Neck turning and reaming

[b money]

Ok so I bought a 308win trim die and I have some 30-06 270 25-06 etc with split necks. I am wanting to reform them to 308win but I'm a little confused on neck reaming and turning. I've read up on both as I eventually need to buy a neck turner for my 300rum but there is very little info on neck turning and reaming when reforming cases. So what's the proper method?

[dtknowles]

Just my opinion but you will want to ream your formed 308 brass. Ream to remove more than just a little neck thickness, turn to make uniform or remove a small amount of neck thickness. You can get there with just turning but it will take longer and you will have to go in stages and not try to take all the material off in just a couple passes.

Tim

[country gent]

The sinclair catalogs used to have a good selection of turners pilots and caseholders. Look in benchrest releated info to find information also. I neck turned for concentricity and thickness reamed to get close and smooth the necks surface. I reamed in a die so the case neck didnt expand around reamer. then sized on the neck turners pilot and turned neck thickness to provide needed loaded round dia, and concentric neck thickness.

[Doc Highwall]

This site has a lot of technical articles that will keep you busy for a while.

http://www.accurateshooter.com/technical-articles/reloading/complete-precision-case-prep/

[williamwaco]

Each method is better for different applications. For your current application I would ream.

[EDG]

Reaming is not a very good process in general. It is best suited for a person with limited knowledge, skill, measuring equipment and interest in learning more. Reaming is a simple process of buying the tools and using them without doing much measuring, thinking or decision making. It is all built into the tools.

You will not even know enough to decide if you need to ream. In many cases there is no need to ream. Commercial brass is so thin and many chambers are so large that you do not need to ream. Have you ever measured the diameter of your chamber neck? It is easy to do but you need a micrometer and a case to sacrifice. If the chamber neck is .004 or larger than the neck of a loaded round there is no need for reaming or turning unless you are interested in more uniform necks. If you want more uniform necks you will not really get there with reaming.

If you ream without a reamer die the reamer, such as the short Forster reamers can only follow the existing hole and since the reamer is not adjustable you can only get a dimension that is the product of the reamer size. If the neck walls vary (uneven thickness) the reamer will do nothing to improve that.

If you use a long reamer that is guided by a reamer die the reamer may be forced to ream on center or close to it. However the reamer is still not adjustable so the results are just the product of the reamer size. You will not know if the tool will ream on center until you buy it and try it. With either reamer size you have a tool that is limited to being used on a single bore size. In the case of the reamer die it is not usable on any other round. The long reamers and reamer dies are very expensive. For me they are too expensive unless found second hand at give away prices.

The neck turning tool is adjustable and with suitable pilots and case prep you can turn any caliber neck to any thickness. However you need a couple of different micrometers and the willingness and interest to learn how to use the mikes and the turning tools. The time and the labor involved should be immaterial since you only have to do it once per case.

If you are only trying to save $15 worth of junk brass none of these processes are worth much time, trouble and expense. If your time is so valuable, you would probably be much better off to find 500 or so LC .308 cases and forget about salvaging old cases just to make .308s.


I understand salvaging old cases to make .300 Savage or many different Mauser rounds and other rare and expensive cases but .308s are so cheap they are not worth the trouble to make. However if your chamber neck is large enough that you don't need to ream or turn you will only have to form and trim the brass. Then anneal it. But you still need a micrometer to make the measurements and make that decision.

I make 6.5X53R Dutch brass from .303 British brass.
I have to push the shoulder back and I have to neck it down. The loaded rounds measure .288 over the neck so I size the brass to .286 in the neck.
However the chamber measures .299 to .300 depending on the rifle that I check. There is absolutely zero need to turn these cases or ream them since the brass neck to chamber neck is sloppy loose even with reformed brass.

[dtknowles]

Reaming is not a very good process in general. It is best suited for a person with limited knowledge, skill, measuring equipment and interest in learning more. Reaming is a simple process of buying the tools and using them without doing much measuring, thinking or decision making. It is all built into the tools.

You will not even know enough to decide if you need to ream. In many cases there is no need to ream. Commercial brass is so thin and many chambers are so large that you do not need to ream. Have you ever measured the diameter of your chamber neck? It is easy to do but you need a micrometer and a case to sacrifice. If the chamber neck is .004 or larger than the neck of a loaded round there is no need for reaming or turning unless you are interested in more uniform necks. If you want more uniform necks you will not really get there with reaming.

If you ream without a reamer die the reamer, such as the short Forster reamers can only follow the existing hole and since the reamer is not adjustable you can only get a dimension that is the product of the reamer size. If the neck walls vary (uneven thickness) the reamer will do nothing to improve that.

If you use a long reamer that is guided by a reamer die the reamer may be forced to ream on center or close to it. However the reamer is still not adjustable so the results are just the product of the reamer size. You will not know if the tool will ream on center until you buy it and try it. With either reamer size you have a tool that is limited to being used on a single bore size. In the case of the reamer die it is not usable on any other round. The long reamers and reamer dies are very expensive. For me they are too expensive unless found second hand at give away prices.

The neck turning tool is adjustable and with suitable pilots and case prep you can turn any caliber neck to any thickness. However you need a couple of different micrometers and the willingness and interest to learn how to use the mikes and the turning tools. The time and the labor involved should be immaterial since you only have to do it once per case.

If you are only trying to save $15 worth of junk brass none of these processes are worth much time, trouble and expense. If your time is so valuable, you would probably be much better off to find 500 or so LC .308 cases and forget about salvaging old cases just to make .308s.


