Issues with over pressure?

[jb79]

So to start I am new to reloading and load development, I’ve read a ton on here and it’s been very help full but after yesterday I’ve got some concerns about my load.
Shooting a 300wm Christensen Mesa that was shooting pretty good with factory 180’s but wanted to try the 212 ELDX. Have a buddy that reloads that I trust, so he loaded me some bases off the nosler 210 he had in his book.
69.5 of 4831sc
CCI mag primers
3.45 OAL
not sure on brass as it was what he had

They group extremely well with most touching each other if not the same hole, should have taken a picture. The problem was a couple of the brass came out like this

and a few the bolt was extremely difficult to open after fired. We had 20 loaded and shot in 5 round groups letting the barrel cool in between. There wasn’t any signs that could tell of brass dis formation but did notice if the brass wasn’t perfectly shiny they seemed to be the ones that would come out. Hope this make sense!
My questions are, are we over pressured, should we back it down a grain? Is it the brass not being perfectly clean? Is it seated to deep, went of the factory loads I had but I am going to buy the tool to measure OAL.
Like I said it’s all new to me so any help will be appreciated.

 

[Elkslayer67]

Not sure what you are showing in the picture, if it is the neck not being perfectly round that more than likely is due to ejection.
Look at the primer to see about over pressure. The primer will be flattened into the pocket.
If not you probably are looking at one of the following dirty brass, brass length, or brass sizing. Are the reloaded rounds harder to chamber? Brass will fire form to the chamber of the rifle it is fired out of. If you reload it without resizing it it will work perfectly fine in the same rifle but have issues with another due to variance in chambering. The neck length lengthens with every shot and should be checked between reloads and trimmed. Hope this helps.

 

[jb79]

Yes the pic is to show the neck with a dent on one side, I thought the same thing so I was careful to grab one before it hit the table and it was also dented, it doesn’t happen on ever round just a few.
The primers didn’t seem flattened but will double check the spent cases.
Yes they were harder to chamber then the rounds that fired with no issue, so I stopped shooting those. We started separating my 300 brass from his so we could have form fire brass for each Rifle.
I am going to purchase new brass and give it another go. Thanks for the input

 

[Elkslayer67]

Sounds like all you need then is a full length sizing die (use on new and new to the rifle brass) and a case trimmer. The dent on the neck happens when the casing hits the receiver on ejection. The harder the ejection the more it dents. That is why you see it on the ones that stick.

 

[jb79]

Thanks elkslayer I’ll give it a go and report back, great place for info as always!

 

[tdot]

I can only offer advice based on my own experience. But when I wanted to get into reloading I was also helped by a friend. However once I really jumped in and learned from other sources, I was amazed at the lack of knowledge of the person who taught me, and honestly the bad/dangerous habits and methods he had. I have tried to show him a few new ideas since, but that has never gone very well. So I dont bother anymore.

Take this as friendly advice that I offer with hesitation. But there are a couple of bits of info in your story that would make me wonder. If your friend didn't help you to work up to the load that you tested in your rifle and had never reloaded for it. That's one concern. The fact that you had a stiff bolt lift and didnt stop to check, also a concern (doubly so, if you hadnt worked up to the load and know it was safe). Did he know before hand that the brass from the two rifles shouldnt be mixed? Was he looking for pressure signs at the primer and heasd of the case? And there are a few other little items that make me wonder too.

If it was only "dirty" brass that resulted in a stiff bolt lift. Could it have been oil on the case? It doesnt take much, but if the case can slip in the chamber during firing, it will result in a load that appears over pressure, while other matching loads dont.

 

[Boomer51]

extremely difficult to open after fired

Would make me concerned about a significant overpressure. Did you measure velocity?

 

[Mtslackcountry]

Using load data from a different bullet is red flag... hard bolt lift red flag. Unknown: if brass was clean, trimmed to spec, resized with full length resizing die. Lots going on here. Best thing you can do is get a reloading book and familiarize your self with the whole process. Good luck and be safe!!!

 

[jb79]

All very good points, I am learning as I go on the reloading side of things and plan to get my own set up when possible. I’ve talked to my buddy and we are going to start over again and work our way up as detailed in many threads on here, starting with new brass and full length sizing die. I appreciate all the advice and hope to report back with a good/safe load!

 

[Redrockhunter]

Best to back off.