Why the "Click" .."Bang"?

[blackbird]

Hi, have been home loading for about 5yrs but recently started loading for my .300 win mag. 180grn load are fine with N160 powder but loading 220grn bullet with 52.5 grns of N560 powder the test shot replies with an off putting click from the firing pin...pause then the bang. The round performs ok but does anyone know the reason for the pause. Don't want the next "Click Bang" to be my😉 thanks guys

[Turnup]

Hang fires can happen occasionally, which is exactly why all shooters are (should be) trained to hold on aim and NOT OPEN THE BREECH after the click - timing varies from 10 to 30 seconds depending on whom is talking. Never had a hang fire take even close to 10 seconds - in my experience with metallic carts (rimfire and centrefire) the delay has been only a little more than long enough to notice, so well less than one second. I suspect that the 30 second timing comes from times gone by when mercury fulminate primers were the norm, but this is pure speculation on my part.

Usually a one-off and I have seen no learned discussion as to why they happen in metallic cartridge guns. If your reloads give repeatable hang fires then someone might be interested in doing some research on them.

Hang fires in muzzle loaders are much more common. In percussion guns usually attributed to blocked nipple, and in flintlocks usually attributed to over full or blocked vent hole (and in matchlocks hang fires are pretty much a design feature!).

[loiner1965]

are you using the same powder / bullet combination
is it happening all the time or just a few out of a batch
can be alot of things like .....primer not fully seated or damp case prior to filling with powder etc

[pbranthwaite]

52 grains isn't a lot in a big case like 300WM, perhaps the delay is the primer flash reaching the powder?

[tacfoley]

Why are you shooting such noticeably-reduced charge?

The Vihtavuori manual notes that the lowest charge should be 69.8gr of N160 for this weight of bullet.....

Sometimes, having a too low charge can be as risky as too much. The phenomenum of surface detonation has been known to wreck revolvers, when the flash from the primer ignites the entire surface area of a powder charge lying at the 'bottom' of the case, rather than sequentially initiating a burn-through from the bottom of a column of propellant.

When I make reduced loads of H4198 in my .45-70 Govt, I ensure that the charge is packed into the case by using a scrunched-up paper filler to take up the space between the bottom of the bullet and the top of the charge.

tac

[blackbird]

52 grains isn't a lot in a big case like 300WM, perhaps the delay is the primer flash reaching the powder?

Thanks for the replies, I was taking the data from the Vihtavuori web site however couldn't find round nose bullets. I have taken data now for different bullet type ( still not round nose ) and increased charge to 70gr powder before click bang stopped😳 it must be down to, as you say the large case, little powder and the time it takes to ignite. For the record the data for HPBT starts at 52.5gr but the data for the same weight match bullet starts at mid 60s, the max for the other bullet type is less than this....why??? There's plenty of room and no more weight in the bullet for the same powder. Is it to do with accuracy? I can't see it is the usual safety reason. Sorry if I am sounding stupid but asking the question is the only way to get an answer. Thanks again for all your help😉

[blackbird]

Why are you shooting such noticeably-reduced charge?

The Vihtavuori manual notes that the lowest charge should be 69.8gr of N160 for this weight of bullet.....

Sometimes, having a too low charge can be as risky as too much. The phenomenum of surface detonation has been known to wreck revolvers, when the flash from the primer ignites the entire surface area of a powder charge lying at the 'bottom' of the case, rather than sequentially initiating a burn-through from the bottom of a column of propellant.

When I make reduced loads of H4198 in my .45-70 Govt, I ensure that the charge is packed into the case by using a scrunched-up paper filler to take up the space between the bottom of the bullet and the top of the charge.

tac

Thanks for the reply however this data was for N560 and as it was a heavier bullet and different powder I wanted to start at the low end and work up rather than going to the max.

[loiner1965]

Why are you shooting such noticeably-reduced charge?

The Vihtavuori manual notes that the lowest charge should be 69.8gr of N160 for this weight of bullet.....

