How to blowup your rifle

[Pdvdh]

As to how I charge the cases. I have one cartridge holder with primed and ready to go cases and one that is empty. I move one case over then I individually weigh each charge on a scale. Once the charge is ready I have a small powder funnel that I place over the mouth of the case. I then pour in the powder. Move the next case over and repeat. I do small batches, 20-50 max. In this instance it was just 20 rounds in total.

I don't know what others do, but after I have a batch of cases charged with powder, I use a flashlight to compare the powder levels in all of the casings while they're stacked side by side in the plastic case holder. It's pretty easy to identify even a 2-3 grain difference if the powder fills the cases up to anywhere near the shoulder. If I see any that look suspicious, I re-weigh them to make sure I wasn't daydreaming when I weighed the powder charge. I also like to reweigh a couple just to ensure the scale (electronic or balance beam) is consistent.

 

[Pdvdh]

Shot an awful lot of Fed 215 and Retumbo in cold weather. Though funky primer stuff can lead to a not ideal ignition!

Same here, with with both Federal 210s and 215s. A lot of it over chronographs. Haven't noticed any problems with ignition or with larger ES in cold weather over the years.

 

[Pdvdh]

It just wasn't like a full detonation that would blow the action apart.

Everything I've read over the years consistently indicates it's very hard to blow an action apart. It can be done, but a partial case full of powder detonating is not likely to do so. Just about takes a fast burning shotgun or pistol powder to rupture a modern bolt action rifle from the videos and articles I've seen/read.

 

[Pdvdh]

Yes operator error has to be considered, and it's easy, and comforting to let it go at that, but I believe every once in awhile (while we're waiting for ice out) to bat it around a little.

We've batted this with the ugly stick pretty good. Nothing wrong with that.
Best Post in this Thread was the picture of the Rem 700 parts and pieces. It prompts me to concentrate, establish a process, be methodical, and double check powder charges when reloading my ammo.
I've improperly charged casings in the past. But I've always caught it before seating the bullet. I've charged cases without primers in the past also. So **** can and does happen. The older I get, I seem to be more complacent and find that I make more mistakes while reloading. To make up for that, I double check things. I consider my best QA/QC check to be the visual examination and the comparison of each batch of powder charged cases - prior to seating a bullet in any of the cases.

 

[Magnumdude]

Here is the next idea that comes to mind. What is the possibility of an oversized bullet? Somehow a 338 in a 308 box? Not sure that it could even be seated. It seems like it would need to be something drastic like this to creat this much pressure.

Steve

The 338 bullet would not have chambered in the 30-378 chamber.

 

[J E Custom]

The detonation is just the whole powder column going at once vs a burn, the ones I've seen you could hear a very definite difference in the ignition, like a flint lock, hammer drop small pop then a large ignition accompanied by a puff out the action.
Powder bridging is also bad juju but I don't get that as a cause here with the 30 cal hole, fresh reload and a common powder for that case.

I had this happen once while fire forming one of my wildcats. The sound was exactly as you described. Having never heard it before, I stopped fire forming And went on to something else until I could get home and try to figure out what and why.

I went back to my loading notes and wrote down the load to compare with the load on the case card with the fire form loads to make sure I hadn't used the wrong load. Then I proceeded to pull the/a bullet from one of the loads to inspect everything and weigh the powder charge.

After everything checked out I knew that the fire form load I figured it was to low for the case capacity (119 grains of powder)even though the load was 106 grains behind a 250 grain bullet.

So I pulled all bullets and dumped the powder and started over with 108 Grains on some and up to 112 grains on the others with the intent to Look for the best fire form load and then use that Load from then on.

This was a new wildcat with zero load data and I had to start somewhere. 108 worked well but left the shoulder junctions less that sharp requiring one more fire forming to get Chamber dimensions.

The point is, even a 106 grain load can be a squib load based on the chamber volume, so you have to keep good records and pay attention
when firing any Load and don't make component changes with out reducing the load. I normally use the middle load for the parent cartridge for fire forming with good results and accuracy, but this was an unknown cartridge and had I not paid attention I could have made a mistake that would not be pleasant. The OP didn't get this chance but maybe others will when/if they hear this sound and quit before something happens.

Thanks for reminding me BG. Although I will never forget that sound, I don't want to hear it again. "EVER"

J E CUSTOM

 

[Winkfish]

I called Federal this morning. They indicated that their primers are designed for uniform ignition from -40 to +125F. They agree there was an obvious pressure issue but provided no recommendations.

 

[Winkfish]

Just got off the phone with Berger. Phenomenal conversion and they were very informative. I will be sending over some additional information to them and just as curious as many of the folks reading through this thread to see if they can assist in determining a root cause.

 

[Bowfishn]

What they didn't try to blame someone else before looking things over, hmmm I like them.

 

[Winkfish]

The folks at Berger gave me a call back after discussing the problem and looking at the photos I sent them.

Their response was that have have fielded a couple call from folks experiencing pressure signs in larger cartridges pushing heavy bullets. What they found in a couple instances was that the lands were too close to the bullet and that their was not enough of a jump resulting in pressure spikes.

They mentioned that in one case the rifle manufacture replace the barrel due to the lands being too short.

Just another variable to consider.

They asked if I could load up a dummy round and test to see what sort of jump I may have.

Given that the 190, 210 grain rounds have a different profile may account for some of the reason I did not see an issue before.

Hopefully the rifle will be in the hands of Bigngreen on Friday and we can see what that barrel / chamber looks like.

The folks at Hodgdon and Berger have been quite nice and the two tech guys I talked to actually know each other. It was nice to see that they took the time to look things over and provide a response.

 

[bigngreen]

Generally the Rem 300 RUM has a generous throat and the 230 seats out pretty good, well beyond mag length to reach the lands but I can put a solid number to that soon.

 

[orangediablo]

As someone newer to reloading and starting to work with my first cat, this is an awesome read. Can't wait to hear more.

 

[RockyMtnMT]

Out of curiosity, did they address the possible issue of differing copper alloys in the barrel?

Steve

 

[Snyper708]

They agree there was an obvious pressure issue but provided no recommendations.

I fired the first round. 3129fps and I couldn't lift the bolt. Something was seriously wrong. I broke off the bolt handle trying to open it at the range hitting it with my hand trying to open the action.

Was that the only "pressure sign" you saw while working up the loads?