I recently found some neck turning equipment for a really good deal and couldn't pass it up. I am knew to neck turning but I would like to have a general discussion about the topic. I have read that some reloaders turn to get rid of high spots on their necks. Is there any benefit to this? Also what is too thin for say 300 Win Mag brass? Finally I have read that neck turning can help with neck tension. Any input and discussion would be appreciated.
Discussion about neck turning
- Thread starter EE_Reloader
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Brass thickness in necks is rarely consistent. It is common for it to vary 1 to 1.5 thousandths side to side. Some brass is thick enough that when you seat a bullet you don't have adequate clearance in the chamber throat to release the bullet. Obviously this is dangerous and must be checked.
As far as turning necks, size it, then run a mandrel in the neck. This will make the ID consistent and push irregularities to the outside.
Lightly skim turning the brass will remove inconsistencies and make the neck thickness more uniform. This will translate into much better neck tension consistency. If you have clearance issues you need to measure neck thickness with a ball micrometer and remove enough to get 3-5 thousandths clearance when you necks expand in firing.
This is just the tip of the iceberg, but a good start for understanding what you're about to start
As far as turning necks, size it, then run a mandrel in the neck. This will make the ID consistent and push irregularities to the outside.
Lightly skim turning the brass will remove inconsistencies and make the neck thickness more uniform. This will translate into much better neck tension consistency. If you have clearance issues you need to measure neck thickness with a ball micrometer and remove enough to get 3-5 thousandths clearance when you necks expand in firing.
This is just the tip of the iceberg, but a good start for understanding what you're about to start
GLTaylor would you recommend turning until you get brass around the entire neck or is just getting the high spots enough?
Depends on what you're after and how consistent your necks are. If you just want to even up thickness for better neck tension consistency, skim turn. Parts of your necks won't be touched by the cutter (the thin portions of the neck you're trying to match). This works very well for even tension and better accuracy.
If you have a clearance issue, you will likely have to involve the whole neck and remove more brass. The net effect will be the same.
Consistent neck thickness for even tension Plus adequate clearance to release the bullet and keep pressure down.
If you have a clearance issue, you will likely have to involve the whole neck and remove more brass. The net effect will be the same.
Consistent neck thickness for even tension Plus adequate clearance to release the bullet and keep pressure down.
Ok. I purchased some 300 WM Winchester brass and was tempted to neck turn them. I own a ball micrometer due to some other work I do, so I will take a few measurements and see what thickness I want to turn them to.
Justice1327
Well-Known Member
First you need to size them and then use the appropriate mandrel to push the inconsistencies out. Then use the ball Mike to measure. Typically you don't want to go thinner than .010 per side.
Unless necessary for clearance (tight neck), .010 is pretty thin. .012-.013 is more common.
From all the reading I have done on turning necks, you want at lease .012 to .013. One thing for sure is you want to come up with an even cut all the way round if wanting to leave more thickness on the neck case. Bullet tension is even all the way around. Another way to think about it is your chamber is perfectly round, and the neck isn't. The bullet goes into the neck and it's perfectly round. When fired the case neck expands, and with the neck being uneven it pushes the bullet to one side more than the other starting it down the tube offset. it all depends on what you want out of your hand loading. If you are going to long range shooting, then more needs to be put to obtain the grouping need to do the job. I am not much on yards beyond 500yds, but I want tight groups. my rifle sighted in correctly, so my shot placement is there. The only person to blame is you if you miss or pour shot placement.
Mike, your explanation makes a lot sense to me. So I should start by expanding the case with the appropriate mandrel then taking a measurement of the necks with the ball mic? I would expect to see some variation in thickness around the case but at this point I can decide what I would like the necks thickness to be? Then I would adjust the neck turner to the desired thickness and turn my cases? I would probably need to turn a number of cases before I arrive at the thickness that I want?
Look at at what Justice 1327 is saying on how to do it. He I feel is right on. After cutting your necks I would anneal them. You can go on line get more info on cutting necks. There other items you need to watch for in cutting necks. I would start at a thickness, and see how they group. Neck tension has a lot to due to accuracies in releasing the bullet so it's the same each time. I have been changing my reloading process here as of late. The other is I won't cut all my cases either. I have to see how they perform. I have or I am getting higher end brass such as Peterson, or Lapua brass. I am changing from weighting my brass in case weight to volume weight. Your 300 Win Mag is good rifle. No problem in reaching out with it either. One of my rifles is a 308 Norma Mag the older brother to the 300 Win Mag. The 300 Win Mag is a better cartridge and more case to hold powder.
Mike,
I followed what Justice mentioned and I cut some necks last night and they looked ok. I have 100 pieces blue bag Winchester brass, and cut 10 to .013". I am curious as to the discussion of neck tension. I am working on making hunting ammo; with that said what would be your recommendation for neck tension. I keep hearing .002" but is that number ok for all ammo or should I go a bit more with ammo used for hunting maybe .003". Any help would be appreciated. Also thanks everyone for answering and helping this noob learn something new. Much appreciated.
.002 nk tension is pretty common. Let your rifle tell you what it likes. Try some at each .002 and .003. If you load Absolute Hammers, go .003 or more.
Rardoin
Well-Known Member
I would send a dozen cases off to DJ's Brass service and let him turn them for a complete cleanup. Then do some side by side unbiased comparison between turned and unturned necks and let the target provide the answer whether it is something that is beneficial in your case. This is a cheap way to decide if it is something worth your while without investing in a bunch of gear that may collect dust. I have done extensive testing at 600 and 1000yds looking for consistent .3 moa precision. I don't run tight neck chambers and I no longer turn necks. I do have a bunch of expensive turning gear collecting dust
.
.Rardoin, I didn't even know this was a thing. I guess I should have done some more research but I got a pretty good deal on the equipment. Plus with the Covid lockdown and winter I have some free time to burn. I would rather spend it learning something news instead of boozing or watching TV. Thanks for the knowledge.
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