AR x39

[stinsonbeach]

Unless anyone has any specific questions, I'll quit annoying everyone w/ "updates".

This is the last update - tho I shall continue to monitor this thread.

Bad news:

I figured w/ the new firing pin - mandatory (see above) - all problems would be solved.

Nope.

I've tried all manner of combinations to get the trigger weight down to something manageable.

Nope.

Today I tried red-yellow JP spring combo. Fire a few then nothing. Light strikes. That tells me the crappy Russian ammo primers are inconsistent. Whoa! Big surprise there!!!

Tried Timney 3# & 4# firing control groups.

Nope.

...& the 4# WILL set off .22's but not the Wolf / Berden x39's

So here - it seems to me - is the bottom line:

ya' have to use the stock hammer spring w/ the full sized hammer & the "enhanced" FP, making the friggin' trigger weight in excess of 7.5 lbs! ...& that's w/ a JP yellow trigger spring! The trigger spring doesn't matter so you may as well use the lightest.

That sucks as I was trying to get that Russian round out to about 300 meters within 6". Not w/ a stock AR hammer spring!!! ...& because I don't want to reconfigure that lower, I now have to go out & get a dedicated one w/ stock fire-control group. Now that really sucks!!!

If anyone has an epiphany out there, please let me know.

-jb

Edited June 20, 2012 by stinsonbeach

[Sleepswithdogs]

Thing I didn't like about the stock trigger, aside from the heavy pull, was the long pull. Since stock fire control groups are so cheap and easy to come by, how bout trying to reshape the hammer profile. The ledge at the bottom that hooks and releases the hammer is way to tall. In addition, (I'm obviously not a gunsmith! ) you might change the angle of that ramp slightly, making it easier for the trigger to slide off of it. If this isn't safe, I'm sure someone will pipe up and say so, but if nothing else, making the ramp shallower will go a long way to "lighten" the trigger. Even though it is the same wt, you could make it a very short pull so it would feel lighter.

TAR

Edited June 20, 2012 by Sleepswithdogs

[stinsonbeach]

Thing I didn't like about the stock trigger, aside from the heavy pull, was the long pull. Since stock fire control groups are so cheap and easy to come by, how bout trying to reshape the hammer profile. The ledge at the bottom that hooks and releases the hammer is way to tall. In addition, (I'm obviously not a gunsmith! ) you might change the angle of that ramp slightly, making it easier for the trigger to slide off of it. If this isn't safe, I'm sure someone will pipe up and say so, but if nothing else, making the ramp shallower will go a long way to "lighten" the trigger. Even though it is the same wt, you could make it a very short pull so it would feel lighter.

TAR

Great info!

I've found that screwing w/ stock trigger-groups is pretty much a waste of time. It's either replace them or leave'm. I've polished; ground; recanted; taken off here; taken off there & nothing seems to help the stock fire control set...but you know, I might just give this another try. Your suggestion seems like a good idea & I have a baggie of hammers & triggers, so if I screw it up - there's plenty more where that came from.

Thanks for the idea.

-jb

[Chills1994]

You would think there would be an AR15.com thread on this very same topic.

What is the typical trigger pull weight for an AK47?

[stinsonbeach]

You would think there would be an AR15.com thread on this very same topic.

What is the typical trigger pull weight for an AK47?

Ok - you got me thinking.

Just went out & w/ my Lyman gauge & the AK was 5 1/4 # . . . that miserable AR x\39 w/ stock DPMS fire control group was - get this - >9#'s!!!

No wonder I'm pissed off!

Now., that being discovered, how come I'm having to use a 9# FC-group when the AK is just over 5?

I was resigned to the fact I had to use stock FC group & be done w/ it, but you've opened a new can of worms!!!

I'm not happy again.

What now?

[jjw]

Unless anyone has any specific questions, I'll quit annoying everyone w/ "updates".

This is the last update - tho I shall continue to monitor this thread.

Bad news:

I figured w/ the new firing pin - mandatory (see above) - all problems would be solved.

Nope.

I've tried all manner of combinations to get the trigger weight down to something manageable.

Nope.

Today I tried red-yellow JP spring combo. Fire a few then nothing. Light strikes. That tells me the crappy Russian ammo primers are inconsistent. Whoa! Big surprise there!!!

