SEAR MOD: CHUFF less with your ULT, still SAFE for your BOLT

[Jack & Coke]

Sup y'all

I'm sure I'm not the first to do this, but like the wheel, it was an idea born out of nessessity... and an enjoyment of tinkering with things.

Although I'm getting more used to my new ULT on/off assembly, I still chuff a lot if I try to shoot really fast (i.e. fanning, twitching, walking).

I've spent a lot of time trying to fine tune everything with all different shim combinations. It has helped a lot, but I can still make the ULT on/off setup short-stroke (chuff chuff). Gawd, you should see me shoot a cocker... OMG! Cocker triggers and me don't mix

Anyways, I started looking at the trigger pull relationship to chuffing the ULT.

My idea is to shorten the pull without changing or affecting the sear-to-bolt lock-up relationship.

What I have done is alter the moment arm of the trigger rod. I used a drill press and a carbide bit to drill a second hole into the sear. The metal of the sear is tempered and VERY tough! I almost gave up on drilling!

By shortening the distance of the moment arm (0.15" up the verticle arm), it shortens the trigger pull travel by approximately 18%. However, this is at the expense of a greater trigger pull force requirement.

The initial results after a little bit of testing this mod:

- the trigger pull is shorter
- the trigger pull is heavier than stock sear and ULT on/off assembly
- the trigger pull is lighter than stock sear and stock RT on/off assembly
- much less chuffing!
- still can chuff-but mucho less...
- no damage to sear/bolt lock up relationship!

I figure, that under frenetic rapid firing, I am not letting the trigger fully travel the required distance in order to avoid chuffing. By shorten the required trigger pulling distance a small bit, I am able to reduce (not eliminate) the amount of chuffing I end up with while trying to shoot fast. This is at the expense of a super light trigger.

comparative scale:

Configuration 1
ULT on/off
stock sear
long trigger travel distance
light pressure trigger return force

= lightest trigger pull force, greatest chance of chuffing during rapid fire

Configuraiton 2
ULT on/off
MOD sear
shorter trigger travel distance
light pressure trigger return force

= medium trigger pull force, less chance of chuffing during rapid fire

Configuraiton 3
stock RT on/off
stock sear
long trigger travel distance
high pressure trigger return force

= heaviest trigger pull, minimal chance of chuffing during rapid fire

My goal was to tinker with Configuration 2 to fit my flavor/style of shooting.

I want to go from:

long + light pull + lots of chuffing

to

short + med pull + reduced chuffing

Some people may not chuff at all... that's nice! Then this post is not for them.

I'm just sharing what I've been tinkering with.

I don't think anything will malfunction. But you never know... after a few thousand rounds I'll report back and resurect this thread to post my field test findings. Of course, now that I'll be rockin' my brand new TUNAMAX, it'll be a while before I finish testing this mod...

NOTE: All of the standard precations concerning the sear/bolt relationship have been adheared to (i.e. sear still has full movement, the bump on the top of the sear still hits the body, there's still a gap between the sear rod and the trigger, etc.)

[Jack & Coke]

pic 2

[Jack & Coke]

calcs

[powerofthegospel]

Nice work man! I was readin about somethin similar to this in the workshop forum (i think that's what it's called). Seems to be a very effective compromise, hopefully it'll work for ya. As for me, i gotta wait on an x-valve, then a ult before i can try any of this. Still great to see people tinkering with their guns, that's half the fun! I love to mess with stuff on my gun too, it just usually ends up with me posting what i've done and somebody telling me why you can't do what i did.

Peace,
J.J.

[Jack & Coke]

Thanks

Like I said, this is just an experiment... no conclusions yet..

So far so good! The true test will be after a few days of paintball play.

[abaez]

Awesome jack. I'm having the exact same problem you are (chuffing during a sequence of fast trigger pulling) and I am very interested in your findings. I was thinking of going back to the regular trigger and selling my ult but I think I'll hang on to it and see how things turn out with your tests.

[rpm07]

keep us informed on how it goes

[Jack & Coke]

Thanks for the positive feed-back guys...

I'm currently drooooooling over my brand new TUNAMAX, so it may be a couple weeks before I can test anything with this sear mod idea... sorry

I have 3 stock sears to play with.

The one I drilled has the hole 0.15" higher than normal.

On the next sear I drill, I'll put to hole a wee bit higher (maybe 0.25" off-set). I'll have to look at how the trigger rod lines up with the trigger.

After I have 3 different sears (stock, 0.15", 0.25"), it should be more apparent what the optimal balance would be.

Like Tunaman once told me...

AGD designs and ships you a product that they feel will work MOST of the time. The setup may not be pushing the limits of high performance, but it works when you pick it up!

Just like the Level 10 set-up...

