No 4 7.62 build

Howdy guys, this ones going to be pretty involved...
I've got the bones of the project together, but I still need a 7.62 mag and a 7.62 extractor, I'm sure they'll turn up in due course, hopefully in short order.
So, I've got a good set of wood, with a short butt that I might replace with a normal, a 7.62 proofed receiver with bolt and fitting bolthead, a Shultz-Larsen heavy target barrel, threaded for an M17 receiver, all small parts, bar the extractor, and a number of open sights to pick from, I'm leaning towards a PH5C.
I will thread and chamber the rifle to suit the receiver, shorten and profile the barrel to the approximate dimensions of the Lithgow 7.62 heavy No4 profile, fit the barrel, solder on the foresight block, open out the barrel channel, stock up the forend in the standard method around the action, but centre bed the barrel at the centre band (in a morticed timber block), fit the butt, fit the guards, cleanup the woodwork and soak it in hot boiled linseed oil, test for accuracy. Adjust the trigger, and setup the target sights, or maybe the standard sights??
Additionally, I'm going to give phosphating prior to painting the metal parts a run on this rifle.
Anyway, I think there is a very nice rifle at the end of this.
Here are the major components as they stand now.

Hey TBone, what about attempting to fit a shortened /10 round L1A1 magazine into the project? I'm thinking of a ribbed backstrap that will engage the existing magazine strap and.......... and........

PM sent re extractor

Tom,

Best way to turn the barrel (if you dont have a taper turning arrangement) is remove the taper whats on then start to step it like a mauser K98 barrel, like I did on the Mk V.

Tom

Exciting project. I am looking forward to watching this one evolve.

For the 7.62mm mag try Fultons.

They have just found one for me. Not cheap but with the strong $AUD the pain will be quickly forgotten.

Paul

I cheated ... and got one that Charnwood had done earlier (No. 5 on a No. 4 action). Re-stocked and now with a hung trigger after P.L. sent me the adapter.

There was a rumour that Charnwood 7.62mm magazines were in the process of being re-produced. Anyone know any more about them? Hopefully, this time the ejectors will be more secure

Just picked up a Sterling mag for this little project, as new in the plastic!

Tbone

Do you have your 7.62 extractor as yet?

If not let me know and I will send you one

Paul

Many thanks, was kindly helped out on that one. Cheers.
Tom

Well today has been good!
I threaded and chambered the barrel, cut down the muzzle and crowned it. I had a No4 Lithgow heavy profile 7.62 barrel on hand for reference, and the target barrel i had was very similar in profile so I didn't bother reprofiling it. As it was I had my hands full!
It wasn't with out incident either. I threaded the tennon first and then cut the chamber too deep, then needed to relieve the shoulder and the face of the tennon to get correct CHS. It left me with a runout groove of 4mm which is more than ideal, but is safe none the less.
So next time cut the chamber first, then thread.
The other barrels for comparison are a Lithgow No4 heavy profile 7.62, and a standard No4 .303. This one is a bit heavier than a No4 heavy and a bit longer, being the same as the standard No4.
i cut a recessed 90 degree crown, so all that is left on this is the extractor cutout, and I havn't decided whether to do it on the lathe or with a hack saw and file, or maybe just order a slitting saw for the mill... might as well buy the right tool, I'm planning on doing heaps of this...

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 ;)

Quote:

---

Originally Posted by 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

---

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?

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.

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.

Quote:

---

Originally Posted by 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

---

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

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.

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

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.

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.

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.:thup:

Looking good Tom, waiting for the range report.
The PH sight is a doddle to use once on target adjust the plate at the side to that distance then your set, if your at 600 next time just wind it up to 6 and your off.....

I do prefare these or similar anyday over a scope (in good daylight) trouble is my eyes dont agree with my preferance.

Shot great, got a 48.7 on the application at 200, then 10/10 hits on the figure 12 in the single snap (4 second exposures) for a total of 98.7. You beauty!! 300m is next week, if I can hold the centre bull there, I'll have a little party. Anyway all good.

Today was a disaster! 58/100. Terrible conditions though. None the less, I feel deep shame... deep, deep shame. Tempered significantly by the fact that I'll have a range to continue to shoot on for years to come!! Home Page

The deep shame has to be lessened by the courts giving you guys the range back. Well done to the NSWRA for having the cojones to take this all the way and win.

Got the old girl out at 700m today, shot a 40.3/50 and a 43.3/50, so not the best shooting really, but the rifle is more or less doing what it should and those dropped points were mostly me. I did however have a couple of shots I called good turn up as magpies.
I can't see that there would be anything too wrong with the bedding, but I might pack the top of the barrel against the top rear guard guard above the centre bedding point, as many of the old timers say theirs were done. Couldn't hurt. Also I have done no load development what so ever, so there is another definite avenue for improvement, may be before any barrel packing shenenigans... Pretty silly to have missed that one, load development is a must!

100m last Saturday, top scored for the day with a 98.3. You ripper!

I had been getting some unexplained fliers at 300, and beyond and while scores were good at 100, and 200m groups were nothing special. I was very confident that the bedding was fundamentally good, but thought the packing above the centre bedding block might help (as they all seem to have it), but I thought my loads 42gn of 2208 behind a BJD-HBC, loaded quite short were very suspect, as they're very light.
I added the packing above the centre bedding block, and put together some loads using 43gn AR2206H behind 155gn sierra matchkings, loaded out to 73mm, and it just shoots like a laser. No signs of excess pressure.
I shot it in a 300m grade today with the full bore guys, and got a 66.4/70, I dropped 1 pt low, one high, and one magpie at 3 O'clock, I called the two 4's but snatched the trigger a little to earn the 3.

So that's it for this one, rifle, load, sight setup, feeds and extracts, shoots great. I'm going to use it for my service rifle, and full bore rifle for the next good while.

Very nice work, light years ahead of anything I could contemplate but I do know a gunsmith with 2 DCRA 7.62 barrels, new receivers, wood, mags and extractors - he just doesn't have the time to build the rifles. I'm going to try to get him to do them, I've always wanted a 308 LE.