Tried Timney 3# & 4# firing control groups.

Nope.

...& the 4# WILL set off .22's but not the Wolf / Berden x39's

So here - it seems to me - is the bottom line:

ya' have to use the stock hammer spring w/ the full sized hammer & the "enhanced" FP, making the friggin' trigger weight in excess of 7.5 lbs! ...& that's w/ a JP yellow trigger spring! The trigger spring doesn't matter so you may as well use the lightest.

That sucks as I was trying to get that Russian round out to about 300 meters within 6". Not w/ a stock AR hammer spring!!! ...& because I don't want to reconfigure that lower, I now have to go out & get a dedicated one w/ stock fire-control group. Now that really sucks!!!

If anyone has an epiphany out there, please let me know.

-jb

i am confused by all the technology. why are u changing things if it runs 100% with the new f/pin

1. is it because of a heavy trigger pull

2. unreliability

3. just had to screw with success

my 7.62's all run with any lower's. (13 of them)i run with them. and on my work guns. (we are a tactical trg company doing government contracts.) my work guns all have "street triggers, that are Giselle(?) non adjustable.

i am not a match trigger guy as all i shoot is outlaw 3 gun in the Carolina's run by military guys.

i shot Benning and Rock Castle because Jeff Cramlit is a long time friend.

i am confused as to what is happening.

BIG HINT go back to what was working as a base set up. go to a Giselle if u need a light trigger.

Edited June 24, 2012 by jjw

[Chills1994]

since the firing pin floats in an AR's bolt and bolt carrier group...

Could you try taking the BCG from a regular AR15 and putting the AR39 firing pin and bolt in it?

Or just comparing the lengths of an AR15 firing pin to your new AR39 firing pin?

Does this ammo manufacturer make .223 ammo?

Put an AR15/.223 upper on your AR39 lower. Then load a steel cased .223 round into it. Try to fire it off, does it go bang?

if the .223 round goes bang, then to me it sounds like the hammer has enough uuummph behind it... The ammo/primers for 7.62X39 suck???

Headspace maybe?

Ya know how the revolver shooters go all ga ga eyed over Federal match pistol primers because their hammers are sprung so lightly. That might be your last/best option... Just reload for it.

[stinsonbeach]

i am confused by all the technology. why are u changing things if it runs 100% with the new f/pin

1. is it because of a heavy trigger pull

*** YES!

2. unreliability

*** only w/ a light fire-control group

3. just had to screw with success

*** of course!!!

my 7.62's all run with any lower's. (13 of them)i run with them. and on my work guns. (we are a tactical trg company doing government contracts.) my work guns all have "street triggers, that are Giselle(?) non adjustable.

i am not a match trigger guy as all i shoot is outlaw 3 gun in the Carolina's run by military guys.

*** I'm a trigger whore - but I also realize that I'm shooting a Russian rd that has an effective range of 300 & just may get lucky to 500 if the weather gods permit...but a 9# trigger? Unacceptable now that I know my AK only has a 5+ pull. I was content when I thought my only option was a stock AR fire-control group but not now, thanks to ----------- I just had to check w/ a gauge & now I'm back on the hunt.

i shot Benning and Rock Castle because Jeff Cramlit is a long time friend.

i am confused as to what is happening.

*** I can't get it to go "bang" w/o a brutal trigger

BIG HINT go back to what was working as a base set up. go to a Giselle if u need a light trigger.

*** I was always under the impression that Geissele's were 2-stage. I hate 2-stage.

Ok so it boils down to this: I need about a 6# trigger to set off the crappy Berden primers. How do I go about it?

[stinsonbeach]

since the firing pin floats in an AR's bolt and bolt carrier group...

Could you try taking the BCG from a regular AR15 and putting the AR39 firing pin and bolt in it?

Or just comparing the lengths of an AR15 firing pin to your new AR39 firing pin?

Does this ammo manufacturer make .223 ammo?

*** I'm shooting cheap-o Wolf 123gr w/ Berden primers at about .20 to 30 cents / rd

Put an AR15/.223 upper on your AR39 lower. Then load a steel cased .223 round into it. Try to fire it off, does it go bang?

