light primer strikes with lighter triggers?

[rraisley]

You were not paying attention to what I was using as an example. With the original example I was showing a captured length that was 3 inches less than the free length. After cutting the spring the free length is less so the amount of compression preload will be a shorter multiple and my example was based on a theoretical spring so when I cut 3 coils off and remounted it the compression preload of a shortened spring would be a lower multiple than the original 3 inches. I was using 2.75" as the amount of compression length to fit in the same captured space. Of course that varies by the dimensions of the parts and the space.

Sorry if I didn't understand your example. Most (ALL?) springs in firearms fit between two stops, and we don't have the luxury of compressing them a specific amount. They just end up a specific overall length (compressed or uncompressed).

The point I was making was that for any spring fitting between two such points, cutting it, while increasing the spring constant, will /reduce/ the force it exerts, between those stops, unless it is stretched or the mounts are changed.

 

[Plumbago]

rraisley::: You are not missing a thing. You are correct in your calculations for real world effect on a firearm with a rebounding fireing pin, such as the 15-22......If you are having any light FP strikes, it is most likly caused by the fact you have lightened the Hammer spring, by cutting, bending, or replacement; done to no doubt lighten the trigger pull......If you are satisfied with the lightened trigger pull, and not to debate the merits of this.......To correct the light strickes, from the rebounding FP, with a lightened hammer spring, you will most likly need to cut the length of the Fireing Pin Spring period .....Here is the real "formula" that works: Remove the FP and spring from the bolt. With the spring still installed on the FP. Look at the end of the FP that fires the shells, and then Cut the FP spring, two FULL coils LONGER than the length of the FP, past the end of the FP. I believe this to be about optium length FP spring for a lightened hammer spring setup. This is what works for me.... However if you just can't take my word for it, then make several longer cuts and try them....best regards Plum

 

[stavman11]

rraisley::: You are not missing a thing. You are correct in your calculations for real world effect on a firearm with a rebounding fireing pin, such as the 15-22......If you are having any light FP strikes, it is most likly caused by the fact you have lightened the Hammer spring, by cutting, bending, or replacement; done to no doubt lighten the trigger pull......If you are satisfied with the lightened trigger pull, and not to debate the merits of this.......To correct the light strickes, from the rebounding FP, with a lightened hammer spring, you will most likly need to cut the length of the Fireing Pin Spring period .....Here is the real "formula" that works: Remove the FP and spring from the bolt. With the spring still installed on the FP. Look at the end of the FP that fires the shells, and then Cut the FP spring, two FULL coils LONGER than the length of the FP, past the end of the FP. I believe this to be about optium length FP spring for a lightened hammer spring setup. This is what works for me.... However if you just can't take my word for it, then make several longer cuts and try them....best regards Plum

may try this this week...

went out this am and had a few Light Strikes

just ordered some replacement springs from fastenal like Lock&Load did just in case I HOSE em up...LOL

Great discussion guys..... that HORSE got his Butt beat





Stav

 

[stavman11]

new SPRINGS should be here friday

Just SNIPPED off 3 coils ISH..........

See how she works on Sunday........

More Learning... i LOVE it....... was REAL oily inside Firing Pin... all cleaned and LUBED and ready ta go.....



Stav

 

[stavman11]

Well after My Above Spring adjustement went out and Lobbed 575 rds down range

Started out PERFECT......
Then a few Light Strikes Started. Seemed mostly when i was plinking and Not using Slide Fire

In Conclusion... It's not PERFECT...... not sure if PERFECT is possible... BUT it is STUPID fun......

So My testing is done..... and Ill enjoy one of the FUNNEST toys I have

...

 

[mkauder]

I installed a Jard 2ib trigger in my gun, and found a couple of issues, mostly the failure to reset the trigger. I resolved this by lightly polishing the black steel rails that the bolt run on, polishing the recoil spring rod, and polishing the hammer face, and the portion under the firing pin that cams the hammer back during recoil. When I did this, I started having failures to fire - not even leaving mark on the cartridge. I had slightly rounded the top of the hammer during the polishing process, and I guess that was just enough to kill sufficient momentum from the firing pin to stop ignition. My solution was to lengthen the front/muzzle end of the slot in the firing pin that the roll pin rides in, just a couple thousands of an inch, so that the firing pin protrudes out the back of the bolt just a couple of thousands more - hammer hits a fraction sooner and longer. NO More failures to fire. This mod does not affect how far the firing pin will travel forward, so there will be no danger of primer puncture.

Mark K.

