30 Nosler chamber in 300 Win Mag barrel?

[Welldone 7.5]

i have. 300 Win Mag chambered barrel. Can I ream it to 30 Nosler and it clean up without any problems. Will it need to be set back a thread or so?

 

[shortgrass]

I'd set it back 1 turn. If it is a factory barrel, I wouldn't do it (unless you want tp pay me my standard hourly rate, of course, but I'd try to talk you out of it, first). Chamber prints are easy to find; www.saami.org. Expect to have feed work with this 'conversion', as the Nosler is based upon a shortened Ultra-Mag case. You'll need a ultra-Mag magazine box, too. This is not a "drop-in". What do you expect to gain from this conversion, other than velocity of course? Is the current chamber dead-center of the bore? All else being equal, accuracy is in the quality of the barrel. Best expected result, after much work, would be a rifle with equivalent accuracy, just a bit faster and with more expensive brass. It's a lot of work for 100fps increase in velocity

 

[RWO]

Look here and compare to 300WM. https://www.americanrifleman.org/articles/2017/5/3/upping-the-ante-the-30-nosler/
also here: http://saami.org/specifications_and...ns/download/Z299-4_ANSI-SAAMI_CFR.pdf#page=13

RWO

 

[Welldone 7.5]

I hear ya. You make some very valid points and I probably will well enough alone. Just got in one of those “ what if I did this “ modes. Don’t worry , be happy with your vanilla .

 

[shortgrass]

Yep! Plain ol' vanilla will git 'er done! No need to re-invent the wheel.

 

[hogpatrol]

As shortgrass posted, you'd need a setback, otherwise not an option for a straight rechamber. PUlled the comparison off of AmmoGuide


Sorry, but based on your settings, you cannot ReChamber your .300 Winchester Magnum firearm to .30 Nosler because the .30 Nosler employs a different case/rim construction than the .300 Winchester Magnum.
Also, the case of the .30 Nosler is too narrow at the top of shoulder.

Also, the case of the .300 Winchester Magnum is too wide at the bottom of shoulder.

NOTE: A qualified gunsmith can sometimes work around reported problems with special-case techniques not considered here, such as 'barrel setback'. Always consult with a qualified professional.