What sort of accuracy or consistency should be expected when shooting 12 gauge 2.75-inch shot shells with slugs from a 2.75-inch chamber and cylinder bore?

Well a lot depends if the shotgun has a sighting system besides the standard bead.

I seen hundreds of different shotguns shot with thousands of 2.75 inch foster type slugs fired during police qualifications over 30 plus years.

I haven't shot enough sabot slugs to have an opinion on them.

The biggest factor was the sights and the shooter.

With good rifle sights, peep sights, scope most could keep them on a 8x11 target at 100 yards.

With a plain bead the kill zone of a B27 target out to 50 yards.

At 25 yards I saw lots of sub 4 inch groups.

Of course there was always the exception some shot fantastic others not so good.

The only way to know is to buy several brands of slugs shoot them for group out of your shotgun and see what happens.

If memory serves old data for Brenneke slugs gave 3-4 in groups at 50 meters. They have a new sabot round that may perform better in a rifled shotgun barrel. You may consider a rifle choke tube too with sabot rounds.

Here is another alternative: https://leeprecision.com/bulle...ng/bullet-slug-mold/

This would work well with a rifled choke tube, that is if you can cast your own.

I have the lee slug mold very mixed results with it.

So much that I just bought a couple of cases of foster slugs and for got about it.

You need a rifled bore for sabot slugs. All we can use here is slugs so I have fired a lot of them. I can hit a deer every time at 125 yards with my Rem 1100, with skeet barrel and scope and have done it many times.
With regular foster slugs.
So, the answer to your question is, it depends on a lot of factors.
Gun.
Barrel.
Sight type.
Type of slugs.

Interesting demonstration of Foster type slugs:

https://www.youtube.com/watch?v=jRPo19DWlZY

I'm convinced that I must shoot a sample of several slugs and saboted slugs to confirm accuracy-consistency either way. Right now the shotgun has no rear sighting system of any sort. Front sight is a usual small bead.

How can I temporarily affix a sight system of sufficient precision to the shotgun to have confidence in slug/sabot shooting tests? If the shotgun achieves consistent pattern of 4 inches at 75 yards, that's the ammunition to use. I will stop sampling at that point — that is, I will not keep going with testing to try to find a more consistently accurate ammunition. I'll then have a permanent sight system installed on the shotgun. If testing shows insufficient accuracy, well, I've had some fun shooting. And I didn't invest in a useless precision sight system.

Does it have vent rib there are several styles of sights that clamp on vent ribs

quote:

Originally posted by p dog shooter:
Does it have vent rib there are several styles of sights that clamp on vent ribs

If you are shooting a Remington autoloader or 870 pump, B Square makes a scope mount that uses the holes for the pins in the receiver of the gun. You can zero with slugs, deer hunt, then pull off the optic and go back to rabbit or bird hunting and keep your optic zeroed.

My experience with foster style slugs was a 6" pattern at 50 yards was all the better I would do with the double bead system.

8" with a red dot at 100 yards.

With a scope and a rifled barrel for sabots, I had most shooting at 4" or less at 100 yards, some were able to put a 5 shot group that was an inch and a half at that distance...

BUT

The slugs varied both to grouping and point of impact by brand, weight, velocity, and lot number.

The ones that shoot 1.5" were Winchester's high velocity ones using Nosler handgun bullets. They are VERY lot to lot different. Point of impact shifts over 6" from lot to lot. That was with a Winchester SX2 with fully rifled barrel.

I hunt deer locally with a handgun now to avoid the frustration.

quote:

Originally posted by Naphtali:
What sort of accuracy or consistency should be expected when shooting 12 gauge 2.75-inch shot shells with slugs from a 2.75-inch chamber and cylinder bore?

Could always shoot an Ithaca "Deer slayer II" at 2" at 100 yds with Lieghtfields sabots. The shot gun trigger is hard to squeeze off, but thought it was good enough to kill a deer.

Being from Ohio where for many years we were forced to use slugs, here is my personal experience.

Remington 11-48 12 ga. smoothbore IC 26" barrel gets 2 inch groups at 75 yards shooting Remington 2 3/4 inch Foster slugs. I have had rifle sights added to the barrel.
Remington 11-87 12 ga. with 22 inch rifled barrel and with a leupold 2x8x33 scope mounted gets 1.5 inch groups at 100 yards with now discontinued 1 1/4 ounce 3 inch Remington Copper Solid Slugs (sabots).
Now using either the Remington Copper Solid or Barnes Expander at 1 ounce in a 3 inch case, groups at 2 inches at 100 Yards (sabots).

Remington SP-10 10 gauge autoloader with a 20 inch smoothbore barrel with rifle sights, shooting 1 3/4 ounce Federal Foster Slugs give 2 inch groups at 100 yards. (I would love to get some 2 ounce copper solids for this one!). This one is a HAMMER on soft skinned game.