Concentricity and Urban Myths

[Harpoon1]

For years conventional wisdom has been that “pulling an expander ball” up through the neck of a case caused concentricity issues. That is, the case was weaker in tension than in compression and we all happily stumbled along in agreement. People pulled the expander ball assembly out of their resizing dies and added a neck resizing expander mandrel to their brass prep regime. An audible hush fell over the crowd! Life was good!

Enter SAC, (Short Action Custom) and their tapered bushings.

https://youtu.be/D2Gei8Wo6UA

And

https://youtu.be/KqB4wrHO7fQ

Maybe it’s not quite as simple as we first thought?

Anyway, it’s been almost a year now and they, (SAC bushings), have cut my concentricity issues down to almost non-existent. And that’s with re-employing an expander ball to the resizing operation. No more mandrel, or associated extra step.

Lube, resize with SAC bushing and expander ball (I use the Whidden expander ball system because the diameter is adjustable). Done! Just the like the old days but, with almost no runout!

Happy 4th of July Folks!

[CJW]

Interesting post Poon…..

[BliksemDonder]

Things do not matter until they do. Concentricity of rounds do matter when shooting at long ranges with high accuracy requirements. Too many reloader shooters do not get to the level of where it is noticeable when the ammunition is not concentric and fitted to the chamber.

Even when possessing and using the same tools too many reloader / shooters are out of their comfort zone and cannot craft accurate ammunition.

[Harpoon1]

Maybe I should have stated this earlier but, my goal is to build the most accurate “Hunting” ammo, for the least amount of “sweat equity”! Cost is secondary, (well, kind of) at least for me, YMMV!

Time is money! (time is the “real” cost for me) I don’t mind paying a little more up front so I can cut corners and still maintain superior accuracy! In fact, that’s my goal! Right? I also don’t mind mind buying “quality” factory ammo.

“As simple as possible but no simpler!” A. Einstein!

[Klem]

Interesting videos.

I'm thinking if you're going to go to this effort to make the necks concentric then neck turning will be part of it. Plus shooting it out of a gun where you can see the effort and expense on the target, and that degree of accuracy is important to you.

[Harpoon1]

Interesting videos.

I'm thinking if you're going to go to this effort to make the necks concentric then neck turning will be part of it. Plus shooting it out of a gun where you can see the effort and expense on the target, and that degree of accuracy is important to you.

“If you’re going to go to this effort………….”! LOL!

What “effort”?

You’re swapping bushings, that’s it! Period.

[biodsl]

I've been using a Redding F/L bushing die for the Grendel since the beginning. For the Creed, I'm using a 'match' Hornady non-bushing die. I've never been impressed with my Creedmoor groups. I'm going to upgrade the Creedmoor die and give the SAC bushings a go.

[jasper2408]

I bought the SAC bushings to try on my Redding dies as I did not like the Redding bushings results. Haven't shot anything to try them out on yet as I am messing with my pistols so far this summer. I use Mighty Armory dies now though for full length sizing of my rifle calibers as they give fantastic concentricity compared to all of the other brand dies that I have used. I do neck turn though.

[Klem]

“If you’re going to go to this effort………….”! LOL!

What “effort”?

You’re swapping bushings, that’s it! Period.

I was referring to the effort and complexity mentioned in your first post and the videos.

[jasper2408]

For years conventional wisdom has been that “pulling an expander ball” up through the neck of a case caused concentricity issues. That is, the case was weaker in tension than in compression and we all happily stumbled along in agreement. People pulled the expander ball assembly out of their resizing dies and added a neck resizing expander mandrel to their brass prep regime. An audible hush fell over the crowd! Life was good!

Enter SAC, (Short Action Custom) and their tapered bushings.

https://youtu.be/D2Gei8Wo6UA

And

https://youtu.be/KqB4wrHO7fQ

Maybe it’s not quite as simple as we first thought?

Anyway, it’s been almost a year now and they, (SAC bushings), have cut my concentricity issues down to almost non-existent. And that’s with re-employing an expander ball to the resizing operation. No more mandrel, or associated extra step.

Lube, resize with SAC bushing and expander ball (I use the Whidden expander ball system because the diameter is adjustable). Done! Just the like the old days but, with almost no runout!

Happy 4th of July Folks!

Are you still using PEG-75 lanolin to lube your cases?

[Mesa1978]

Demonstrated accuracy improvements?

[Harpoon1]

I was referring to the effort and complexity mentioned in your first post and the videos.

Ok, well that makes more sense! Glad to hear it!

[Harpoon1]

Are you still using PEG-75 lanolin to lube your cases?

Yessir but running a much thinner mixture now. The Lanolin never settles out into a blob anymore. Guessing 14/1 or thereabouts. Still feels like I’m resizing in Cold Butter!

[Harpoon1]

Demonstrated accuracy improvements?

To be fair, no. I haven’t documented any “improvements”!

OTOH! I’ve got way too many guns and calibers in the rotation, in various stages of load development to keep track of. Always trying new powder/primer/brass combos.

I gotta believe, less runout has to help, at least to some degree! YMMV.

[DHD]

Interesting post. I have experimented with buying different brands of sizing dies and use bushing sizers with no expanders as a rule. I also neck turn (21st Century set-up) for certain calibers. I owned a Neco gauge and tried to drive myself crazy using it. So many variables so much time and money.

I've looked at the SAC stuff, own and use more than a couple Whidden die sets, own and use more than a few Wilson die sets (both hand dies and their newer standard bushing sizers), Forster dies, Redding dies etcetera.... I know I have 4 different brands of bushings in just one size. Hell, I even point bullets and anneal my cases. In short I'd have to admit I love experimenting. I like knowing I'm not alone and might not be nuts afterall (who am I fooling).

Mesa1978 asked a good question and Harpoon1 gave a good honest answer. Personally I have noticed the most accuracy improvements from a simple primer change to an already decently tuned load (after all the fun stuff was done to my cases that is). The hunt never ends for me but my shooting partner will tune a load and stop there. He seems quite happy and his groups are fine. Maybe I am nuts.

Sorry for the rambling post but the topic is one of my favorites.

[Harpoon1]

I've looked at the SAC stuff, own and use more than a couple Whidden die sets, own and use more than a few Wilson die sets (both hand dies and their newer standard bushing sizers), Forster dies, Redding dies etcetera.... I know I have 4 different brands of bushings in just one size. Hell, I even point bullets and anneal my cases. In short I'd have to admit I love experimenting. I like knowing I'm not alone and might not be nuts afterall (who am I fooling).

Currently running a Redding Full Length Bushing die body, with a Whidden decapper/expander ball assembly and SAC bushings. Between the SAC bushings and the Whidden adjustable size expander balls, the neck tension combinations are almost limitless. With fewer steps but, with mandrel like runout!

FWIW: some one commented on another forum that LE Wilson also puts a taper in their bushings too and at about half the cost of the SAC bushings. Ive purchased several in different calibers, just haven’t had a chance to see how they work……….