M305/M14 trigger reworking.
- Thread starter 870supermag
- Start date
I hate to be the one to break the bubble and i don't want to come off sounding like an ass ....... but much of this trigger job gets an epic fail. please don't get offended, that is far from my intention.
the issue of trigger jobs needs some addressing. i have taken some detailed pics here at home and will be uploading them tonite..... it's gonna take some time due to dial up.
that last pic concerns me big time....... do NOT adjust the front hammer hooks as shown in the last pic.
There is one way and one way only to reduce trigger pull and it has not been shown in your pics.
the correct steps are to first, ensure a positive two stage, clean and crisp break, even if the pull is still heavy. This is achieved by first, ensuring there is no sear drag at the hammer hook wall.... which if present, means the trigger/sear assembly is not fully at rest. This must be rectified prior to any other "adjustment" outside of polishing surfaces to remove parkerizing. Stones are a dangrous thing, they remove material faster than you think they might.
I use two tools for trigger jobs , a large fine stone, it's a 3x2x6" block and one, xxfine triangular file, 1/8" wide and tapered and thats it.
I will endeavor to show what the correct steps to a proper trigger job entails..... just bear with me as i get the pics from my camera onto photobucket..... might not be till tomorrow afternoon with my dial up internet.
for those of you who "must do" thier own trigger job, I highly suggest you ignore most of what you see on youtube and other places on the internet and get yourself a copy of Jerry Kuhnhaussen's 30 cal service rifle shop manual, the difinitive work on rifle smithing the m14.
the pics and method i will endeavor to describe are practiced USMC armourers and national match armourers steps for a correct and safe m14 trigger job
the issue of trigger jobs needs some addressing. i have taken some detailed pics here at home and will be uploading them tonite..... it's gonna take some time due to dial up.
that last pic concerns me big time....... do NOT adjust the front hammer hooks as shown in the last pic.
There is one way and one way only to reduce trigger pull and it has not been shown in your pics.
the correct steps are to first, ensure a positive two stage, clean and crisp break, even if the pull is still heavy. This is achieved by first, ensuring there is no sear drag at the hammer hook wall.... which if present, means the trigger/sear assembly is not fully at rest. This must be rectified prior to any other "adjustment" outside of polishing surfaces to remove parkerizing. Stones are a dangrous thing, they remove material faster than you think they might.
I use two tools for trigger jobs , a large fine stone, it's a 3x2x6" block and one, xxfine triangular file, 1/8" wide and tapered and thats it.
I will endeavor to show what the correct steps to a proper trigger job entails..... just bear with me as i get the pics from my camera onto photobucket..... might not be till tomorrow afternoon with my dial up internet.
for those of you who "must do" thier own trigger job, I highly suggest you ignore most of what you see on youtube and other places on the internet and get yourself a copy of Jerry Kuhnhaussen's 30 cal service rifle shop manual, the difinitive work on rifle smithing the m14.
the pics and method i will endeavor to describe are practiced USMC armourers and national match armourers steps for a correct and safe m14 trigger job
No offence taken Thomas I look forward to seeing your write up as this was only my understanding of a us military guide to reworking a trigger unfortunately it had no pictures. I gave it a shot and for me it made a huge difference in my trigger. With that being said I can’t wait to get a better understanding of what else I can do. I will remove the pics and write up but will leave the post up so people can see that there is something in the works.
Kayser Sose
CGN Ultra frequent flyer
- Location
- Southern Van Isle
...eagerly awaiting...
okay.... please excuse my "illustrations" i'm not so good at drawing those arrows and things in the editing programs hehehe
I'm just gonna dump the pics here and then sort them out and add some comments.
The only two working tools you will require are a flat fine or xfine stone and a 1/8th tapered, 3 side the same , xfine triangular file, do not use a diamond type file no matter how fine. all of the following is perfromed with the triangular file, and if the stone is used it will be mentioned.
Once hammer hook wall clearancing has been established (scroll down the page for those instructions), proceed with the following
okay so you have your trigger group in pieces
take your trigger and break it down to disconnect, sear/trigger and pin. some of these are a pain in the ass to remove, but don't even start working your trigger parts unless you can seperate these two parts.
