I just load for speed at this point. No real load development since the first round of load development. I check SDs/EDs and that's about it.
6gt
- Thread starter Dthomas3523
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I just load for speed at this point. No real load development since the first round of load development. I check SDs/EDs and that's about it.
Hahaha, I was playing with trueing my MV at 600 and then my BC at 750/1000 throughout the day... but with the barrel still speeding up, I had to remind myself now and again to just have fun shooting and not worry about it yet... but, yep, if setteled in, and MV is still right at 600, BC might need to come up a click at 1000.
If that, even... ha ha. That looks closer to .05 mil, even...BC might need to come up a click at 1000.
Well, now that you said that, it was off a Shmedium/tank trap and I'm still adjusting to a new eyes/contacts Rx... so it could've just been me. I find most times it's the monkey pulling the trigger that's the problem, don't want to rule that out too fast lol.
So, the other day when it looked like I was a click or so low or my BC was slightly off at 1000, it wasn't that...
I noticed that Strelok was showing I was getting 2880fps... which seemed wonky and/or too good to be true for 32gn of Shooter's World Precision Rifle (AKA "fake Varget", known to usually be a grain or so slower than Varget).
Seemed hot to me for only 32gn, and I started to wonder why I was getting so much speed?
I decided to measure the distance to the lands, and my generic-break-in/virgin-brass-load was only 0.009" off. That's too close for me, so I decided to seat the remaining rounds I've already got loaded deeper to .100" off like I'd prefer to run it for its lifetime. I figured that would scrub off a little speed, not a huge amount, but something.
Well, got to the range, and the first shot at 100 (to confirm zero before going out further) showed me at least 2-3 tenths low. That was the problem... I hadn't fixed my zero after the barrel had sped up during that first 100 rounds.
My MV wasn't 2880fps, it was more like 2720fps (which jives) and my zero was messed up lol.
The moral of the story is, it's almost always the monkey pulling the trigger...
(FWIW the usual .100" off w/ 112gn Match Burner looks good, 5 at 750, Shmedium/tank trap ...with correct dope this time lol.)
I noticed that Strelok was showing I was getting 2880fps... which seemed wonky and/or too good to be true for 32gn of Shooter's World Precision Rifle (AKA "fake Varget", known to usually be a grain or so slower than Varget).
Seemed hot to me for only 32gn, and I started to wonder why I was getting so much speed?
I decided to measure the distance to the lands, and my generic-break-in/virgin-brass-load was only 0.009" off. That's too close for me, so I decided to seat the remaining rounds I've already got loaded deeper to .100" off like I'd prefer to run it for its lifetime. I figured that would scrub off a little speed, not a huge amount, but something.
Well, got to the range, and the first shot at 100 (to confirm zero before going out further) showed me at least 2-3 tenths low. That was the problem... I hadn't fixed my zero after the barrel had sped up during that first 100 rounds.
My MV wasn't 2880fps, it was more like 2720fps (which jives) and my zero was messed up lol.
The moral of the story is, it's almost always the monkey pulling the trigger...
(FWIW the usual .100" off w/ 112gn Match Burner looks good, 5 at 750, Shmedium/tank trap ...with correct dope this time lol.)
I’m just getting to know my 6. Still the 6.5 is continuing to impress with 2200+ rounds down the tube.
Back to the point, it seems really quick to get to the next target. Running back to back short stages, the 6GT is consistently beating the 6.5 CMon time However, it must be my old blood or worse, my shooting too many hard kickers through the years, but I for one cannot tell much difference in the recoil. I suppose a steady diet of shooting heavily loaded 35’s and occasionally something in the 40’s for rifles and 44 magnums and magnum loaded 45’s kind a ruins a fellow for a fine shooting light recoiling rifle.
However, as mentioned, I have noticed the recoil impulse between the Creedmoor and the GT is different, with the GT snappier. Now the RPR in 6.5 Creedmoor does have a noticeable difference in recoil, but it is markably different from my two rifles in MPA chassis.
