Well, I can only speak for mine. My barells were cut to 18 1/4" and Colonial screw in choke tubes installed. Works like a charm.
'*' designates full choke (F). '*-' designates improved modified choke (IM). '**' designates modified choke (M). '**-' designates improved cylinder choke (IC). '**$' designates skeet (SK). '***' designates cylinder bore (CYL).
They came with modified on the right side and full on the left in the 28" and 30" barrels and imp. cyl . and modified in the 26" barrelled models from the factory, from my research, but a lot of owners had them opened up to whatever they wanted, so you have to measure them to be sure.
Yes. Rifled slugs are intended for smoothbore barrels (abot slugs aer for RIFLED barrels). Best accuracy with rifled slugs is USUALLY a modified choke, but can be safely fired thru any choke less than EXTRA full choke.
Modified describes a choke. Invector is a system of choke tubes.
The improvement
no, the improved modified is between a full choke and a modified choke check out this website http://www.wildfowlmag.com/tips_strategies/shotgun_062304/
GO TO BROWNING WEBSITE AND GET CHOKE SPECIFICATIONS FOR DIFFERENT CHOKES AND MIKE END OF BARRELL
Perazzi shotgun choke markings are as follows the KG xxxx is the gram weight of the barrels the 18.4 being .724", 18.5 being .729" is the internal bore diameter of the barrels the circles with a dot in the are the points of choke old Europeain markings the choke with 1 dot is full, 3 dot is modified, 5 dots is cylinder. guns with choke tubes the markings go from 1 to 10. each number times .004" equals the points of choke. there fore full choke is 10 and represents .040" choke. down to 1 which is .004" improved cylinder Perazzi shotgun choke markings are as follows the KG xxxx is the gram weight of the barrels the 18.4 being .724", 18.5 being .729" is the internal bore diameter of the barrels the circles with a dot in the are the points of choke old Europeain markings the choke with 1 dot is full, 3 dot is modified, 5 dots is cylinder. guns with choke tubes the markings go from 1 to 10. each number times .004" equals the points of choke. there fore full choke is 10 and represents .040" choke. down to 1 which is .004" improved cylinder Perazzi shotgun choke markings are as follows the KG xxxx is the gram weight of the barrels the 18.4 being .724", 18.5 being .729" is the internal bore diameter of the barrels the circles with a dot in the are the points of choke old Europeain markings the choke with 1 dot is full, 3 dot is modified, 5 dots is cylinder. guns with choke tubes the markings go from 1 to 10. each number times .004" equals the points of choke. there fore full choke is 10 and represents .040" choke. down to 1 which is .004" improved cylinder Perazzi shotgun choke markings are as follows the KG xxxx is the gram weight of the barrels the 18.4 being .724", 18.5 being .729" is the internal bore diameter of the barrels the circles with a dot in the are the points of choke old Europeain markings the choke with 1 dot is full, 3 dot is modified, 5 dots is cylinder. guns with choke tubes the markings go from 1 to 10. each number times .004" equals the points of choke. there fore full choke is 10 and represents .040" choke. down to 1 which is .004" improved cylinder Perazzi shotgun choke markings are as follows the KG xxxx is the gram weight of the barrels the 18.4 being .724", 18.5 being .729" is the internal bore diameter of the barrels the circles with a dot in the are the points of choke old Europeain markings the choke with 1 dot is full, 3 dot is modified, 5 dots is cylinder. guns with choke tubes the markings go from 1 to 10. each number times .004" equals the points of choke. there fore full choke is 10 and represents .040" choke. down to 1 which is .004" improved cylinder Perazzi shotgun choke markings are as follows the KG xxxx is the gram weight of the barrels the 18.4 being .724", 18.5 being .729" is the internal bore diameter of the barrels the circles with a dot in the are the points of choke old Europeain markings the choke with 1 dot is full, 3 dot is modified, 5 dots is cylinder. guns with choke tubes the markings go from 1 to 10. each number times .004" equals the points of choke. there fore full choke is 10 and represents .040" choke. down to 1 which is .004" improved cylinder Perazzi shotgun choke markings are as follows the KG xxxx is the gram weight of the barrels the 18.4 being .724", 18.5 being .729" is the internal bore diameter of the barrels the circles with a dot in the are the points of choke old Europeain markings the choke with 1 dot is full, 3 dot is modified, 5 dots is cylinder. guns with choke tubes the markings go from 1 to 10. each number times .004" equals the points of choke. there fore full choke is 10 and represents .040" choke. down to 1 which is .004" improved cylinder
As you correctly assumed the stamping of the numbers 2 & 4 on the barrel flats designates the choke of each barrel. 2 being the designation for a modified choke and 4 for a full choke.
from smallest pattern to largest: full improved modified modified improved cylinder cylinder (no choke)
You can use steel shot with a choke anywhere from cylinder to modified, i wouldn't recommend using steel with a improved modified or a full choke.
Yes, all Browning Invector and invector plus barrels can shoot steel shot.