28 nosler barrel life

[Reelamin]

686

924

Hmmm??? My 7stw is right at 1k down it with the same amounts of R22 and R25 and has not changed one bit. It was abused in my use standard shooting ground hogs. If that theory chart holds true to my real world results I'm happy. I'll be handing my 28 down with the original barrel to the grand kids after so it can be used for 20-25 years or so.

 

[chav0_12]

84.5 of retumbo

Is that with 195s? What's your COAL?

 

[Reelamin]

Is that with 195s? What's your COAL?

Nope just regular 160AB hunting bullets at 33-3350. It will only shoot the long high BC hunting bullets ABLR and ELDX.....edit....into 1-1.5". I don't and won't shoot any current TARGET bullets or re labeled target bullets at animals I want to kill quickly.

 

[Mikecr]

What is that telling me? If I'm willing to accept 0.5" groups, isn't that going to be different than I'm willing to accept 3" groups?

Accurate barrel life represents a shift point, where consistent best accuracy leaves.
To detect it, you first have to attain it.

If content with 3" groups then you're probably not going to 'see' further degradation anywhere near the accurate barrel life point.
Could probably shoot 5,000 28nosler rounds before it get's worse than 3" (when bullets start blowing up).
Another thing to keep in mind is that shot timing is a big influence to barrel life. You could destroy a 28Nosler barrel in one range session. My calcs for 28Nos default at 50sec shot rate, and 717 ABL drops to 144 ABL if you did a lot of group shooting with a 10sec shot rate. If you shot 1 every 10min you could probably extend ABL x2, but I have no way to predict that.
Pressure plays a big role, and of course powder temperature and amount.
If you wanted to manage it, moly (in particular) extends ABL by cooling the charge temp as it vaporizes. That's why you see MV drop with use of moly (not reduced friction). But then many people step up their charge to compensate, and barrel life goes right back down. So I no longer compensate for moly, and really it's surprising to me that anyone still uses it.

 

[Griffith187]

686

924

Thank you sir. That seems to fall right in with what I've been seeing! Thanks again

 

[Reelamin]

Accurate barrel life represents a shift point, where consistent best accuracy leaves.
To detect it, you first have to attain it.

If content with 3" groups then you're probably not going to 'see' further degradation anywhere near the accurate barrel life point.
Could probably shoot 5,000 28nosler rounds before it get's worse than 3" (when bullets start blowing up).
Another thing to keep in mind is that shot timing is a big influence to barrel life. You could destroy a 28Nosler barrel in one range session. My calcs for 28Nos default at 50sec shot rate, and 717 ABL drops to 144 ABL if you did a lot of group shooting with a 10sec shot rate. If you shot 1 every 10min you could probably extend ABL x2, but I have no way to predict that.
Pressure plays a big role, and of course powder temperature and amount.
If you wanted to manage it, moly (in particular) extends ABL by cooling the charge temp as it vaporizes. That's why you see MV drop with use of moly (not reduced friction). But then many people step up their charge to compensate, and barrel life goes right back down. So I no longer compensate for moly, and really it's surprising to me that anyone still uses it.

I thought I...edit...posted the groups I was acceptable with getting. I will now to clarify. My 7stw did not and does not shoot a load I use in it over .5" at 100yds. Not MOA those are actual old inches. It's 160 load was .5" at 3300. It's 120 was .25-.5" at 3600 and it's last 175 is .5" at 3250.

My 28N shoots 160 at 33-3350 into .5-.6. I'm not going to test anything else because I know the bullet will perform and the other bullets I tried it would not go under 1"

Now to clarify my standards. Currently and for the last 30 years I won't hunt with a rifle or load that will not hold a maximum .75" groups at above "max" or very
close to max velocity for weight. I will use a different rifle or load that meets my minimum standard.

I don't know nor really worry too much if my standards are more or less than others or the internet's. It works for me and I use what I have confidence in. It may change at some point and I have not had to so far.