Nucleus Light Primer Strikes

After cleaning the bolt, and swapping in the Bix N Andys trigger, my son ran 25 rounds today with no failures. Statistically, this means nothing, but it made my day so far! Will report here with any further developments. FYI , the 6BR is serial # 10X and my friends 6.5 x 47L is serial # 24X.
 
I went to the range yesterday to put the first rounds thru my Nucleus build. It is a SA Left Hand in .223 with a Huber 2 stage trigger. I had light strikes with both American Eagle 55gr FMJ and Hornady 55gr Steel Match. 20 to 25% failure to fire with both types of ammo. I like everything else about the action. I will be ordering the 19 pound spring today and the 22 pound spring when it is available. I hope one of the new springs solves the problem.
 
It sounds like changing the spring is a real bitch so I would try disassembling the bolt and cleaning out the grease before changing the spring.

I'm going to do that preemptively today on my Nucleus.
 
It sounds like changing the spring is a real bitch so I would try disassembling the bolt and cleaning out the grease before changing the spring.

I'm going to do that preemptively today on my Nucleus.
I, too, would strongly recommend doing that. They shipped my Nucleus with a LOT of rust preventative all over it, and it could be that this is getting up inside the actions and slowing the firing pins down from what they should be doing.

In fact when I took mine apart again this past week to re-install the 16 pound spring I found even more of the original oil that I ended up wiping off, or at least I'd assume it was the original stuff since I never added more inside the bolt.

As an update for this weekend's results, I shot 30 rounds for a quick test with new bullets using my original 16 pound spring and new TT Diamond. Didn't have any issues, so my fingers are crossed that it was just some strange interaction with the trigger itself. The next match I intend to go to is on the 13th, so if I end up going I'll report back again once I get more rounds through the gun with this combination.
 
I realize this might be an issue for some, but hopefully it's only affecting a few. I've put over 250 rounds through mine in the last two days, zero issues. This includes handloads using both Federal 210M as well as BR4 primers, and 4 different types of factory ammo. I preemptively switched to the 19lb spring and use a Bix'n Andy trigger FWIW. I love this action so far
 
  • Like
Reactions: BLKWLFK9
I disassembled my bolt and found less grease than I was expecting.

I found that a Q-tip with the cotton mostly removed is the perfect size to clean out the firing pin hole in the bolt head.

I took off some grease, not all. I left some on the cocking cams, bolt lugs and the bolt head retaining pin. Hopefully enough to keep things lubed but not enough to gunk up the firing pin.

If I get any light strikes after that, I'll just get the 19lb firing pin spring because I'm not sure I would be able to keep the bolt significantly cleaner than it is now.
 
I took mine out for the first time on Saturday and shot 50 test loads. It functioned perfectly, no light strikes or FTF's. The primers had very good firing pin indents on them, so I don't see any issues with the spring.
 
One thing I'm interested in trying, since Nitriding is helpful for corrosion resistance and I live in a dry enough climate to feel comfortable having no oil at all inside my bolt, is dropping the entire bolt (disassembled) into my ultrasonic cleaner filled with some isopropyl alcohol to try and flush out all oil present within the bolt assembly. From that point I could lubricate the necessary pieces (bolt lugs, locking cams, etc.) and know that the rest of them should be bone dry. I didn't have issues previously, but I imagine it definitely would hurt to give my bolt a good deep cleaning since it's been out in the wind and dust for several matches.
 
  • Like
Reactions: BLKWLFK9
One thing I'm interested in trying, since Nitriding is helpful for corrosion resistance and I live in a dry enough climate to feel comfortable having no oil at all inside my bolt, is dropping the entire bolt (disassembled) into my ultrasonic cleaner filled with some isopropyl alcohol to try and flush out all oil present within the bolt assembly. From that point I could lubricate the necessary pieces (bolt lugs, locking cams, etc.) and know that the rest of them should be bone dry. I didn't have issues previously, but I imagine it definitely would hurt to give my bolt a good deep cleaning since it's been out in the wind and dust for several matches.

When u do lube the cams and such, try some of the Wilson combat ultima-lube. feels like taking a couple pounds off the bolt lift.
 
Check, then double check after a couple dozen rounds, the tighteness of the actual firing pin assembly in the bolt. Had similar issues (light strikes) with Bix n Andy. Problem was that after about 20-40 rounds the screw that holds the firing pin assembly in the bolt would work is way out. Not like fall out... but loosen up enough to cause light strikes. Had to tighten it down three times out of 100 rounds, and tightening it always fixed the problem immediately. I just added a drop of locitite the fourth time I screwed it down tight. No issues since.
 
