Headspace and blown primer

[Bill K]

Looks and sounds too me, that that load, that you had for other rifles, was too hot for this one and the way it is set up.
Do they work fine in the rifle they were originally loaded for ?
If so, then you may have your answer. Don't use them in the new rifle.

 

[Trtr0611]

The bolt looks severily damaged to me. Are the black areas carbon or pits? Has to be hot loads.

It was pretty dirty. I’ll post a cleaner pic. There don’t seem to be any pits but it looks like there is a small scratch by the firing pin hole.

 

[linebaugh]

To generate that pressure you are not having a simple headspace problem. As noted above in other posts start looking elsewhere.
Your neck is possibly long for the chamber or (probably the actual culprit) you had an overcharged load or possibly the wrong powder or bullet weight.

 

[Trtr0611]

Looks and sounds too me, that that load, that you had for other rifles, was too hot for this one and the way it is set up.
Do they work fine in the rifle they were originally loaded for ?
If so, then you may have your answer. Don't use them in the new rifle.

I’m thinking that is the answer. I had loaded that round for another rifle. That particular rifle had shot those loads just fine. As I said before I’m gonna put some factory loads through it before I load any more handloads. I just hope I didn’t damage anything.

 

[Trtr0611]

To generate that pressure you are not having a simple headspace problem. As noted above in other posts start looking elsewhere.
Your neck is possibly long for the chamber or (probably the actual culprit) you had an overcharged load or possibly the wrong powder or bullet weight.

I’m thinking the culprit is definitely the ammo.

 

[Bill K]

If you cycle a couple rounds, without firing them and they feed and eject as they should, nothing is probably damaged with one max round.
See then how the factory rounds feel, do and measure them after firing. Hopefully all will be fine, then just load rounds, worked up in this rifle and it's chamber. Safe and sound is the way to play.

 

[INTJ]

I recently put a Savage pre fit barrel on a Axis receiver. I also replaced the stock with a Boyd’s Pro Varmint. When I installed the barrel I checked the headspace with certified gauges. I got the stock fitted well and the barrel floated. I measured the OAL at 2.853 with a Hornady gauge. I didn’t have any factory ammo but had some handloads at 2.8 OAL. I had fired these loads through another rifle. I also measured the case headspace with a Hornady comparator at 1.625. When I fired the first round everything felt ok but when I went to open the bolt, the bolt slid out about an inch and hung up. The case was still in the chamber and the extractor was riding the rim of the receiver opening and binding up. I took it to a gunsmith and he got the extractor loose and the case was not stuck. He looked it over and put a bore scope in it, checked the headspace and said it looked fine. I know I should have put factory loads through it but I’m stumped why the primer blew out so severely. It blew the case head out so much it won’t fit in a shell holder. It also looks like there is a small mark on the bolt face. I can put up pics later. My thought is maybe the case had too much headspace and slammed into the throat of the chamber causing over pressure. Does 1.625 seem short on headspace? Anybody that loads .243 mind giving input? Thanks

The weird part of this the bolt coming back and inch then hanging up. Cases are tapered and even if a hot load freezes the bolt, once the case starts moving out it usually comes out.

Something I have seen frequently is if a case has been fired in a larger diameter chamber a couple of times, sized, then fired in a smaller diameter chamber, there will likely be resistance when lifting the bolt, especially at the top of bolt lift as the extraction cam is engaged. That isn't due to a hot load, it's just that the brass seems to "remember" it's larger diameter and tries to go back.

Regardless, the right answer in this situation is to start over with new brass and a mild load. If this chamber is tighter in diameter then you won't likely be able to use brass fired in another chamber for it.

 

[Trtr0611]

The weird part of this the bolt coming back and inch then hanging up. Cases are tapered and even if a hot load freezes the bolt, once the case starts moving out it usually comes out.

Something I have seen frequently is if a case has been fired in a larger diameter chamber a couple of times, sized, then fired in a smaller diameter chamber, there will likely be resistance when lifting the bolt, especially at the top of bolt lift as the extraction cam is engaged. That isn't due to a hot load, it's just that the brass seems to "remember" it's larger diameter and tries to go back.

Regardless, the right answer in this situation is to start over with new brass and a mild load. If this chamber is tighter in diameter then you won't likely be able to use brass fired in another chamber for it.

I should have probably clarified a little better about the bolt. The handle lifted fine and when I pulled the bolt back, the extractor slid out of the side of the bolt and hung on the receiver. What happened was the force of the primer blowing out expanded the case head so much it dislodged the extractor and the detent ball came out. The extractor couldn’t catch the brass so it stayed in the chamber. The case didn’t stick at all. All the pressure went into the primer.

 

[carlsbad]

Sounds like a load issue rather than a headspace issue to me.

