I am getting ready to dimple my barrel and want to get the right drill bit. There are many threads here talking about nitride barrels, but I don’t see any about regular stainless barrels. Which bit do I need? This is the barrel I have.
https://ballisticadvantage.com/18-inch-223-wylde-spr-rifle-length-ss-premium-barrel-ops12.html
Good condition (sharp) carbide will knock it out. Center punch first makes it easier. Drill press makes it really easier.
If you don’t know what drill to use you probably aren’t a machinist. If not a machinist you probably don’t have access to the tools you need to do it correctly. A drill bit isn’t one of them. If I wanted a barrel dimpled I would hire a professional.
You do not need a special drill bit to drill a dimple in stainless steel. Especially the type of stainless barrels are made of. You definitely do not need to go out and buy a carbide drill.
Drilling a dimple isn’t rocket science, nor is it making a flawless cube with nothing but a file (as used to be introductory training for machinists in Germany).
Agree, but will add that a lot of consumer drill bits are total junk and won’t work. I’ve had new cheap drill bits, with TiN coating!, that wouldn’t drill a hole in unhardened A36 steel (that’s common, cheap, soft steel for the non-technical).
OP: any quality bit for metal should work. The better quality bits sold at big box stores are OK, or you can order one from an industrial supplier like Bisco Tool (http://www.biscotoolsupply.com/drill-bits-metric-drill-bits-mm-drill-bits) or McMaster-Carr (https://www.mcmaster.com/). You want at minimum a high-speed steel (HSS) bit, which is the lowest grade typically offered for drilling into metal. HSS coated with TiN is better IF the steel itself is good, but TiN is sometimes applied to junk bits for the consumer market, so it’s no guarantee. If you’re special ordering from one of those supply houses I would get a cobalt-steel bit. You don’t need that level of hardness, but it will minimize the risk of having an issue drilling because of the hardness of the workpiece vs. the bit, and will stay sharp longer, and we’re talking a dollar or two of added cost for one bit. As Todd K. said, you don’t need a carbide bit, and you don’t want one either because they are more likely to break on you if using a less-than-perfect setup.
Prick punch (60-deg angle), center punch (90-deg angle) and then a center drill would do it …
I’ll just leave this right here…
Coffee hadn’t kicked in yet. I assumed he wanted to dimple a barrel like this.
Not sure how Larue dimples his “Rearden Steel” barrels but the dimple hole has a flat bottom.
SIONICS dimple is the same, probably a flat face drill bit.
https://www.mscdirect.com/product/details/80381601
It’s actually done here in America too, as of 2017, except we were allowed .003” tolerance on all dimensions.
What size bit do you guys use?
Normally an 11/64". Go slow, maybe a drop of oil per dimple. Shallow yet close to the diameter of the bit should suffice. Might start with a 7/64 after you center punch. Here you go; this works. https://www.youtube.com/watch?v=NufnAnjxQlE
As stated, a carbide isn’t necessary if you can find an otherwise quality bit. Short bit preferred.
Same dude shows a jig being used if interested. https://www.youtube.com/watch?v=PMm6nieDP2M
lefty223 is right. Prick punch to mark spot, Center punch to widen the previous punch mark, so the drill does not wander. Lastly, drill dimple with a center drill. Best to use a drill press, rather than free hand. Use WD or aero-kroil, or cutting fluid, to keep the bits cool.
I was planning on getting a 5/32” bit. I have a dimpling jig.
Sounds like you’re gtg. Good luck (not needed).
That’s what I thought too.
Correct tool would be a 4 flute end mill.
Center cutting end mill.
True but I usually will start the hole with a drill bit then use the end mill to square up the bottom.