Brass separation question

[jelenko]

Review carefully the instructions for setting up fl Redding sizing die, often I can size brass to fit ammo checking Gage and firearm Without cam over, or even touching shell holder with die.

Just to this point. Setting up Forster or RCBS sizing dies according to the included directions has always over sized my brass.
The best approach is to first set if a fired case will easily chamber - if so, you're good to go.
If the fired case doesn't chamber, start with the sizing die so it's just barely pushing the shoulder back [you'll need case headspace gauge for this]. Check if the case will chamber easily, if not, keep adjusting the sizing die in little smidgens and test for chambering after each smidgen.
After the case first chambers easily, measure it with the case headspace gauge. Now you can decide if you want to further push the shoulder back and know how much clearance you'll have in the chamber.

 

[243winxb]

Brass can be damaged on the 1st firing, if headspace is excessive. .010" 0r more.

I suspect an AR15 parts gun with excessive headspace.

When picking a barrel, buy the same brand bolt/carrier.

There is no substitute for headspace gauges.

 

[bozo699]

The first thing that should be done is take the reloading die instructions and use it to light a fire it’s all there good for!….. For your bolt gun you need no tools to set your headspace if you don’t want to!.. you can use your chamber to set your dies. Use brass that was previously fired from said rifle, Strip your bolt, and use the Alex Wheeler method for setting up your die for proper head space it’s dead nuts accurate!… for your machine gun buy a bump gauge for your vernier calipers do as others have suggested and measure virgin brass and measure it then measure fired case from that rifle and that will tell you how far it’s stretching if it’s excessive you should fix the problem but in the meantime use the bump gauge to set your die to set the shoulder back about .003-.004 on the machine gun the bolt rifle .002 is about right.
You can go to Wheelers site and watch his video on how he does the strip bolt method for your bolt rifle.
Just a thought keep your machine gun brass separate and only use it in that rifle.
Wayne

 

[rdb8847]

Thanks for all of the replies. Thought I could make use of all of my 555 LC brass in my 223 bolt gun. I am known for being frugal (cheap). But when it comes to this I refuse to cut corners. Im assuming Lapua virgin brass is the solution and learn to adjust my sizing die to match my chamber. Thanks again. I will go check out the Alex Wheeler video

 

[Coyotefurharvester]

I run 556 range brass in AR and bolt guns. I check(sized) AR designated brass with a Lyman ammo checker. Bolt guns are sized to fit properly for the rifle. Standard fl sized and same brand shell holder, after universal decap and removing the crimp. I hunt in sub zero weather, I find AR brass needs abit more sizing to load first round from aluminum mags without FA. I usually set for 0.004-.0045, have not had a case head separation.

 

[SKWERLZ]

I always measure fired brass them size down approximately 3 thou for a semi and a bit less for a bolt gun.
Following the directions often over sizes the cases leading to separations.

 

[old codger]

I find that an RCBS Prec Mic is a good tool for setting up resizing dies.

 

[mac86951]

I find that an RCBS Prec Mic is a good tool for setting up resizing dies.

+1 Hornady makes inserts for the tolls you have already, you'll want something that sits somewhere on the shoulder. Note, none of these tools are "calibrated" so we're giving you reference numbers. Set your die up for a 0.001 to 0.002" for bot guns, and i recommend 0.002-0.004 for ARs. As others have said, it's about how much sizing is needed for your gun after firing to minimize the brass stretching, not sizing to minimum each time. This is also why you've.got to watch out for brass fired in different rifles.

For 30-06 i have a bent paperclip tool that fits into the neck and i can gauge how much the "separation" ring is forming thru the life of the brass; but for 223 it would need to be a sharpened point for the smaller ring. Perhaps that's overkill, better to keep brass lots for one rifle only starting from new.

-Mac

 

[pdhntr]

Thanks for all of the replies. Thought I could make use of all of my 555 LC brass in my 223 bolt gun. I am known for being frugal (cheap). But when it comes to this I refuse to cut corners. Im assuming Lapua virgin brass is the solution and learn to adjust my sizing die to match my chamber. Thanks again. I will go check out the Alex Wheeler video

There may be another issue that is causing the problem.

Your AR is possibly over-gassed or, for what ever reason, is unlocking the bolt while the chamber pressure is still high. While the brass is still "stuck" in the chamber and hot, the bolt will unlock and try to pull the case out. I have seen this several times before and the brass fractures in the same place yours has.

Measuring shoulder to base on these cases can lead someone to believe the chamber has excessive head space.

A typical case head separation, where excessive sizing is the cause, will take place just above the base of the case, much lower on the case than yours show.

If it were mine, and I wanted to shoot the cases in a bolt gun, I would install an adjustable gas block and see if that helps.