*** my AR lowers shooting 9mm or 5.56 go "bang" w/ everything. JP yellow-yellow; red-yellow; Timney 3 & 4 #'s. I wound up building a dedicated lower just for that x39. I certainly won't shoot it w/ anything else! ...but w/ that stock fire-control group it'll set of a 105!!!

if the .223 round goes bang, then to me it sounds like the hammer has enough uuummph behind it...

*** that is EXACTLY so

The ammo/primers for 7.62X39 suck???

*** that is also EXACTLY so

Headspace maybe?

*** nope because they are not re-loads

Ya know how the revolver shooters go all ga ga eyed over Federal match pistol primers

*** that is ALL I use in my match ammo. I've never - not once - had a primer failure & I'm shooting autos w/ skitzy triggers.

because their hammers are sprung so lightly. That might be your last/best option... Just reload for it.

*** I thought about that - for maybe 14 seconds - but why should I re-load when I can get them all done-up in nice little boxes for .20 - .30 cents / ?

Nope - I've got to figure out how to set off those brutal Berden primers w/o having to use two hands to pull the trigger!!!

I'm all ears to any & all suggestions...

Edited June 24, 2012 by stinsonbeach

[Chills1994]

How does your AK run with that same ammo?

[stinsonbeach]

How does your AK run with that same ammo?

*** 100%

[Sleepswithdogs]

Factors that determine trigger pull and force of hammer strike:

Wt of hammer

Wt of springs

Friction of the sliding pieces

Length of "pull" on the sliding surfaces

Geometry of the pin placement/component shape

If anyone can add something I haven't thought of, please chime in.

From what I have been able to gather what makes a JP or Giselle trigger better is not only the spring, not only the wt of the hammer, somewhat the smoothness of the mating surfaces, but a major factor is the geometry of the hole placement in the hammer. As far as I can tell, this is why changing wt, changing springs, polishing, hasn't done it in the past for you. A big factor is the placement of the pin holes. in the hammer etc.

Now I will say, when I had a Mini-14 and I didn't like the trigger, I took it to a smith and he did some polishing, reshaping etc, and came out with a really fine trigger. A friend showed up with an AR, and we exchanged rifles for a bit, his was a 2 stage (of unknown origin) and we both agreed that the Mini had a better trigger.

Anther option, (and I also really don't like heavy or long trigger pulls) if a good trigger wasn't on the market, take the design of a good trigger and head to a machine shop and have a couple of components made, then use the best springs you can find, probably JP.

TAR

Edited June 24, 2012 by Sleepswithdogs

[stinsonbeach]

Factors that determine trigger pull and force of hammer strike:

Wt of hammer

Wt of springs

Friction of the sliding pieces

Length of "pull" on the sliding surfaces

Geometry of the pin placement/component shape

*** the last is very interesting

If anyone can add something I haven't thought of, please chime in.

From what I have been able to gather what makes a JP or Giselle trigger better is not only the spring, not only the wt of the hammer, somewhat the smoothness of the mating surfaces, but a major factor is the geometry of the hole placement in the hammer. As far as I can tell, this is why changing wt, changing springs, polishing, hasn't done it in the past for you. A big factor is the placement of the pin holes. in the hammer etc.

*** any suggestions as to what after-market trigger group would give me the punch to hammer those Russian primers & still give me a smooth minimal trigger pull?

Now I will say, when I had a Mini-14 and I didn't like the trigger, I took it to a smith and he did some polishing, reshaping etc, and came out with a really fine trigger. A friend showed up with an AR, and we exchanged rifles for a bit, his was a 2 stage (of unknown origin) and we both agreed that the Mini had a better trigger.

Anther option, (and I also really don't like heavy or long trigger pulls) if a good trigger wasn't on the market, take the design of a good trigger and head to a machine shop and have a couple of components made, then use the best springs you can find, probably JP.

*** that sounds like a good idea, but I'm not about to get that deep into it - remember we're talking about the AK round - 300 yds - not a Chey Tac reaching out 2000! All I'm after is a reasonable trigger pull that'll set off those Berden primers 100% of the time. In today's world that doesn't seem undoable now does it?

TAR

[Chills1994]

Zak Smith ( demigod llc) has an article online about how the AK round is kinda dumbed down. He hinted that it could be reloaded to higher velocities.