Back to the point, it seems really quick to get to the next target. Running back to back short stages, the 6GT is consistently beating the 6.5 CMon time However, it must be my old blood or worse, my shooting too many hard kickers through the years, but I for one cannot tell much difference in the recoil. I suppose a steady diet of shooting heavily loaded 35’s and occasionally something in the 40’s for rifles and 44 magnums and magnum loaded 45’s kind a ruins a fellow for a fine shooting light recoiling rifle.
However, as mentioned, I have noticed the recoil impulse between the Creedmoor and the GT is different, with the GT snappier. Now the RPR in 6.5 Creedmoor does have a noticeable difference in recoil, but it is markably different from my two rifles in MPA chassis.
I'll only be running it this slow for its first 300 rounds, for the first firing on the brass. I loaded them all up with a generic load months ago.
I'll add another grain or two and see what I get...
~2850fps would be ideal IMO, but I don't see myself adding more than two more grains at most, I'll see I guess.
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Quite a few of the better PRS shooters in the country run their BR variants or 6gt’s in the 2750 area.
You don’t lose much at all
High 2700's to mid 2800's is a good place to be on my last 3 barrels.
Just an FYI/PSA…
I’ve had 11 FTFs over my first 200rds with some brand new Alpha OCD “Gay Tiger” head-stamped brass purchased through GAP.
Not a huge deal, but it was annoying until I figured it out (with the help of another experienced shooter because at first I didn’t think of it and was starting to think I was going crazy). I've bumped some shoulders back a little too much and learned that lesson before, but never expected to see it with new brass. There's a first time for everything though lol.
Apparently, the virgin brass’ headspace is too short (6 thou below SAAMI minimum which is 1.357"). The shoulder datum on the ones that fired is now 1.360", while the still-virgin ones that didn't go off measure 1.351".
I guess I’ll have to disassemble them and then put them back together long to jam them a little in order to blow them out.
Just something to look out for if you purchased some of this stuff or ever run into this… I'm glad I didn't have to learn this lesson at a match or I'd be pissed lol.
ETA: FWIW, I did some more measuring detective work, and looks like my Origin/Proof SS prefit combo (checked with Go/No-Go gauges) will still light off cases that are ~4 thou below SAAMI minimum (~1.353", which is what most of the new brass measures), but seems the ~2 thou difference between those and the ones that are ~1.351" is enough to make them not go bang.
I’ve had 11 FTFs over my first 200rds with some brand new Alpha OCD “Gay Tiger” head-stamped brass purchased through GAP.
Not a huge deal, but it was annoying until I figured it out (with the help of another experienced shooter because at first I didn’t think of it and was starting to think I was going crazy). I've bumped some shoulders back a little too much and learned that lesson before, but never expected to see it with new brass. There's a first time for everything though lol.
Apparently, the virgin brass’ headspace is too short (6 thou below SAAMI minimum which is 1.357"). The shoulder datum on the ones that fired is now 1.360", while the still-virgin ones that didn't go off measure 1.351".
I guess I’ll have to disassemble them and then put them back together long to jam them a little in order to blow them out.
Just something to look out for if you purchased some of this stuff or ever run into this… I'm glad I didn't have to learn this lesson at a match or I'd be pissed lol.
ETA: FWIW, I did some more measuring detective work, and looks like my Origin/Proof SS prefit combo (checked with Go/No-Go gauges) will still light off cases that are ~4 thou below SAAMI minimum (~1.353", which is what most of the new brass measures), but seems the ~2 thou difference between those and the ones that are ~1.351" is enough to make them not go bang.
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Origin, the primers are 6 thou below the case head (that's the first thing I thought too, it's not that), the brass was just "born" with the shoulders too short.
Can a case even move .006" in an Origin when the breech is locked? My alpha brass has short primer pockets and I get zero to -.001 below flush. Honestly, .012" of firing pin travel shouldn't be a problem. I'd call Zermatt and run it past them. Protrusion should be .045" which should leave you plenty of firing pin travel for proper ignition.
