Misfires with the 45/70 BC

[Aushooter]

I seem to recall reading on this forum about misfire problems connected to the hammer block on the BC's. Can anyone help me with this little delema?? I recently bought a BC in 45-70, bought 40 federal factory loads because brass is so hard to come by here in OZ. I pulled the bullets, loaded 33gr of ADI 2207 behind my own 405 cast bullets with PMC primers. I shot all 40 of those baby's without a hitch. I loaded the same load only this time with a new tin of 2207 and a new packet of PMC primers. Went to the range today, the first 3 rounds no problem, the fourth....click....nothing. Thinking its a misfire, i pull the case out to find the bullet is half way up the barrel. I push the bullet out with a cleaning rod, and a whole lot of powder follows. The next round, same thing happens, i clean out the barrel again, the next round fires fine, the next doesn't fire, same thing with a bullet half way down the barrel. Out of 40 rounds, 10 have the mishap. Is this somehow connected to the hamnmer block not letting the firing pin hit the primer full on? Or do i have a bad batch of powder? Or primers? Or? I'm at a loss.......I'm assuming the primer isn't igniting the powder. Anyone?

[Rusty~Gunn]

If the bullet gets stuck in the barrel, and the power isn't burnt, maybe only the primer is igniting. Did you confirm this by re-shooting just the brass case (no power/bullet)? I bet just the primer is going off and shooting the bullet part way down the barrel. I can't explain why the powder isn't burning.

[quickdtoo]

Welcome! Sounds like bad powder to me, the primer is pushing the bullet down the bore, I'd be contacting ADI to replace that powder unless you can pin the blame on some other factor like contaminated brass prior to it being handloaded.

Tim

[Aushooter]

Thanks. Yes i have emailed ADI, no response yet, this all happened this afternoon. What would contaminate the brass? This is the second load in these cartridges. Would my mixture of bee's wax, parafin wax, vasoline and alox react with the powder or brass?(not that there would be that much on the base of the bullet, i did wipe them off)

[quickdtoo]

The brass could have sizing lube in it, I wouldn't think the bullet lube would be a problem unless it got too warm and the lube melted. Since the powder was new, it's more than likely the culprit, I've had bad Hodgdon powder, ADI makes Hodgdon powders.

Tim

[Macphoto]

I have had similar problems using a Contender in 44mag and not crimping the bullet.  Much of the powder actually melted, but did not ignite.  Crimping solved the problem.  Just a thought.

[Aushooter]

Thanks Tim. Macphoto, you might be onto something. The cast bullet from my Lee mould drops at .455 - .456 which is undersize. There is no problem with accuracy, i've been blessed with 3/4" groups at 50 yards with the ones that do go bang. Maybe the undersize (and slighty out of round i might add) bullet just isn't creating a good enough seal in the case to get the pressure required for the powder to burn. Or maybe i'm just talking out of my proverbial .

[Chas.]

A few months ago, I had that exact same problem with Hodgdon H4198, which is the equivalent of ADI 2207.  I suspect that they are the same powders, just branded differently.

http://www.gboreloaded.com/forums/index.php/topic,200319.msg1099032710.html#msg1099032710

[gcrank1]

A change in casting alloy may get you bigger dia. bullets. What are you using?
Even so, lead is a lot more slippery in bore, thus faster than jacketed for a given load. Your inertial start pressure with the heavy bullet is still there, and crimp may help ignition, but in single shots with a proper size bullet for the throat, crimping usually doesnt help accurracy.

[Aushooter]

My lead mixture is 9 - 1 WW's and 50/50 solder. I've used that mix in my 30/30 and 6.5 carcano for years, its always been good to me. Just to update, ADI has not replied to my email. I did although, load 20 rounds using a dacron filler over the powder and a good tight crimp on the bullet, i'm away hunting this weekend, fingers crossed i dont get any projectiles stuck up the barrel, i dont really feel like carrying a cleaning rod around the counrtry side

[gcrank1]

FWIW, after reading quite a bit about loads with overpowder wads, especially dacron, resulting in chamber rings (right at the bullet base position) I will no longer use such. I do tip the barrel up to settle powder to the primer, then lower, sight & shoot. Tests have shown that has much less shot to shot velo variation than forward or laying across the bottom.
There is no fix for a chamber ring other than a new barrel. The damage seems to be cumulative, though has started in testing with few shots on some, more on others. Mystery there, but the fact it is repeatable in testing and does occur makes me not want to do it to my gun.

[Aushooter]

Excuse my ignorance....but what is a chamber ring?

[gcrank1]

Think of a barrel bulge where a fired bullet hits an obstruction causing an impacted area within the bore. Now move that picture back into your chamber where the unfired cartridge is positioned. Right where the bullet is sitting in the case neck is where this impacting of the chamber neck, resulting in a bulging 'ring' occurs. It is often only discovered when cases become hard to extract and once out show an outward expanded narrow band, 'ring', which is hanging it up in chamber.
It is speculated that there is a pressure 'wave' which slams into the bullet base and then directs outward, radially (if I get this right). Anyway, it has been duplicated in testing and I dont need any more troubles than Ive got, so I just wont use an over powder wad of any kind, any more in smokeless powder loads.

[Aushooter]

Thanks for the info gcrank1.