High Pressure?

[GBG]

On a percussion rifle, hammer blow back to the half or full cock position is considered an indication of excessive pressure. Are there any warning signs for a flintlock, other than recoil or muzzle blast?

 

[rduncan]

I think a blowback is most likely if you "short-start" a bullet (don't shove it all the way against the charge. That allows more pressure to build up before the round starts to move. Or somebody tried to use smokeless powder which will result in a blowup rather than a blowback.
Has been said that (depending on the rifle) only a certain part of an overcharge burns and the rest gets blown out the muzzle. Somebody else can test that and I'll stand back and watch...
For a flinter, the only warning would be the flare from the vent that singes the beard of the guy next to you!

 

[Zonie]

If the guy 2 benches down from you on your right has smoldering eyebrows and his left sideburn is blazing brightly it indicates your breech pressure is too high or your touch hole is too large (or both). :hmm:

 

[hanshi]

What Zonie said plus this observation. If the flash hole in the nipple is too large, Hammer blow back often occurs even with light loads.

 

[Rifleman1776]

It may be an indication of one of several different things and/or a combination of those things. It can be caused by an improperly designed nipple; very weak mainspring; or gross overpressure.
Whatever the cause it must be corrected before continuing to use that rifle.

 

[nchawkeye]

I thought the OP was asking about Flintlocks, not percussion guns....

 

[Rifleman1776]

I thought the OP was asking about Flintlocks, not percussion guns....

Yer right. I did not get fully caffinated this morning. Oh,well. :redface:

 

[Loyalist Dave]

The only "warning" that two flintlock shooters that I know and saw got was the crack in the stock from the wrist through the forward lock screw..., plus the big recoil. However, the recoil they were both used to were not much less than the overloaded rounds that cause the cracks. Both reacted with "wow that was different" as opposed to "yeeeouch that was a big kick".

LD

 

[Stumpkiller]

If the side of your flint nearest the vent erodes (seriously). Might also be if you can't keep a vent hole to 1/16" . . . but there are other causes there.

If you are using anything near a sensible load with blackpowder you should never encounter excessive pressures. Also, if you set the ball by hand with finger pressure alone it should go back out the barrel properly.

A bulged or ringed barrel is your warning that you had an obstruction that elevated pressures.

 

[Many Klatch]

Regular overloading of a flintlock will cause the blast from the touch hole to erode the pan. I have heard of pans being almost cut in half this way.

Many Klatch

 

[mb3]

Not that this will answer your question regarding a flintlock but; I had the hammer reset on a percussion musket shooting a moderate load. Turned out the nipple had eroded over time and opened up venting gas to the face of the hammer. I changed out the nipple and never had an issue with that rifle again.