• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Gunsmithing M40a1 crown

grunt0311

Sergeant
Full Member
Minuteman
May 25, 2008
492
11
46
OH
What is the correct crowning tool to do the crown? I have seen some on brownells but I wanted to make sure that I am getting the correct one. If everyone knows please let me know. Thank you
 
Re: M40a1 crown

Most grind their own tooling to some degree with relief and angle to suit. I use a brazed on tip tool for crowning ground to a certain angle. HSS works just as well. A lathe with a four jaw and spider works best.
 
Re: M40a1 crown

#1 looks like HSS, ditch #2 & #3. You can buy Rex95 in .500" and grind your own to match tool #1 that you've shown.
 
Re: M40a1 crown

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DocEd</div><div class="ubbcode-body">Never seen an M40a1 with an 11 dgree crown. </div></div>

+1 - Deep recessed perpendicular....