Savage tenon thread LENGTH (small shank)

[SupressYourself]

I'm having a problem headspacing a new custom barrel for a Savage Impulse. I have the barrel nut back as far as it will go (ran out of threads), and when the barrel is threaded into the receiver to where the nut hits, I still have about .020 headspace. I got to measuring the length of the threads (from breech to last thread), and the custom barrels are shorter.
Savage factory: ~1.600
Custom: ~ 1.550

I've done some research, and while large vs small shank / thread pitch specs are everywhere, I'm not finding much for what the LENGTH of those threads up the shank should be. I've seen both 1.600 and 1.550. This says 42.06 mm, which would be 1.655.
Are my custom barrels just not threaded to spec, or is something else off?

 

[FEENIX]

I'm having a problem headspacing a new custom barrel for a Savage Impulse. I have the barrel nut back as far as it will go (ran out of threads), and when the barrel is threaded into the receiver to where the nut hits, I still have about .020 headspace. I got to measuring the length of the threads (from breech to last thread), and the custom barrels are shorter.
Savage factory: ~1.600
Custom: ~ 1.550

I've done some research, and while large vs small shank / thread pitch specs are everywhere, I'm not finding much for what the LENGTH of those threads up the shank should be. I've seen both 1.600 and 1.550. This says 42.06 mm, which would be 1.655.
Are my custom barrels just not threaded to spec, or is something else off?

Custom? Is it a pre-fit, or a gunsmith did the threading/chambering?

 

[grouse]

How thick is your recoil lug?

 

[joelpend]

In my experience there is normally a generous amount of extra thread length on Savage barrels. Of course if you use a thicker recoil lug that requires a longer thread.

 

[Radman]

I'm having a problem headspacing a new custom barrel for a Savage Impulse. I have the barrel nut back as far as it will go (ran out of threads), and when the barrel is threaded into the receiver to where the nut hits, I still have about .020 headspace. I got to measuring the length of the threads (from breech to last thread), and the custom barrels are shorter.
Savage factory: ~1.600
Custom: ~ 1.550

I've done some research, and while large vs small shank / thread pitch specs are everywhere, I'm not finding much for what the LENGTH of those threads up the shank should be. I've seen both 1.600 and 1.550. This says 42.06 mm, which would be 1.655.
Are my custom barrels just not threaded to spec, or is something else off?

It just sounds to me that the threaded (boss) area is too short.

 

[SupressYourself]

How thick is your recoil lug?

.220. It's the same one that was on the factory barrel. Seems I could shave about .020 off the recoil lug and / or the face of the barrel nut to make it work, but I'm worried about keeping those surfaces perfectly flat.

 

[SupressYourself]

Custom? Is it a pre-fit, or a gunsmith did the threading/chambering?

It's a prefit.

 

[SupressYourself]

It just sounds to me that the threaded (boss) area is too short.

It is certainly shorter than the factory Savage barrels. That's why I'm wondering what the proper spec is. Either they didn't make the barrel to spec, or (it wouldn't surprise me) Savages own spec doesn't work for their Impulse rifles.

 

[Fisher T&C]

The length of the threads should be 1.60"

 

[SupressYourself]

Here we see 5 barrels, positioned every-other. The 3 silver-colored barrels are from the same prefit manufacturer, and the black and painted barrels are factory Savage. The sharpie is just there to help point out the ends of the threads.
The factory Savage are a good .050 longer. I only need about .020 to headspace properly.

 

[44-40]

If you have the correct barrel nut I believe the small shank is longer and the large shank shorter in oal... but if it all threads together action and barrel with barrel lug in place, up against the go gauge...with out the barrel nut ...then just cut .040" off the barrel nut in the lathe ...if your barrel nut threads on to the barrel and has the correct threads. Called shorten the nut....the .040 will give ya enough if your measurements are correct. A simple job.

 

[FEENIX]

It's a prefit.

IIWY, I'd send it back for them to correct it.

 

[joelpend]

You are so close, if you have a rotary tool you can relieve a very short section of the barrel nut thread, .020 is less than 1/2 of a full thread on a 20 pitch.

 

[TXTrained]

How thick is your recoil lug?

Good Question