I exchanged emails with Ray at Zermatt about it, and per usual he was willing to try and help me by shipping me out a new firing-pin assembly before I'd even asked... I told him "thanks, no thanks" for now, because I honestly don't think it has anything to do with that.
It looks like it's just the new brass with the really short shoulder, but yeah, if I have further issues with it I'm going to try a different firing-pin assembly because I agree, the firing-pin protrusion is worth looking at.
I've got something like ~5000rds on the Origin with maybe 2-3 FTF's over that whole time before I started with this new brass... and I even just installed a fresh firing pin spring (preventative maintenance while sussing out and replacing a faulty TT Diamond).
Until they all go bang the jury is still out, but I'm pretty confident it's just the brass. I could be wrong, wouldn't be the first time lol. I'll see I guess...
(You're making me a little paranoid now though haha, I'm going to have to measure my firing-pin protrusion now lol.)
Another option may be to seat primers shallower until you get all of the brass fire-formed. It isn't optimal but neither is ignition failures.
before you do anything drastic, seat a bullet out so that the case headspaces on it. You could be having 2 very small problems both add to make a larger problem. I have deprimed many live primers without incident. Can also pull the bullets partially out then seat them as a jam fit. I probably wouldn't change the primer, just give it a restrike.
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Yeah, my plan is to re-load the ones that didn't go off long enough to be jammed
*After further thought, since the problematic brass is 9 thou below the fired brass that went bang, I'll load them 10 thou into the lands to account for that, plus anything wonky between the firing-pin protrusion and my primer depth (paranoia, thanks @Cascade Hemi lol) and as long as the primers aren't duds, I should be good. I'll see lol.
BTW, firing-pin protrusion is a fun thing to try and measure using calipers lol. Mine is somewhere between .007" and .017"? IDK, getting a legit measurement seems beyond the envelope of my skill lol.
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Your measurements are spot on. My impact precision proof prefit was exactly the same as yours, as was my alpha brass measurements. I was concerned myself initially. My gunsmith allows for about .005 runout on headspace, where as I'm assuming proof does the max allowable for any slop between actions. So basically I had about .009 runout on my brass after 1st firing. I did not have any ftf though. Cci 450 primers
Thanks for confirming that you've seen the same problem.
After doing some more measuring of things, I don't think the issue is with Proof allowing more headspace than is needed though, and I think the cause of the "headspace headache" falls squarely on Alpha.
Post-firing my cases are 1.360", SAAMI spec is 1.357" - 1.364". Proof has their headspace parked right in the middle, 3 thou over the minimum (in my case anyway). I don't think that's so bad.
Good thing brass is malleable.
Had a few sticky bolts in a match so I tuned my load down a tad. Bolt throw is lot smoother now with the new load and will see how it is in a match coming up. Two groups from different days to affirm it.
Impact 737
Proof Comp contour 26” 1-7
109 ELDM’s
RL 15.5 33.3grs
CCI 450
Alpha brass
CBTO 1.920
.002 Neck tension
Checking data at 501yds 5 shots
Impact 737
Proof Comp contour 26” 1-7
109 ELDM’s
RL 15.5 33.3grs
CCI 450
Alpha brass
CBTO 1.920
.002 Neck tension
Checking data at 501yds 5 shots
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Earlier, when I said the Alpha Gay Tiger brass was giving me a problem due to having short shoulders, ~6 thou under (1.351") SAAMI minimum (1.357"), it was, and still is, but I thought my brass was growing post-firing to 1.360"... I was wrong about that last part.
The brass is still giving me headaches with 16 still unfired out of 300 over 3 different range trips trying to get it fire-formed...
Turns out I was getting a bad measurement due to the primers being puckered outward slightly (another side-effect of the shoulders being too short and resulting loose/bad fit in the chamber).