 

[eseaton]

I installed a Jard 2ib trigger in my gun, and found a couple of issues, mostly the failure to reset the trigger. I resolved this by lightly polishing the black steel rails that the bolt run on, polishing the recoil spring rod, and polishing the hammer face, and the portion under the firing pin that cams the hammer back during recoil. When I did this, I started having failures to fire - not even leaving mark on the cartridge. I had slightly rounded the top of the hammer during the polishing process, and I guess that was just enough to kill sufficient momentum from the firing pin to stop ignition. My solution was to lengthen the front/muzzle end of the slot in the firing pin that the roll pin rides in, just a couple thousands of an inch, so that the firing pin protrudes out the back of the bolt just a couple of thousands more - hammer hits a fraction sooner and longer. NO More failures to fire. This mod does not affect how far the firing pin will travel forward, so there will be no danger of primer puncture.

Mark K.

How did you lengthen the "front/muzzle end of the slot in the firing pin that the roll pin rides in, just a couple thousands of an inch, so that the firing pin protrudes out the back of the bolt just a couple of thousands more"?

Thanks

eseaton

 

[photoracer]

Another thing you can do is combine a light trigger spring with a higher rate hammer spring. I was going to try that myself until I just found out that JP already sells just such a kit. It includes the "yellow" trigger spring with the "red" hammer spring. Or if you buy the "yellow" spring kit just install the trigger spring.

 

[eseaton]

light strike issues

rraisley::: You are not missing a thing. You are correct in your calculations for real world effect on a firearm with a rebounding fireing pin, such as the 15-22......If you are having any light FP strikes, it is most likly caused by the fact you have lightened the Hammer spring, by cutting, bending, or replacement; done to no doubt lighten the trigger pull......If you are satisfied with the lightened trigger pull, and not to debate the merits of this.......To correct the light strickes, from the rebounding FP, with a lightened hammer spring, you will most likly need to cut the length of the Fireing Pin Spring period .....Here is the real "formula" that works: Remove the FP and spring from the bolt. With the spring still installed on the FP. Look at the end of the FP that fires the shells, and then Cut the FP spring, two FULL coils LONGER than the length of the FP, past the end of the FP. I believe this to be about optium length FP spring for a lightened hammer spring setup. This is what works for me.... However if you just can't take my word for it, then make several longer cuts and try them....best regards Plum

Did anyone actually try this and did it work. Seems that it would with no need to buy replacement springs. Now, can someone tell me how to remove the firing pin and spring so I can make the above adjustments?

Thanks

eseaton

 

[Plumbago]

eseaton: remove bolt from firearm...remove bolt from rails...tap out pin on side of bolt with 1/16" drift....Fp will come right out....clean FP, spring and Bolt housing....measure twice, cut once, as above, cut spring, reassemble in reverse order....there are some disassembly videos out there if need be.....best regards Plum

 

[stavman11]

well after 575 Rounds yesterday only had 1 Light strike during the day....
I tried to Modify the springs I got like You mentioned Plumbago, but the fastenal Springs I got per someones post (cant remember who) where a Little Large in Diameter and didnt seem to fit smooth like the stock one....

So I just cleaned the FP and inside the chamber with a Q-Tip and that was it (I had already trimmed the spring once)


I did a LOT of Mag Dumps with the SlideFire as well as a lot of PLINKING at targets... and Only 1 Issue..

was pretty happy for sure.....

 

[stavman11]

Another prefect day yesterday

After last wed I had a few trigger issues.... checked my Timney and the trigger was loose a bit... re set the set screws and all was dialed

400+ rounds yesterday and not 1 issue of Light Strikes, most full mag dumps but at least 5-25rd plinking also....

so be sure and check yer triggers that they stay tight.....


FYI


Stav

 

[strobro32]

Yes I had a few light primer strikes and failures for the trigger to reset while my Timney 3# trigger was installed not to mention my trigger pins walking out a few times. Then I removed the Timney and did the $10 JP reduced hammer springs/ light hammer mod.

I have since put 850 rounds with 40 grain CCI MM RN using my 200 round drum and a couple of 25 round mags. It has been flawless, O function problems.

 

[mkauder]

How did you lengthen the "front/muzzle end of the slot in the firing pin that the roll pin rides in, just a couple thousands of an inch, so that the firing pin protrudes out the back of the bolt just a couple of thousands more"?

Thanks

eseaton

I pulled the FP from the bolt, and then using a abrasive cutting disk on my Dremel tool, I carefully cut a way a little metal on the FP.

 

[deallad]

I have been cutting the FP spring down a turn at a time and it has worked just the odd light strike

 

[filbert]

I have been cutting the FP spring down a turn at a time and it has worked just the odd light strike

Sorry to resurrect this... but how many turns did you end up cutting? the 3 that someone recommended above?

 

[Bunsin]

Light strikes and Jewell trigger

I had this same issue when I dropped in a Jewell trigger into the rifle a while back. I solved it by putting in a slightly stretched pen spring (You can do a search for Jewell triggers in the forum and the pics will come up from last year). After ~5k more rounds without any FFF issue that was not ammo related I will say that the firing pin spring is ridiculously over rated for the system...