22-250 blown primers!

[243winxb]

I broke down and bought new brass,Winchester. I started off with the 32.0 grn.Then I still had primers blowing out

I deleted the 31.3 gr suggestion, because you started with 32 gr. Do use the starting loads. The charge should not be the problem?

A tight chamber neck may be possible? Compare neck diameter of loaded to fired. Fired should be a bit larger.

 

[shooter1niner]

jonb,
Are you using a Wilson cartridge case gage? Or a gage that checks from the datum diameter on the shoulder to the case head? If not you need to. This will verify that you are not pushing the shoulder back too far when sizing.
Taking .002" off the breach face and reaming sounds a bit fishy to me. .002" is not much, a piece of loose leaf paper is about .003" to .0035" thick. Typically from min to max headspace is about .005" or .006".
To cut the breach face I'm pretty sure the barrel has to be removed from the receiver. The barrel then reinstalled and the chamber recut. I'm thinking you most likely didn't have excessive headspace to begin with.
This rifle have sights on the barrel? Smith would have had to take a full thread off in order to have the sights be located correctly when barrel reinstalled.
While I'm not a gunsmith I am retired toolmaker that worked in the toolroom of a gov't. arsenal.

I'm cornfused...

 

[jonb32248]

jonb,
Are you using a Wilson cartridge case gage? Or a gage that checks from the datum diameter on the shoulder to the case head? If not you need to. This will verify that you are not pushing the shoulder back too far when sizing.
Taking .002" off the breach face and reaming sounds a bit fishy to me. .002" is not much, a piece of loose leaf paper is about .003" to .0035" thick. Typically from min to max headspace is about .005" or .006".
To cut the breach face I'm pretty sure the barrel has to be removed from the receiver. The barrel then reinstalled and the chamber recut. I'm thinking you most likely didn't have excessive headspace to begin with.
This rifle have sights on the barrel? Smith would have had to take a full thread off in order to have the sights be located correctly when barrel reinstalled.
While I'm not a gunsmith I am retired toolmaker that worked in the toolroom of a gov't. arsenal.

I'm cornfused...

No to the case gauge just digital calipers. I said .002 from memory. Not sure what he told me. He did take the barrel off and then reamed it when finished. No it doesn't have iron sights. It's a custom job that never had them.It has a Mauser 98 action and hand carved stock. A gunsmith from when I lived in NYS made it back 35-40 yrs. ago. Thanks

 

[jonb32248]

I deleted the 31.3 gr suggestion, because you started with 32 gr. Do use the starting loads. The charge should not be the problem?

A tight chamber neck may be possible? Compare neck diameter of loaded to fired. Fired should be a bit larger.

I did check neck diameter from fired to unfired. Before is .248 fired is .257. Going by memory due to company here tonight for dinner.

 

[shooter1niner]

Digital calipers cannot tell you if the shoulder is pushed back too far. If it was it would create an excessive headspace condition although the problem would not be with the chamber but with the ammunition.

 

[jonb32248]

Digital calipers cannot tell you if the shoulder is pushed back too far. If it was it would create an excessive headspace condition although the problem would not be with the chamber but with the ammunition.

I'll see where this next step goes before I spend more money on tools. Burt thanks for the advice.

 

[shooter1niner]

enjoy your dinner and company...

 

[243winxb]

Homemade Comparitor-
Compare a factory ammo fired case to your full length sized case. The head to datum measurement of the sized case should be about .005" less/shorter then the factory fired case.

Use a 357 mag brass, as shown. A 38 special should work also. I use the wood to help alignment and raise the calibers up to the primer area. May work better with primers removed. These still have thee used primers.

Not checking chamber head space, only comparing fired vs sized brass.

 

[jonb32248]

View attachment 764157 View attachment 764155 View attachment 764156 Homemade Comparitor-
Compare a factory ammo fired case to your full length sized case. The head to datum measurement of the sized case should be about .005" less/shorter then the factory fired case.

Use a 357 mag brass, as shown. A 38 special should work also. I use the wood to help alignment and raise the calibers up to the primer area. May work better with primers removed. These still have thee used primers.

Not checking chamber head space, only comparing fired vs sized brass.

Ok I will look into it tomorrow, thanks.

