What size of 4-jaw independent chuck on a 12”x36” lathe?

[jlficken]

Why not make them? They don't appear very refined, nor complex, though I can't clearly see the locking lugs. For $1k I'd be trying (also, it seems we in the US get our knickers ripped on anything from the UK).

GsT

I lack the confidence at machining to make something like that when it’s all that stands between my face and the bolt of a very expensive rifle flying back into it at high velocity.

I haven’t even made anything on my new mill yet beyond making a little block square(ish), LOL.

Maybe someday I’ll get there but it’ll be awhile.

 

[GeneT45]

I lack the confidence at machining to make something like that when it’s all that stands between my face and the bolt of a very expensive rifle flying back into it at high velocity.

I haven’t even made anything on my new mill yet beyond making a little block square(ish), LOL.

Maybe someday I’ll get there but it’ll be awhile.

Understood. I started this hobby to work on my firearms and it kinda ...grew... ;-) Side note, there's enough mass in a bolt that it won't actually come back at terrific velocity. Fast enough that you don't want your face in the way, but probably not fast enough to escape the receiver. What rifle are those for?

GsT

 

[jlficken]

Understood. I started this hobby to work on my firearms and it kinda ...grew... ;-) Side note, there's enough mass in a bolt that it won't actually come back at terrific velocity. Fast enough that you don't want your face in the way, but probably not fast enough to escape the receiver. What rifle are those for?

GsT

They're for an Accuracy International AT.

It's good to know that if I attempted to make it and messed it up shouldn't kill me in theory at least, LOL. 50K psi+ just makes me nervous.

I know one guy that built his own 50BMG from scratch...I was impressed.

 

[yota]

At least with ammo you stop at some point worried about expiration dates.

I have a bunch of surplus .303 British for my enfields that is pretty old and it works fine. also, 30:06 in garand clips that is still good.

 

[GeneT45]

They're for an Accuracy International AT.

It's good to know that if I attempted to make it and messed it up shouldn't kill me in theory at least, LOL. 50K psi+ just makes me nervous.

I know one guy that built his own 50BMG from scratch...I was impressed.

Pfft! What's a few tens of thousands of PSI among friends?! ;-)

I was wondering if it was for an AI. I have an AWSM (old school, like me...) but it's a conventional barrel with the lugs in the receiver.

One of my unrealized projects has been to build a bolt gun that used an AR-style bolt (short bolt throw!) and see how it fared against more conventional bolt actions.

GsT

 

[jlficken]

Pfft! What's a few tens of thousands of PSI among friends?! ;-)

I was wondering if it was for an AI. I have an AWSM (old school, like me...) but it's a conventional barrel with the lugs in the receiver.

One of my unrealized projects has been to build a bolt gun that used an AR-style bolt (short bolt throw!) and see how it fared against more conventional bolt actions.

GsT

I always wanted an AWM in 300WM but they’re too rich for my blood now so I “settled” for a TRG-42 in 300WM instead.

That sounds like a fun project. I’m honestly not sure how that’d work out.

 

[epanzella]

My 12x36 Grizzly came thru from the factory with an 8 inch 4 jaw and a 6 inch 3 jaw.

 

[jlficken]

My 12x36 Grizzly came thru from the factory with an 8 inch 4 jaw and a 6 inch 3 jaw.

Lucky!!!

For all I know this one did too, however, it was used when my Grandpa got it in the early 90's so I'm just happy it has the 8" face plate and change gears still with it.

 

[jlficken]

I took some more measurements.

There's cats in the shop now for the winter so don't judge me for the fuzz on the threads as the chuck has been off for a few days now and even though the lathe is covered it gets everywhere

The smooth part of the spindle left of the threads measures exactly 55.00mm so there's that.

Thread pitch gauge:



Apex of threads in metric:


Apex of threads in standard:

 

[GeneT45]

You need to drop that thread gauge down into the threads and look at it with lighting from behind. If you hold the gauge just right, you should be able to block all light, except at the crest and root of the thread.

I'd try first seeing if the manufacturer can identify the thread. As an alternate, measure the pitch diameter with some thread wires (after ascertaining the pitch) and see what you come up with.

GsT