I figured this out when I discovered that, even with my sizing die touching the shell plate, it still wasn't bumping the shoulder back, duh, probably because the post-fired cases are actually ~1.356" at the shoulder (not 1.360"). As most of you reading this know, usually, most times, touching the shell plate with a FL die results in ~5-6 thou of bump (around SAAMI minimum) and you have to back dies off to get the usual 1.5-2 thou of bump most of us are looking for... well, my shoulders aren't being bumped because they aren't even SAAMI minimum yet.
The good news is, the gun is a f'ing laser and hammers, so at least there's that, but this Alpha brass is giving me a terrible first impression of their product. I'd honestly rather shoot Hornady brass at this point, 6-7 thou below SAAMI minimum isn't due to it being special or Gucci, it's BS, and when I paid more money for fancy brass I thought I was paying for them not letting shit like this get out the door, and make no mistake, this shit shouldn't have made it out into the world.
For the third time, I pulled/disassembled the ones that wouldn't go off and then purposely upped the neck tension by skipping the mandrel step in my process and will be jamming these next ones 20 thou into jam (normal neck tension and 10 thou of jam wasn't enough). I'm also using a different brand/batch of primers just to rule out me having a bad batch of CCI 450s. Hopefully, with these extra measures taken in order to make sure the case is wedged in there enough to allow for a successful primer whack, they will finally go bang.
I'm going to load 100 more rounds at my usual/preferred .100" off to try, because they should go bang like that without me having to lend a helping hand jamming them, but that's it, I don't have enough confidence in this brass to burn any more primers and bullets on it. If I get any more FTF's with this shit or any brass-related shit at all with it on the second load cycle/firing... it goes in the trash can.
Dear Lapua,
Please make 6GT brass so I can buy it.
Thanks.
The brass is still giving me headaches with 16 still unfired out of 300 over 3 different range trips trying to get it fire-formed...
Turns out I was getting a bad measurement due to the primers being puckered outward slightly (another side-effect of the shoulders being too short and resulting loose/bad fit in the chamber).
I figured this out when I discovered that, even with my sizing die touching the shell plate, it still wasn't bumping the shoulder back, duh, probably because the post-fired cases are actually ~1.356" at the shoulder (not 1.360"). As most of you reading this know, usually, most times, touching the shell plate with a FL die results in ~5-6 thou of bump (around SAAMI minimum) and you have to back dies off to get the usual 1.5-2 thou of bump most of us are looking for... well, my shoulders aren't being bumped because they aren't even SAAMI minimum yet.
The good news is, the gun is a f'ing laser and hammers, so at least there's that, but this Alpha brass is giving me a terrible first impression of their product. I'd honestly rather shoot Hornady brass at this point, 6-7 thou below SAAMI minimum isn't due to it being special or Gucci, it's BS, and when I paid more money for fancy brass I thought I was paying for them not letting shit like this get out the door, and make no mistake, this shit shouldn't have made it out into the world.
For the third time, I pulled/disassembled the ones that wouldn't go off and then purposely upped the neck tension by skipping the mandrel step in my process and will be jamming these next ones 20 thou into jam (normal neck tension and 10 thou of jam wasn't enough). I'm also using a different brand/batch of primers just to rule out me having a bad batch of CCI 450s. Hopefully, with these extra measures taken in order to make sure the case is wedged in there enough to allow for a successful primer whack, they will finally go bang.
I'm going to load 100 more rounds at my usual/preferred .100" off to try, because they should go bang like that without me having to lend a helping hand jamming them, but that's it, I don't have enough confidence in this brass to burn any more primers and bullets on it. If I get any more FTF's with this shit or any brass-related shit at all with it on the second load cycle/firing... it goes in the trash can.
Dear Lapua,
Please make 6GT brass so I can buy it.
Thanks.
Always deprime brass that you’re using for shoulder bump measurements!!! It ensures that you’re really measure the head and not a primer standing slightly proud or something.
