Blown primers on 6.5 CM-Problem Solved on page 6!

[Oldtime Shooter13]

Nosler Load Data

https://www.nosler.com/media/load_data_assets/pdfs/6.5-CM-140gr-version-9-0.pdf

You should also take bullet measurements and primer in consideration when creating your own load from manuals. Your load is clearly over max to blow primer not only once but three times. Looks like your other shot is cratered. 41.0 grains is max load for 140-142 Nosler bullet with Federal 210 primer and Nosler brass. I would back your load down 8-10%. 6.5CM is not going to be a rocket ship with heavy bullets. I found 6.5 CM to be accurate with heavy bullets, but if you are looking to get 3000fps, it's not your huckleberry! You will find accurate loads for 6.5 CM with heavy bullets 140-143gr. In the 2500-2600fps range. CM is not a 6.5-284. I've got a 7mm to cover my 140-175gr. Hunting needs.

 

[Lefty7mmstw]

I have the RCBS Chargemaster and a Franklin Arsenal electronic scales, and I weigh every charge on both scales. If it's more than a tenth off, it goes back into the hopper. It's possible they are both off, but they'd have to be both off on the same load.

not really a fan of electric only on scales. I see way too many issues dumping charges from my Lyman to my RCBS 505 beam to trust the electric scale for much at all...

 

[Lefty7mmstw]

Nosler Load Data

https://www.nosler.com/media/load_data_assets/pdfs/6.5-CM-140gr-version-9-0.pdf

You should also take bullet measurements and primer in consideration when creating your own load from manuals. Your load is clearly over max to blow primer not only once but three times. Looks like your other shot is cratered. 41.0 grains is max load for 140-142 Nosler bullet with Federal 210 primer and Nosler brass. I would back your load down 8-10%. 6.5CM is not going to be a rocket ship with heavy bullets. I found 6.5 CM to be accurate with heavy bullets, but if you are looking to get 3000fps, it's not your huckleberry! You will find accurate loads for 6.5 CM with heavy bullets 140-143gr. In the 2500-2600fps range. CM is not a 6.5-284. I've got a 7mm to cover my 140-175gr. Hunting needs.

yup... we are what I consider to the wall in the creed that found itself in my house just under 2700 fps with a 143 eld-x or 140 Speer... 41 h4350 in hdy brass on the eld-x and 43 I 4831 with the 140 speer... a component switch to heavier walled brass wouldn't work without a powder charge drop for this rifle.

 

[pdog shooter]

I just cant wrap my head around the part when you though it was ok to shoot the second shot. And the third shot? You know the definition of insanity? Not saying you are insane here. But did you really expect the third time would be better? You blow a primer like the ones in your pics and you pull the plug right now on that load. And yes the difference in powder capacity is probably what caused your issue. Plus the fact that you didn't start low and work up. These are golden rules of reloading that can never be deviated from. It's probably the number one rule every reloader learns when he starts. Your situation just confirms this as a must. Thanks for sharing. If it keeps only one more person from a world of hurt it was worth your effort to post this. Safety first.
Shep

Thats what the vent holes are for
How do you do the emogi things?

 

[Lefty7mmstw]

I just cant wrap my head around the part when you though it was ok to shoot the second shot. And the third shot? You know the definition of insanity? Not saying you are insane here. But did you really expect the third time would be better? You blow a primer like the ones in your pics and you pull the plug right now on that load. And yes the difference in powder capacity is probably what caused your issue. Plus the fact that you didn't start low and work up. These are golden rules of reloading that can never be deviated from. It's probably the number one rule every reloader learns when he starts. Your situation just confirms this as a must. Thanks for sharing. If it keeps only one more person from a world of hurt it was worth your effort to post this. Safety first.
Shep

Italian tune up for the rifle... Blow enough carbon out and it'll run fine... Seriously, one blown primer is a big enough red flag to stop and reassess the entire situation as that kind of pressure can/will cause metal fatigue even if the rifle properly vents the blown case.

