Mossberg 12 Gauge rifled, ported slug bbl

[K75RT]

I do realise I can "slug" the bore; I contacted Mossberg and asked if they could give me the averages of their 12 ga cantilevered ported 12 and they said they do not know! however the twist is 1:32....looking to build a slug sizing die but want a starting point....have seen bore and groove dia all over the place. Slugging a 12 sucks! But it appear to be the next option....if you have pertinant info as to the Mossberg 12 Ga Rifled, ported please reply...TY

[centershot]

I never slugged mine but if you are so inclined, see if you can get some .735" round balls from Track of the Wolf. They'll go down pretty easy.

[K75RT]

Thank You

[missionary5155]

Far cheaper to get yourself one large fishing weight of near diameter. Any fishing supply place has them. Can increase diameter with a little vice squeeze or hammer wack
Add a couple drops of oil and down it goes.

[dverna]

There was a suggestion posted a few years ago to take a slug or round ball, put it in a wad and push it through the barrel. IIRC it was suggested about 10 lbs of force was ideal (use a kitchen scale to measure). By measuring it you will get the diameter of the rifling. Then add the difference between the rifling and the bore to get the bore diameter. I would plug the muzzle about 1/2" back and pour Cerrosafe in to get the depth of the rifling.

I would be leery of driving a tight fitting slug through a shotgun barrel. Not much "meat" to them.

[dsh1106]

Here's my .02
Don't try to drive a projectile and slug through a rifled barrel, been there down that....[smilie=b:[smilie=b:[smilie=b:

Take a .735 RB (pure Pb) a push/drive it through from the breach end using a wooden dowel, you'll be able to measure the bore size when you're done.

Scott

[Blood Trail]

Or buy some cerrosafe and make a casting of your barrel at the muzzle.


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[243winxb]

The bore and groove diameters are all over the place in my barrel. It can be seen by just looking. Its wavy.

My Mossberg Cantilever 12 Gauge rifled, ported slug bbl works well following the Lee Key Drive loading data, when casting with the Lee mold.

The pure lead slug expands to the bore on firing. The plastic wad seals it.

[K75RT]

Thank you, All