Pilot Diameter Chart
Copyright 2019, Fred Zeglin, reprinted by permission of the author.



These Charts come from Fred’s book, “Gunsmith Tools, Cutters, & Gauges – A Primer“.
There is so much more in the book, check it out!

Copyright 2019, Fred Zeglin, reprinted by permission of the author.



These Charts come from Fred’s book, “Gunsmith Tools, Cutters, & Gauges – A Primer“.
There is so much more in the book, check it out!

Before accepting a barrel for machining to accept screw-in chokes, you must measure the outside diameter (O.D.) to determine if there will be sufficient wall thickness after machining. “Mike” the O.D. of the barrel and the O.D. of the tap for the particular gauge. Subtract the O.D. of the tap from that of the barrel,…
We have seen a ton of demand for Ackley calibers since the publication of Fred Zeglin’s two new books in 2017. For this reason we have created a category on the 4D web site to separate out all Ackley cartridges making them easier to find. They still appear in the standard caliber listings as well….
Fall of 2020 issue of the “One Good Shot”, association President Art Lamontagne wrote about our services here at 4D. Art ordered the reamer on his own nickle and we did not know about his affiliation with the organization. [gview file=”https://4drentals.com/wp-content/uploads/2020/11/TCA_fall2020.pdf”]
Art of the Gun @ Mitchell Museum in Trinidad Colorado was held the weekend of June 9-10, 2017. This event was held in conjunction with the 70/40 Anniversary of the TSJC Gunsmithing Program. 70 years ago P.O. Ackley helped start the first gunsmithing program at any college in the U.S. 40 years ago the School joined…
Updating this post from 2017: We now have over 2100 reamers and are still adding more tools all the time. Thanks for your continued business! ********************************* As of October 2017 4D Reamer Rentals LTD now has over 1100 reamers to serve your gunsmith rental needs. It’s pretty exciting how much this company has grown over the…
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