 

[bomberodevil]

Nosler Load Data

https://www.nosler.com/media/load_data_assets/pdfs/6.5-CM-140gr-version-9-0.pdf

You should also take bullet measurements and primer in consideration when creating your own load from manuals. Your load is clearly over max to blow primer not only once but three times. Looks like your other shot is cratered. 41.0 grains is max load for 140-142 Nosler bullet with Federal 210 primer and Nosler brass. I would back your load down 8-10%. 6.5CM is not going to be a rocket ship with heavy bullets. I found 6.5 CM to be accurate with heavy bullets, but if you are looking to get 3000fps, it's not your huckleberry! You will find accurate loads for 6.5 CM with heavy bullets 140-143gr. In the 2500-2600fps range. CM is not a 6.5-284. I've got a 7mm to cover my 140-175gr. Hunting needs.

I was using the Hodgdon load data since it used the same primer, bullet and powder, and I was below the max in their data. I don't load anything for max velocity, but for accuracy. On my 6.5 CM, 270 Win, 270 AI, and 30.06, all my velocities for hunting loads are well below what many others post, and I'm good with that. I'm not trying to max the speed. Usually the best accuracy is within a grain of book max, so that's why I was starting there. My starting load also is more than a grain below what I have with the exact same rifle and load, with the difference of Nosler 140 AccuBond bullets vs the ELDX, at .030" off the lands. I made an assumption and I was wrong.

 

[JAYgs8163]

I know, I should have stopped immediately, that was really sloppy of me. I'd never had a blown primer before, after many years of hand loading. I guess it wasn't sinking in what the issue was at first. I knew there would be different characteristics between the manufacturers of brass, I just wasn't expecting that big of differences. I knew before to start low, and I thought I was low enough. Lessons learned!

Thanks to you all for your feedback. It's never too late to learn and hopefully my mistakes will help someone else down the road.

"Low enough", not even close to the low enough and work up standard. I probably would've started 2-3 grains off max data, especially when you have varying components from what the published manual/data shows. Anyways….. lesson learned hopefully!!

 

[436]

I have the RCBS Chargemaster and a Franklin Arsenal electronic scales, and I weigh every charge on both scales. If it's more than a tenth off, it goes back into the hopper. It's possible they are both off, but they'd have to be both off on the same load.

Can you double-check your RCBS with a good balance beam scale? I've never dealt with the Frankin, but I do have an RCBS Chargemaster and they can go a little wonky if any powder goes down the powder balance plate hole.
The second thought, which someone may have brought up is an enlarged primer pocket. Good luck, Cheers

 

[pdog shooter]

Have you notice that Hodgdon load max for 147 is greater by 1.8 grains that for 140 bullets? Cant figure.

 

[Rosebud]

I know, I should have stopped immediately, that was really sloppy of me. I'd never had a blown primer before, after many years of hand loading. I guess it wasn't sinking in what the issue was at first. I knew there would be different characteristics between the manufacturers of brass, I just wasn't expecting that big of differences. I knew before to start low, and I thought I was low enough. Lessons learned!

Thanks to you all for your feedback. It's never too late to learn and hopefully my mistakes will help someone else down the road.

Wait until you get a case head seperation. I've only had one in 40 + years of loading. After about the fifth firing I start looking for the ring around the head inside the case. Use a paper clip bent into the shape of all letter L, scrape the inside, if you feel a grove in the bottom toss them, they're about to go.

 

[jsthntn247]

Measure the diameter of the bullets. Chance you got some over size.

 

[bomberodevil]

Can you double-check your RCBS with a good balance beam scale? I've never dealt with the Frankin, but I do have an RCBS Chargemaster and they can go a little wonky if any powder goes down the powder balance plate hole.
The second thought, which someone may have brought up is an enlarged primer pocket. Good luck, Cheers

I have a Dillon beam scale that I use on occasion to confirm the electronic scales. I don't have 100% confidence in the electronic scales, but I do measure every load on two scales, with the thought that both likely won't be off the same amount on the same load. If they are off, I re-weigh them. If they are off twice, I dump the powder back into the hopper and re-dispense the charge.

 

[Chas1]

I never start near max load. drop back to at least 39.

 

[bomberodevil]

Measure the diameter of the bullets. Chance you got some over size.

Never thought of that one, I'll do some spot measurements.