Yet another neck tension thread.

[gman47564]

Its all factory brass.. it all can create a doughnut.. the material in the shoulder is thicker than the material in the neck.. as the case grows the shoulder migrates into the neck creating a doughnut.. guys that turn necks pushes this doughnut to the outside and then turn it off.. i dont turn necks so i turn this doughnut off from the inside with a reamer.. the doughnut really doesnt hurt anything left there if the boat tail and bearing surface junction stays above it.. this is just my opinion..do what ya want with it..

 

[243winxb]

guys that turn necks pushes this doughnut to the outside and then turn it off.. i dont turn necks so i turn this doughnut off from the inside with a reamer..

Reaming works when the neck is held in a die, while reaming. But how smooth is the finish cut.

 

[CharlieNC]

On a different note it is surprising to me that 20fps yields 12in vertical spread at 600yd. I shoot 223 in fclass out to 600 and that is nothing like I experience. How did you develop your load? If you found a good node, your vertical should not be that sensitive.

 

[IHFarmer07]

If you are indeed turning your necks to a uniform thickness, using a bushing die WITH NO EXPANDER BALL to provide no more than .003" of friction, performing a very careful inside chamfer and either lubricating your necks or using a coated bullet (best for uniform release in my opinion), I would start looking elsewhere for any velocity deviations. Do you weigh each charge on a good scale to 1/20th of a grain or less? Check flash hole uniformity? Try different primers? Sure that all pieces of brass are trimmed to same length AND at least .003" shorter than the max length for your chamber? There is always a reason for those issues and process of elimination sometimes just has to be done. Sometimes it can be quite amazing the size difference of flash holes in some brass. I once nearly went crazy before I found that my chamber was cut short in respect to the neck, meaning I needed a trim length much shorter than "book" trim length for the cartridge. When you think you have done everything right and begin to question individual pieces of brass - you can do what I do. I take 100 rounds of very carefully loaded match ammo and I shoot every round over the chrono while practicing. Each piece is marked with a velocity on a piece of masking tape. Then take any aside that are way out. You can shoot them again over the chrono when practicing to verify it is the brass - which the problem almost certainly will be if it occurs twice. As to the remaining 90% to 95% or so that made the cut the first time - organize them in your loading tray by starting with, for example all within 3 f.p.s., then the next higher 3 f.p.s. group, and so on until you are done. When I change to a new group, I either leave a space or place the beginning round of the new batch upside down so I know when I'm switching to a new velocity. While I wouldn't expect the brass to shoot within 3 fps of what it did previously (due to differences in humidity in powder, primer difference, bullet diameter variation or weight, etc.), what I have done is take out the ones I know were way off and just eliminate them from being a potential problem. If my grouping the rest increases the odds of most of the ammo behaving similarly on the next firing - it is worth it.

Sorry, been a LONG day.....I try to be careful on the inside chamfer. Yes I have a A&D Fx120i that I measure down to a single kernel of powder or a .02 of a grain. No not on the flash hole as starline is pretty good with that. Yes tried different primers. I trim to book length but I have measured my chamber and it can handle longer necks on the brass but just trying to stay with book length. Yeah I starting to sort according to what I can feel is tighter on the neck, like it has more of a tighter pinch, and start sorting according to the velocity. I believe the issue is something with the neck area as I can feel the tightness and that correlates to a velocity spike and I'm loading a bit on the hot side of things.

 

[IHFarmer07]

Take the neck turned brass and bushing die. Adjust bushing to size 1/2 to 3/4 of the neck.
No expander needed when using the correcf bushing. Aim for .002" neck tension.
A donut will not be a problem any more, but will be in a tight neck chamber.

Factory brass should not have a problem donut and should never be inside neck reamed. Use the bushing as i said above.

View attachment 1137005 View attachment 1137006

That's what I always thought but I have no first hand knowledge of it

 

[JFrank]

Excuse me
I read that you are using a F/L die without the expander ball , I didn’t read you to say anything about a bushing die. I’m also wondering why your turning necks, are these rounds intended for a tight neck chamber?

