifle for it!!

Tbone, That looks like a fun project. Lots of little challenges. Did you have any problem drilling the ejector hole? I was thinking it might be easier if that hole was located and drilled before machining the recess?Salt Flat

HEY TBONE, How goes the .223 project? Salt Flat