7.7 Jap misfire - The Firearms Forum

vahunter · 11-28-2004, 07:48 AM

I have a 7.7 Japanese which has been sporterized that I use for hunting. I have fired the gun approximately 40 times without incident. Yesterday I was deer hunting and pulled the trigger only to hear a very unwelcome click followed by no discharge of the gun. Upon inspection of the cartridge it was evident that the primer had been indented, but not very deeply. Therfore I expect a problem with the gun, not the primer. I have not had a chance to shoot the gun since but even one misfire in forty is to many. Could the firing pin be to short? Any other ideas or solutions? Where can I get instructions on bolt dissasembly? The weather was not abnormal (really cold or wet) at the time of the incident but I should note that I recently had a new trigger from Brownells installed and have only fired the gun 5 times since. Thanks

CountryGunsmith · 11-28-2004, 08:39 AM

Most probably crap in the bolt keeping the firing pin from reaching full protrusion.

Here's your disassembly instructions:

1: Holding the bolt body in one hand, with the other hand press in on the round safety as far as it will go and turn it clockwise until it stops. Remove it slowly to the rear.

2: Remove striker and striker spring. That's it, except for turning off the standard extractor if you like.

vahunter · 12-01-2004, 06:09 AM

Thanks . . . what was that about turning off the standard extractor? What is it, why would I do it and how would I do it etc? thanks

CountryGunsmith · 12-01-2004, 06:31 PM

Removing the extractor from the bolt body. Not going to be necessary for what you need.

fletchbutt152 · 12-05-2004, 02:17 AM

I don't know about the trigger assembly, but I think the gunsmith may be right. I have gotten too much crap stuck in the bolt. It has a long travel which takes longer to open and close (thus more time for @#%# to get in it, especially in brushy situations).

Anyone know of reliable reloaders...i'm in the dorm and powder kegs are somewhat frowned upon. You'd think since you're in the military they'd let you keep weapons...at least locked up. Someone needs to change some policies (sorry needed to vent).

Thanks,
Fletch

vahunter · 12-07-2004, 07:03 AM

I load my own ammo, but I know that Norma has carried the a load for the 7.7 in the recent past. I dont know if they still do, but a couple yeras ago they did and the price was somewhere inthe neighborhood of $40/box.

Also, if I am not mistaken, countrygunsmith is actually referring to crap such as oil, bits of metal, etc within the actual bolt body itself. You must dissassemble the bolt and clean the firing pin and inside of the bolt. I wonder though if anyone else has ever had a problem with a firing pin being to short as the result of years of impacting primers. I did have a .22 rimfire once that had this problem. By removing the square firing pin and hammering it I was able to lenghten it sufficinetly to completely solve thproblem.

CountryGunsmith · 12-07-2004, 07:57 AM

Crap inside the bolt is correct.

As far as firing pins shortening, the steel firing pin should not shorten from a lifetime of impacting the softer brass primer. The reason a rimfire firing pin might shorten is because it is being peened down by dryfiring. The rimfire pin will hit the barrel face on most older .22's if no cartridge case is in the chamber. Hence, the popular use of snapcaps or fired .22 cartridges when practice firing. Note that many newer .22's have a firing pin stop that allows dryfiring without the firing pin hitting the breechface.

Of course, centerfire firing pins do not have that particular problem. Most centerfires can be dryfired without problems, with the notable exceptions of those designs that are subject to firing pin breakage.

11-28-2004, 07:48 AM	#1
vahunter Member Join Date: Nov 2004 Posts: 15	7.7 Jap misfire I have a 7.7 Japanese which has been sporterized that I use for hunting. I have fired the gun approximately 40 times without incident. Yesterday I was deer hunting and pulled the trigger only to hear a very unwelcome click followed by no discharge of the gun. Upon inspection of the cartridge it was evident that the primer had been indented, but not very deeply. Therfore I expect a problem with the gun, not the primer. I have not had a chance to shoot the gun since but even one misfire in forty is to many. Could the firing pin be to short? Any other ideas or solutions? Where can I get instructions on bolt dissasembly? The weather was not abnormal (really cold or wet) at the time of the incident but I should note that I recently had a new trigger from Brownells installed and have only fired the gun 5 times since. Thanks --> Last edited by vahunter; 11-28-2004 at 07:49 AM..