Sounds like your smith may have did a crap job on headspace. I have had 4 6gt and a 22gt barrel(s). All have been chambered to go plus 001 and new alpha brass grows 003 from new, I bump it back 002. Easy easy.Earlier, when I said the Alpha Gay Tiger brass was giving me a problem due to having short shoulders, ~6 thou under (1.351") SAAMI minimum (1.357"), it was, and still is, but I thought my brass was growing post-firing to 1.360"... I was wrong about that last part.
The brass is still giving me headaches with 16 still unfired out of 300 over 3 different range trips trying to get it fire-formed...
Turns out I was getting a bad measurement due to the primers being puckered outward slightly (another side-effect of the shoulders being too short and resulting loose/bad fit in the chamber).
I figured this out when I discovered that, even with my sizing die touching the shell plate, it still wasn't bumping the shoulder back, duh, probably because the post-fired cases are actually ~1.356" at the shoulder (not 1.360"). As most of you reading this know, usually, most times, touching the shell plate with a FL die results in ~5-6 thou of bump (around SAAMI minimum) and you have to back dies off to get the usual 1.5-2 thou of bump most of us are looking for... well, my shoulders aren't being bumped because they aren't even SAAMI minimum yet.
The good news is, the gun is a f'ing laser and hammers, so at least there's that, but this Alpha brass is giving me a terrible first impression of their product. I'd honestly rather shoot Hornady brass at this point, 6-7 thou below SAAMI minimum isn't due to it being special or Gucci, it's BS, and when I paid more money for fancy brass I thought I was paying for them not letting shit like this get out the door, and make no mistake, this shit shouldn't have made it out into the world.
For the third time, I pulled/disassembled the ones that wouldn't go off and then purposely upped the neck tension by skipping the mandrel step in my process and will be jamming these next ones 20 thou into jam (normal neck tension and 10 thou of jam wasn't enough). I'm also using a different brand/batch of primers just to rule out me having a bad batch of CCI 450s. Hopefully, with these extra measures taken in order to make sure the case is wedged in there enough to allow for a successful primer whack, they will finally go bang.
I'm going to load 100 more rounds at my usual/preferred .100" off to try, because they should go bang like that without me having to lend a helping hand jamming them, but that's it, I don't have enough confidence in this brass to burn any more primers and bullets on it. If I get any more FTF's with this shit or any brass-related shit at all with it on the second load cycle/firing... it goes in the trash can.
Dear Lapua,
Please make 6GT brass so I can buy it.
Thanks.
Nope, no Gunsmith needed, Origin/Proof prefit, checked with Go/No-Go gauges, spun on in my garage (just like my last 4 barrels). The headspace on my action/barrel is not the problem.
The Alpha brass I have is short and out of spec, period. I know I'm not the only one dealing with this since another guy had already mentioned he had the same problem earlier in the thread, and I've already talked to 2 guys at my club that have had issues with 6GT Alpha brass.
I'm not losing sleep over it or anything, but I'm a fairly experienced reloader, I've loaded tens of thousands of rounds and I'm still having a hard time getting all of this brass fire-formed since it's so short. A new reloader would likely have no idea how to deal with this and would definitely be bothering/blaming their Gunsmith.
6GT isn't a wildcat, it's a SAAMI cartridge, so really there shouldn't be any fire-forming of anything at all in order to make it work. That's kind of the whole point.
FWIW, I do have some virgin Hornady brass on hand, just 50 pieces I figured I might need as I lost some of the "good stuff" at matches, and for comparison, the .375 datum on the Hornady brass measures 1.355", ~5 thou taller than the Alpha stuff and within 2 thou of SAAMI minimum. No doubt the Hornady stuff is close enough that it would all go bang on the first try.
I just hope it doesn't give me any more problems, and for my OCD's sake, I hope I can get the 16 to go bang that haven't yet.
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I know, that's how I figured out the number I had gotten earlier when I made my first hasty measurement was bad. Not being able to bump the shoulder just reminded me that I needed to decap some of the brass and get a "real" measurement to figure out what was going on...
