The Accurate Reloading Forums
Chattered Crown cut fix

This topic can be found at:
https://forums.accuratereloading.com/eve/forums/a/tpc/f/9411043/m/3831061572

05 July 2023, 23:02
KevinNY
Chattered Crown cut fix
I tried to fix a dinged crown on a 300 Win Mag with a rented 45 degree crown cutter from 4D and while the ding is gone I have some chatter marks. Should I just shoot it and leave it alone if its good or is there a way to clean it up as an amateur without machine tools like myself?
06 July 2023, 00:37
Duane Wiebe (CG&R)
4D?....wouldn't be surprised if the reamer was dull AND chipped.

Manson sells a tricky, multi part hand crowning tool. but you may be better off sending the barrel to a a compotent gunsmithl since the tool is spendy
13 July 2023, 05:39
rcraig
Just how bad is it? See how it shoots.

Or something like this in the proper diameter and grit:

https://www.globalindustrial.c...ding-point-metal-a40
13 July 2023, 06:33
slivers
Trying to 'clean-up' chatter that was created using hand tool, with another hand powered tool would be an exercise in futility.


13 July 2023, 19:49
dpcd
Right: to fix it correctly it has to be pulled, set up, and machined; however, just shoot it.
13 July 2023, 21:56
larry miller
Maybe you could find a grinding stone the right shape & chuck it in a drill to smooth it up. I don't think you can clean up chatter with hand tools.
13 July 2023, 22:31
dpcd
Leave it alone....it is probably at least, true.
14 July 2023, 02:15
jeffeosso
see how it shoots .. if it's okay, leave it alone


opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
14 July 2023, 19:12
Duane Wiebe (CG&R)
Well...gotta disagree from the "leave it alone" posts.

Were it my rifle, I'd go crazy every tiome I looked at that crown...and I think the OP is of the same opinion.

So..Why not fix it properly?

Get a threaded brass ball frpm MSC...probably something like 3/4-1"

Install a threaded rod on the ball,. dip it in griding compound and spin it against the crown with a drill motor.


When cleaned up, you will also benefit fron a PERFECT , perpendicular crown.

Old idea .....
16 July 2023, 20:39
KevinNY
I have not shot it yet but will try it first before anything else. Somewhat lucky that it is a 300 WM with a removable brake, so it won't generally be visible and it's on a well worn synthetic stocked hunting gun. I will however give it a shot with the brass ball lapping. What grit is suggested?
16 July 2023, 22:11
custombolt
Kevin

Ball knob.

https://www.mscdirect.com/product/details/06871156


Life itself is a gift. Live it up if you can.
17 July 2023, 01:13
Wstrnhuntr
quote:
Originally posted by Duane Wiebe (CG&R):
Well...gotta disagree from the "leave it alone" posts.

Were it my rifle, I'd go crazy every tiome I looked at that crown...and I think the OP is of the same opinion.

So..Why not fix it properly?

Get a threaded brass ball frpm MSC...probably something like 3/4-1"

Install a threaded rod on the ball,. dip it in griding compound and spin it against the crown with a drill motor.


When cleaned up, you will also benefit fron a PERFECT , perpendicular crown.

Old idea .....


Beat me to it. A round headed brass screw works.



AK-47
The only Communist Idea that Liberals don't like.
17 July 2023, 03:44
slivers
Depends on how bad the chatter is. Me, I'd have it cut properly on a lathe and call it a lesson learned,,, hand powered tools like were tried don't work well, ,,,,,especially rented ones.


22 July 2023, 19:23
Woodhits
This question makes me think about an article that I read in G&A 20-30 years ago. The author, who I believe was Ross Seyfried, chucked a Sierra bullet into a drill and coated the ogive with lapping compound. He used it to clean up a damaged crown. I hadn’t thought about it in years (I’ve got two lathes and no need to try it) but I’d love to go back and re-read it.
22 July 2023, 20:19
dpcd
That is a dumb idea. Copper is way too soft to crown a barrel with.
24 July 2023, 00:17
JamesStambough
I think I remember that article. It was a 300 Weatherby with damaged crown he used a 416 or 458 solid with valve grinding compound. A little different than a jacketed soft point.
24 July 2023, 04:14
KevinNY
Last 5 rounds I had loaded from my aoudad trip looked promising today. 1st shot was spot on and my 100 yard group was decent but with some vertical stringing. Will need to load and shoot some more.