Our IPSC 3gun rifle brethern in Europe are able to push the 7.62X39R to make the major power factor cutoff of 320.

So that's 2,580 fps for a 124 grain bullet. Or 2,077 fps for a 154 grainer.

I don't what that does for range though.

[Sleepswithdogs]

Stinson, I don't believe you are the only one having these problems. I guess if it were me, first thing Mon I'd give JP a call and see what they suggest. These people have made a very good living by being innovative, willing to think out of the box. IMO this is a good place to start.

Speaking for me only, I'd also take a grinding wheel the the stock parts to see what could be made out of them. So what if it ruins the temper, the idea is to understand what's not working in that trigger. Parts can always be re-tempered.

I'd lighten the hammer, polish the mating surfaces and re-angle the ramp. I'd look at moving the pivot hole geometry. Maybe even cut a new hammer with a gig saw and a grinding wheel. (I once watched a guy make entire, BEAUTIFUL guitars from solid blocks of wood using a gig saw. I would have never thought that possible.)

I have always been one who wants to give it a try for myself. I have found no matter what you want to do in life, there are always a myriad of people who will tell you it can't be done, or they tried it and failed so you will fail also if you try. Big G use to call it, "You can't get there from here." What I have found is if you never put your sail up, your never going to get out of the harbor. I'd rather try and fail than fall for, "it can't be done," and so I didn't try. No one's ever done it until it gets done then all the followers jump on the band wagon and say it wasn't so hard, they could have done it if they really wanted to but Idle was on...

See a problem, find a solution, do the laundry, walk the dog.

TAR

Edited June 25, 2012 by Sleepswithdogs

[stinsonbeach]

Zak Smith ( demigod llc) has an article online about how the AK round is kinda dumbed down. He hinted that it could be reloaded to higher velocities.

Our IPSC 3gun rifle brethern in Europe are able to push the 7.62X39R to make the major power factor cutoff of 320.

So that's 2,580 fps for a 124 grain bullet. Or 2,077 fps for a 154 grainer.

I don't what that does for range though.

*** 2800 beats 2300 everytime - my problem is because they are so cheap, I find it hard to justify reloading them. If I'm going to all that trouble - & expense - I go .308.

Fact is, I want a Les Baer 20" so bad I can taste it! ...but then again, I want an open gun, "...cheeseburger. I want a milk shake... Spaulding you'll get nothing"!!!

-jb

[stinsonbeach]

Stinson, I don't believe you are the only one having these problems. I guess if it were me, first thing Mon I'd give JP a call and see what they suggest. These people have made a very good living by being innovative, willing to think out of the box. IMO this is a good place to start.

*** that's a pretty good idea

Speaking for me only, I'd also take a grinding wheel the the stock parts to see what could be made out of them. So what if it ruins the temper, the idea is to understand what's not working in that trigger. Parts can always be re-tempered.

I'd lighten the hammer, polish the mating surfaces and re-angle the ramp. I'd look at moving the pivot hole geometry. Maybe even cut a new hammer with a gig saw and a grinding wheel. (I once watched a guy make entire, BEAUTIFUL guitars from solid blocks of wood using a gig saw. I would have never thought that possible.)

*** see here's the thing: I built this upper simply because it would be simple. Simple assumption. As a friend of mine likes to say, "...nothing's easy...you step in puppy s* when you get up in the morning." That comes from his personal experience!

I have always been one who wants to give it a try for myself. I have found no matter what you want to do in life, there are always a myriad of people who will tell you it can't be done, or they tried it and failed so you will fail also if you try. Big G use to call it, "You can't get there from here." What I have found is if you never put your sail up, your never going to get out of the harbor. I'd rather try and fail than fall for, "it can't be done," and so I didn't try. No one's ever done it until it gets done then all the followers jump on the band wagon and say it wasn't so hard, they could have done it if they really wanted to but Idle was on...

*** if you knew me you see that that thinking is right up my alley - only problem is this wasn't suppose to be a problem! ...a simple "do"...that & it's really not worth the hassle to get it "just right". It is after all the AK round. That said the trigger on this thing is simply "...too much, Jerry." (I think I've been watching too much TV!). I just want to get it manageable w/o dedicating too much more time to it. Silk purses & sow's ears, et al.