Contact alpha, they'll do you right. Hopefully you have some new unfired for them to measure. Your 375 bump gauge(depending on type) is a mass produced tool, just used as a reference, not a certified measure. Check your go and no go gauge with your 375 comperator, what do they measure vs your brass? Gauges aren't always full spec either. Just shoot and don't bump till you have to I guess. ADGs last lot of 65prc brass had necks so think I had to turn off over a full though per side to have 4k nk clearance. I've been using a lot of alpha brass lately, 22,6,6.5cm, 22 and 6gt,6bra, none has been short but the bra, it was 006 under go, but traditionally a 6bra is cut go -004, so made sense. I've seen a few proof tikka prefits well out of spec, but that could been the action vs chamber. I've got ocd 6gt and 22gt from 5 total lots, and all have been close. They're releasing a lot of 6gt right now and will be buying another 300pcs for another project, I'll see if it's considerably shorter. I have noticed newer lots have had less consistent neck thickness vs older lots, their qc has slipped some, I can attest to that.Nope, no Gunsmith needed, Origin/Proof prefit, checked with Go/No-Go gauges, spun on in my garage (just like my last 4 barrels). The headspace on my action/barrel is not the problem.
The Alpha brass I have is out of spec, period.
The minimum the shoulder should measure, using the .375 shoulder datum per the SAAMI print, is 1.357" (SAAMI spec is 1.364" - .007"). The Alpha Gay Tiger brass that I have all measures/measured 1.350" - 1.352", 5-7 thou less than SAAMI minimum.
I'm not losing sleep over it or anything, but I'm a fairly experienced reloader, I've loaded tens of thousands of rounds and I'm still having a hard time getting all of this brass fire-formed since it's so short. A new reloader would likely have no idea how to deal with this and would definitely be bothering their Gunsmith.
What is annoying is this isn't the first time Alpha has sent bad brass out into the world. One doesn't have to search too hard to find multiple instances over the last couple of years of them putting out jacked-up stuff in all sorts of cartridges like Dasher, 6BRA, 6.5CM, etc. Someone should have measured it and caught it before they put it in the fancy plastic box.
The brass being this far out of spec would be annoying with almost any wildcat, except, 6GT isn't a wildcat, it's a SAAMI cartridge, which means there's a universally recognized specification for manufacturers to adhere to, so really there shouldn't be any fire-forming of anything at all in order to make it work. That's kind of the whole point.
I just hope it doesn't give me any more problems, and for my OCD's sake, I hope I can get the 16 to go bang that haven't yet.
What really sucks is, considering how short the fired cases are after the first firing, it's probably going to take 2-3 more firings before they're fully fire-formed to my chamber... that's ~900-1200 rounds, maybe half of the barrel's useable life, just to get the brass fully fire-formed.
Shit, after typing that last part, I don't know why I'm still even bothering with it honestly. Maybe they don't even know it's f'ed up? I may contact Alpha and see what they can do, maybe they'll exchange this shit for stuff that's actually in spec?
I'm going to try and get it sussed out on my own if I can, if I can't, I'll contact Alpha and see what they say.
I loaded 100 tonight out of the ones that went off on the first firing, and as long as those don't give me any further problems, I'll call things good.
The 16 that refuse to go off are annoying, but sooner or later I'll figure out how to set them off and then I will finally have peace again lol.
Run a 6.5mm mandrel into the neck, then neck the case back down to where your bolt closes with slightest resistance to fireform against a false shoulder. Or seat a bullet to jam 10k into lands to keep the case from coming forward upon pin striking primer. Should get it to go bang.
If that’s an accurate measurement, it’s a problem.
Should be able to use back end of caliper to get close & protrusion should be .030 - .035 For ARC actions or double what you stated.