*************************************************************
POLISH only, the two angled flats, removing parkerizing only. USE STONE for top pad and the file for the smaller lower pad, maintain a sharp edge and debur edge only. This edge is hardness critical and excess filing will cause premature failure of this part due to wear. It and the rear hammer hooks are what keep you safe from out of control or out of battery fire, keep this in mind when working these parts.
******************************************************************
next we take the trigger sear part, polish the sides, first at the bottom, below the sear and up to the sear, working across the part, bring to polish and remove any machining marks.... one side is usually worse than the other. Some deeper machining marks may have to be left alone so reach a reasonable polish and enough is enough. REMEMBER, at this point we are doing nothing to the sear surfaces, only the sides of the trigger body itself.
Then move to the top side of the trigger and work the sides next to the sear protrusions to a polish, carefully keeping with the sear angle, down along the part. The triangular file will allow you to clean into the 90 degree edges where sear protrudes from trigger body. work these edges carefully, very carefully, but get them cleaned up as most often these are not 90 degree in the corners...... be VERY carefull not to affect the sear surfaces during this step, just the metal of the trigger body. bring to polish both sides.
with the sides of the trigger polished , next we take the file and very gently polish the parkerizing from the upper sear faces. The lower edges of the sear angle where the under side of the sear meets the upper sear faces are critical and hardness critical so be very careful keeping these forming a nice clean sharp edge without removing material other than parkerizing and burring.
*****************************************************************
This pic shows the 3 locations on the hammer that get our attention. not shown is the large pad on one side that rubs the innner wall of the trigger housing and the safety locks on the top edge of this part. You can polish this pad, only the pad, only deburr the edges as needed if at all. And you can polish the areas around the hammer pin hole, both sides if desired.
other wise, here we have a hammer and the HAMMER HOOK WALL is pointed to. Take your assembled trigger group, prior to any work, lock the hammer back into the sear and as you push "forward" on the back of the actual trigger, try and push down the hammer..... if it doesn't travel freely, if it "drags" on the sear edge, the hammer hook wall will need to be filed to 100% clearance prior to taking any steps to further work on trigger. This should be the first pic in line and the first step you take before all others.
This clearancing can be done with the trigger group assembled , under good light, with the 1/8, tapered xfine file BEING EXTREMELY CAUTIOUS to ONLY fille the hammer hook wall, right to the hammer hook surfaces BUT AGAIN..... DO NOT DISTURB the inside surfaces of the front hammer hooks. This is a tedious task, tested between filings by locking the hammer repeating the test outlined above. keep clearancing until you have 100% clearance and the sear and hammer no longer contact between sear edge and hammer hook wall. Once finished, your sear will be at full rest and any further trigger work can now commence.
Now, the front hammer hooks that engage the sear, these are NOT TO BE MUCKED WITH, polish ONLY. look at the hooks, you will see the inside flats, these engage the sear. remove parkerizing only, allow minor machining marks in these surfaces to wear themselves in, do not attempt to file true and flat. IF you feel a slight tick once assembled and you pull the first stage but not to break and you feel a small tick in the trigger..... you may have to gently debur the corners where the hammer hook wall meets the inside front hammer hooks...... but hopefully you were carefull during wall clearancing
there is one more small angle on the front hammer hooks on the bottom outside, this is what rides down the top sear surfaces as the hammer goes into lockup. polish these small pads, DO NOT alter angle. DO NOT attempt to shorten or otherwise modify angles of the front trigger hooks, they are cleaned up for feel only and your rifle can become very dangerous , very fast if these hooks are shortened or hardness is disturbed.
********************************************************************
Now the rear hammer hooks.... THE ONLY location in your entire trigger group that is modified to reduce trigger pull. But first, Polish the top flats only, maintain angle. Look at the very tips of the rear hammer hooks. you will see a flat and a small pad at an angle under the flat tips. Polish only, this small angled pad, this bears against and pushes back the disconnect.
