cantilever scope barrels?

[Axis II]

I have a Mossberg 500 with the cantilever scope mount that I sighted in sunday. if I put the field barrel back on will it be okay to put the slug barrel back on and it still be sighted in?

 

[desidog]

It should be fine or darn close...but the only way to know for sure is to test it yourself!

 

[Virginian]

Theoretically yes. I have seen three where the zero stayed true, and one where it changed slightly every time. I do not know why, and yes I did look.

 

[rcmodel]

That is the whole reason for the cantilever scope mount on the barrel in the first place.

It should stay very close to zero because the scope & barrel are one solid unit.

rc

 

[fouled bore]

I don't have any problem with mine. Try it out and let us know your results.

 

[Axis II]

I was going to upland hunt this week then shotgun season Monday so really cant check zero again. no range access close by.

 

[PapaG]

I think about the only thing that could, or would affect zero is how tight you turned the barrel nut down when replacing the barrels.

 

[243winxb]

No change with my Mossberg 500 12ga.

 

[oldillini]

Maybe I am lazy, but I didn't want to change my barrel out with changing seasons. Or maybe I just used it as an excuse to buy another gun.

 

[Virginian]

Please explain the barrel nut theory.

 

[AI&P Tactical]

When you sight in an optic on a cantilever mount you are sighting the optic to the barrel. Like another member said, that is the purpose of a cantilever mount.

So, you could take another shotgun and put that barrel on it and you are still sighted in. There is nothing that could change it other then dropping the barrel and damaging the optics.

 

[rcmodel]

I could see where barrel nut tension would change barrel harmonics and alter the zero slightly.

But shooting shotgun slugs, would it matter anyway if zero changed 1" at 50 yards???

rc

 

[243winxb]

A lot number change on the slugs will make the most difference. I would get 10 boxes (50) all the same brand/lot. Now I load the Lee key drive slug. Not as accurate as factory, but good enough.

 

[PapaG]

What RC said on nut tension. I've played with 500s and 870s and turning the nut down "snug" versus "tight" (an additional click or so) makes a couple inches difference.
I'm using my home cast Lyman sabot slugs in both 12 and 20, new, unskived cases, and SR4756 powder and getting some groups close to what the Fed Premiums give. Nice to practice with 20 cent loads and hunt with the two dollar stuff (after verifying zero, of course).
I can, with my 500 20 canti, pull the barrel, replace it and be within an inch of previous zero. My son does the same with his 500 12. We've developed "feel" for the tightness.
I've read some people put a channel lock on the nut and really torque it down but no one gets near my guns with a pair of pliers or channel locks. Period.