Does cutting down a smoothbore shotgun barrel effect slug accuracy

[50caliber123]

I had the chance to shoot an old mossberg 500 with a barrel cut from 28" (labeled) to 20". With just a fiber optic front sight I was able to pull off an impressive 3" group at 25 yards standing unsupported with 3" 1oz brenneke slugs. I noticed that the barrel has a heavy profile to it, narrowing as it gets closer to the muzzle.

 

[DPris]

Cutting the choke off can affect accuracy, but (no offense) 3 inches at 25 yards standing is no yardstick to measure by.
Denis

 

[Waywatcher]

Shorter stiffer barrels are supposed to be more accurate; less whip they say.

(E.g. 18" slug vs 28" bird barrels)

 

[Onmilo]

Who cut the barrel down?
Did they bother to true and face the muzzle ninety degrees to the barrel wall?
Is the fibre optic front sight post sticking down into the barrel or was it installed correctly?

Since there is probably no choke to the barrel now, this will also affect accuracy with some loads shooting better than others, i.e. Brenneke slugs usually shoot better in unchoked barrels and Remington Foster type slugs usually shoot better in barrels choked modified or improved.

Since you appear to be satisfied with the results you obtained, the question seems somewhat moot.

 

[451 Detonics]

Did they bother to true and face the muzzle ninety degrees to the barrel wall?

This is the biggest factor, if not cut true accuracy will suffer. A good gunsmith will actually recrown a cut barrel.

 

[garyw]

I happen to have just had the ultimate smooth bore slug gun. It's actually a 1950's H&R 349 that's been modernized the RIGHT way. Fully adjustable rear fiber optic sight, elevation adjustable XS tritium front sight, Improved recoil pad, light trigger job, and the barrel drilled and tapped for remington style screw in chokes. Here's a pic.



Here's some target pics,



All that was done using nothing but a sling, shot at 50yds with winchester value pack 2.75" slugs.

What do you guys think?

 

[Dave McCracken]

When a barrel is cut, accuracy can be improved, degraded or remain the same. That last, IMO, is least likely.

It's only partly a crapshoot. Sometimes a shortened barrel does not shoot as well with a given slug as before, but it does better with a load previously not that accurate in that barrel.

To the OP, 3" at 25 yards offhand is not bad. From the bench, using a supported position, you can expect to halve that. Do practice from hunting positions so you can achieve that Minute of Venison we all need to do.....

 

[DougW]

Bought an 1100 that had a full choke vent rib barrel cut to 20". The barrel works fine, just throws a slug 2' low at 25 yards. The vent rib is too high to be accurate. Would be OK for buck to 20 yards. It is in the parts box, not being used.