I understand salvaging old cases to make .300 Savage or many different Mauser rounds and other rare and expensive cases but .308s are so cheap they are not worth the trouble to make. However if your chamber neck is large enough that you don't need to ream or turn you will only have to form and trim the brass. Then anneal it. But you still need a micrometer to make the measurements and make that decision.

I make 6.5X53R Dutch brass from .303 British brass.
I have to push the shoulder back and I have to neck it down. The loaded rounds measure .288 over the neck so I size the brass to .286 in the neck.
However the chamber measures .299 to .300 depending on the rifle that I check. There is absolutely zero need to turn these cases or ream them since the brass neck to chamber neck is sloppy loose even with reformed brass.

How dare you tell someone what they need to know instead of just answering their question :-) Good show. Of course he might just want to try some case forming to teach himself how to do it and the 308 is just a gun he owns. Good point on the size of his chamber, he might not need a reamer, he could form brass, neck turn and have a nice fit if he is lucky.

Tim

[dtknowles]

I wonder if he knows about annealing???

Tim

[b money]

Thanks for the advise so far. I have indeed annealed many cases before. And as far as why I'm trying to form 308 brass? It is a project that I wanted to learn. I could very easly buy lapua or Peterson brass(and I do) but I just wanted to tinker and try this out. I also understand what reaming and turning are doing as I have taken classes in machining and worked in shops. I have just never applied both to reloading and case forming. I'll have to track down a ball mic and get a chamber cast. It's a factory 700p chamber so I'm guessing it's pretty generous.

[CWME]

Needing to ream/turn depends on the chamber as already stated but the brass being formed also plays a role. I made 22-250 brass out of 20 RP 260 cases and didn't need to do anything other than uniform the necks a bit with turning. I made 20 more with Federal Match 308Win cases and needed to ream and turn because they were a lot thicker. To the other point, 22-250 is not rare/expensive/hard to find but I didn't need or want to drop $ for cases when I had some odd batches of range pickup brass on hand. Those 40 cases I made paired with 20 range pickup 22-250s should last me a long while feeding that rifle. Annealing is an essential step, especially when making shorter cases of smaller caliber. I make 6BRX from 30-06/308, 22-250 from 260/308, .221 fireball from .223, .222 from .223, 300BO from .223, all are annealed at least once. 6BRX gets done twice, parent case and then after forming.

[lotech]

I'm sure there are exceptional situations, but based solely on my experience with a variety of cartridges over the last 50+ years, I've yet to find a need for inside neck reaming. However, I have found the neck-turning procedure to be not only a beneficial step but sometimes an essential one depending on the situation, particularly when using oversized cast bullets that are considerably larger in diameter than jacketed ones.

The annealing process has become quite popular in recent years and is probably performed far more often than necessary. However, if done correctly, it does no harm and probably contributes to brass longevity. I used to re-form .25-35 and .30-30 brass in making .219 Zipper cases. Annealing was essential. For routine handloading, I question the necessity of annealing, but certainly won't criticize those who see a need for it. All our situations are at least slightly different.

[EDG]

You can measure you neck diameter easily with a case that you know will chamber in your rifle.

Just expand the case mouth in a trumpet shape with a tapered punch or larger caliber bullet nose. Expand it about .020 to .030 over size.
Then place the case in the chamber and shove it home with the bolt. The chamber neck will squeeze the edge of the case mouth down to size. Then extract the case and measure the diameter of the case mouth. If this is a new process for you, repeat with several cases until you get consistent results.


Thanks for the advise so far. I have indeed annealed many cases before. And as far as why I'm trying to form 308 brass? It is a project that I wanted to learn. I could very easly buy lapua or Peterson brass(and I do) but I just wanted to tinker and try this out. I also understand what reaming and turning are doing as I have taken classes in machining and worked in shops. I have just never applied both to reloading and case forming. I'll have to track down a ball mic and get a chamber cast. It's a factory 700p chamber so I'm guessing it's pretty generous.

[country gent]

One thing to remeber is necking up walls thin necking down walls thicken. Thin necks are less of a problem but may affect case life due to expanding more being sized down more. Thick necks have more issues as to concentricity, bullet release, seating tensions, and sizing force required. Reforming brass can be done and can be a usefull way to get cases for an obsolete caliber or for one thats rare and hard to find. I have made 357 Herrets from 30-30. necking up to 35 caliber pushing shoulder back and a heavy trim, 243 from 308. Normally 1 pass thr die a trim and neck turn to true up neck and thin. 222 rem from 223. 1pass thru seater die and 1 thru sizer to form a medium trimming, and neck turn as some of the original shoulder becomes neck. Areas to watch are shoulder position, only form new shoulder back enough to chamber with light resistance. Wall thickness of neck and or loaded round dia. Brass hardness after reforming, annealing may be required. A chamber cast of the chambers neck is a big help. These dimensions help you know what your doing and keep you safe. Special tools are made for neck turning and reaming. I perfer using a decimal machine reamer of the correct size to leave .001-.002 for neck turning. Sinclairs, Brunos, and others sell these tools. When reaming its easier to use a modified die to support the case neck so it dosnt swell around reamer and not cut. A die with a bushing to support the rreamer and neck makes reaming quick and easy. Another handy tool is a neck thickness gage It has a anvil with a indicator reading thickness, when set to zero it quickly reads neck wall thickness and concentricity, easier than a ball mike does. The last thing is a good high pressure sizing lube since you are working cases with much more force reforming them than simply sizing them.