• 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!

  • Site updates coming next Wednesday at 8am CT!

    The site will be down for routine maintenance on Wednesday 6/5 starting at 8am CT. If you have any questions, please PM alexj-12!

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....