I have found them for sale NIB for $599 to $795
100-500
50-500 USD depending on specifics
NO! The 1187 barrel was for remington shotguns,the auto-5 shotgun is a browning shotgun.
NO, DO NOT ATTEMPT TO DO SO!!!!!!!!!!!!
.Manufacturer suggested retail price was$ 932.00 its worth 750.00 in 100% condition $275.00 in 60% condition.
The 1187 is a safety modified Reminton 1100. The safety was changed in 1987, hence the model number change from 1100 to 1187.
50-500 usd
priceless
The value of a 20 gauge Remington 1187 Premier typically ranges from $600 to $1,000, depending on its condition, age, and any included accessories. Factors such as original packaging, modifications, and the current market demand can also influence its price. For an accurate valuation, it’s advisable to check recent sales or consult with a firearms appraiser.
If you go to Remington's web site, you can request one or download one.
300 or so
IMHO you would be better served by ordering a replacement manual for free on the Remington site.