Followup for Kaboom Today by OP gingerman/DoneNout

[Bob Wright]

that's what I am worried about Bob

I like the K&M neck turner with reaming pilot. If you cerrosafe cast your chamber, you'll know that neck diameter to turn brass to, and do it right after you neck down the brass. That would prevent fire forming issues you might have in the neck. Then keep inspecting as you go. Rich Sherman has seen it a bunch, GL Taylor, Bean, Lance Kenyon The list goes on.

 

[243winxb]

The case didnt stick in the chamber. If high pressure, it would have.

The brass may have been damage on the 1st fire forming.
If the KABOOM was on the 2nd firing, the stretch & high pressure already damaged the brass.

Link Bad brass, because of the nice even break? Would have been a lot different in a Remington 700 action.

 

[victor3ranger]

 

[MagnumManiac]

Anyone know what the correct diametrical clearance between the case neck and chamber should be?

.003" is ABSOLUTE minimum, even this dimension can cause issue if you do not measure your brass neck wall accurately.

Cheers.

 

[Dirtrax]

Ok, this has me concerned about the fireforming and necking down that I will be doing soon to form my 7STW brass.
This is all new to me even though I have loaded for 40yrs.
I am concerned about creating these donuts and not having the proper tools to remove them before loading up full power loads.
My initial forming will be the COW method

When forming brass for my 7mm Practical I used an inside reamer and skimmed the outside of the necks. I've never had to remove a donut since them. I use a mandrel on this cartridge so I may be pushing what little donut that forms out. I'm of the mindset that necking down causes more of a bulge at the neck junction than normal sizing. Therefore reaming it out initially is a very good idea.

 

[Calvin45]

Absolutely agree

Wait a minute where's he going? Did I miss something?

 

[fordy]

Gday Bob

Thankyou & wow from your skills to what happened

Cheers

 

[fordy]

Gday Calvin45

Wait a minute where's he going? Did I miss something?

He's a pig hunting or extremely close to going I believe or may have been

Overall He's sick of the white noise brigade & peanut gallery that inhabit here but I do believe he may return as he is one that is missed by some already I see & I'll personally let him know next time I chat to him as the knowledge he is prepared to share is one we should all be greatful for even though sometimes we may disagree

Not many will show how they messed up or what happened so others can learn from these things

It's a rare attribute to have these days & the true depth of his personal character

Cheers

 

[victor3ranger]

I for one really appreciate any knowledge and experience they can throw at me, I always felt that was the only way we learn and grow.
I hope he comes back

 

[Beluebow]

The brass may have been damage on the 1st fire forming.

+1

 

[Hand Skills]

Wait a minute where's he going? Did I miss something?

I think these two threads pretty much cover it;

Bullet Construction vs Lethality

www.longrangehunting.com

Did Wipeout Products Ruin My Barrel?

I let Wipeout Accelerator sit in my barrel for 45 mins yesterday. When I patched it out, rust colored product poured out the end. Now I have what looks like corrosion etching/deposits through the bore. I called Wipeout and was reassured I wasn’t seeing rust, just the chemical reaction between...

www.longrangehunting.com

Here is a link to the original kaboom thread in case anyone is interested - it may be hard for some to locate.

Kaboom 💥 Today 😟

Things shooting good with 1x fired 708AI brass. (Lapua) 12th round shot and gun explodes out the mag well, ruptures mag and extractor. Ruptured case easily fell out the chamber. The separation line looks too clean. Bad brass? 11 fired cases look fine. No serious pressure signs.

www.longrangehunting.com

 

[Calvin45]

I think these two threads pretty much cover it;

Bullet Construction vs Lethality

www.longrangehunting.com

Did Wipeout Products Ruin My Barrel?

I let Wipeout Accelerator sit in my barrel for 45 mins yesterday. When I patched it out, rust colored product poured out the end. Now I have what looks like corrosion etching/deposits through the bore. I called Wipeout and was reassured I wasn’t seeing rust, just the chemical reaction between...

www.longrangehunting.com

Here is a link to the original kaboom thread in case anyone is interested - it may be hard for some to locate.

Kaboom 💥 Today 😟

Things shooting good with 1x fired 708AI brass. (Lapua) 12th round shot and gun explodes out the mag well, ruptures mag and extractor. Ruptured case easily fell out the chamber. The separation line looks too clean. Bad brass? 11 fired cases look fine. No serious pressure signs.

www.longrangehunting.com

Oh for crying out loud!!!! It happened AGAIN!

 

[Pdvdh]

.003" is ABSOLUTE minimum, even this dimension can cause issue if you do not measure your brass neck wall accurately.

Cheers.

MagnumManiac,
Do you still believe excessive pressure caused none of this? As you posted in mid-August? You were absolutely certain. Too funny

MagnumManiac said

You've tagged angry emoji's in response to my posts. Yet... close your posts with "Cheers".

So... generally a cheery guy? Who disagrees angrily?

"I honestly believe you don't know what you're talking about. An excessive pressure event, not a case failure, ALWAYS results in case FLOW into every possible recess in the bolt face, and obviously when the case ruptured due to a case defect, the gas was correctly directed into the mag well. Like it's supposed to…
My question to you is…how many ruptured firearms have you seen and how many have you determined the cause of such ruptures?
I have seen dozens in myriad of scenarios, such only 1 being caused by a case rupture very similar to this. Excessive pressure, nor excessive headspace caused any of this."

 

[nksmfamjp]

Anyone know what the correct diametrical clearance between the case neck and chamber should be?

0.001-0.005….I find 0.003" best if I'm neck turning to fit. On the other hand, I think there is also an optimal neck thickness for neck tension…..I'm not sure what that is.

this is probably the best way to determine that:

I had a tight neck in my 7RM. My gunsmith said .003-.004 diametral clearance and keep checking. If bullets don't slip into them after firing, go more. Turning tool I used is K&M with a carbide reamer/mandrel. It also fixed my Nosler brass with donuts.