Then with the stone, and your trigger group fully assembled AND lightly greased, evenly and squarely, remove very small amounts off the tip ends of the rear hammer hooks. with each slight working of the stone, FIRST take the file and debur the top edge of this surface as needed but be careful not to break the angle, SECOND push the hammer down until it begins to contact the face of the disconnect and look straight down, ar the tips even and true to the disconnect? Remember these observations and carefully correct if need be as you stone the tips. again keep the tips flat and square and test often. Last of all , DO NOT REDUCE A CHINESE TRIGGER GROUP TO UNDER 5 LBS or you are flirting with disaster. You don't have to believe me....... but don't say i did not warn you.
as for increasing trigger pull if you have gone slightly too far? scroll up and look at the pics..... the back spine flat of the trigger body, where the disconnect would come into contact, is filed or stoned at this point to gain a small recovery in trigger pull weight..... but it's a small recovery so best thing is to not need to do it at all
hope this helps..... right now with dial up it's the best i can do for ya. There are other places to polish as well, but as for hammer and trigger/sear alterations...... I've covered all you need to know...... forget everything else you have been shown , told or read on the internet about achieving a clean 1st stage and adjusting trigger pull. There is only ONE correct procedure to follow and above is my attempt to shed some light on it. Have fun
I'm just gonna dump the pics here and then sort them out and add some comments.
The only two working tools you will require are a flat fine or xfine stone and a 1/8th tapered, 3 side the same , xfine triangular file, do not use a diamond type file no matter how fine. all of the following is perfromed with the triangular file, and if the stone is used it will be mentioned.
Once hammer hook wall clearancing has been established (scroll down the page for those instructions), proceed with the following
okay so you have your trigger group in pieces
take your trigger and break it down to disconnect, sear/trigger and pin. some of these are a pain in the ass to remove, but don't even start working your trigger parts unless you can seperate these two parts.
*************************************************************
POLISH only, the two angled flats, removing parkerizing only. USE STONE for top pad and the file for the smaller lower pad, maintain a sharp edge and debur edge only. This edge is hardness critical and excess filing will cause premature failure of this part due to wear. It and the rear hammer hooks are what keep you safe from out of control or out of battery fire, keep this in mind when working these parts.
******************************************************************
next we take the trigger sear part, polish the sides, first at the bottom, below the sear and up to the sear, working across the part, bring to polish and remove any machining marks.... one side is usually worse than the other. Some deeper machining marks may have to be left alone so reach a reasonable polish and enough is enough. REMEMBER, at this point we are doing nothing to the sear surfaces, only the sides of the trigger body itself.
Then move to the top side of the trigger and work the sides next to the sear protrusions to a polish, carefully keeping with the sear angle, down along the part. The triangular file will allow you to clean into the 90 degree edges where sear protrudes from trigger body. work these edges carefully, very carefully, but get them cleaned up as most often these are not 90 degree in the corners...... be VERY carefull not to affect the sear surfaces during this step, just the metal of the trigger body. bring to polish both sides.
with the sides of the trigger polished , next we take the file and very gently polish the parkerizing from the upper sear faces. The lower edges of the sear angle where the under side of the sear meets the upper sear faces are critical and hardness critical so be very careful keeping these forming a nice clean sharp edge without removing material other than parkerizing and burring.
*****************************************************************
This pic shows the 3 locations on the hammer that get our attention. not shown is the large pad on one side that rubs the innner wall of the trigger housing and the safety locks on the top edge of this part. You can polish this pad, only the pad, only deburr the edges as needed if at all. And you can polish the areas around the hammer pin hole, both sides if desired.
other wise, here we have a hammer and the HAMMER HOOK WALL is pointed to. Take your assembled trigger group, prior to any work, lock the hammer back into the sear and as you push "forward" on the back of the actual trigger, try and push down the hammer..... if it doesn't travel freely, if it "drags" on the sear edge, the hammer hook wall will need to be filed to 100% clearance prior to taking any steps to further work on trigger. This should be the first pic in line and the first step you take before all others.
This clearancing can be done with the trigger group assembled , under good light, with the 1/8, tapered xfine file BEING EXTREMELY CAUTIOUS to ONLY fille the hammer hook wall, right to the hammer hook surfaces BUT AGAIN..... DO NOT DISTURB the inside surfaces of the front hammer hooks. This is a tedious task, tested between filings by locking the hammer repeating the test outlined above. keep clearancing until you have 100% clearance and the sear and hammer no longer contact between sear edge and hammer hook wall. Once finished, your sear will be at full rest and any further trigger work can now commence.
