What does ignition blueprint/trueing include. What would ignition blueprint/trueing include on a defiance ruckus action.
- Thread starter mjwilcox38
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Tig weld bolt for timing extraction, timing the cocking piece to the trigger sear while keeping near 240k pin fall. Some of the work I know of anyways.
I was thinking more along ignition.
Timing igniton is timing up the cocking cams, to pass the cocking piece over to the sear eliminating cock on close, or over cocking, all while trying to keep traditional 240k pin fall, as previously stated. Proper firing pin protrusion is also kept in mind through this process. It may require re cutting the cocking cam helix.
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An defiance action should be good. Or not?? I think I'm talking more along lines of ensuring spring is changed, polish everything to ensure reliable ignition. I saw a YouTube video where they made the GAP between shroud and firing pin cock indicator larger to reduce contact.
Defiance has cock on close typically. To get it perfect it needs cocking cam helix recut and the cocking piece slightly shortened. The man to do this work perfectly is Alex Wheeler of Wheeler Accuracy. Defiance blows my mind, near 2k for a poorly timed action. A fn 750$ Mac bros does it better than a deviant. Oh and controlled headspace too. Defiance is 10 mins from my house, and I won't use em.
What would I get by having the helix reputation and cocking piece shortened
Re cut not reputation.
What actions out there come with all this already completed.
I'm sure this was a Cortina video. I don't know off hand if anyone offers exactly what he does but if you talked to a good smith or machinist wouldn't be an issue to have it done.
I know he clearances the shroud, and polishes the pin and changes the spring, I'll watch the video again tonight and let you know if there's anything else
I know he clearances the shroud, and polishes the pin and changes the spring, I'll watch the video again tonight and let you know if there's anything else
The timing on a Defiance is as good as it gets. It will have about .020" cock on close. That is perfect for my desires.
406shootist says defiance actions needs cocking cam helix re cut. What would I gain having that done to a defiance action. I have ruckus and tenacity.
Nothing. You need to look into bolt timing a bit more before you get anything done. I don’t think you need anything done.
You need to check the pin fall and the cock on close of each individual action to determine what it needs. There is likely nothing to be gained. I doubt 406shootist has ever timed a Defiance action.
I've modified the cocking piece to eliminate cock on close, this dropped pin fall to 0.223, so the action/bolt was sent to Wheeler where he recut the bolt in his mill to give it 0.240 pin fall again with zero cock on close. So yeah I do have a bit of experience with that. I've also done this with Christensen rifles, they maintained near 240k pin pall after so no cam timing was needed. Timed a few kelbly and Impact with different trigger hangers. My ARC and newer zermatts have been well timed to TT triggers(did have to swap cocking pieces on an early origin via zermatt for free). My bats and lone peak have been good with BnA.
What did you see on paper after having this done. How do you tell if an action is well timed?
How do you check this?
Thank you
I have defiance actions with trigger tech diamonds
The timing in ref to the cam is to do with the hand off between the trigger and cocking piece. Like I said you need to get more educated on the topic before you do anything. It’s a pretty niche thing you are looking at.
To measure cock on close(or decocking on close, some actions over cock on opening), you need to get a cliper and measure the position of the cocking piece in reference to bolt shroud with the bolt in the cocked position before the cocking piece is passed off to the trigger sear. Measure it after the bolts closed and cocked on sear. A properly timed action will have no/minimal change between the two measurements. Now, drop the pin by pressing the trigger. Measure the shroud to cocking piece again. Subtract 2nd measurement you took, from the last you took and that's total pin fall. You can now measure firing pin protrusion from the bolt face as well.
If measurement 1 is less than measurement 2, you have cock on close. This is remedied by shortening the forward face of the cocking piece by interfacing them together. However doing this shortens pin fall numbers, lower the firing pin travel distance, supposedly this can lower fp energy and decrease consistency of ignition. The gold standard for desired pin fall on a 700 clone is 0.240". However a bighorn tl3 has pretty short pin fall(0.200-0.190 depending on trigger used) but I still get pretty tight sd numbers. Lightened firing pins(fluted/lighter alloys) and increased fp spring rates can make up for the lost energy by shorter pin fall.
If measument #1 is longer than #2, the rear of the bolt body that the cocking piece rides onto after cocking can be machined down, reducing total cocking distance, bringing the two measurements together for correct timing.
The cocking ramp inside the bolt body that the cocking pieces rides up on as the bolt is opened, is multi dimensional. X Y and Z, as when done properly is not a totally perpendicular shape to the bolt body, but it's helical when done right. This smoothens the travel of the cocking piece.
So yes there is a lot of depth into the process of what you're inquiring knowledge about.