One of the reasons I don't like the savage design. The OP is chasing headspace, even after he and a gunsmith have confirmed it is OK.

 

[INTJ]

I should have probably clarified a little better about the bolt. The handle lifted fine and when I pulled the bolt back, the extractor slid out of the side of the bolt and hung on the receiver. What happened was the force of the primer blowing out expanded the case head so much it dislodged the extractor and the detent ball came out. The extractor couldn’t catch the brass so it stayed in the chamber. The case didn’t stick at all. All the pressure went into the primer.

Got it. Still, start with new brass and I think you will be fine.

 

[Trtr0611]

Sounds like a load issue rather than a headspace issue to me.

One of the reasons I don't like the savage design. The OP is chasing headspace, even after he and a gunsmith have confirmed it is OK.

I just ran a factory load through it and it was fine so I’m convinced it isn’t a headspace issue. What threw me off is the bullet that the bad round was loaded with measured OAL 2.85 in the new barrel. I believe the barrel I originally loaded them for measured about the same. The OAL of the round that was fired was 2.8 which should have been fine. I haven’t measured the COAL which could potentially be different in each barrel. I’m usually very thorough in checking the charges in my loads but I could have made a mistake. I’m fairly new to gunsmithing so could you explain the Savage design flaw? I’m not being sarcastic but I’m genuinely curious.

 

[carlsbad]

Allowing the owner to set the headspace can lead to errors or distractions. It isn't a design "flaw", per se, I just have seen problems with it and people making serious mistakes that open it up for criticism. I said i don't like it. I didn't say it won't work.

Your factory round also had a factory charge.

 

[338 Mollett]

It would be interesting to see how close the bolt is to the barrel.

 

[INTJ]

I just ran a factory load through it and it was fine so I’m convinced it isn’t a headspace issue. What threw me off is the bullet that the bad round was loaded with measured OAL 2.85 in the new barrel. I believe the barrel I originally loaded them for measured about the same. The OAL of the round that was fired was 2.8 which should have been fine. I haven’t measured the COAL which could potentially be different in each barrel. I’m usually very thorough in checking the charges in my loads but I could have made a mistake. I’m fairly new to gunsmithing so could you explain the Savage design flaw? I’m not being sarcastic but I’m genuinely curious.

Anyone who can safely reload can safely check headspace. In simple terms the bolt--minus firing pin and perhaps the ejector, needs to just close on a go gauge. It should also NOT close on a go gauge with a piece of cellophane tape fixed to it. If you don't like the cellophane tape on the go gauge then use a no-go gauge.

If headspace is a little tight that isn't terrible, but too loose is very bad. IIRC, a typical no-go gauge allows .004" headspace and a typical field gauge allows .006" of headspace. The cellophane tape on the go gauge allows .002".

 

[Trtr0611]

Something I failed to measure or check was the neck. On the load that blew, the neck measures about 50 thousands smaller than the factory load I shot through it today. A bullet will slide right into the factory neck but will not fit in the blown primer case. That makes me think the neck was jammed in and caused the over pressure.

 

[Trtr0611]

Anyone who can safely reload can safely check headspace. In simple terms the bolt--minus firing pin and perhaps the ejector, needs to just close on a go gauge. It should also NOT close on a go gauge with a piece of cellophane tape fixed to it. If you don't like the cellophane tape on the go gauge then use a no-go gauge.

If headspace is a little tight that isn't terrible, but too loose is very bad. IIRC, a typical no-go gauge allows .004" headspace and a typical field gauge allows .006" of headspace. The cellophane tape on the go gauge allows .002".

My go gauge has a very slight resistance and the no-go gauge won’t go at all. I’m thinking this isn’t a headspace problem.

 

[INTJ]

My go gauge has a very slight resistance and the no-go gauge won’t go at all. I’m thinking this isn’t a headspace problem.

Sounds perfect to me!

 

[Old Navy]

That makes me think the neck was jammed in and caused the over pressure.

If the case is to long the bolt is going to be very hard closing.

 

[Doom]

EDIT:
I missed the OP later post. Sounds to me like you had a hot load. Do you have another from the same session that you can disassemble and weigh the powder?

Original

I didn’t see COAL or COL. I would be suspicious that your bullet was in the lands. I suspect the two chambers on these barrels is quite different in the leade/throat area.

I doubt that the brass length is an issue, but that should be easy to check. Pull the bullet on the round, dump the powder, measure the mouth id, chamber the cartridge, eject it and re-measure.

 

[Trtr0611]

Update: Put 15 factory loads through the barrel with no problems. Put together 10 full length sized handloads and got a pretty good group on the last 5 shots. Now on to better load development and maybe bedding the stock. Thanks for all the replies and advice.