No 4 7.62 build

[Claven2]

FWIW, to those who were curious, you don;t need a taper attachment to profiel a long barrel. You just turn the barrel between centers with a lathe dog and offset the tailstock - I do it all the time

[tbonesmith]

FWIW, to those who were curious, you don;t need a taper attachment to profiel a long barrel. You just turn the barrel between centers with a lathe dog and offset the tailstock - I do it all the time

Do you put a fixed steady in the middle of the barrel? I had been wondering if you did how many times you'd need to move it whilst turning it down. Or is there some other way you avoid the chatter? If it's anything odd could you post a photo of the setup please, because I want to do it next time?

[jmoore]

We often just rest a big dead blow hammer on the rotating part to prevent chatter. Either the face or the juncture of head and shank. Another method is to build large globs of duct sealing compound ("dum-dum" in our shop) and restrain it with vinyl tape. And this on parts costing upwards of US$60,000. (The real high dollar stuff usually doesn't need it.)

Photos if you need 'em. I just have to take them.

ETA: I reckon you already know the the usual tricks to avoid chatter- Small radius on the cutter's nose- aggressive feed rate- smallish depth of cut- positive rake but not too positive, unless a negative rake works for some odd reason- speed as slow as can be managed without sacrificing surface finish. (I hate running slow RPMs! Especially with carbide inserts.) Also, the angle of the leading edge of the cutter can change the tendency to chatter.

If chatter starts, break out the belt sander! Get rid of the tool marks before proceding.

But all of that seems pretty obvious, so it's mostly for those who haven't gotten into this kind of mess before.

[tbonesmith]

So no pic's, but tonight I machined a new aluminium bush for the barrel vice ( to suit this barrel) got the barrel breeched up, marked for the extractor cutout, pulled it out and cut it with a hacksaw and files. Worked fine and pretty neat. Then breeched it up again, and checked for headspace and function with the extractor in place. All good!
I was thinking of putting a milling cutter in the lathe and clamping the barrel to the tool post, but couldn't sort it out tonight. Saw a nifty barrel vice for just this sort of thing mounted on a tool holder for a quick change tool post on another forum. I think I'll sort out something like that in the future. I could make the I.D. of the vice/clamp the same as my other barrel vice and share the same bushings.
So happily I've now got a barrelled action with correct CHS.
Next I have to fit it to the stock. I'm tempted to router out the barrel channel to accommodate the barrel, but I'm a bit wary of the possibility of catching some grain and blowing out the side of the forend. Anyway I'll come to that soon.
Cheers.

[bigduke6]

FWIW, to those who were curious, you don;t need a taper attachment to profiel a long barrel. You just turn the barrel between centers with a lathe dog and offset the tailstock - I do it all the time

What about the traveling steady? or are you using a few fixed ones?

[tbonesmith]

Hi guys, I've made sound progress.
The action has been fitted to the stock. Luckily I didn't have to patch the draws as I could just fit it from where it was. Had a few dramas, but nothing major. Anyway I inletted the forend for the heavy barrel by hand with my favorite gouges, and got the bedding pretty well Mickey Mouse.
I considered leaving the barrel to float, but thought as I originally did that it could use a bit of support in the middle, hence the patch. I roughed out the inletting on the mill and squared it up by hand, then fitted a block, and roughed out the profile in it before gluing it in.
Checked it out and the rifle ejects well.
Anyway there's more to do, but the major stuff is done. I hope to use it next weekend.
We shall see!!
I think this will be a fine little rifle.

[dman69]

Well done Tom! What you're doing is well outside my skill set (I'd probably make bubba look like da Vinci ), but it's really fascinating stuff. Looking forward to the range report!

[tbonesmith]

Howdy Gents! Tonight I fitted the mid band pressure pad. I hit the barrel with bearing blue and inletted with gouges until there was even pressure through out its surface area. This pad lifts the barrel about 1/2 mm from the bottom of the barrel channel(or deflects the forend), either way there is substantial upward pressure.
If you're wondering why I didn't just make the pad from the existing forend by inletting for the barrel and leaving a pad protruding, it's because I couldn't be 100% sure the barrel was naturally centred in the channel as the pad would have the capacity to deflect the barrel left or right a bit.
It would have been easier to prop the barrel up a bit and put in a pad of epoxy bog or devcon, but I think thiss method adds something and i like doing it this way... even if it does take another 2 1/2 hours...
I'm not going to be selling this one so I should get some joy out of it at least.

[tbonesmith]

Sorry for distinct lack of pics, but I've got the rifle together now, and had it at the range at 300m today. Everything worked very well. I took 3 rounds to find the target, and once on, put a decent score in (90.3 including a washout for the first scoring shot). The rifle feeds, extracts and ejects, discharges reliably and shoots accurately.
I have yet to tidy up the woodwork, and strip the rifle for a thorough clean and grease prior to final assembly.
It wears a PH5C which is a sight I havn't used before, seems really nice, and everything is more or less as it should be.
I am very happy with the threading and chambering, and I'm sure that I've got a rifle that will fully look the part as well as do the business... which is how I like them.
I'll post pics soon.

[tbonesmith]

I sanded the stock and stained it to match the butt, also I plugged the old rivet holes around the centre band, as I had to remove the reinforcing there to fit the barrel. I soaked the wood in a hot linseed oil bath for a few hours, and let it dry for a week.
Everything was thoroughly cleaned and greased beneath the wood, and I now have a very nice looking, well set up rifle. At the moment its got a little bit of wet BLO on it, it won't be that shiny when it dries.
I'm wrapped with this, and as I mentioned I'll do my best to hang onto this one... do my best... we'll see.
Anyway it's been numbered to match along with the year so noone shouts "shenanigans!!". I just like them to match, and hey it's mine, so I'll do what I like.
With this guy I took alot of time with the fit of everything, the butt plate, the butt, the forend, bolt, trigger peined the front band to retain the front top guard, everything. I hope it pays off with some good scores over the coming year or so.
I havn't used a PH 5C much but have always like the look of them, same with the sterling mag, I think they'll go great. Even found a nifty foresight protector, to protect my foresight! Tomorrow is 200m, so we shall see how it goes.