 

[IHFarmer07]

On a different note it is surprising to me that 20fps yields 12in vertical spread at 600yd. I shoot 223 in fclass out to 600 and that is nothing like I experience. How did you develop your load? If you found a good node, your vertical should not be that sensitive.

I can't exactly remember what the velocity spread was but a 2'X2' plate was missed at 786yds with aiming in the middle and I had my V3 on (not on the barrel, have a home made apparatus that threads in the stock), and the velocity was higher...…..can't remember if it was 40fps or 20. I picked the best "flat" spot I could and worked with it. It may not be the best but it works really well until I get one of these cases that have a tighter feel or a tighter pinch on the mandrel and 9 out of 10 times that case will have a higher velocity. I feel it an issue with the brass or my process of working with the brass not the load itself.

 

[IHFarmer07]

Excuse me
I read that you are using a F/L die without the expander ball , I didn’t read you to say anything about a bushing die. I’m also wondering why your turning necks, are these rounds intended for a tight neck chamber?

Correct, I’m using a FL forester die but I do and have played very little with a bushing FL die.
Well I was trying to figure out what what going on here with some brass having a tight neck “feel” while others didn’t feel as tight, and what I mean by this is the mandrel didn’t feel like i did much to the neck at all while others felt like I was sizing a lot. This is NOT a tight chamber but before I was not turning the necks and I was trying something and I did test loads before and after some were turned some not and it seems more accurate. If I can, I would like not to turn the necks.

 

[IHFarmer07]

To inside neck turn what is needed? And what brand works the best? I assume I would need a trimmer with a inside neck turning attachment right? Wilson or forester or whatever. I trim my brass, do the rest of case prep on a Frankford Arsenal case prep machine. Or will a cordless drill with the inside neck tool work?

 

[gman47564]

I use a forster original case trimmer with a forster inside neck reamer.. seems to work well...

 

[jobhopper66]

^^^^This video is really worth watching, Joe really puts out a wealth of information. I personally have watched it more than once.

 

[boltfluter]

Stop annealing as a test. You are removing/destroying the layer of carbon that acts as a lubricant for bullet seating.

Paul

 

[243winxb]

Ok just measured a few cases, now this could be the problem, maybe not idk, .248” od at the mouth and .249” od at where the neck turning tool stopped on a sized empty shell. Loaded round on 2 rounds are .249 at the mouth and .250 at where the turning tool stopped.....now I have been using a .2225" mandrel but on these I thought I’d try the forester die with the decapping/sizing stem just to try and find something that solves the problem. The forester die specs are supposed to be .248” and .249 with .001” spring back. Also I have found with the turning tool that the turning arbor that the case goes over, I can put the arbor in the case to a point and then it gets tight at the base of the neck junction where the shoulder starts. It’s like it has a donut there, which I’ve heard of, but never thought it can happen to factory brass that don’t have to go through a process to make this cartridge.

There does seem to be a .001" donut? Before turning with the .2225"(turning?) mandrel , are you using an RCBS expander? Other brands use a expander first, before turning. https://www.sinclairintl.com/reload...ss-steel-neck-turning-mandrels-prod33136.aspx

The forester die specs may need to be tighter, more sizing, so the expander can work correctly?

Or the brass needs to be neck turned again, with the cutter at the same setting. The 2nd pass, at the same setting, removes just a tiny bit more brass.

The .001" difference between mouth and neck/shoulder just doesnt seem right.

Reaming- Push brass to the outside with an expander. Then cut it off by outside neck turning.

Inside neck reaming needs the brass neck to be held in a die, while reaming.

 

[boltfluter]

I do like cake!! Lmao!