 

[Leatherstocking]

Agree with Shooter.
Can't really imagine how a primer can fall out before you open the bolt, in a bolt gun. Or even back out eneough to fall out as the bolt is opened. Have you compared the shoulder datum to base dimension of once fire brass to your FL sized cases?
When you pull the trigger, the the firing pin drives the case forward until the shoulder of the case hits the shoulder of the chamber. Pressure starts to rise, and the thinnest part of the case, the mouth and neck, expands and sticks to the chamber. The primer can back out at this point. Then the case stretches until the base hits the bolt, driving the primer back into the primer pocket. If the length of the case from shoulder to base is too short, this is thought to cause case head separation.
What I'm getting at is if you have a longer chamber, and a shorter case from base to shoulder, that might be a problem to consider.
Also wonder what kind of scales and how you calibrate them.
Hope you sort it soon.

 

[jonb32248]

Agree with Shooter.
Can't really imagine how a primer can fall out before you open the bolt, in a bolt gun. Or even back out eneough to fall out as the bolt is opened. Have you compared the shoulder datum to base dimension of once fire brass to your FL sized cases?
When you pull the trigger, the the firing pin drives the case forward until the shoulder of the case hits the shoulder of the chamber. Pressure starts to rise, and the thinnest part of the case, the mouth and neck, expands and sticks to the chamber. The primer can back out at this point. Then the case stretches until the base hits the bolt, driving the primer back into the primer pocket. If the length of the case from shoulder to base is too short, this is thought to cause case head separation.
What I'm getting at is if you have a longer chamber, and a shorter case from base to shoulder, that might be a problem to consider.
Also wonder what kind of scales and how you calibrate them.
Hope you sort it soon.

I don't have the knowledge that you guys have on all this. All I can say is when I open the bolt the primer is somewhere under the bolt, etc. The primer pockets are too big after to accept a new primer so they are garbage.I don't have any way to measure the chamber and has been my a thought that maybe the bullet is touching the lands. But if I am under the maximum length, wouldn't the round be far enough away to not cause over pressure? The scale is a Franklin and I cal. using the weight included. The other one is similar, I forget the manufacturer.I also have an RCBS balance beam.I will check one against the other.

 

[MEHavey]

34gr is a 50ksi load in a 65ksi cartridge.... 32gr is 42ksi ......walk in the park at any reasonable case volume.
Completely blown out primer/pocket is 80,000 psi (+)

Something else is going on -- grossly wrong -- either powder weight/energy is wrong, or the neck is not releasing.
- Does the cartridge drop* freely/completely into the chamber (aka semi-plunk test) and then simply drop back out when you raise the rifle vertically? Or does it stick in the chamber ?
- Do you have check weights for the scale ? (and/or... how much does that 53gr Hornady weigh when on the scale?
- Last (if last variable/powder is suspect) go get some IMR4895, and try 34 grains of that.

* Push it in hard w/ your thumb. Does it stop dead, or feel like you're press-fitting the last bit in and sticking?

 

[jonb32248]

34gr is a 50ksi load in a 65ksi cartridge.... 32gr is 42ksi ......walk in the park at any reasonable case volume.
Completely blown out primer/pocket is 80,000 psi (+)

Something else is going on -- grossly wrong -- either powder weight/energy is wrong, or the neck is not releasing.
- Does the cartridge drop* freely/completely into the chamber (aka semi-plunk test) and then simply drop back out when you raise the rifle vertically? Or does it stick in the chamber ?
- Do you have check weights for the scale ? (and/or... how much does that 53gr Hornady weigh when on the scale?
- Last (if last variable/powder is suspect) go get some IMR4895, and try 34 grains of that.

* Push it in hard w/ your thumb. Does it stop dead, or feel like you're press-fitting the last bit in and sticking?

Very informative! I will be looking into this method, never heard of this but will ck. The bullets all vary slightly but rught around either 52 or 53 depending which one I'm using, right now 53.Yes I have the ck weight and ck before use.

 

[RugerOldArmy]

Taking .002" off the breach face and reaming sounds a bit fishy to me.

Yep. It sure doesn't sound like much. I would expect a smith to cut more off the breach, re-thread, and ream. On a straight barrel, more like an inch. Was this a tapered Sporter barrel?

Hopefully, there was a miscommunication on that.

It may still be a matter of the old brass, already abused from firing in a chamber with excessive headspace. As I understand it, the fired new factory cartridge brass is fine.

