Concentricity/Neck Turning/Culling Cases:

[freddiej]

Brass prep that I have seen that is always a good idea or an excellent idea;
#1, uniforming the flash hole, centering it as well.
#2, neck turning or neck reaming your necks. now I neck ream. this is because RCBS at least used to make a special sizing die that allowed you to put a specifically sized reamer to make your necks, concentric, and set at minimum useful thickness. this kind of neck prep made several rifles go from 2+ MOA down to less than 3/4 MOA without anything else. with load developments I achieved 1/2 MOA or better with several rifles. Yes, I am a devoted neck reamer for all cartridges I own reamers sets for.
#3, trimming to a uniform length. I like to split the trim to length and the max length and trim a bit more often.
#4, volume, there are two ways to do this. one involves a liquid in your cases and weighing them twice (once dry and once filled), or you can weigh them once dry. depends on the school you come from. I will use either one.
#5, always fire and resize your brass before uniforming your brass. brass stretches in wild ways the first firing.
#6 set your dies to size your brass 0.001 to 0.003" under the chamber length to keep stretching and over working your brass.
#7, anneal after every other reloading. at least that is what I do and it keeps brass around much longer.

later tatters.

 

[beaver hunter]

awesome , thanks

 

[Alibiiv]

Most neck turning tools turn the outside of the neck while it is held by an inside Mandrel. Necks must be sized to fit the Mandrel perfectly in order to get consistent wall thickness.

I have seen recommendations both ways. Most of the best benchrest shooters turn necks before firing but that's likely driven by the fact that they usually have tight necked chambers.

With standard chambers, I don't think it matters at all so I usually do it up front as part of my overall new case prep process.

Another thing to think about is the dreaded donut. Depending on my chamber and my bullet length, I might be pushed one way or the other.

I've been using a Sinclair mandrel neck sizer, eliminates the dreaded donut. I know that it adds an additional step in the case prep, however I'll never go back to the standard neck sizing plug in the resizing die. I use an RCBS (?) universal depriming tool along with the mandrel neck sizer.

 

[Susquatch]

I've been using a Sinclair mandrel neck sizer, eliminates the dreaded donut. I know that it adds an additional step in the case prep, however I'll never go back to the standard neck sizing plug in the resizing die.

At first, I read your post and my heart skipped a beat. Has Sinclair developed a mandrel based neck sizer?

So I went looking and only found the neck turning equipment that I have been using for a very long time.

The mandrel you mention isn't really a neck die. It is a tool that is used to size the neck prior to neck turning. When paired with Sinclair's neck turning tools, the mandrel produces a neck of the perfect inside diameter to provide optimum clearance for the Sinclair outside neck turning tool.

Although I am absolutely certain that it can be used to size necks for reloading, I really don't think it's ideal for that purpose.

The Sinclair mandrel and associated mandrel holder dies do not support the case in any way at all. The case basically sits unsupported in the holder die and the mandrel floats around a bit such that it can self center on the neck. In a perfect world maybe this works. But we don't live in a perfect world. Any irregularities in the case base or neck hardness profile will result in a significant loss of concentricity.

I do agree that it would eliminate the dreaded donut.

However, in my opinion, you would be better off using your mandrel die before turning necks (as per its design intent) and then using a competition bushing die (either in-line die or sliding sleeve) to size your necks. I don't believe there is any benefit to the extra step you are currently using, and I think you may actually be making things worse.

That's just my opinion. I would add that I've never heard of anyone in the winner circle at rifle competitions who sizes their necks that way. If it worked, they would all be doing it!

That said, I would also add that it is not unsafe and might be better than using standard (non-sliding) sizer.

Each to his own - your mileage may vary.

 

[Alibiiv]

At first, I read your post and my heart skipped a beat. Has Sinclair developed a mandrel based neck sizer?

So I went looking and only found the neck turning equipment that I have been using for a very long time.

The mandrel you mention isn't really a neck die. It is a tool that is used to size the neck prior to neck turning. When paired with Sinclair's neck turning tools, the mandrel produces a neck of the perfect inside diameter to provide optimum clearance for the Sinclair outside neck turning tool.

Although I am absolutely certain that it can be used to size necks for reloading, I really don't think it's ideal for that purpose.

The Sinclair mandrel and associated mandrel holder dies do not support the case in any way at all. The case basically sits unsupported in the holder die and the mandrel floats around a bit such that it can self center on the neck. In a perfect world maybe this works. But we don't live in a perfect world. Any irregularities in the case base or neck hardness profile will result in a significant loss of concentricity.

I do agree that it would eliminate the dreaded donut.

