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New trigger for Ra

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.


Blue Water Wanna Be
Mar 27, 2001
Im planning on running an experiment on the RA trigger mech.
Im looking into doing some heat treat on a RA trigger mech according to a "custom speargun thread". Hopefully Ill be able to match a RA and perform an annealing process which will match the Riffe trigger mech in strength.
For all of us who have had a RA trigger mech fail on use, what was the failure mech? Was it the sear or the associated gear ,IE sear mounting equip.?
My goal is to run the RA trigger mech with two 20mm bands.
(1)Please reply with any info that can be of assistance.
(2)What material is the RA trigger mech? 304SS, 316ss, Monel etc.
I work with some people that perform heat treat as a profession (sp?).

Thanks in advance

When my ra trigger mech broke the sear snapped clean. I don' t really understand how you are going to make this work. But hope it does best of luck.


The extra hardening probably will help, to what extend I don't know. My logic tells me that if Ivan can break his sear under 150 kg of force, the problem lies with the metal not the hardening. As far as I know hardening makes the metal more brittle and not actualy much stronger, a bit maybe. Why not machine a completely new trigger sears, at the most there will be only two. One for ur finger and one for the shaft end sear. The other point to notice is that a wider or thicker sear will last longer cause it has more surface area to bear the load. I don't know RA trigger sears but my non- XHD JBL uses about 2mm thick trigger sears. The XHD version has extra surface added/welded which is made of Tungsten Carbide, perhaps some 4mm thick. The Rife sears are 4-5mm thick.

If u can get ur hand on Monel, it will be best. Use 304 instead of 316 SS. Stay away from SS with L rating which means low carbon. This is highly corossion resistance but strength wise not good. 17-4 SS is another possibility, shaft is made of this, I heard.

The next weak link are the trigger pins which hold the 2 trigger sears. If the pins can handle the load, next watch out for the pistol grip. If it is made of plastic, it has to bear the load of the pins. 150 kg relying on small pins that exert pressure on the plastic pin holder ( in pistol grip ) is downright dangerous. Imagine the typical pin size is about 2-3mm diameter. When the gun is loaded with 150kg of force, 2 ends of the pin which hold the sear for the shaft will be handling the load. Since the load is going towards the muzzle, the effective load area for the pin holder is not the total circumference, but 1/2 of it only.

If you can ever make both trigger sears thicker and thus stronger, you need to worry most of the pin holder in that plastic pistol grip, later worry about the pins. The older JBL Woody uses plastic pistol grip ( brown color ), the failure is at that pin holder, cause it is made of plastic.

The other factor to consider is that, is RA trigger sear design good enough to sweet release 150kg of force ? Some trigger will become super hard ( if not jammed up ) one it reach the threshold limit. Non XHD JBL is one of them, that is why the XHD one is different. Riffe trigger is unique. U can use 2 or 5 bands and the release is almost the same, a hallmark of a good trigger. The way it is installed on the gun is another strong point. It comes in a unit including its own housing. Just drop it in , secure it and use it, unlike the JBL that you need to dismantle the pistol grip and can access the trigger sears one by one. The beauty of this trigger assy is that, since it has its own housing, the housing bear the load plus two big bolts that secure it. The load is then transfered to the recess cut out in the teak barrel and the two bolts. Wood is strongest when you press it againts its grain, and it sure can take a lot of pressure.

The Metal Tech Riffe is another trigger mounting genius design. It is assembled as such, the load is beared by both the plastic butt end and two bolts that goes thru the thick aluminum barrel. Can't explain properly with out photo.

I fear one thing most, ur RA pin holder in the pistol grip. The best tigger sears and pins design and material is useless if it eventualy break that pin holder.

Why don't you get Omer pistol grip and modify it somehow. I heard it can take 2 x 20mm safely. Confirm with Omer on that kind of pressure.

Good points to ponder.
If it turns out that the pin is the weak link I can just as well heat treat it.
Control of the cooling process eliminates the brittle nature acheived by a quick quench, IE air cooling vice a quick quench with oil.
PER a NACE document....
"The hardenable alloy steels are low-alloy steels with1,2, or 3% Chromium and .5 or 1% molybdenum. These additions make the steels hardenable, which means that by using the proper heat treatment the strength of the steels can be improved.
When cooled from 723C the austenite structure of the steel is transformed to a different crystal structure depending on the cooling rate. A rapid cooling rate results in the formation of martensite, an extremely hard but brittle phase. This phase is prone to cracking when not heat treated at lower temps to soften the structure (tempering). A slower cooling rate will result in the formation of banite and pearlite; these phases are much tougher that martensite."
This is just in the brain child phase. I just wanted some feed back to see if its feasible/practical. Not to mention Im on the Night shift at work with way too much time on my hands.;)
I knew I could count on you for some feed back:)
Heres some cool links I found.

http://uet.edu.pk/dmems/PptHardening.gif http://spearguns.netfirms.com/tipscast.html

The Omer grip would be nice and most likely My final answer.
I found this at Momentoffame.com, it is apparently Mark Labocetta's of OMER USA. I emailed him today to see what trigger mech it is. As you said it would be much easier to go with one of these than to mess around with a "home grown HT".


Looking at the rubbers, that trigger should be worthy. Afterall Mark has all the Omer toys, he will choose what is best and safe for him I am sure. Good luck.
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