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I need to order a NOE case neck expander plug for .309 boolits and for the life of me I can't find the rule of thumb thread on what size NOE neck expander to order. I thought Al had the explanation on his site but I can't find that either. Can anyone lend me a hand?
Most people recommend .001" over the bullet diameter. I have found that .002" over the bullet diameter works best for my 9MM, .357 and 45 ACP rounds. Since they don't cost much, I would purchase both.
This may help. There are other threads. I use whatever my boolit diameter is for the smaller number and a few thou larger for the larger number. Example: 310 dia. Boolit I use.314 x .310.
https://www.google.com/url?client=in...hIybLVOdakc08L
I shoot for .002 under bullet diameter - .308 expander for a .310 boolit. Works perfect for my 03’s.
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He first number is the flair, the second the size expansion you want. I go with the size I want the boolit to be, so if I want a 0.002 over bore I go with a 0.311 the same as I size my boolits and then crimp.
I dunno if this additional thread will help or further confuse, but...
https://castboolits.gunloads.com/sho...and-dimensions
all that said, I had been having issues with my 9mm bullets getting swaged by the case using the logic/sizing presented in the threads. I am currently using the NOE A362 expander (.362 x .358) for my .358" bullets and my problems have gone away. I will add the 9mm case is a whole different animal than the OP's .309" bottleneck and it's needed neck tension. In other words this example does not apply to the OP's needs. IMO
Here's a pretty good youtube explanation. The guy in the video lives real close to NOE's store/shop and he seems to present the information as he gets it from Al face to face.
https://www.youtube.com/watch?v=e9waFJCbrt0
Somewhere else I read guys try to match the (math determined) middle number to the size of their sized cast bullet. So the .311 x .307 Exp. Plug would be the proper choice for a .309" bullet.
As PJEagle suggested they are pretty cheap and I will usually by on both sides of what I think I need just in case. The shipping for a single expander will quickly prove the penny wise logic.
edit note: corrected the expander info I was/am using for my .358" 9MM cast bullets. Sorry for having post bad info.
For .309 bullets, if you desire .002 neck tension you'd want a 311x307. If you only want .001 neck tension then order 310x306.
I ordered one plug for exact bullet diameter, one a .001 under and one a .001 larger. Hopefully, one of those will work. I just hope Al has everything in stock that he says he has. Thank you everyone for your help.
Quote:
Originally Posted by Bazoo
I think you subtracted when you should have added. For a 309 bullet with .001 neck tension, you would want .310x.308, based on your example. I would suggest a .312x.308 would be the better choice. There is some spring back in brass and you want to start the bullet without touching the case walls, so you need a slightly bigger step.
You can always call NOE, IME they will always return your call within 24 hours and are super helpful. Of all the companies I’ve ever dealt with over the phone NOE and Trigger Shims.com have by far been the best to deal with as far as a prompt response.
You can call it like this, but it's a source of confusion. The 0.002 neck tension rule came from bench rest shooters who neck sized. They used w/e mandrel that resulted in the case neck outer diameter growing by 0.002 after seating the bullet. That's the max you ever need to get full neck tension, since brass springback is slightly less than that (in any caliber up to 50).Quote:
For .309 bullets, if you desire .002 neck tension you'd want a 311x307. If you only want .001 neck tension then order 310x306.
When you use an expander plug that is 0.002 smaller than your bullet, the case springs back by 0.0015-0.002. If you measure the OD of the case neck before and after seating your bullet, it's going to grow by 0.004. In addition to getting full neck tension, your bullet finished expanding that case neck the last 0.002. In a hard case and soft bullet, that can result in bullet swaging. Even if using hard bullets, it can result in reduced concentricity, since the bullet tilts more easier when seating than a solid steel expander plug.
Going any smaller than your bullet diameter cannot increase neck tension. But it may be wise to go smaller so you can retain full neck tension when loading smaller diameter jacketed bullets.
In my testing, using various sized expanders and bullets, if I use a bullet that is .003 larger than the expander, it always resulted in bullet swaging. Now... it didn't always swage the entire base driving band. Sometimes it swaged only half the band resulting in something akin to a bevel based bullet. Would that cause leading? Maybe, maybe not. I just don't do it on principle, I don't want my bases swaged.
I tested with two alloys, wheel weights, and ww/soft mixed 50/50. The results were the same for those, .002 larger bullet didn't swage, and .003 did. I didn't have any harder alloy bullets to test. I don't normally have Lyman #2 or Linotype or similar "hard" alloys on hand.
^Seems like you tested to see the smallest expander that worked for your own cartridges. That's what a safety-oriented person would probably do. And that rule works for your loads, so it's great.
I have gone the opposite way, to see how large you can go with the expander and still get full neck tension. Full bullet diameter always gives full neck tension.
I have no problem with your suggestion to the OP of going 2 under. That's fine to suggest. And it will work for most reloaders in most cartridges. (Might have some issues in 9mm, specically!)
But calling that "0.002 neck tension" is a source of confusion for newcomers to the game. I did a lot of research to make sure I was safe, when finding out I had to go larger than 2 under to get my 9mm to shoot right. And most people were like you, claiming the max size you can go and still get "2 thous neck tension" is a plug that is 2 thous smaller than the bullet! The guys who discovered this "2 thous" standard were not going by the size of an expander plug. They were measuring the brass, itself, after neck sizing. If you go 2 under on the expander plug, the brass will be up to 4 thous smaller than the bullet.
So not only you call a plug 2 under to be equal to "2 thous tension," you say 1 thous under will give "1 thous tension." So a plug equal to the bullet size would give... zero neck tension? That sounds kinda scary to a new reloader. Don't we want as much tension as possible? Well all three of these sizes will give the exact same tension. The maximum you can get.
To dumb it down for anyone who was worried, like I was: If you are neck sizing, the "2 thous" smaller than bullet is the largest you want your case to be to ensure you get 100% neck tension. If you are expanding with a plug, the maximum size your plug can be to guarantee 100% neck tension is the exact same size as your bullet!
If your cartridge has poor neck tension, it's bad brass or sizing die. I've had that happen with weird headstamp super thin 45ACP cases. I pulled bullets, resized, and used the stock small expander, and the neck tension was exactly as weak and dangerous. You'd need a smaller sizing die to reload that brass, safely.
FYI guys. This is for my .309 JDJ 14 inch Contender. I'm sizing at .309 since the bore slugged at .308. I ended up using the .310 plug. Boolitt doesn't easily push into the neck with hand pressure. The first range trip showed potentially great accuracy at 50 yds. Deer season came along and the club closed to range for the duration. Next time will be further ladder testing at 100 yds. Thank you all for your help!
Yep. I don't shoot a lot of jacketed bullets, but I've loaded and shot some in cases expanded with a "cast" expander plug 1 thou larger than the bullets. (Probably a little less than a full thous, though. My NOE plugs all measure half a thous smaller than the number, on my digital calipers.) The neck tension was pretty nearly the same, as far as I can determine it.
For benchrest shooters playing with neck tension, you have to use plugs LARGER than the bullet before tension starts to decrease below max, and even then it seems to be the last few tenths of thou that make the biggest difference.
I'm guessing most of these benchrest guys are going the other way and doing minimal necksizing, though.