I think I killed my .243

[SaskShooter]

The other day, I loaded up a few rounds for my .243 Winchester, and tried out some new powder- Winchester 760. I loaded up some 95 gr Nosler Ballistic Tips over 41 grains of 760. The Lee Reloading Manual lists a maximum charge of 42 grains, so I figured 41 would be just fine.
This rifle usually shoots under MOA, but with this load, it put my first two shots very close together, then the rest shot around 2 MOA. Weird.
Once I finished shooting, I grabbed my brass off the ground and noticed that one of the shells was very black and had a small hole in the case head. It was just touching the edge of the primer. Further inspection revealed a matching dent in the .243's bolt face.
I checked and double-checked, and my powder charge was, indeed, set at 41 grains.

All subsequent groups from this gun have been 1.5- 2 MOA, and showed erratic tendencies, or stringing.

Anyone have any advice, or is my beloved .243 now a wallhanger?

 

[Marble]

Take it to a smith and pray for mercy.

 

[el si]

You blew a weak spot in the primer or primer pocket. The result was flame cutting of your bolt face.

 

[SaskShooter]

You blew a weak spot in the primer or primer pocket. The result was flame cutting of your bolt face.

So, are you saying it was possibly an issue with the brass or primer?

 

[7 loader]

OOPS! Always start at the lower end of the powder charges. Never that close to the top. Every gun is not alike. Your max may be lower than than the gun the manufacture used to develope the info in the book.

 

[SaskShooter]

I know, I'm a *******. I have already tried loads with Varget and Benchmark (starting at the bottom, and working up slowly), and at least 7 different bullets. Every time, I could not get any accuracy until I was near maximum, so I ASSumed I'd be safe with a grain below max, as I had never had any signs of excess pressure before.

 

[MachV]

If a gun can throw them out to 2moa they can throw them into one hole every once in a while=2 shots dont make an accurate load!
As long as the primer just flame cut the bolt and nuthing is sticking up you are where you were(did I spell that right?)
W760 and H414 have been great powders for me over the years but they tend to be a lot temp sensitive and prone to spikeing at the top end. In your case I'll bet it was just a weak spot in the brass/primer though. The Lee manual must have some age to it as 41grains of W760 is about 3 grains more than I would start with? I use W760 and H414 for 55 grain BT loads but use a slower powder(Hunter,R22,Retumbo or Magnum) for the 95-105s

 

[Canadian Bushman]

I agree with mach V. In my experience, I dont get very good accuracy with my loads near max. I would make sure the bolt face has no raised metal and try again working up like you did with the other load combinations.

 

[SaskShooter]

I agree with mach V. In my experience, I dont get very good accuracy with my loads near max. I would make sure the bolt face has no raised metal and try again working up like you did with the other load combinations.

As I said, I've tried three powders and at least seven different bullets, and I have never seen accuracy near MOA until I've gotten close to max loads.

Thanks God, there is no raised metal on the bolt face. Hopefully I'll be able to make that stringing go away yet...

 

[CogburnR]

I would clean the barrel well then put a tight fitting patch in and feel the barrel for loose and tight spots. If you don't feel anything weird try a load that was previously accurate(varget,4350).

I picked up a 7 mag cheap that had a barrel bulge right at the end from a hot load. Otherwise it checked out ok. My buddy cut off the barrel behind the bulge and it became a sub-moa shooter. I don't know how it shot for the guy that owned it before but it shoots well now after removing the bulge(about 1 1/4" off the end).

 

[Canadian Bushman]

I understand. Is there any way your accuracy problems could stem from another issue, not related to the cartridge. Maybe loose bolts on the stock, or barrel fouling.

Also do you have any proven loads that are loaded in once fired brass that you can test the rifle with?

 

[7 loader]

I know, I'm a *******. I have already tried loads with Varget and Benchmark (starting at the bottom, and working up slowly), and at least 7 different bullets. Every time, I could not get any accuracy until I was near maximum, so I ASSumed I'd be safe with a grain below max, as I had never had any signs of excess pressure before.

That is strange. But my 7mm is like that. Except with tha Hornady rd nose 154 gr. They shoot 1.5 in at 100 yds with all loads. these are my "Bush Hogs" for hunting in heavy cover.

 

[SaskShooter]

I'll be testing out a few more things yet. I already disassembled and reassembled to make sure everything was tight, bedding looks good, so I'll give it a try with one of my proven loads- 70 gr Nosler Ballistic Tip over 40 grains of Varget.