See a problem, find a solution, do the laundry, walk the dog.

*** - nice, Grasshopper!

The call to JP tho is a great idea. Will let you know.

-jb

TAR

[Sleepswithdogs]

Ah, simple/easy things... I dread those every time I pick up a wrench to do something on my truck. No matter how simple a job is, it can always turn into a Stephen King thing in a heart beat. Strip a screw (why is it always the last one that has to come out!!!), part no longer available.

See a problem, find a solution, do the laundry, walk the dog.

Ya, I kind'a liked that one too! Was listening to some pilot who had just set a record of some kind and then he came home and his wife made him take out the garbage, he was laughing about it. But isn't that life.

[caspian guy]

my situation is slightly different than yours, my russian ammo upper is 5.45x39.

If you could tolerate a 2 stage I was able to get a decent trigger using an rra nm trigger group and a red hammer spring.

The only real issue I ran into was all the extra pressure from the hammer spring caused the hammer to get stuck on the disconnect hook. The simple fix for that was to lightly polish the surface of the disconnect hook of the hammer to slightly reduce the friction (being careful not to change the geometry) after that it reset and functioned correctly. I'll have to check it on the pull gauge but I think it ended up being right at 5lb.

[stinsonbeach]

Ah, simple/easy things... I dread those every time I pick up a wrench to do something on my truck. No matter how simple a job is, it can always turn into a Stephen King thing in a heart beat. Strip a screw (why is it always the last one that has to come out!!!), part no longer available.

See a problem, find a solution, do the laundry, walk the dog.

Ya, I kind'a liked that one too! Was listening to some pilot who had just set a record of some kind and then he came home and his wife made him take out the garbage, he was laughing about it. But isn't that life.

I saw some of your hobbies. A good book on the subject is - if my wiffle-ball brain can remember - "First the Ecstasy; Then the Laundry." Can't remember x whom however.

Edited June 25, 2012 by stinsonbeach

[stinsonbeach]

my situation is slightly different than yours, my russian ammo upper is 5.45x39.

If you could tolerate a 2 stage I was able to get a decent trigger using an rra nm trigger group and a red hammer spring.

The only real issue I ran into was all the extra pressure from the hammer spring caused the hammer to get stuck on the disconnect hook. The simple fix for that was to lightly polish the surface of the disconnect hook of the hammer to slightly reduce the friction (being careful not to change the geometry) after that it reset and functioned correctly. I'll have to check it on the pull gauge but I think it ended up being right at 5lb.

I'd kill for 5#'s!!!

At this stage - because it's a rifle & will never be other than a bipod or rest piece - a 2 stage might work, but it's gotta' be 100% reliable.

Edited June 25, 2012 by stinsonbeach

[Sleepswithdogs]

Ah, simple/easy things... I dread those every time I pick up a wrench to do something on my truck. No matter how simple a job is, it can always turn into a Stephen King thing in a heart beat. Strip a screw (why is it always the last one that has to come out!!!), part no longer available.

See a problem, find a solution, do the laundry, walk the dog.

Ya, I kind'a liked that one too! Was listening to some pilot who had just set a record of some kind and then he came home and his wife made him take out the garbage, he was laughing about it. But isn't that life.

I saw some of your hobbies. A good book on the subject is - if my wiffle-ball brain can remember - "First the Ecstasy; Then the Laundry." Can't remember x whom however.

Ya, that's me, "Jack of all, master of none", but haven't given up on finding that "One thing."

Curly: Do you know what the secret of life is? [holds up one finger]

Curly: This.

Mitch: Your finger?

Curly: One thing. Just one thing. You stick to that and the rest don't mean shit.

Mitch: But, what is the "one thing?"

Curly: [smiles] That's what *you* have to find out.

[jjw]

my situation is slightly different than yours, my russian ammo upper is 5.45x39.

If you could tolerate a 2 stage I was able to get a decent trigger using an rra nm trigger group and a red hammer spring.

The only real issue I ran into was all the extra pressure from the hammer spring caused the hammer to get stuck on the disconnect hook. The simple fix for that was to lightly polish the surface of the disconnect hook of the hammer to slightly reduce the friction (being careful not to change the geometry) after that it reset and functioned correctly. I'll have to check it on the pull gauge but I think it ended up being right at 5lb.

