neck thicknesses

ARlife4me said:
at the thickness you prefer it at is more of a preference than what wouldn't work?
Click to expand...
Anything smaller than .012" doesn't last long with many cycles of sizing, even with only .003" clearance, this is due to the total movement of .005" up and down constantly, even with annealing.
Thinner necks also grow thinner each sizing cycle…
If you have a rifle, factory or custom, with neck clearance larger than .004", I wouldn't worry about trying to match brass to suit. It's a waste of time, just live with whatever it is. My custom 25-06 has .006" neck clearance, Norma brass, although excellent brass, splits the necks even with annealing after a half dozen re-sizes. Winchester brass splits about double that number and Remington brass hasn't split yet, but only on 3 sizings so far.

My 6.5-284 project went into the bin because the only brass available was Euro, the chamber reamer was not mine and brass had to be turned down to .011" wall thickness to fit, it was a NECK TURN ONLY chamber reamer. This didn't sit well with me, so that barrel is now my 264WM A191 chamber for 150/156g bullets. The other blank is now a 6.5-300 Weatherby…

Cheers.
 
MagnumManiac said:
Anything smaller than .012" doesn't last long with many cycles of sizing, even with only .003" clearance, this is due to the total movement of .005" up and down constantly, even with annealing.
Thinner necks also grow thinner each sizing cycle…
If you have a rifle, factory or custom, with neck clearance larger than .004", I wouldn't worry about trying to match brass to suit. It's a waste of time, just live with whatever it is. My custom 25-06 has .006" neck clearance, Norma brass, although excellent brass, splits the necks even with annealing after a half dozen re-sizes. Winchester brass splits about double that number and Remington brass hasn't split yet, but only on 3 sizings so far.

My 6.5-284 project went into the bin because the only brass available was Euro, the chamber reamer was not mine and brass had to be turned down to .011" wall thickness to fit, it was a NECK TURN ONLY chamber reamer. This didn't sit well with me, so that barrel is now my 264WM A191 chamber for 150/156g bullets. The other blank is now a 6.5-300 Weatherby…

Cheers.
Click to expand...
this is not about what i do and don't have, it's about what would be or could be best or better? the last 2 custom barrels i've bought for ar's required me to send in 3 dummy rounds for chambering. what i didn't consider was chamber dimensions to match the brass being used? headspace was done correctly along with throating i wanted as it was shorter than what it would've been in most ba's. the next custom chambering will be done with more questions about the reamer to my brass matching. knowing answers on this thread could help in doing so? hopefully getting all the brass from the same batch (i like having 1k minimum to start a new cartridge) or having same batch of factory ammo (still 1k to start with). with 1k of brass or factory ammo of the same batch i could hopefully get 10x reloaded? i'll keep in touch with you and a few others that have been a great help in my endeavors on something i know very little about! i've been thinking about getting a mic, so it might be time for me to do it. what i do have is this (below). maybe it's a start, but might need something better?
1728951295809.png
 
when i sent in the dummy rounds i did a fl size and made sure all 3 had the same ctbo measurement. also, all 3 had the same coal. at the time i didn't know about the mags that had a longer coal possibilities (magpul pmag 2.830" vs acs/larue @ 2.60-2.870"ish), but did have it throated .100 longer than the ctbo's i sent in. on another note, i have uni-throaters for nearly all calibers i shoot (especially in ar's).
 
ARlife4me said:
when i sent in the dummy rounds i did a fl size and made sure all 3 had the same ctbo measurement. also, all 3 had the same coal. at the time i didn't know about the mags that had a longer coal possibilities (magpul pmag 2.830" vs acs/larue @ 2.60-2.870"ish), but did have it throated .100 longer than the ctbo's i sent in. on another note, i have uni-throaters for nearly all calibers i shoot (especially in ar's).
Click to expand...
You'll have to tell me about those uni throaters sometime. So you like a healthy jump DTL?
 
Brathany said:
You'll have to tell me about those uni throaters sometime. So you like a healthy jump DTL?
Click to expand...
i seated them deeper as so i could go longer with heavier bullets. most fmj's ctbo are further out than match bullets for the reason of the longer throat. i shoot lots of fmj's in both ar's and ba's. also helps if i decide to single feed factory ammo that's longer. with the mags that gives me an extra 30 to 40 thou more coal, the jump lessens and the throat last longer. how many people do you know that has put over 2,500 rounds of 264wm ammo threw the same barrel and still has good accuracy? longer jump can be good.
 
