This rifle was built by Mossberg and was labeled the 800B. The "B" series was sold thru Montgomery Wards and other large reatilers. All Mossberg model 800 .243 rifles manufactured had a twist rate of 1 in 10. So I believe it is safe to the twist rate is 1 in 10.
all .22-250 shoot 1&14 twist unless custom made to shoot long extra heavy custom bullets above 60gr. this rifle in question does not, it has a standard 1&14 twist
According to Linda in the customer service department at Browning Winchester at (800) 945-5237 the 12 Ga models have a 1 in 28 twist rate.
Model 800 with no letters was made 1967-1970
Mossberg customer service- Telephone: (800) 363-3555
The Mossberg 800 series was made between the early sixties to late seventies.
No published sn data
50-500 usd
Depending on the part, try Numrich (gunpartscorp) website, or try Mossberg- I think your rifle is a Mossberg 800.
No published sn data.
It is a Mossberg Model 800.
% rate:= 100/800 * 100%= 0.125 * 100%= 12.5%