I'd kill for 5#'s!!!

At this stage - because it's a rifle & will never be other than a bipod or rest piece - a 2 stage might work, but it's gotta' be 100% reliable.

my work guns all have geissele (?) triggers that are NOT ADJUSTABL. they are sorta 2 stage but not a lot just smooth. t/t/ mu guy who is o.o.c. when he called in last nite. he puts all our gear together. (colt trained ex army armorer). says thats what's in my guns. i have not been to warehouse to look.

f.y.i. i would carry this if its s.h.t.f. scenario

11.5" upper

8 mags

aim point

light

250 Rd's 7.62. (any) butdo have HP

goes with my 11.5" m-4 in .556

with these 2 i can find ammo anywhere in the world.

close friend and mentor Ken Hackathorn asked me several weeks ago if i would carry this to war ???. f-----g "a" tweety rover. in a heartbeat.

i cant shoot an AK in 7.62 because a cheek bone injury in Nam" recoil is truly painful. (before some 1 asks)

love the bullet hate the ak platform.

hope this helps best i can do.

want shoot my 5x45 11.5" m-4 Rok Cstle.waiting for them to give me an answer. it is not a real .556 rd but i think they will let me as i am no way a major player. just having fun runnin' & gunnin'. also watching all the gear queers with the fancy toys.

good luck

Edited June 25, 2012 by jjw

[stinsonbeach]

my situation is slightly different than yours, my russian ammo upper is 5.45x39.

If you could tolerate a 2 stage I was able to get a decent trigger using an rra nm trigger group

*** waz'at?

and a red hammer spring.

The only real issue I ran into was all the extra pressure from the hammer spring caused the hammer to get stuck on the disconnect hook. The simple fix for that was to lightly polish the surface of the disconnect hook of the hammer to slightly reduce the friction (being careful not to change the geometry) after that it reset and functioned correctly. I'll have to check it on the pull gauge but I think it ended up being right at 5lb.

*** if you think about 5 - close enough

I'd kill for 5#'s!!!

At this stage - because it's a rifle & will never be other than a bipod or rest piece - a 2 stage might work, but it's gotta' be 100% reliable.

my work guns all have geissele (?) triggers that are NOT ADJUSTABL. they are sorta 2 stage but not a lot just smooth. t/t/ mu guy who is o.o.c. when he called in last nite. he puts all our gear together. (colt trained ex army armorer). says thats what's in my guns. i have not been to warehouse to look.

*** was on Brownells & because I don't normally consider a 2-stage I didn't know what I was looking at. Which do you recommend?

f.y.i. i would carry this if its s.h.t.f. scenario *** this is mine:

11.5" upper 11" upper w/ can

8 mags 7 mags

aim point EoTec 512 or Mepro M-21

light no light

250 Rd's 7.62. (any) butdo have HP 200+ 9mm

goes with my 11.5" m-4 in .556

with these 2 i can find ammo anywhere in the world.

*** this is mine:

11" upper w/ can

7 mags

EoTec 512 or Mepro M-21

no light

200+ 9mm CQC w/ a .355 cal suits me - zero pulse - maybe you should look into it w/ your cheek

always go "battle field shopping"

close friend and mentor Ken Hackathorn asked me several weeks ago if i would carry this to war ???. f-----g "a" tweety rover. in a heartbeat.

i cant shoot an AK in 7.62 because a cheek bone injury in Nam"

*** Nam? B 1/4 3rd MarDiv '68-'69 mos 0331

recoil is truly painful. (before some 1 asks)

love the bullet hate the ak platform.

*** love the AK hate the bullet

hope this helps best i can do.

*** thanks for the info

want shoot my 5x45 11.5" m-4 Rok Cstle.waiting for them to give me an answer. it is not a real .556 rd but i think they will let me as i am no way a major player. just having fun runnin' & gunnin'. also watching all the gear queers with the fancy toys!

*** if I won the lottery THEN you'd see "gear queer"!!!

good luck

Edited June 26, 2012 by stinsonbeach

[Sleepswithdogs]

Any progress??

I wouldn't mind picking up a different upper for hunting, something like .300 blackout.