Gunsmithing Set Back Questions

[bohem]

Here's a couple questions for those "in the know"

<span style="font-weight: bold">Background:</span>
I'm building a 6.5-06, I have a bull barrel with no taper, 28" shilen and figured I could get a couple setbacks out of it, probably 2.

My reamer is a PTG, floating pilot. I own it, my dad or I will be cutting the chamber, more likely him since I don't usually have time to get to his shop.

I hear this thing will get me about 1200 rounds, maybe a touch more if I'm kind to the fire rate. I've begrudgingly accepted that. I now have heard that a setback won't buy me another barrel life, but maybe a few more rounds, it's not worth it the work. I thought I'd get 75% more life from the barrel, possibly another 150% if I set it back twice.


<span style="font-weight: bold">Questions:</span>

1) Since the reamer is mine and rechambering it will only cost me some sort of favor like helping my dad split wood one morning when I come to visit, is it true that a setback will extend a 1200 round barrel to 1500 rounds or can I get maybe 2k out of it with the setback?

2) Can I set it back more than once? I don't understand why not from a stress/erosion point, but I've been wrong with "edumakated guesses" before

3) I was also told (and this one seems really off to me) that a HSS reamer can't be used to set back a barrel because the throat and initial portion of the barrel will have hardened.

I know my dad has set back one of his friend's 22-250's and he had no issues with the carbide reamer, it didn't make any complaints. I've cut hardened steel with hand ground tools that I've made myself and other than being careful, they worked fine.

Can someone answer these for me?

 

[our gang]

Re: Set Back Questions

You can set it back as many times as you like as long as the barrel diameter is big enough. Unless you shoot the barrel red hot, you should get a lot more than 1200 rounds from it. As a "ute" my "chuck" rifle was a 25-06 shooting max loads of 4831 behind an 87 gr Sierra SP. I got 2800 rounds before the groups went over 1 MOA. That was a 30" 1.5" no taper barrel. Set it back to 28", groups went back to .75 MOA and put another 1000 through it before selling it. Bullets and barrels have improved a lot since 1960.

 

[eddieharren]

Re: Set Back Questions

Since your dad is doing the work, wouldn't he be the one to ask, and trust, in this matter?

 

[bohem]

Re: Set Back Questions

Mr. H, thanks about that 25-06. I was hoping to see that kind of barrel life but I've been told by about half a dozen people to expect no more than 1200, now two other people said setbacks won't buy me much.

I couldn't understand how it wouldn't help, why would guys do it then?

He was asking the same things as I was and stuff didn't seem to make sense to either of us.

 

[usmc7980]

Re: Set Back Questions

You can set it back 100 times if you want. That will give you a nice chamber but if the rifling itself becomes jacked up the barrel is done.

 

[bigmac125]

Re: Set Back Questions

I shoot alot and set my barrel back on my 6.5-06 about every 2000 to 2500 rnd's. When I set them back I set them back 1.5 to 2 inches and keep a close eye on it with my bore scope and by pouring a casting slug to check the rifling. As far as the hss reamer it will cut you just need to watch your feed rate.
Sorry, not to make anyone mad, just giveing my $.02 on a gun I shoot alot.
GOD bless,
Mac's

 

[bohem]

Re: Set Back Questions

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: macssubmoa</div><div class="ubbcode-body">I shoot alot and set my barrel back on my 6.5-06 about every 2000 to 2500 rnd's. When I set them back I set them back 1.5 to 2 inches and keep a close eye on it with my bore scope and by pouring a casting slug to check the rifling. <span style="font-weight: bold">As far as the hss reamer it will cut you just need to watch your feed rate.</span>
Sorry, not to make anyone mad, just giveing my $.02 on a gun I shoot alot.
GOD bless,
Mac's </div></div>

Thanks guys, I'm glad I didn't give up on this venture before I made chips on it, thanks so much for the help. This clarifies what I'd thought was the case, but once in a while something that seems reasonable just doesn't work.

USMC, I figured that was the case but the way some guys make it out a setback is a short term fix that doesn't do much more than waste your time.

I'm very excited to build this rifle, when I start cutting I'll be sure to post a thread on it.

 

[HPitts]

Re: Set Back Questions

I have found that after setting a shouder back , that the barrel shoots better than the first chambering . Could be from the throat wear that that the lands are tapered and it is easyer on the bullet.

Howard