Hammer gun cartridge issues

[ChrisPCarter]

I have an old Joseph Lang underlever hammer gun that I'm having a couple of issues with.

 

I'm getting pierced primers on both barrels almost every shot and one firing pin looks longer than the other.

The right barrel pin protrudes about 2.5mm and the left must be about 4mm. It's non-rebounding hammers so it's the first time I've really noticed how far they stick out.

What would the normal length be when struck?

 

Just to confuse matters I had my first fail to fire a couple of weeks ago, where the primer looked to have been given a good hit but it didn't go off. Just a duff cartridge? I've been using paper cased Eley Grand Prix but the primers are being pierced on other cartridges I've tried too.

 

Another thing with the paper ones is a lot are splitting open along their length when fired - no problem with plastic ones.

Is this normal???

 

The gun has been re-proofed for nitro and the chambers lengthened to 2.75".

Are either of these a safety issue or can I carry on using it and get it looked at after the season ends?

 

Apart from that I've never shot so well with a side by side, despite it being very open with no chokes as such it certainly hits what I point it at on "average pheasants" and woodcock.

 

Chris.

[matone]

Would have thought 2.5mm ok but 4mm is too long,all dependent on headspace.Just measured a non rebounder which I shortened the pins on and they`re 2.75mm and cause no issues.Paper cases do split lengthwise on occasion ,so wouldn`t worry about that one !

Edited December 18, 2016 by matone

[ChrisPCarter]

Cheers, this is what I thought but just wanted to be safe.

How easy is it to take the pin out?

Is it just a case of unscrewing the nut around the top of the pin?

Does a pierced primer cause any damage to the gun?

[matone]

Yes they just unscrew.May have a small coiled return spring around them too.I wasnt getting pierced primers,so perhaps try some different cartridges too.

Never had any problems caused by pierced primers personally but better if it doesn`t occur ,no doubt.

[ChrisPCarter]

I've tried 4 different cartridges from Eley, Fiocchi and Gamebore so I think it must be the pins.

They do look quite pointed but one is definitely a bit longer than the other. Both barrels are doing it though, so maybe they are both too long.

[bruno22rf]

Presuming this gun is new to you then the pins are simply too long - bit of amateur Gunsmithing is most likely the cause of your woes. As these small items are so important to the correct use of the gun then it might pay you to get a reputable Gunsmith to alter the pins - if they are spring loaded then that will help but if not then I believe this needs to be done with some care as the pins can protrude from the breach face as the barrels are closed and catch on the underside of the extractor - a touch of heavy grease will help prevent this once the pins are correctly fitted as it helps them to "stick" back after opening the gun.

[wymberley]

Half cock?

[bruno22rf]

Harsh but true wymberley - unless of course you are suggesting that putting the hammers at half cock will prevent them catching on the extractor - if they are dry and loose they can easily fall forwards and get trapped underneath as you close the gun....if you look underneath the extractors on these older guns you should see 2 areas that are ground back to help push the pins backwards as the gun is closed (sometimes the whole lower edge is radiused) but if the pins are way oversize they will still catch and could be broken quite easily...now there's a headache to be avoided.

[Gunman]

With no rebounding locks there has to be an amount of free float on the strikers , be they fitted with return springs or not which I would doubt . When the hammers are down and resting on the strikers they should protrude about .050".However if pushed they should protrude to about .075"/.080" ..I would hazard a guess that either the strikers have been replaced or that with use the nipples have worn so the hammers are falling slightly further than they should . This needs to be seen to quickly IMHO.

As to the cases splitting would suggest over sized chambers of faulty cases again this needs checking .

[wymberley]

Harsh but true wymberley - unless of course you are suggesting that putting the hammers at half cock will prevent them catching on the extractor - if they are dry and loose they can easily fall forwards and get trapped underneath as you close the gun....if you look underneath the extractors on these older guns you should see 2 areas that are ground back to help push the pins backwards as the gun is closed (sometimes the whole lower edge is radiused) but if the pins are way oversize they will still catch and could be broken quite easily...now there's a headache to be avoided.

 

 

With no rebounding locks there has to be an amount of free float on the strikers , be they fitted with return springs or not which I would doubt . When the hammers are down and resting on the strikers they should protrude about .050".However if pushed they should protrude to about .075"/.080" ..I would hazard a guess that either the strikers have been replaced or that with use the nipples have worn so the hammers are falling slightly further than they should . This needs to be seen to quickly IMHO.

As to the cases splitting would suggest over sized chambers of faulty cases again this needs checking .

Thanks for the expertise, Guys.

 

Had a look at the bottom of the extractor and no radius but just two groves that the strikers have worn. Both strikers extend well over that dimension as stated.

 

Have only just got the gun and some things need doing. Sooner rather than later is usually easier both for the 'smith and on one's pocket, so I'll mention the above points when Dennis of UK Gun Repairs gets his hands on it on Wednesday.

 

Cheers

[bruno22rf]

2 grooves - just as I mentioned, thick grease on the firing pins will stop your pins rubbing on the extractor - when you open the gun the spent catridge will force the pins backwards - thick grease holds them there thus preventing them protruding thru the breach face as you close the gun.

[Vince Green]

Its not just that the return springs on the pins have died of old age is it? This sounds to me like an old gun that's been put back into use after years of inactivity and the little springs on the pins have corroded and snapped.

Edited December 19, 2016 by Vince Green

[buze]

I took my gun apart recently, removed the pins and there was no sign of springs (borken or not) in there; so SOMEHOW it's likely it's been working like that for a long time. I also think the extractor catches the pins when opening the gun, but as @bruno says, perhaps thicker grease will help. My pins definitely have a 'shave' tho, the were clearly meant to be oriented one way.

 

Haven't shot my gun with real carts tho, only dry fired it, so I can't tell anything really.

[bruno22rf]

It's quite common to find firing pins without return springs.

[demonwolf444]

Lots of hammer guns were made without return springs - you tend to find those held with a gub screw through the fence lack the clearance for a return spring.

 

The ones with a six sided hex screw holding the pin captive from the rear usually have return springs but sometimes they don't.

 

In many old guns the pin can be bent from dry firing over the years resulting in pins sticking forward even when they have a return spring.

 

Probably worth removing the pins and giving the area a clean out with some solvent and a q tip the reason being that if you are having pierced primers you don't know how much soot and fouling and gunk will have worked its way back past the pins.

 

If the gun has cut outs on the extractor then its likely it never had return springs - these cut outs are not from a life time of wear but the angles are carefully situated to push the pins back as the guns broken.

 

Also the springs are sometimes just really past it.

 

I have a pack of a couple of hundred firing pin springs which normally fit most hammer guns ( if they were made to have springs ) if you want some PM me.

Edited December 20, 2016 by demonwolf444