You can set-up the Level 10 kit so that it's ultra-high performance (i.e. strongest spring, loosest carrier), but it then becomes super tempramental. The tolerance for error becomes so small that the tiniest of things can make the gun konk out on you (i.e. o-ring leaks, bolt-stick, etc.).

I'm sure there is a limit how high I can put the hole in the sear before it starts to degrade perforance. It's a point of diminishing returns.

But that's the fun part about tinkering and experimenting... pushing the limits

[QUINCYMASSGUY]

great minds think alike

Hahaha, yeah this is very familiar...

http://www.automags.org/forums/showthread.php?s=&threadid=94876

I was working on this too a month or two back, check out page 3 and 4 of this thread, I was unable to produce it though because you're right, drilling that thing is a pain. And basically the thread got about as much attention as a CD titled "Rosanne Barre sings the blues" and got totally ignored by anyone who could provide input or possibly produce it (with some exceptions like classicmagplayer who was smart) which aggravated me so I gave up on it. I am very happy someone came through with it, feel free to use my thread as a reference, we troubleshot many issues and came up with pros and cons. I would love to get my hands on one of these, let me know if you can hammer me out one and I'll paypal you the cost of the sear. And if you wanted to compare notes, shoot me a PM. Look forward to hearing from you and seeing how certain people view this idea now that someone has made it a reality.

Great work man, let me know how it goes. Did you have to change the sear pin at all to compensate for the new angle?

[Jack & Coke]

Thanks for the reference!!!

I guess I totally missed the boat on that thread

Originally posted by classicmagplayer

LOL!

I'm about a month behind your guy's discussions... I feel like the guy how comes to the party late and starts telling a joke that was already told earlier in the evening.

Great thread by the way! Thanks for the link. Of what I've read, you guys have some good thoughtful dialog going on there...

I think drilling holes is good.

I think this is NOT as good:



It messes up the intelliframe relationship (i.e. microswitch)

Great stuff... I'm going to crash now. I'll catch up more with your thread tomorrow. I'm going to tuck my new Tunamax under my pillow now and go to dreamy land... (don't tell the wife!)

[Jack & Coke]

Re: great minds think alike

Originally posted by QUINCYMASSGUY


Great work man, let me know how it goes. Did you have to change the sear pin at all to compensate for the new angle?

Sorry, I forgot to answer your question...

I did not have to change the sear pin to compensate for the new angle.

There's so much room in the frame that the angle didn't matter too much.

The location where the trigger rod contacts the trigger could be raised a little. However, this would in turn end up defeating the purpose of drilling the hole in the sear

[billybob_81067]

Go to your state fair!

they make these drill bits that are like masonry bits, only instead of the carbide tip it's an even harder somethin or other... lol, sorry I'm not sure exactly what the material is. But anyways I saw these at the Colorado State fair and the guy at the booth was drilling through ceramic tiles and files, and all kinds of crazy crap... It was cool. The only downside is that the bits are a wee bit expensive.

[QUINCYMASSGUY]

SEAR

Thanks for acknowledging my previous work J+C, and even though you started telling the joke after I did, you're the one who actually made it through to the punchline (completion) so you definitely deserve credit for that.

The image you showed was an earlier one that was shot down quickly. The ones mostly involving drilling a higher hole on a sear and putting a diagonal edge on the trigger so the pin sits perpendicular to the trigger like it does in a normal setup is the material more relevant to this.

I'll look into the drill thing. My whole intention of the post was to draw enough interest that one company (AGD, Tuna, etc) would take it up and produce them standardized and maybe through a little R+D find the optimal setup. My stuff was all theoretical, but it looks like J+C is handling the R+D. Having a machine shop do one is expensive, and I wasn't about to when I wasn't even sure if it would work. It does (to all the doubters.. HA HA!) and having an AO member like J+C involved can only push the project along that much quicker.

J+C, I need to draw up the image and I can't while in TX on business (which I am till Friday), but I have an idea on how it can get to a 30oz (less than 2lb) mouseclick and still follow all the principles of this idea. I'll keep you posted.

Again, excellent work J+C, have fun with your new Mag and now that we made it a reality let's see where it goes. People, you like the idea, post and say it! That's what will get this pushed to be mass-produced. It would be a very inexpensive replacement sear mod if it went into mass production by J+C or someone. Definitely plenty of bang for the buck so make it known you like it.

[Jack & Coke]

QUINCYMASSGUY ->

billybob_81067,

Well, since our fair isn't for a while (LA County), what kind of bit would you guys suggest I buy if I went to Home Depot?

[Jack & Coke]

What's the trigger pressure of:

1. stock sear + RT on/off

2. stock sear + ULT?

how many ounces or pounds?

thanks