Headspacing / can't tighten barrel on enough.

[zloe]

Hi all,
Trying to complete my second build. This one has been a bit of a challenge. Working with a SS criterion barrel for 6.5 swede. Have a magnum receiver that I'm trying to work over to make work. I've got the barrel nut on as far as it will go. Then I've screwed the barrel to the receiver. Currently unable to bottom out on the go-gauge. Still using the magnum bolt head for the moment, but shouldnt the Bolt head contact the gauge? Currently the barrel nut, the lug, and the receiver are mated together and not contacting the gauge. Any ideas? The barrel nut will NOT go on any further. The barrel nut is also old, likely pre 99 if that matters.

Thanks for any ideas. I will put standard bolt head and Bolt together when new (smaller) firing pin arrives, but don't see how that will help with headspacing.

[JW]

My first thought is to check the dimensions of the gauge
If it is correct I would wait on the correct bolt head and see if things change
Jack

[Mthomas90]

The headspace will change with the new bolt head. I would think you should be able to set it with a magnum bolt head though.

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[Zero333]

You can try to see if a empty case will work just to verify it's the proper HS-gauge.

Measure how far down the threads go from the breech face and compare it to other Savage barrels you have on hand... This will give you an idea if Criterion didn't thread it far enough or if it's still something else.

[zloe]

Good thought. I'll compare the HS gauge to an actual cartridge.

[sharpshooter]

See if it will headspace without the nut. This will tell you if there is enough threads on the barrel, or if the nut needs some more relief. Some of the older nuts were small in diameter on the relief cut, preventing them from screw on farther.

[Whynot]

As Sharpshooter said- remove the nut from the barrel and see if it will headspace. (even though you will have to set it with the correct bolt head... but just to figure out the problem). If it is bottoming out and hitting the bolt then you either have a bad gauge or a oversized chamber. I put a new barrel on a old savage action and it did the same thing- I put the barrel nut in the lathe and cut out the last 3 threads so that I could take it farther on the barrel - and that fixed it. It would have been easier to get a new barrel nut but they were out of stock. Very old barrel nuts are slightly different than the new ones-- on the old factory contour barrel it didn't matter,- but putting on a heavy barrel showed the problem.

[Robinhood]

Sharpshooter told you how to check the nut. Once you get that worked out, pull the firing pin out so length is not a factor. Install the new .490(.473) head for the Swede. Set the head space. Wait for parts you need to complete the bolt assembly. Check and set the firing pin protrusion and done.

Before you install a barrel you should drop the gauge in the breach and measure protrusion. There is not a lot of room for error. 99.9 percent of the time they are right, however it is too easy to check to not do it.

[zloe]

What is protrusion supposed to be?
WITHOUT the nut I can get the gauge to mate with the new Bolt head.
Seems it is the old nut...
I have an axis barrel I could use the nut from, however the nut will not come off... I think it's the blueing salts. Barrel is off the receiver, but that nut will only come off about 3 full turns and seizes up something fierce. Bluing salts everywhere...

[zloe]

I've learned a lot from this project.
1. Ejection pin is different lengths in some Bolt heads
2. Axis Bolt heads are interchangeable with 10/110 series
3. If you have the old larger firing pin and a newer, small diameter bolt head, you can order the $5 smaller firing pin and it works well with the newer Bolt heads.
4. My old magnum bolt head had a cutout in the back end of it (closer to the safety). I used angle grinder to shave enough off of the newer standard bolt head to make it fit. Works well (I think). I had a hard time finding ANY bolt heads with the cutout for older flatback receiver bolts...

[Evlshnngns]

.12 roughly. Mine was .13x. That's dropping brass into the barrel before installation.

[tobnpr]

What is protrusion supposed to be?
WITHOUT the nut I can get the gauge to mate with the new Bolt head.
Seems it is the old nut...
I have an axis barrel I could use the nut from, however the nut will not come off... I think it's the blueing salts. Barrel is off the receiver, but that nut will only come off about 3 full turns and seizes up something fierce. Bluing salts everywhere...

Penetrating oil (Kroil, etc.), stand barreled action on end, let soak down into the threads. Re-apply as needed, leave overnight.
If still no luck, apply some heat to the nut, try again. Part is cheap enough, you've got a match-grade barrel, a new (trued) nut would be my choice...

[mnbogboy2]

In a pinch you can use a dremel and small stone on the inside of the muzzle side of the nut and carefully remove a thread or two. This will not disturb the original "square" of the mating surface nor will it disturb any blueing or external finish. All depends on how much room you need. Thick aftermarket recoil lugs often call for this.
Randy

[zloe]

In a pinch you can use a dremel and small stone on the inside of the muzzle side of the nut and carefully remove a thread or two. This will not disturb the original "square" of the mating surface nor will it disturb any blueing or external finish. All depends on how much room you need. Thick aftermarket recoil lugs often call for this.
Randy
Somehow I've made it this far in my life without a dremel...
I did notice that the aftermarket barrel nuts appear to have no threads at the muzzle end of the nut. as seen here. https://www.eabco.net/Savage-Barrel-Lock-Nut_p_14687.html
The old nut I'm working with have the threads throughout.

I just bought a EABCO nut.

TIP: it was cheaper on EBAY through the EABCO store by a few dollars after shipping.

[mnbogboy2]

My first dremel was used mainly for porting race car heads. Some how my son in another state ended up with it. Like a lot of tools my second one usually sits idle for most of the time but sure comes in handy when needed. Also they are not overly spendy.

Some of the older nuts have the remnants of threads showing all the way to the front. These have been relieved to clear the unthreaded shank. If the shank of the replacement barrel is a tad larger than the stock one they still interfere.

Glad you got a new one coming.
Good luck,
Randy

[zloe]

Some of the older nuts have the remnants of threads showing all the way to the front. These have been relieved to clear the unthreaded shank. If the shank of the replacement barrel is a tad larger than the stock one they still interfere.

Randy
I think you've nailed it, threads interfer with the slightly larger "light Varmint" barrel.
I would love a dremel. But I've gotten good with files, angle grinder, etc. just haven't need one. It certainly would have been the best tool for the job many times over at this point ha ha. Someday...

[zloe]

EABCO Barrel nut got here. It fixed the headspacing problem. Thanks all. Good info.