Now, the front hammer hooks that engage the sear, these are NOT TO BE MUCKED WITH, polish ONLY. look at the hooks, you will see the inside flats, these engage the sear. remove parkerizing only, allow minor machining marks in these surfaces to wear themselves in, do not attempt to file true and flat. IF you feel a slight tick once assembled and you pull the first stage but not to break and you feel a small tick in the trigger..... you may have to gently debur the corners where the hammer hook wall meets the inside front hammer hooks...... but hopefully you were carefull during wall clearancing
there is one more small angle on the front hammer hooks on the bottom outside, this is what rides down the top sear surfaces as the hammer goes into lockup. polish these small pads, DO NOT alter angle. DO NOT attempt to shorten or otherwise modify angles of the front trigger hooks, they are cleaned up for feel only and your rifle can become very dangerous , very fast if these hooks are shortened or hardness is disturbed.
********************************************************************
Now the rear hammer hooks.... THE ONLY location in your entire trigger group that is modified to reduce trigger pull. But first, Polish the top flats only, maintain angle. Look at the very tips of the rear hammer hooks. you will see a flat and a small pad at an angle under the flat tips. Polish only, this small angled pad, this bears against and pushes back the disconnect.
Then with the stone, and your trigger group fully assembled AND lightly greased, evenly and squarely, remove very small amounts off the tip ends of the rear hammer hooks. with each slight working of the stone, FIRST take the file and debur the top edge of this surface as needed but be careful not to break the angle, SECOND push the hammer down until it begins to contact the face of the disconnect and look straight down, ar the tips even and true to the disconnect? Remember these observations and carefully correct if need be as you stone the tips. again keep the tips flat and square and test often. Last of all , DO NOT REDUCE A CHINESE TRIGGER GROUP TO UNDER 5 LBS or you are flirting with disaster. You don't have to believe me....... but don't say i did not warn you.
as for increasing trigger pull if you have gone slightly too far? scroll up and look at the pics..... the back spine flat of the trigger body, where the disconnect would come into contact, is filed or stoned at this point to gain a small recovery in trigger pull weight..... but it's a small recovery so best thing is to not need to do it at all
hope this helps..... right now with dial up it's the best i can do for ya. There are other places to polish as well, but as for hammer and trigger/sear alterations...... I've covered all you need to know...... forget everything else you have been shown , told or read on the internet about achieving a clean 1st stage and adjusting trigger pull. There is only ONE correct procedure to follow and above is my attempt to shed some light on it. Have fun
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there is much more to completing a tuned and polished "NM or civillian match" trigger job.
The best recommendation I can give if you are like me and must do it yourself , invest in a copy of the Jerry Kuhnhaussen 30 cal service rifle shop manual. The diagrams and details , along with instructions and warnings are all there to be sponged up.
None of the explanations and photos i've shown above instruct on correct trigger pull reduction as it relates to SAFE disconnect to sear hammer hook hand off. Nor does it cover what to do if you have an out of spec trigger part, which are correctable in some cases but not something that can be explained on the internet.
NONE of the above is "MY" way of doing things or my opinion. Everything I practice with trigger modifications is contained in the 30 cal service rifle shop manual.
The best recommendation I can give if you are like me and must do it yourself
, invest in a copy of the Jerry Kuhnhaussen 30 cal service rifle shop manual. The diagrams and details , along with instructions and warnings are all there to be sponged up.None of the explanations and photos i've shown above instruct on correct trigger pull reduction as it relates to SAFE disconnect to sear hammer hook hand off. Nor does it cover what to do if you have an out of spec trigger part, which are correctable in some cases but not something that can be explained on the internet.
NONE of the above is "MY" way of doing things or my opinion. Everything I practice with trigger modifications is contained in the 30 cal service rifle shop manual.
Wasnt attempting to change my pull , merely clean up my trigger and honestly i think i did ok for a first time . so blah
my response in this thread was not directed at you...... not sure why you thought so.
When folks here start posting pics of "how i did my m14 trigger job" it's important for those that have experience in such things to speak up. I'm not trying to scold anyone, but instead post insightful and correct information so people don't go doing things to thier trigger groups that could cause them serious bodily harm. Or as Hungry would say if this is a little more tasteful... follow the instructions above..... or your #### will fall off
I always thought that the posting of correct info by many folks on this site was a major reason so many people come here, sorry if it ruffled someones feathers a little, wasn't my intention.