 

[jonb32248]

Did the plunk test with two new cases and bullets no primer for now. Went right in without any resistance and dropped right out again.Will load up three rounds tomorrow and test fire. One of two load manuals I have (Sierra) have min. load at 32.5 gr. I think that's a good place to start.

 

[Leatherstocking]

749-005-148WS
Hornady Lock-N-Load HeadspaceTool Set w/Bushings

Mfr Part: HK66

Above is the more accurate version of the 357 case as recommended by 243win. Part # from Sinclair International.

 

[Nature Boy]

Carbon?

Never tried or used, but maybe worth a try. http://www.boretech.com/products/c4-carbon-remover

Had carbon build up in my old 40x, took a lot of scrubbing to remover with #9 and a brush. But there was NO increase in pressure that i could see on fired brass.

The carbon ring can be felt when running a tight patch into the bore. It seemed to be right at or a little past the throat/leade area.

All else being OK, I vote for carbon ring in the throat

 

[Blue68f100]

What's the history on the powder? Old new? Could be you have powder that has/is going bad running the pressures up. Also confirm your using rifle primers and not pistol. They are rated for different pressure ratings and you can not use a pistol primer in a rifle.

 

[JackSprat]

I guess you could start conducting experiments like pulling a bullet from a couple factory shells,and dumping the charges in your reloading brass,and seating the pulled bullet in one at the same OAL as factory,and seating your reloading bullet in another like you normaly do,and I would also run one of the brass that you pulled the bullets from through the sizind die,and load it as normal,and see if it causes any issues..I guess you could also pull the bullet from a factory shell,and size it with your dies,and put the factory powder,and bullet back in place and see if it causes problems..I bet your gunsmith would rebarrel it free,or very cheap if you supply the barrel, since you have already spent money on him,and it didn't resolve your issue.

 

[jonb32248]

Powder is brand new. I am planning on cleaning this morning. Not long ago I did do a do a cleaning with Barnes lead removal solution. So I don't know how much could be there now.

 

[MEHavey]

- If you some commercial ammunition, try it: If no problem -- then no problem with the rifle/the barrel/the chamber/the throat. (and cleaning ain't the problem at those pressures either)
- If the bullet weighs out correctly (as it did): Then no problem with the bullet/weight/powder recipes in the manuals -- or the scale itself
- If the primer is standard large rifle: Then no problem with the ignition. (even a pistol primer wouldn't blow itself and the pocket out completely. It would just pierce)
That pretty much leaves us with a powder problem.

Again, I'd go beg/borrow/steal a couple tablespoons of IMR4895, and load w/ 34 grains of that to get a handle on whether we have a bad powder lot

 

[jonb32248]

View attachment 764157 View attachment 764155 View attachment 764156 Homemade Comparitor-
Compare a factory ammo fired case to your full length sized case. The head to datum measurement of the sized case should be about .005" less/shorter then the factory fired case.

Use a 357 mag brass, as shown. A 38 special should work also. I use the wood to help alignment and raise the calibers up to the primer area. May work better with primers removed. These still have thee used primers.

Not checking chamber head space, only comparing fired vs sized brass.

Now if I understand this correctly. Take a larger caliber case, I don't have .357 or .38 so I used a .40 cal, and put my case inside the .40. I did this and came up with the measurement of .005". shorter. I never heard of this but hope this is what you meant.The .40 goes against the shoulder of the 22-250, correct?

 

[MEHavey]

You don't have a headspace problem with that degree of primer/pocket destruction.
But am I seeing that the rifle does fire commercial ammunition OK?

 

[jonb32248]

You don't have a headspace problem with that degree of primer/pocket destruction.
But am I seeing that the rifle does fire commercial ammunition OK?

Yes factory ammo works fine with no sign of over pressure like flattened primers.Just so aggravating when you think the problem is solved but it's back. I went back last night and checked the fired cases that I used thursday at the range and they were all 'older' brass.I kept one of the cases that the primer came out but threw away the other two. So I don't know if the other two were new brass or not.Before the repair I was experiencing primer's coming out on new cases. Today I will load new cases and test fire them, I appreciate all the input. This is the only site I have found that has help like this.

 

[MEHavey]

Then I'm going to out on a limb and suggest that 4895 switchout.