870 ButtStock Sling Swivel Location/ Measurement

[Mank10]

Thanks for the add/forum!

I am building a 870 Riot Clone and looking for the correct 513t Buttstock 1 1/2” sling swivel.

How far from end of buttplate is the screw installed?

Measurements? There is a dimple in bottom of stock at 3 1/4”. Is this the correct location?

Thanks!

[BKinzey]

Looked up a 513t stock. All I saw were rifle stocks, for a .22 IIRC.

Got pics?