Blowing primers

[cowboybart]

I put together a 22-250 on a Savage 110. The rifle started out life as a 243, but when I bought it, the barrel was pretty much shot out. I found a heavy 22-250 barrel and installed it.
I set up the headspace on a full length resized case. Bolt closing is easy. My load is 34gr of 4064 and a 55gr Hornady bullet. The first 3 were OK with a mild flattening of the primer. On the next 5, the primer was punctured by the firing pin and bolt lift was stiffer. On the last one the bolt lift was HEAVY and the pierced primer fell out of the case.
Did I set headspace up too tight - causing high pressures??
Why did they progressively get worse??

[stumpjumper400]

I'm sure someone else will chime in with a better answer. The only way to be sure it's not a headspace issue is use an actual headspace gauge to set headspace. Some people do it with a fired case but I'm on the other side of the fence. There is no telling what size chamber the fired case was made from. Yes you can resize it. Are your dies set properly? Did you use a chamber case gauge to check it. There are just too many variables for me to use a case as a headspace gauge.

Steve

[hcpyro13]

How close together were your shots? Chamber pressure tends to rise with temperature. If your first shots from a cold barrel were flattening primers, heat could have driven you over the edge. I've been known to load a little warm, but if your cold bore shot is flattening the primers something is not right. More information is needed to even try to determine a desktop analysis of what's going on. Is the brass new? How many firings on it? were your bullets jammed or seated to jump to the rifling? I've experienced flattened primers and ejector marks when I didn't back off far enough and was jammed into the rifling. Just a thought. I do prefer to use a go-gauge when I headspace.

If these were your first loads with the gun, where did you start with your loads? If you're at the bottom of the published data you need to take a close examination at what is going wrong. Loose primer pockets, pressure to high, bad primers, etc.

-Jake

[ellobo]

I have never experienced this myslef, but I have read that too much headspace will cause the expanding case shoulder moving forward will cause the head of the cartridge back against the bolt head and produce what looks like ovepressure. Tighten up on the headspace until it gets hard to close the bolt Then back off until the bolt will close easily or use some scotch tape on the head of the case to make the case a no-go guage.

El Lobo

[Nor Cal Mikie]

You could have two different things going on. Case could be too small for the chamber. Shoulder pushed back too far for the headspace of the barrel? If that's the case, the second or third loading of that case should correct it once the shoulder is blown out or, reset the headspace. And if the case is loose in the chamber, (short headspace) it can blow the primer out of the pocket, get pierced by the firing pin before as the round gets fired.
I would back off the powder charge about one grain and go from there. And if the primer is blown out, more than likely the case is junk if the primer won't stay in place. Brass is cheap. Throw it out.
And my guess is if it's a factory chamberd barrel, you can't reach the lands with the lighter bullets? Load a couple long. (single feed) Stuff the bullets into the lands. That will hold the case back against the bolt head and see if you still have the same problem.

[gotcha]

F/L sizing dies are notorious for over-sizing cases. ( HD SP too short) I have a F/L die that reduces fired brass HD SP by .012" when set to the shell holder. You didn't mention If you put tape on base of case when you HD SP'ed? If I understand correctly you are basicly using your F/L die as a HD SP gauge. If your die is over-sizing, which is possible, You are reducing the size of the chamber & the sized cartridge. Lower case volume = higher pressure. We're here to help. If you can provide more details we can be more specific. Example: Do you have a HD SP comparator to meas. differences in un-fired, F/L sized & fired brass? Is it possible the case used for HD SPing was crushed slightly? So, please give us more info so we can get out of the realm of SWAG. Thanks, Dale

[cowboybart]

The brass is once fired stuff that I traded into. I wanted to FL size them in order to get them all the same size. I used a FL sized case as a go gauge. I did not put tape on the case to try for a "no go". The dies are an older Herters set and should be good dimension wise. I talked to a local 'smith about using factory ammo to headspace on and he said that factory ammo now a days is so undersized that it won't give you an accurate reading. I do not have a case comparator or any way of measuring to a datum line.
I'm gonna go over headspacing and see if I can tighten it up. Maybe it moved when I tightened the barrel nut.

[gotcha]

O.K......... When re-Hd SPing lay a piece of tape across bbl, BBL nut & receiver. Cut tape w/ razor at front of bbl nut & at bbl nut/ receiver mating surface. Any movement of tape alignment of BBL upon torquing would indicate movement. Try to grip the bbl in vice as opposed to gripping receiver since the heavy bbl will impart lotsa' leverage on bbl threads making it more difficult to turn bbl. "Shade tree" HD SP gauge: A 1/4 " drive, 5/16th socket will slip over cartridge neck & rest on shoulder. (22-250) & allow you to take comparative readings. Your unsized 1X fired brass would be a better go-gauge. ( hope you've got a few you haven't F/L sized yet) You're taking a bit of a chance that the 1X fired brass came from a properly HD SPed chamber. You'd know that better than I, so procede w/ that in mind. ..... Fill the case w/ epoxy to prevent crushing it when HD SPing. Once you've got the chamber dimensions right we can eliminate that variable regarding blown primers. Any Questions? PLEASE ask. Lotsa guys here w/ more "smarts" than me. I'm sure they'll chime in too :D Dale

[GaCop]

When it's all said and done, the use of a proper GO gauge will eliminate variables. The GO gauge can also be your NO GO by putting a piece of Scotch brand tape on the base. The bolt should just start to move and then abruptly stop indicating your head space is good. I recommend investing in a Wilson case gauge, it will show you if your brass is being correctly or incorrectly sized.

Try a piece of Scotch tape on your sized cases. If the bolt closes on that, your head space is way too loose. Your sizing die should be bumping the shoulder about .002/.003". What is the base to shoulder dimensions of your brass fired in the chamber?

[brtelec]

I could not agree more with GaCop. You should always head space with a proper go gage. Your problem definitely sounds like a head space problem, but regardless of what it turns out to be head space should be addressed first.

[Wildboarem]

I have a Stevens 200 I built to a .260 rem in a CBI barrel. I used the case method to set my headspace. I haven't had any HS problems but I too have blown primers. Mine was do to tighter neck dimensions in my chamber (tight chamber). The cases that measure over .0015 have issues so I have to turn all my brass down to .0012-13. I read a post on here where someone was having the same issue. It was pointed out that if a bullet would not drop freely into a fired case neck, either the case was to thick or the chamber was tight. I haven't had a problem since neck turning ( unless I accidentally forget to turn one, it will blow the primer) Not saying this is the issue but it could be.

[stangfish]

I want to add to GaCop's advice. Set your headspace to the correct gauges and then set your die to match that headspace. You will need to get a means of comparison between a once fired case and a resized case such as the Hornady headspace gauge kit to use with calipers or any of the other quality case gauge manufacturers.
Hornady



RCBS



Read the part about resizing brass and how far to bump the shoulder back.

http://www.kriegerbarrels.com/Proper...246-wp7875.htm

[cowboybart]

I set the headspace tighter - Gonna see how that works.

[scope eye]

Also you can also set the bullets deeper in to the brass that will relive pressure.

[Blue Avenger]

all the brass is the same brand? Mixing case brands could do it.

[keeki]

I always use a resized case and have never had a headspace problem. I use once fired factory brass, bump the shoulder back .002" and screw the barrel down to it with my hands as tight as I can get it. Then I lock my nut down with a stout blow from a wooden mallet. put some scotch tape on the brass and its very hard to close, put another piece on and it wont close. Always good to go. You definately have a headspace problem though because I shoot 36.8gr of 4064 with 55gr bullets and have no problem.