11-28-2004, 08:39 AM	#2
CountryGunsmith Advanced Senior Member Join Date: Jan 2003 Location: Deep Piney Woods of East Texas Posts: 5,116	Re: 7.7 Jap misfire Most probably crap in the bolt keeping the firing pin from reaching full protrusion. Here's your disassembly instructions: 1: Holding the bolt body in one hand, with the other hand press in on the round safety as far as it will go and turn it clockwise until it stops. Remove it slowly to the rear. 2: Remove striker and striker spring. That's it, except for turning off the standard extractor if you like. __________________ The autonomic nervous system provides for involuntary muscle function - the work of breathing, digestion, and so forth. On some folks, that's a pure waste of ingenuity.

12-01-2004, 06:09 AM	#3
vahunter Member Join Date: Nov 2004 Posts: 15	Re: 7.7 Jap misfire Thanks . . . what was that about turning off the standard extractor? What is it, why would I do it and how would I do it etc? thanks

12-01-2004, 06:31 PM	#4
CountryGunsmith Advanced Senior Member Join Date: Jan 2003 Location: Deep Piney Woods of East Texas Posts: 5,116	Re: 7.7 Jap misfire Removing the extractor from the bolt body. Not going to be necessary for what you need. __________________ The autonomic nervous system provides for involuntary muscle function - the work of breathing, digestion, and so forth. On some folks, that's a pure waste of ingenuity.

12-05-2004, 02:17 AM	#5
fletchbutt152 Member Join Date: Oct 2003 Location: Wisconsin Resident Posts: 8	Re: 7.7 Jap misfire I don't know about the trigger assembly, but I think the gunsmith may be right. I have gotten too much crap stuck in the bolt. It has a long travel which takes longer to open and close (thus more time for @#%# to get in it, especially in brushy situations). Anyone know of reliable reloaders...i'm in the dorm and powder kegs are somewhat frowned upon. You'd think since you're in the military they'd let you keep weapons...at least locked up. Someone needs to change some policies (sorry needed to vent). Thanks, Fletch

12-07-2004, 07:03 AM	#6
vahunter Member Join Date: Nov 2004 Posts: 15	Re: 7.7 Jap misfire I load my own ammo, but I know that Norma has carried the a load for the 7.7 in the recent past. I dont know if they still do, but a couple yeras ago they did and the price was somewhere inthe neighborhood of $40/box. Also, if I am not mistaken, countrygunsmith is actually referring to crap such as oil, bits of metal, etc within the actual bolt body itself. You must dissassemble the bolt and clean the firing pin and inside of the bolt. I wonder though if anyone else has ever had a problem with a firing pin being to short as the result of years of impacting primers. I did have a .22 rimfire once that had this problem. By removing the square firing pin and hammering it I was able to lenghten it sufficinetly to completely solve thproblem. Last edited by vahunter; 12-07-2004 at 07:10 AM..

12-07-2004, 07:57 AM	#7
CountryGunsmith Advanced Senior Member Join Date: Jan 2003 Location: Deep Piney Woods of East Texas Posts: 5,116	Re: 7.7 Jap misfire Crap inside the bolt is correct. As far as firing pins shortening, the steel firing pin should not shorten from a lifetime of impacting the softer brass primer. The reason a rimfire firing pin might shorten is because it is being peened down by dryfiring. The rimfire pin will hit the barrel face on most older .22's if no cartridge case is in the chamber. Hence, the popular use of snapcaps or fired .22 cartridges when practice firing. Note that many newer .22's have a firing pin stop that allows dryfiring without the firing pin hitting the breechface. Of course, centerfire firing pins do not have that particular problem. Most centerfires can be dryfired without problems, with the notable exceptions of those designs that are subject to firing pin breakage. __________________ The autonomic nervous system provides for involuntary muscle function - the work of breathing, digestion, and so forth. On some folks, that's a pure waste of ingenuity.