Last edited:
Check, then double check after a couple dozen rounds, the tighteness of the actual firing pin assembly in the bolt. Had similar issues (light strikes) with Bix n Andy. Problem was that after about 20-40 rounds the screw that holds the firing pin assembly in the bolt would work is way out. Not like fall out... but loosen up enough to cause light strikes. Had to tighten it down three times out of 100 rounds, and tightening it always fixed the problem immediately. I just added a drop of locitite the fourth time I screwed it down tight. No issues since.
When you talk about the screw holding the firing pin assembly into the bolt, are you referring to the bolt shroud itself becoming unscrewed from the bolt body or are you talking about something else?
 
When you talk about the screw holding the firing pin assembly into the bolt, are you referring to the bolt shroud itself becoming unscrewed from the bolt body or are you talking about something else?
 

Attachments

  • 2C13474A-F7B0-4ACC-8FC5-7503B299261F.jpeg
    2C13474A-F7B0-4ACC-8FC5-7503B299261F.jpeg
    312.3 KB · Views: 75
Fired one box prime 6.5 CM ammo through my brand new assembled Nucleus.
100% function, though I did disassemble and clean out most of the oil from inside the bolt and firing pin channel/spring area.
 
Went to the range again with more BR4 primed Lapua brass with the 16 pound spring in and had no issues. That's 70 rounds down the tube now with no light primer strikes, which is longer than the Calvin Elite could go without light strikes using the original 16lb spring (it had 1 in about 200 rounds with the 19 lb spring).

I've got a match on Saturday, so hopefully all continues to go well with the 16 lb spring and TT Diamond there. I love the trigger though, it feels great.
 
Still no issues here. I've been through 200 Prime 6.5c, and 40 Hornady ELD. I'll be shooting a match tomorrow with the Hornady. I bought the heavy spring just in case.
 
Ran the first 20 rounds to break in the barrel and zero the scope with the nucleus and pva barrel. Just loaded some Norma 130s 10 k off with 41 gr of Re 16. Shooting and cleaning between shots was averaging about 1/2”. Last 5 shots after barrel was fouled barely ragged a hole. No light strikes with 16lb spring and 205’s.
 
  • Like
Reactions: hereinaz
Just wanted to weigh in. I was having problems with light primer strikes on my first couple trips to the range. Only 50% of the rounds fired. I'm running a Timney 510 trigger for what it's worth.

After reading through this thread, I completely tore the bolt apart. There was a liberal coating of black grease between the bolt shroud and the back of the firing pin assembly. I think that was slowing the pin down enough to stop detonation. I cleaned it all off, gave it a light spray of Rem oil. Then I reassembled the bolt with some anti-sieze lubricant on the cocking cams.

Yesterday at the range the rifle ran 100%. Disassembly and cleaning seems to be the cure. Thanks.
 
I've got about 200 rounds through my new Nucleus, and one PRS type match yesterday. From day one the rifle has ran flawlessly, feeds, fires and functions as smoothly as my TRG'S. I'm running a tubb T7T trigger and a KRG stock with arc mags. Yesterday it rained, then snowed, then blew from 15-30mph. Rifle loved every minute of it, so did I.
 
Was out at Thunder Ranch this week, trying out a Nucleus on a .260. Using a Huber 2-stage, handloaded lapua brass with BR2 primers, started getting an increasing number of light strikes the first day. Got so bad, I swapped out my backup rifle, Stiller action with Bix n Andy single stage. That fired every round I loaded just fine except for the one with the backwards primer (whoops). After reading this thread, it sounds like I need the heavier spring, but will try cleaning the firing pin spring first just to see. I am open to any other suggestions. Thanks.
 
I had my first light primer strikes yesterday so I went online to get the heavier spring. I couldn't help but notice there is a 22 lb. offering now. Are people still having issues with a 19lb spring? I picked up a 19lb, but am just wondering why the 22lb is a thing now.
 
I had my first light primer strikes yesterday so I went online to get the heavier spring. I couldn't help but notice there is a 22 lb. offering now. Are people still having issues with a 19lb spring? I picked up a 19lb, but am just wondering why the 22lb is a thing now.

I thought I saw the 22 pounder when I bought mine, which was right after it hit the website.
 
