Finally over pressured one

[Xxtavixx]

Everyone says it is bound to happen, and I while it is cliché to say, I thought it would never happen to me… I thought it would never happen to me. I keep a good process, I only do one caliber at a time, I have a digital meter, and I load in strict stages. I use a process I figured out over 10 years of reloading now.

I had to redevelop the load for my Savage 116 (110 action in stainless) 270 win as the powder of choice is no longer available so I hit the range yesterday to double test the two most promising loads from this development, so I have shot both of these loads before with no issues. I do groups of five and on shot number 9 I experienced over pressure, 32 degrees at time of event.

The bolt was difficult lift and frozen in forward position, I had to use a 2 x 4 with a small rubber mallet to complete extraction. The brass stayed in the chamber and I used a cleaning rod to push it out. Primer fell out. There were no other indications of over pressure from that shot, other than it being 400 fps faster than expected. Buy the books I was near or at maximum load, but my bullet is seated to be off the lands, which in my rifle is quite the jump.

I took apart the next round from that group and measured the powder and bullet diameter and confirmed my seater was appropriately adjusted. I have no idea what went on with that one round to cause an over pressure, but it happened. My best guess is over thrown powder charge and I did not notice.

I cleaned everything up, nothing I can see looks out of issue. I put in a sized brass with primer and fire function is working, ejection works, etc. Should I have the firearm inspected at this point? Any input?

 

[czgunner]

All same headstamp/lot for your brass?

Sent from my Pixel 3 using Tapatalk

 

[ResearchinStuff]

Any chance that case was wet when you chambered it?

 

[Harvey_NW]

Did you get a magnum primer mixed up in some LRP?

Only other thing I can think of is that I've had my funnel clog up and not dump all the powder into a case, only to move it to the next without spilling, and then dumping a charge on top of that. Typically I use powders that are close to case fill anyways, but if the perfect storm happened I could see that being possible without ever noticing.

 

[Xxtavixx]

All same headstamp/lot for your brass?

Sent from my Pixel 3 using Tapatalk

All starline and same batch

 

[Xxtavixx]

Any chance that case was wet when you chambered it?

dry

 

[Xxtavixx]

Did you get a magnum primer mixed up in some LRP?

Only other thing I can think of is that I've had my funnel clog up and not dump all the powder into a case, only to move it to the next without spilling, and then dumping a charge on top of that. Typically I use powders that are close to case fill anyways, but if the perfect storm happened I could see that being possible without ever noticing.

That is a great point, mine does that if I pour the powder too quickly. Ive always noticed it before, but this is a new powder. I think you are on to something here.

 

[TaperPin]

Sounds like a 7mm bullet was fired in the 270, or powder was mistakingly poured back into the wrong can. I’d at the very least measure any open boxes to see if there are other bullets in the wrong box, and visually check the powder for signs of cross contamination.

By filling all cases with powder before seating bullets and visually comparing them with a flashlight, any odd charges are easily seen. 400 fps isnt likely a primer or few grains of powder. Never returning unused powder back into the can, or at least only allowing one can on the bench at a time eliminates the chance of cross contamination.

It’s a pain, but I’ve seen oddball bullets in a new box, so I measure every one so there isn’t a wrong diameter from the factory, let alone me or someone else mistakingly putting a bullet in the wrong box.

In my 270 a 7mm bullet in a 270 case has enough room to chamber just fine, which scares the heck of me.

Wasn’t it about a year ago when the fellow with a 270 Wby fired a 7mm bullet in his rifle?

 

[Wrench]

I've had re26 do that. Shoot 150 and all is well and I'm enjoying the much faster than published velocity and then..... wammo! Blown primer and all hell broke loose.

If you sand that case in half from the side, you'll probably find the middle of the case has thinned a lot.

 

[Pharmseller]

By filling all cases with powder before seating bullets and visually comparing them with a flashlight, any odd charges are easily seen. 400 fps isnt likely a primer or few grains of powder.

This is what I do, too. Only takes a few seconds.




P

 

[Xxtavixx]

I've had re26 do that. Shoot 150 and all is well and I'm enjoying the much faster than published velocity and then..... wammo! Blown primer and all hell broke loose.

If you sand that case in half from the side, you'll probably find the middle of the case has thinned a lot.

I get the feeling that is about to become one of my practices

 

[prm]

That much pressure is something big. In my experience a primer alone or a small amount of powder would not cause that.

 

[Wrench]

That much pressure is something big. In my experience a primer alone or a small amount of powder would not cause that.

100% either a bit of pistol powder left over or a double base did it's voodoo.

 

[waspocrew]

Which powder and bullet? What charge? Not saying an overcharge didn’t happen, but it’s less likely compared to pistol cartridges that only require a small amount of powder. Too much powder in a 270 win and you’d likely by crunching powder as your first clue.

 

[Gobihawk]

On the powder measure. I have a device hanging on the side. I tap it twice on every load. When I pour powder into case. I tap funnel twice.
My thought is too much powder. If you have enough loaded ammo. You could weigh them. If one is light. That could mean one was over.

I would take rifle to gunsmith and check out your rifle before shooting again.

 

[Xxtavixx]

Which powder and bullet? What charge? Not saying an overcharge didn’t happen, but it’s less likely compared to pistol cartridges that only require a small amount of powder. Too much powder in a 270 win and you’d likely by crunching powder as your first clue.

140g accubond over 54.7 of staball 6.5

 

[djfergus]

Staball 6.5 has a tendency to look like pressure is all good and get just a little bit more charge weight and suddenly way over pressure!

 

[justin davis]

I blew a primer the other day

 

[Xxtavixx]

Staball 6.5 has a tendency to look like pressure is all good and get just a little bit more charge weight and suddenly way over pressure!

I figured it would be temperamental given its velocity, but I still assume I goof’d.

 

[sndmn11]

400fps is like 9 grains.

I once was playing a ladder in 25-06 and wrote down 59.2 when it should have been 52.9. that's ended up being a 3700fps 120gr bullet.

I shoot staball 6.5 in my 30-06, and anything else it can be put in. I am using 59.8grs with a 180gr bullet, so I find it hard to believe the same case with a 140gr (despite being smaller caliber) and quite a bit lessnpowder would be enough to lock the gun up.

I don't have any guesses though.