Sometimes, having a too low charge can be as risky as too much. The phenomenum of surface detonation has been known to wreck revolvers, when the flash from the primer ignites the entire surface area of a powder charge lying at the 'bottom' of the case, rather than sequentially initiating a burn-through from the bottom of a column of propellant.

When I make reduced loads of H4198 in my .45-70 Govt, I ensure that the charge is packed into the case by using a scrunched-up paper filler to take up the space between the bottom of the bullet and the top of the charge.

tac

like tac i have used reduced charges in big cases eg..15gns trailboss in a .577/450 case which can hold 120gns of powder and everything was ok
what i use to do with some powders was to make a circular disc out of cigarette paper and place over the powder before i use a filler to take up the airspace.
some powders are case sensitive and you dont want a flash over which is when the primer flame goes over the top of the lying down powder and ig
nites from the bullet end.
with my martini henry reloading i now fill the case with 60 / 70 / 85gns of bp (still load developing lol) and take the airspace up with backer foam which comes in rolls so i chop off 15mm to 20mm depending on load.
i use to use kapok but fellow shooters complain of the confetti lol

[tacfoley]

Thanks for the reply however this data was for N560 and as it was a heavier bullet and different powder I wanted to start at the low end and work up rather than going to the max.

Apologies.

Brainfart applies.

tac

[blackbird]

like tac i have used reduced charges in big cases eg..15gns trailboss in a .577/450 case which can hold 120gns of powder and everything was ok
what i use to do with some powders was to make a circular disc out of cigarette paper and place over the powder before i use a filler to take up the airspace.
some powders are case sensitive and you dont want a flash over which is when the primer flame goes over the top of the lying down powder and ig
nites from the bullet end.
with my martini henry reloading i now fill the case with 60 / 70 / 85gns of bp (still load developing lol) and take the airspace up with backer foam which comes in rolls so i chop off 15mm to 20mm depending on load.
i use to use kapok but fellow shooters complain of the confetti lol

I never realised you could get fillers! It makes perfect sense that the flash from the primer could go over the laid down powder...not really the ideal situation. Thank for enlightening me😊

[Turnup]

I never realised you could get fillers! It makes perfect sense that the flash from the primer could go over the laid down powder...not really the ideal situation. Thank for enlightening me��

[edit] The below is in respect of NC powders. Airspace in the chamber or cartridge when using BP is quite another thing and should definitely be avoided. [/edit]


With NC powders, it's not really a problem. I and many others have been shooting reduced load .38spl for many years without incident. The classic 2.7 grains of Bullseye fills the case less than 1/4 full. Tests show that in a partially filled case, the powder orientation does have an effect on peak pressures - if the powder is all at the primer end you get max pressure, all at the bullet end gives a lower pressure, and all laying along the length of the case gives pressures somewhere between the two. So putting in a filler will give the highest peak pressure.

Fillers do have their use - if you are looking for the most consistent target load then a filler will ensure that the powder orientation is consistent, giving more consistent MV. (and by the way the filler may cause peak pressures to exceed manufacturer's spec, because there is less expansion space available in the case - use a very low density filler to minimise the lost volume)

Detonation of NC? doesn't happen. This is a long standing internet myth.

Detonation is a specific phenomenon, defined as a deflagration reaction which proceeds through the medium faster than the speed of sound in that medium. Nitroglycerin based commercial explosives detonate in the order of 10 miles per second (specialist explosives achieve even higher detonation velocities). The effects in metals are characteristically different from damage caused by overpressure. Overpressure failures show distortion of the metal by stretching and bending which may or may not lead to bulk failure of firearm components. Detonation damage leads to shattering with minimal stretching/bending.

There is no known way to cause detonation of single, double, or triple base NC powders. Note that such powders are not designated even as low explosives, they are propellants - we would surely not be allowed to have them if they could be persuaded to detonate.

What happens with reduced loads is there is a risk that the bullet does not leave the barrel. Fire another behind that and the result is a barrel bulge or bursting. Inattentive shooters blame the mythical "detonation" rather than themselves.