MagnumManiac said:
Anything smaller than .012" doesn't last long with many cycles of sizing, even with only .003" clearance, this is due to the total movement of .005" up and down constantly, even with annealing.
Thinner necks also grow thinner each sizing cycle…
If you have a rifle, factory or custom, with neck clearance larger than .004", I wouldn't worry about trying to match brass to suit. It's a waste of time, just live with whatever it is. My custom 25-06 has .006" neck clearance, Norma brass, although excellent brass, splits the necks even with annealing after a half dozen re-sizes. Winchester brass splits about double that number and Remington brass hasn't split yet, but only on 3 sizings so far.

My 6.5-284 project went into the bin because the only brass available was Euro, the chamber reamer was not mine and brass had to be turned down to .011" wall thickness to fit, it was a NECK TURN ONLY chamber reamer. This didn't sit well with me, so that barrel is now my 264WM A191 chamber for 150/156g bullets. The other blank is now a 6.5-300 Weatherby…

Cheers.
Click to expand...
It's not that I wanted to turn necks, but when I sized down Lapua 308 to 708, then formed to AI, I had to turn necks. Loaded OD was .3155 for a .316 chamber. Not good. When I move to my .284 WIN LA CIP length I'm getting a .319 necked reamer and escape this icky neck turning. Oh, I think my hopes of up sizing 6.5-284 Lapua to 284WIN are now shot! Thanks! 🤣
 
ARlife4me said:
this is not about what i do and don't have, it's about what would be or could be best or better? the last 2 custom barrels i've bought for ar's required me to send in 3 dummy rounds for chambering. what i didn't consider was chamber dimensions to match the brass being used? headspace was done correctly along with throating i wanted as it was shorter than what it would've been in most ba's. the next custom chambering will be done with more questions about the reamer to my brass matching. knowing answers on this thread could help in doing so? hopefully getting all the brass from the same batch (i like having 1k minimum to start a new cartridge) or having same batch of factory ammo (still 1k to start with). with 1k of brass or factory ammo of the same batch i could hopefully get 10x reloaded? i'll keep in touch with you and a few others that have been a great help in my endeavors on something i know very little about! i've been thinking about getting a mic, so it might be time for me to do it. what i do have is this (below). maybe it's a start, but might need something better?View attachment 609121
Click to expand...
You only need to know seated neck diameter to determine clearance once you determine what number is going to clean up the neck, which is why I base mine on .014". I only turn 80% the length of the neck and only size a smidge shorter than this. YMMV.
You do not need 1k of brass, 300 is all I use per batch, but seeing I have 5 300WM's, I run 300 in each, same goes for 264WM, have 3 of them, 3 25-06's and 2 6.5x47's and 2 22-250's/22-250AI's, the AI uses Lapua SRP brass, and the standard uses LRP brass.

Cheers.
 
ARlife4me said:
when i sent in the dummy rounds i did a fl size and made sure all 3 had the same ctbo measurement. also, all 3 had the same coal. at the time i didn't know about the mags that had a longer coal possibilities (magpul pmag 2.830" vs acs/larue @ 2.60-2.870"ish), but did have it throated .100 longer than the ctbo's i sent in. on another note, i have uni-throaters for nearly all calibers i shoot (especially in ar's).
Click to expand...
I use NEW brass when determining COAL with dummy rounds and I measure with RCBS Precision Mics for seating depth length, confirming with CBTO gauges. If you supply 3 dummy rounds that have been fired and FL sized, it is common they WILL NOT measure the same as NEW brass. The only caveat here is with belted brass, it needs to be fired and knocked back .002" to get precise measurements or neck sized only.

Cheers.
 
MagnumManiac said:
I use NEW brass when determining COAL with dummy rounds and I measure with RCBS Precision Mics for seating depth length, confirming with CBTO gauges. If you supply 3 dummy rounds that have been fired and FL sized, it is common they WILL NOT measure the same as NEW brass. The only caveat here is with belted brass, it needs to be fired and knocked back .002" to get precise measurements or neck sized only.

Cheers.
Click to expand...
all was new brass that i fl sized and none were belted. more to come as with this thread as i need more info to be collected it seems.
 
Thicker brass of a given hardness springs back with more force.
And so thicker brass springs back with more variance.
Lower neck tension will provide lower variance of it.
On the flipside, you need enough tension to please your load.

An example bad thickness presents with the WSSM case. These are simply cut down WSM cases, so necks ended up at WSM body thickness of 20thou or more (depending on cal). People find out the hard way, but it should have been expected lower in precision potential.
When I chose to use the WSSM case for a wildcat, it was planned as neck turned to 13thou. This worked well, as cases turned to 12 to 13thou always have for me.

As far as clearances, I'm against them, and against sizing to recover from them, and every single issue caused by it.
 

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