Jim

 

[K22]

Here's a simple solution to avoid future problems:

1. Start with new cases and dedicate them to a specific rifle.

2. Learn the basics of sizing cases to ensure that case head space is optimum for that specific rifle. There are some inexpensive tools you'll need to measure shoulder bump which is essential for ease in setting up sizing die. Tools: a bump gauge and caliper. I prefer the Whidden bump gauge since it is a single piece with no inserts and it's economical and well made.

3. Use you rifle chamber to verify / check adequacy of your sizing / measuring process. Removing the firing pin assembly will provide a more precise feel for the adequacy of your sizing set up.

4. Always carefully inspect your fired cases before sizing. Spot check die set up periodically with the bump gauge since as cases age they can become hardened and require some minor die adjustment to maintain optimum sizing.

 

[rdb8847]

Ordered 200 pcs of Lapua brass and the Hornady gauge kit for checking shoulder bump for my bolt gun. So now the million dollar question is should I full length size virgin brass and then proceed or just start my bump back .002 from the start.

 

[mac86951]

Ordered 200 pcs of Lapua brass and the Hornady gauge kit for checking shoulder bump for my bolt gun. So now the million dollar question is should I full length size virgin brass and then proceed or just start my bump back .002 from the start.

I'd still size the new brass, it'll iron out case neck deformations due to shipping, etc... Setting up a FL.size die to move the shoulder back is still full length sizing, just working the brass less. For new brass you won't need to move the shoulders at all

-Mac

 

[Doom]

Ordered 200 pcs of Lapua brass and the Hornady gauge kit for checking shoulder bump for my bolt gun. So now the million dollar question is should I full length size virgin brass and then proceed or just start my bump back .002 from the start.

I would not resize new Lapua brass unless I need to clean up a beat up neck. You will also probably not need to set the shoulder back after first firing. Rechamber the fired brass before resizing and if the bolt closes set the shoulder for that dimension and no less. After the next firing you can see if the case grew any more.

 

[762willdo]

It was fired in the AR first?

Winner winner chicken dinner

 

[Coyotefurharvester]

Partially seat a spent primer in a new case, chamber closing the bolt. Measure the increase in length of case, now you have the bolt face clearance(headspace). And you can use your comparator on a max length case(new case with spent primer). New brass will probably be 0.004-0.008 short of the chamber, you just need round,correct I.D. necks for bullet seating. Do not run new brass through the sizing die set to cam over, or even touch the shell holder.

 

[Doom]

Partially seat a spent primer in a new case, chamber closing the bolt. Measure the increase in length of case, now you have the bolt face clearance(headspace). And you can use your comparator on a max length case(new case with spent primer). New brass will probably be 0.004-0.008 short of the chamber, you just need round,correct I.D. necks for bullet seating. Do not run new brass through the sizing die set to cam over, or even touch the shell holder.

Seems like seating the round by hand then closing the bolt would be more accurate. I’m going to try this today to check my 223 bolt gun.

 

[WVRJ]

If I had new brass for the bolt gun I'd keep the sizing die .010 or so above the shell holder and resize the new brass just to make sure it doesn't have any deformities.A simple feeler gauge works good for this.I use the feeler gauge to measure how far off the shell holder I need to set the die for each of my rifles and record it in that rifle's page in my log book.After I shoot the brass the first time,I set the die up so it only resizes the brass enough to chamber smoothly.For me,case gauges are not as precise as the hand fitting method.

 

[L.Sherm]

Don't assume new brass is already short enough at the datum line.
The ADG i got for my 6.5x300wsm is exactly the same as my fired cases so I bump them back .002 new.
Measure its the only way to know for sure.

 

[L.Sherm]

Ordered 200 pcs of Lapua brass and the Hornady gauge kit for checking shoulder bump for my bolt gun. So now the million dollar question is should I full length size virgin brass and then proceed or just start my bump back .002 from the start.

Measure fired then measure new then decide if you need to bump the shoulders.
As stated above I would FL size just depends on wether you need to bump the shoulders or not.

 

[DocCarbon]

With New Brass MEASURE it BEFORE doing anything else . Take and old piece MEASURE it ,does it fit in your chamber ?. Differences between New & Old MEASURE . Now determine just how much you will or won't have to bump the shoulder . As said NEW brass especially Laupa shouldn't need bumping .

YOU MUST DETERMINE YOUR CHAMBER SIZES FIRST ,BEFORE SIZING ANYTHING . DON'T MIX GAS GUN BRASS WITH RIFLE BRASS !. IT LEADS TO TROUBLE AND CONFUSION . Mark them on the base with magic marker .

I often run Gas Gun cases in Rifles and vice versa , However I KNOW MY CHAMBER SIZES and how many firings I have on ALL MY cases . Gas guns can be HARD on Brass , bolt timing off excessive head space , opening breech prematurely stretches cases under extraction and ultimately will fail . They NEVER fail at a convenient time or place . IMO Older Military brass is TOUGHER and should be used for Gas guns and I ought to know ,I'm using WWll and Korean War Brass . Some have #12 firings on them with NO sign of failure and the extractor ISN'T chewing rims either .