Paul

 

[Mikemontminy]

What you should try is getting a gauge pin .0005 under your expander mandrel size. You can get these from Vermont Gage . With the gauge pin you can feel where the problem is. Sometimes it is a donut at the shoulder/ neck junction. If that’s the problem I use a K&M carbide cutting pilot in a cordless drill to remove it. The cutting pilot only cuts at the tip so the neck of the case will guide it in straight. A reamer on the other hand has cutting flutes down the full length so if it is not guided straight in it will potentially ruin your case. Another area to look at on the case is where the inside chamfer ends. Sometimes a burr forms there from cutting and needs to be removed. I use an expander mandrel in a cordless drill and burnish that edge slightly.
I only do this on the ones that feel tighter with the gauge pin. Some people use an easy out for this step. I haven’t tried one but I bet it would work pretty good. The most important thing is the gauge pin. It will let you sort out the problem cases a lot easier and pinpoint how far down the neck the problem is.
Good luck Mike

 

[Ccrider]

How are you “cleaning” the brass?
The amount of lube left in the neck or placed in the neck can effect feel when loading and also effect velocity.

Also, you have to eliminate the outlier pieces of brass as described above or by using whatever method you choose.

What firing cycle is your brass on? Even with annealing, this matters. If you are running hot loads, expect that your velocity will become more erratic as your primer pockets loosen. Also, some pieces of brass seem to give up the ghost for whatever reason earlier than others. I see this mostly on the target with fliers but also lower fps.

 

[IHFarmer07]

You may benefit from watching this video.

I have watched this and I will be watching it again, thank you

 

[IHFarmer07]

There does seem to be a .001" donut? Before turning with the .2225"(turning?) mandrel , are you using an RCBS expander? Other brands use a expander first, before turning. https://www.sinclairintl.com/reload...ss-steel-neck-turning-mandrels-prod33136.aspx

The forester die specs may need to be tighter, more sizing, so the expander can work correctly?

Or the brass needs to be neck turned again, with the cutter at the same setting. The 2nd pass, at the same setting, removes just a tiny bit more brass.

The .001" difference between mouth and neck/shoulder just doesnt seem right.

Reaming- Push brass to the outside with an expander. Then cut it off by outside neck turning.

Inside neck reaming needs the brass neck to be held in a die, while reaming.

I am using a Sinclair expanding die with a 21 Century .2225 and I have an expander and turning mandrel for a .224 from Sinclair and another place.
Yeah that can be, it may need to be sized down more then expanded , turned then resized? What should the process be in what order?

 

[searcher]

If you think you have a doughnut, it is usually pretty easy to determine simply by sliding a bullet into the fired case neck. You will usually feel the resistance when the bullet gets to the neck/shoulder junction. Even without a tight neck chamber, turning the necks just to gain uniformity is well worth the time and effort when shooting distance. I find having turned a lot of brass for standard chambers worth the effort to the point that I even do it for my A/R's. There are a few ways to get rid of the doughnut if you have one. one way is to run a neck expander that pushes a lot of the doughnut to the outside where it can be neck turned away. Since there is some "shrinkage" after you withdraw the expander, this does not entirely get rid of the doughnut but can get a lot of it, especially if you anneal just before this procedure. The other is to run a reamer into the neck. As others mentioned - you shouldn't have any doughnuts with new brass, though imperfect factory brass is not out of the question - and that does go for the flash holes as well. Check it all. And it is pretty normal to have a difference in the neck thickness at the shoulder junction from that of the mouth. That is because the mouth is not under force to spring back after sizing or expanding as the more supported neck/shoulder area is. Even after annealing, then expanding and turning you will find this to be true. Always take your thickness measurements in the same place at the end of the neck towards the mouth. Use the Hornady headspace measuring tool to determine whether your cases truly have the shoulders set back the same - which affects the noted fill difference you saw. Use everyone's ideas as a checklist of elimination. Good Luck.

 

[searcher]

If you go the reamer route - the Wilson is a good choice, especially if you already have the Wilson trimmer. After re-reading your original post, don't think that because it is a bit tighter at the neck juncture than the mouth that you have a doughnut. That differential is normal. When you slide that bullet into the fired as I mentioned before - it will not just gradually get a little tighter, but rather more of an abrupt, tighter fit. A really bad doughnut will usually stop you from being able to easily slide the bullet into the case at all.