What action is this? Never mind found it, Origin. The protrusion numbers I've seen in threads on here for Origin are .045-.055. Seems like a lot to me, but .017 is definitely not enough. They are supposedly adjustable for protrusion & I've seen at least one thread where the guy had the pin come loose from the cocking piece. Might have loosened and backed up??
If it were me I'd call Zermat and get the correct protrusion from them, set it & try again without changing the load. Maybe just fresh primers.
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How do you recommend measuring for firing-pin protrusion..?
I can measure the back end when it’s cocked when I get home, and I know it’s a lot more than 17 thou, but trying to measure how much it protrudes through the bolt face when the firing-pin gets let loose was a PITA in my first attempt lol…
you can also just used the back of the caliper and measure to the bolt face and then the firing pin, the difference is the protrusion.
Pull bolt, decock bolt/cocking piece. Use ass end of caliper, slide stem out at least 0.060, seat stem against bolt face next to protruded firing pin, slide caliper body down to make contact with firing pin while maintaiging as close to parallel angles with bolt face. Pretty sure that's how most folks check fp protrusion. Since you're using and origin, you can measure depth from. Front of lug face, to bolt face, then measure from lug face to tip of protruded firing pin and subtract the two, also gives same measurement as other method. I'd position the caliper body on the bolt in reference of the two arrows, then offset it a lil to get the stem to sit atop the firing pin.
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Ok, it looks like I was measuring the firing-pin protrusion correctly, it just wasn't protruding enough for me to grab a measurement that I thought was accurate, but it turns out that my initial number of ~0.017" was correct at the time.
I spent a good chunk of the day waiting on MF'ers while running errands today and pretty sure I searched out everything that is available online on bolt-action firing-pin protrusion, and especially any info if it had anything to do with Zermatt actions in particular.
I also decided to take up Ray at Zermatt's offer on getting a new/fresh firing-pin-assembly sent my way for just in case.
I found a few things related to Zermatt/Big Horn actions, and everything pointed toward my firing-pin-assembly having been reassembled correctly after changing out the spring. I even found an old thread where Ray from Zermatt chimed in about a TL3 and said that the firing pin needed to be screwed all the way into the cocking piece before setting the set screws, not backed off at all, screwed all the way until it stopped against the cocking-piece and where it wouldn't go any further, just like I had done with my Origin. There are a couple of things out there that describe the process of reassembling a Zermatt firing pin assembly and none of them mention backing off the firing-pin from the cocking piece before locking it down.
Well, I don't know if the design has changed or what, but it appears that backing the firing pin off 3-4 turns from stopped against the cocking-piece is exactly what it needed to give the firing-pin the extra protrusion I needed. I played with it a bit and set the protrusion to ~0.045" which from what I could find is considered correct, and is roughly 3-times the amount of protrusion I had before.
So, sorry Alpha, I may have been coming for your neck too soon.
I won't know for sure until I can check my assembly against the new/fresh assembly, but I think I may have it finally figured out (hopefully anyways). Thing is, I didn't find anything anywhere that mentioned backing off the firing pin and "setting" the protrusion, but that's what seemed obvious and appears to have worked. IDK if that's how it's supposed to be, but it sure looks right, and if I end up breaking the firing pin, at least there's a replacement already in the mail lol.
Thanks for the help Hide peeps, reinforces my opinion that no one person has seen everything, but the collective may have lol!
I spent a good chunk of the day waiting on MF'ers while running errands today and pretty sure I searched out everything that is available online on bolt-action firing-pin protrusion, and especially any info if it had anything to do with Zermatt actions in particular.
I also decided to take up Ray at Zermatt's offer on getting a new/fresh firing-pin-assembly sent my way for just in case.
I found a few things related to Zermatt/Big Horn actions, and everything pointed toward my firing-pin-assembly having been reassembled correctly after changing out the spring. I even found an old thread where Ray from Zermatt chimed in about a TL3 and said that the firing pin needed to be screwed all the way into the cocking piece before setting the set screws, not backed off at all, screwed all the way until it stopped against the cocking-piece and where it wouldn't go any further, just like I had done with my Origin. There are a couple of things out there that describe the process of reassembling a Zermatt firing pin assembly and none of them mention backing off the firing-pin from the cocking piece before locking it down.