I had the same ftf issue the first time out with my nucleus today. Lapua srp brass with cci br4's.
Common theme here seems to be the Calvin elite, which I was running as well.
Cleaned the grease off the striker and switched the trigger out for a huber tonight. I will have a range update tomorrow. For what it's worth, the pin fall is greater with the huber. Look at the difference in the sears in the photo! Black one is the sear out of the huber
20181025_201420.jpg
20181025_201519.jpg
 
  • Like
Reactions: hereinaz
Hmmmm, I get a tiny bit of cock on close with my Huber. The longer trigger sear could do that. The Nucleus is listed as 100 cock on open. I wonder if I timed it whether I would start ftf issues.

Never a failure to fire over 400 rounds fired.
 
I also get cock on close with the huber. I also noticed that the huber doesn't drag on the cocking piece like the Calvin Elite does. I'm curious though, how do you time a trigger like the huber?
 
Last edited:
I also get cock on close with the huber. I also noticed that the huber doesn't drag on the cocking piece like the Calvin Elite does. I'm curious though, how do you time a trigger like the huber?

I don't know for certain. But, the cock on close happens in this case because the sear is further back, so the bolt cams forward as it engages the lugs while the pin spring compresses more.

To "time" it would be to shorten the sear (?) until it was the right length to hold the pin back at the exact point where the Nucleus cock's it. So the sear holds the pin at the same point it is cocked to by the bolt cocking piece.

Take too much off, and the pin is let forward with less spring compression, arecipe for light strikes.
 
I don't know for certain. But, the cock on close happens in this case because the sear is further back, so the bolt cams forward as it engages the lugs while the pin spring compresses more.

To "time" it would be to shorten the sear (?) until it was the right length to hold the pin back at the exact point where the Nucleus cock's it. So the sear holds the pin at the same point it is cocked to by the bolt cocking piece.

Take too much off, and the pin is let forward with less spring compression, arecipe for light strikes.

I believe with Remington 700's, to time the trigger, usually material is taken off the cocking piece where it engages the sear. 700 cocking pieces are ubiquitous and relatively cheap. The same could probably be done on a Nucleus, but I'm not certain on the availability of replacement pieces right now if you mess something up or if you wish to change triggers after timing your action to a specific trigger.
 
I believe with Remington 700's, to time the trigger, usually material is taken off the cocking piece where it engages the sear. 700 cocking pieces are ubiquitous and relatively cheap. The same could probably be done on a Nucleus, but I'm not certain on the availability of replacement pieces right now if you mess something up or if you wish to change triggers after timing your action to a specific trigger.

Yeah, makes sense not to grind on the trigger... I don't know much gun smithing, hahaha, so I am not gonna mess with mine at all.
 
So some are suggesting that cleaning the firing pin might help. I dont see that as an acceptable solution at all. I have exactly 115 rounds on my rifle and I've had 5 failure to fires. There is no way my bolt has gotten dirty enough to cause issues with less than 100 rounds down the tube and exactly 3 range sessions. And if it has, that's not an acceptable piece of kit for me.

As far as it being an issue with Timney triggers, I had a buddy have 1 failure to fire with a trigger tech trigger. And even if it is an issue with Timney triggers, so what?

Timney triggers seem to be pretty popular and it seems as if there are a couple of Remington footprint and clone receivers out there. I think the PVA John Hancock is going to use timney triggers. If there was a thread after thread here on how Timney triggers cause failure to fire on all of the various actions that are based on the 700 footprint then I would say there is a Timney trigger issue. But I'm not aware of such issues. To me this seems to be an ARC issue. Unless ARC sells their rifles with specific triggers installed or with at least a recommendation that you not use one of the most popular triggers on the market, it is their issue.

With that being said, I dont think its ideal that the solution the issue is to sell the stronger spring. IMO those spring should have been shipped out to every nucleus customer who has reported the issue. But I paid my $17 and will wait to see if it resolves the problem.
 
  • Like
Reactions: manki77
^The suggestion to clean the firing pin isn't bc its dirty, its bc of the anti corrosion lube that ARC ships on their actions to prevent rust. Its thick and heavy. That's what you need to clean off. Not dirt and debris from use.
 
So some are suggesting that cleaning the firing pin might help. I dont see that as an acceptable solution at all. I have exactly 115 rounds on my rifle and I've had 5 failure to fires. There is no way my bolt has gotten dirty enough to cause issues with less than 100 rounds down the tube and exactly 3 range sessions. And if it has, that's not an acceptable piece of kit for me.

As far as it being an issue with Timney triggers, I had a buddy have 1 failure to fire with a trigger tech trigger. And even if it is an issue with Timney triggers, so what?