If you where lucky and got to see my original hack job lol you would see that I put right there at the top wait for the pro's to step in and tell me what I did wrong, and I couldn’t be happier that Thomas did. just like he said this is a forum for learning I gave it a shot for the plain and simple reason I could not find the information in detail any where on the internet. I hope this info gets a sticky well maybe not with my opener but I’m sure if Thomas put this in his own thread there would be more than enough interest to command a sticky. Thanks again Thomas and all the people on this site that pass on there experience and knowledge. And try and remember for the most part any comment made in the interest of safety should not be taken as an attack it’s a learning curve but with guns the penalty for mistakes is much grater than most.
Lots of good reflection. I've mentioned in my clinics... DO NOT attempt to lighten your trigger!
If you want a light trigger buy a Savage 110 BA or 112 or Sako TRG or Tikka T3 Tactical or Winchester Stealth or Rem M700 Police or R5!
If you want to smoooooth that first stage then that's a different story. I'm reluctant to tell anybody over the internet my technique I show you in my clinics for fear of creating full auto anti-aircraft guns after you have removed the heat treating layer of about 2 thousandths of an inch by overzealous stoning/sanding/filing/grinding/ dremeling.
So if you are really anxious about your battle rifle trigger and you want a match trigger then by all means send it to M14doctor! He's got the background (btw, I don't...) and he's in a good position to get it done right!
Cheers all, and please be safe... tweak your M14 safely!
Barney
Knowledge is power. A lot of people who like to mess with stuff sometimes miss the fine details. In some cases you have to do some research on metallurgy and such to fully understand things like the different types of metal hardening, and how they are affected by only a little removal of metal.. and tidbits like that. It could literally mean preventing loss of life or serious injury.
Thanks to the doctor for his sage advice.
Personally I learned this stuff when investigating a trigger job on my sks. Didn't improve it too much due to the design of the trigger group, but it did smooth out and have POSITIVE engagement after I was done.. much safer. I even threw in a spring for the firing pin just to be sure I had no full auto If some people were aware how little engagement there was on these things, and mostly negative engagement (as in bump the rifle and it goes off!).. OMG
I do still have to harden the sear though, now that it is tweaked. You can buy these parts already done, but I am stubborn.. lol
Thanks to the doctor for his sage advice.
Personally I learned this stuff when investigating a trigger job on my sks. Didn't improve it too much due to the design of the trigger group, but it did smooth out and have POSITIVE engagement after I was done.. much safer. I even threw in a spring for the firing pin just to be sure I had no full auto
If some people were aware how little engagement there was on these things, and mostly negative engagement (as in bump the rifle and it goes off!).. OMGI do still have to harden the sear though, now that it is tweaked. You can buy these parts already done, but I am stubborn.. lol
I'd rather this not be a sticky but if Hungry wants to add it where he put the stock ferrule mods and other useful tips others have posted, I'm okay with that.
I'd rather give this advice.
what i do is not rocket science. I am able to do what i do because of my fascination with this rifle for over 10 years, and the vast amount of hands on knowledge i have been able to force myself to aquire. My BEST advice is to all those that want to do thier own work to thier own rifles, as I have been doing since my very first gun, is get a copy of the jerry kuhnhaussen book and read your ass off. you may destroy a few parts in your learning curve but you will be getting the very best info you can possibly have, and you will have it at your fingertips.
I have heard that Hungry's tried and true trigger job, which consists of watching a hockey game, including overtime hehehehe and cocking and firing that trigger group all the while .... will smoothen up a stiff new trigger nicely
I'd rather give this advice.
what i do is not rocket science. I am able to do what i do because of my fascination with this rifle for over 10 years, and the vast amount of hands on knowledge i have been able to force myself to aquire. My BEST advice is to all those that want to do thier own work to thier own rifles, as I have been doing since my very first gun, is get a copy of the jerry kuhnhaussen book and read your ass off. you may destroy a few parts in your learning curve but you will be getting the very best info you can possibly have, and you will have it at your fingertips.
I have heard that Hungry's tried and true trigger job, which consists of watching a hockey game, including overtime hehehehe and cocking and firing that trigger group all the while
.... will smoothen up a stiff new trigger nicely 
