Strange hold in window

I don't think the OP said where in the window the hole was (apologies to them if they did!), so I was assuming that for it to be possible there was a sill not too far out of shot.

Which was ambiguous, as he could have been meaning air guns or 'conventional' cartridge guns - so I answered each in turn.

Most people firing an airgun intending to break a window do so from more or less head on, but here the pattern of the damage shows that this was something of a glancing impact, from below and to the right of the window as one looks out of it, and I think that is probably sufficient to explain why the damage looks different from what most people have experienced.

Well, if the round was .170 and the air-rifle .177, it certainly wouldn't have the full force of the correct pellet for the gun. That could also explain the damage, but it doesn't alter the fact that it was a glancing impact and most of the other suggestions - conventional air-gun pellet, small stone or ball-bearing from a catapult - are more likely.

Dunno, in my time with such things, Teflon hadn't been invented.

Do you happen to have a table of glass impact damage caused by various calibres and at various ranges? If the answer is no, then can we surmise that you're making this up?

Another (remore) possibility; the neighbour's washing line.

Has it been put up recently and/or is it elastic bungee cord type material? It seems to have a lot of sag in it for one iten.

In article , Java Jive scribeth thus

Did anyone, or does anyone make a .177 cartridge rifle or gun even?...

Or shall we say .177 with a chemical propellant for the avoidance of doubt;)...

Not that I know of, but US handloaders have produced some weird wildcat cartridges. .17 WMR, that someone mentioned, or .17 HMR are made commercially.

.177 airguns with the CI effect are very naughty and I'm sure no-one would intentionally do such a thing.

I googled conchoidal glass fractures and found some air gun forum. The view was that a lead pellet usually won't do it because it flattens; a point impact is necessary. A steel BB pellet will do it, ITHO.

In message , tony sayer writes

I filled the back end of one with a match head once - disappointing

In message , Onetap writes

Google gives 170HMR as 0.172". air rifle 0.177 is 4.5mm.

Police firearms dept. are generally happy to issue a licence for vermin control as the rounds are reckoned to break up on impact.

Cost of ammo and reduction in waste may also figure. Fox is not included and target side noise also an issue.

In message , geoff writes

Clearly you never tried blank starting pistol caps or even .22 rim fire bird scarer rounds.

Not to mention Hilti...

For the benefit of anyone in authority alerted to this thread, my experience relates to the early 1960's:-)

In message , Tim Lamb writes

We used to nick them from the woodworking master's desk and take them out and drop rocks on them

We used to buy them from the local gunsmiths on the school's tab, then drop stage weights onto them through the trapdoor.