Well, I don't know if the design has changed or what, but it appears that backing the firing pin off 3-4 turns from stopped against the cocking-piece is exactly what it needed to give the firing-pin the extra protrusion I needed. I played with it a bit and set the protrusion to ~0.045" which from what I could find is considered correct, and is roughly 3-times the amount of protrusion I had before.
So, sorry Alpha, I may have been coming for your neck too soon.
I won't know for sure until I can check my assembly against the new/fresh assembly, but I think I may have it finally figured out (hopefully anyways). Thing is, I didn't find anything anywhere that mentioned backing off the firing pin and "setting" the protrusion, but that's what seemed obvious and appears to have worked. IDK if that's how it's supposed to be, but it sure looks right, and if I end up breaking the firing pin, at least there's a replacement already in the mail lol.
Thanks for the help Hide peeps, reinforces my opinion that no one person has seen everything, but the collective may have lol!
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With .045" of protrusion you should be able to set off cases with .025" of travel. I think my new AR Grendel cases expand .020" without any issues. .006" just isn't very much, certainly not enough to require jamming or false shoulders. There's a point where the extractor holds the case and doesn't allow it to travel further into the chamber, probably less than .006".
Yeah, from the looks of it, I should be able to set off anything now. I'll find out at the range tomorrow, but the lack of firing pin protrusion is most likely the culprit.
Before leaving for the range this morning, I did one final search on "Origin firing pin" and found this:
Ray from Zermatt references a "detent" on the firing pin, which was the first time I'd heard it mentioned...
Well, sure enough, there is a detent/notch/hole located within the threading of the firing pin that I had no idea existed. Once I locked the set screws down inside the detent, I rechecked the firing pin protrusion and it was great (~.050").
So it was that all along.
I went to the range and all the rounds went bang (just as I thought they would).
While trying to suss this out over a few range trips I'd shot rounds seated .100" off, and rounds that were .010" into jam... both shot great.
So, using a completely unscientific method of determining seating depth, I decided to just load them all at .050" off and see what I got?
I shot a quick, semi-rapid fire group of 5 shots at 100 and another 5 at 750 off a cattle gate and shmedium bag, and saw pretty much everything I need to see:
Alpha Gay Tiger
Barnes Match Burner 112gn
SWPR 34gn
CBTO 1.925 (.050" off the lands)
= 2887fps
Ray from Zermatt references a "detent" on the firing pin, which was the first time I'd heard it mentioned...
Well, sure enough, there is a detent/notch/hole located within the threading of the firing pin that I had no idea existed. Once I locked the set screws down inside the detent, I rechecked the firing pin protrusion and it was great (~.050").
So it was that all along.
I went to the range and all the rounds went bang (just as I thought they would).
While trying to suss this out over a few range trips I'd shot rounds seated .100" off, and rounds that were .010" into jam... both shot great.
So, using a completely unscientific method of determining seating depth, I decided to just load them all at .050" off and see what I got?
I shot a quick, semi-rapid fire group of 5 shots at 100 and another 5 at 750 off a cattle gate and shmedium bag, and saw pretty much everything I need to see:
Alpha Gay Tiger
Barnes Match Burner 112gn
SWPR 34gn
CBTO 1.925 (.050" off the lands)
= 2887fps
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Alright. When you guys say you found a node what’s it look like. On paper my average speed per group with a ladder test just shows a linear line no dips or anything traditional
That's accurate. I see a cluster of low ES samples. Every .2gr still shows a net change in velocity with enough recorded shots in the sample. "Nodes" is largely untrue when you fire enough shots for a relevant sample.
Got it. I thought you guys were seeing the old school nodes where there is a dip etc. yeah. I see some that yield good es/sd. Thanks