Timney triggers seem to be pretty popular and it seems as if there are a couple of Remington footprint and clone receivers out there. I think the PVA John Hancock is going to use timney triggers. If there was a thread after thread here on how Timney triggers cause failure to fire on all of the various actions that are based on the 700 footprint then I would say there is a Timney trigger issue. But I'm not aware of such issues. To me this seems to be an ARC issue. Unless ARC sells their rifles with specific triggers installed or with at least a recommendation that you not use one of the most popular triggers on the market, it is their issue.

With that being said, I dont think its ideal that the solution the issue is to sell the stronger spring. IMO those spring should have been shipped out to every nucleus customer who has reported the issue. But I paid my $17 and will wait to see if it resolves the problem.
Did you call them and explain the problem? I’m curious if they would ship you a heavier spring for free to resolve the problem if given the chance.
 
So some are suggesting that cleaning the firing pin might help. I dont see that as an acceptable solution at all. I have exactly 115 rounds on my rifle and I've had 5 failure to fires. There is no way my bolt has gotten dirty enough to cause issues with less than 100 rounds down the tube and exactly 3 range sessions. And if it has, that's not an acceptable piece of kit for me.

As far as it being an issue with Timney triggers, I had a buddy have 1 failure to fire with a trigger tech trigger. And even if it is an issue with Timney triggers, so what?

Timney triggers seem to be pretty popular and it seems as if there are a couple of Remington footprint and clone receivers out there. I think the PVA John Hancock is going to use timney triggers. If there was a thread after thread here on how Timney triggers cause failure to fire on all of the various actions that are based on the 700 footprint then I would say there is a Timney trigger issue. But I'm not aware of such issues. To me this seems to be an ARC issue. Unless ARC sells their rifles with specific triggers installed or with at least a recommendation that you not use one of the most popular triggers on the market, it is their issue.

With that being said, I dont think its ideal that the solution the issue is to sell the stronger spring. IMO those spring should have been shipped out to every nucleus customer who has reported the issue. But I paid my $17 and will wait to see if it resolves the problem.

Well, Timney triggers DO have a history of causing a lot of striker drag on M700 clone actions...it's just that the Nucleus is a different animal. Most actions based on the Remington 700 have waaaay more spring pressure than we're getting. It's one of the ways Ted was using to keep the bolt lift light (lighter spring, heavier striker) while still setting off primers. Since the Nucleus is undersprung in comparison, stuff that causes little issues or doesn't show a problem in other actions will cause the Nucleus to fail sometimes. Look for a solution where you like, but a Timney will not be going into my action.
 
  • Like
Reactions: JLP.Payette
Anyone who wants to get rid of their Nucleus, PM me. If guys don't want what Nucleus is, then I don't fault them for going a different direction.

IMO, Rem 700 are over done so that they can be mass assembled and go bang every time even with loose tolerances coming out of mass production. It seems to me that, the Nucleus is not over engineered so they will work with any spec trigger. And, as I am beginning to understand, not all "Rem 700 triggers" are created equally either. Here, Nucleus is designed with a light bolt lift, even though it is 100% cock on open with a three lug system--reducing total bolt lift. I don't mind that the Nucleus is engineered and ships with a spring that may make for light strikes if the trigger does not play well with it. I also bought a heavier spring in case I do run into issues, which I haven't. And, I think it was smart that PVA went with the heavier spring in the Nucleus.
 
After I tossed my bolt in an ultrasonic cleaner to really clean all of the anti-corrosion oil/grease off the firing pin and out of the bolt shroud (plus swapped to a TT Diamond) it solved all of my problems.

They specifically warn against using any lubricant inside where the firing pin travels, and their own grease/oil is no exception. I think a majority of this is just that the action ships out practically submerged and people (including myself) don't take it apart and clean it off fully before use.
 
Upon disassembly of the bolt I found THICK grease. After cleaning, there was an audible difference in sound when dry firing. Then I swapped the CA for the Huber and got a greater pin fall distance. I love the action and feel. I believe my issue is resolved. Time will tell though.
 
  • Like
Reactions: hereinaz
Fair point on contacting ARC, I will contact them tomorrow to see if I can get a refund on my spring. Overall I like the action. It is fast and smooth.

It seems as if I’m not the only one having the issue, and it seems as if the issue is not isolated to just one trigger. I was at the range last Wednesday and there were two different nucleus actions with two different triggers, both had failure to fires.