TT triggers have shorter sear lengths VS BnA triggers in my experience. If an action has say 0.010 of decocking with a TT, most of that will disappear with a BnA trigger. But a BnA trigger will induce more cock on close with an action that already has it present.
If measurement 1 is less than measurement 2, you have cock on close. This is remedied by shortening the forward face of the cocking piece by interfacing them together. However doing this shortens pin fall numbers, lower the firing pin travel distance, supposedly this can lower fp energy and decrease consistency of ignition. The gold standard for desired pin fall on a 700 clone is 0.240". However a bighorn tl3 has pretty short pin fall(0.200-0.190 depending on trigger used) but I still get pretty tight sd numbers. Lightened firing pins(fluted/lighter alloys) and increased fp spring rates can make up for the lost energy by shorter pin fall.
If measument #1 is longer than #2, the rear of the bolt body that the cocking piece rides onto after cocking can be machined down, reducing total cocking distance, bringing the two measurements together for correct timing.
The cocking ramp inside the bolt body that the cocking pieces rides up on as the bolt is opened, is multi dimensional. X Y and Z, as when done properly is not a totally perpendicular shape to the bolt body, but it's helical when done right. This smoothens the travel of the cocking piece.
So yes there is a lot of depth into the process of what you're inquiring knowledge about.
TT triggers have shorter sear lengths VS BnA triggers in my experience. If an action has say 0.010 of decocking with a TT, most of that will disappear with a BnA trigger. But a BnA trigger will induce more cock on close with an action that already has it present.
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Correct me if I am wrong. But if you have good SD numbers all this work would do is make the bolt feel nicer to the touch???
Possibly slightly easier to close but a bit harder to open. IMO a bit of cock on close is good.
I think you were more wondering about making sure there is good ignition which is just firing pin is free to move with enough pin fall and protrusion and sufficient spring force. Basically if you put a fresh spring in it I’d bet everything else is hunky dory
A lot of this theory comes from the benchrest/fclass game, chasing micro accuracy. If sub moa to half minute is you're game, it'll benefit you little other than a silky smooth bolt closure that will likely less upset the rifle when closing the bolt. Cock on close bugs the hell outta me, so I eliminate it if possible with trigger timing via a hanger, or midfield cocking piece.
I measured my tenacity action bolt. Here is what I came up with. It cocks on open. The cocked indicator sticks out .07 when its open. When I pull bolt back and close the cocking indicator slides foward to .05. it comes in. Then when I pull the trigger my indicator goes into the shroud .200. If I measured correctly I have .260 to .270 of pin fall when I press the trigger.
I am curious as to why it goes foward .02 when I close the bolt. If it did not go foward I would have .280 to .290 of pin fall. So maybe designed to do so ????????
That is the handoff of the cocking piece from the bolt body to the trigger sear. That means you have no cock on close and the trigger is .020" farther forward than it needs to be (doesn't really matter). According to your numbers you have .250" of pin fall. (.050+ .200)
Thank you for the video. That was exactly what I was refering to. I watched Cortina inteview Speedy and they were talking about stuff he did in video. The other guys brought up cock on open/close, pin fall, and measuring pin fall so I learned a lot. Thanks for taking the time to answer questions and post video.
The cocking piece doesn't move forward. It is the bolt shroud that moves back when the bolt is closed. The bolt shroud is screwed into the bolt body. When the bolt is closed, the shroud is unscrewed about 1/4 turn. The thread size is 1/2" diameter x 13 threads per inch. 1/4 turn on that size threads is .01923".
Watch the gap between the back of the bolt body and the front of the shroud change as you raise and lower the handle.
So if my action only moves foward .0200 when it is closed it is basically timed perfect???? Is this correct???
Not my action, the shroud moves back on the cocked indicator .02
I'm pretty ignorant on most of this but from what I gather many smiths dont dick with this stuff. Known action, known trigger, cocks and goes boom without notable issue or feeling off - good to go. Someone correct me if that is off base?
I've watched taylor stratton's videos with great interest in relation to this. He indicates even most all the high end custom actions benefit from some tuning and ignition timing efforts. It seems Wheeler has said similar things. From Stratton's website:
I've watched taylor stratton's videos with great interest in relation to this. He indicates even most all the high end custom actions benefit from some tuning and ignition timing efforts. It seems Wheeler has said similar things. From Stratton's website:
From what I have learned in this thread action timing is a preference. As long as it's not disrupting clambering a round it doesn't affect accuracy. And you have .250 pin fall. The rest is covered in Cortina video which is what I was looking for from the start. Flitz and attention to detail will make my defiance actions on par for me.
On my archemedes I have about .005 cocking with the .045 cocking piece and trigger tech trigger, .255 firing pin travel. Just feel effortless to me , and it shoots good too. Also on the new CDC action you can move the trigger hanger to your sweet spot.
