I measured the sizes of the screw-in aperture for the Newton Bolt Peep sight and they are as follows;
Outside diameter of disc = .381"
Rear aperture = .090"
Thread diameter = .279"
Front aperture = .16"
Threads per inch = 32
Hope this helps.
If you would like a Word document with pictures and measurements, email me and I will forward it to you.
If you would like a hard copy, send me your address and I will send a copy.
lswales@live.com

Last edited by 40NT; 12/12/13 06:45 PM.
LSW