However, in my opinion, you would be better off using your mandrel die before turning necks (as per its design intent) and then using a competition bushing die (either in-line die or sliding sleeve) to size your necks. I don't believe there is any benefit to the extra step you are currently using, and I think you may actually be making things worse.

That's just my opinion. I would add that I've never heard of anyone in the winner circle at rifle competitions who sizes their necks that way. If it worked, they would all be doing it!

That said, I would also add that it is not unsafe and might be better than using standard (non-sliding) sizer.

Each to his own - your mileage may vary.

https://www.sinclairintl.com/reload...aspx?avs|Manufacturer_1=SINCLAIR+INTERNATIONA


The above is what I have been using to size/expand the necks on my brass; they come in different diameters for different calibers. I have mandrels for the .270, 30 cal, 35cal, and expand the necks after the brass has been annealed and then resized. To the best of my knowledge this is how the mandrel set up is supposed to be used.

 

[Susquatch]

https://www.sinclairintl.com/reload...aspx?avs|Manufacturer_1=SINCLAIR+INTERNATIONA


The above is what I have been using to size/expand the necks on my brass; they come in different diameters for different calibers. I have mandrels for the .270, 30 cal, 35cal, and expand the necks after the brass has been annealed and then resized. To the best of my knowledge this is how the mandrel set up is supposed to be used.

If you watch the video on the page that your link takes me to, you will, see that the primary purpose of the expander is to prep the neck for neck turning.

However, I did note that they do mention that it can also be used by target shooters to achieve uniform neck tension. While I acknowledge that they might work for that, I don't think it's the best approach, and I have never seen other target shooters use the expander that way. For the reasons given in my previous post, my preference is to use bushings with in line dies or competition dies.

Cheers, and thanks for going an extra mile with me. It is much appreciated.

 

[entoptics]

The above is what I have been using to size/expand the necks on my brass; they come in different diameters for different calibers. I have mandrels for the .270, 30 cal, 35cal, and expand the necks after the brass has been annealed and then resized. To the best of my knowledge this is how the mandrel set up is supposed to be used.

If you watch the video on the page that your link takes me to, you will, see that the primary purpose of the expander is to prep the neck for neck turning.

Brownells sells 2 different mandrels per caliber. The turning mandrels are 0.002" under bullet diameter, and the sizing mandrels are 0.001" under bullet diameter.

Coincidentally, my die/mandrels arrived today. In conjunction with a standard RCBS full length sizing die, stem removed, I produced 18 rounds of 270 win today with ≤0.002" runout, with only one round just shy of 0.003". My last batch of ammo with the standard die had average runout of ~0.004", with only half the rounds ≤ 0.002".

Stemless sized brass had runout of ≤0.0015", with most ≤0.001". After running through the mandrel, only one piece had increased runout of 0.002".

I use a bushing die with my 300 WM, and it is not producing ammo with this low of runout. I average about 0.002", with far more than I like going up around 0.004". I will be switching to the mandrel approach with it as well.

Besides the reduced runout, the seating force was more uniform as well. I turn my necks, and am wondering if I had some donuts. No need to worry about it any more...

 

[Alibiiv]

Brownells sells 2 different mandrels per caliber. The turning mandrels are 0.002" under bullet diameter, and the sizing mandrels are 0.001" under bullet diameter.

Coincidentally, my die/mandrels arrived today. In conjunction with a standard RCBS full length sizing die, stem removed, I produced 18 rounds of 270 win today with ≤0.002" runout, with only one round just shy of 0.003". My last batch of ammo with the standard die had average runout of ~0.004", with only half the rounds ≤ 0.002".

Stemless sized brass had runout of ≤0.0015", with most ≤0.001". After running through the mandrel, only one piece had increased runout of 0.002".

I use a bushing die with my 300 WM, and it is not producing ammo with this low of runout. I average about 0.002", with far more than I like going up around 0.004". I will be switching to the mandrel approach with it as well.

Besides the reduced runout, the seating force was more uniform as well. I turn my necks, and am wondering if I had some donuts. No need to worry about it any more...

I had a custom set of dies make by Hornady for the .270 Ackley Improved, there's no run out whatsoever, really very happy with them; but they were not a cheap date by any means. I've seen a big difference in my groups using the mandrel die for neck sizing and the run out is minimal with my other cartridges; 30-06, .308, .358 and 35 Whelen. Annealing also helped with uniforming the seating force as well.

 

[Mram10us]

simply the wrong choice in case maker to start with.
its gonna be some work.
my 300 win mag match brass was RWS
MY 338 is ADG
MOST ELSE IS LAPUA.
there is no rem nor winchester in match guns

I had and still shoot Rem brass in 300rum and edge out to 1400yds. You are fine