Nucleus Action Break in issue?

[JH54]

Just got to the range with my new JHR, I’m extremely happy with the accuracy which is .25-.30 5 shot groups, however, the action leaves a bit to be desired for myself. I’ll preface this by saying most of my experience with bolt action rifles is my TRG-22 and the M2010 (active Army 10 years so far). I tend to work a bolt with vigor (which I have paid for at Fort Benning and Fort Bragg), but when I run the Nucleus it binds pretty tight if you apply any pressure in the X + axis IE tail of bolt to the right.
I would like to hear from anyone who has been running one of this will smooth out with break in or if it’s just the nature of the design. I should add that my TRG doesn’t do this nor have I experienced it with the M24/M2010.

 

[Ledzep]

You have to push all the way forward before rotating down. I think I know what bind you're talking about, and it revolves around the plunger on the bottom left side of the shroud. Take it out (not long term, just to test) and see if the bind goes away. It may break in some, but I cut a small chamfer on it in a lathe.

 

[BLKWLFK9]

If it's not what Ledzep said, take the bolt apart. Remove the extractor. Get some 600 grit sand paper, lay it on a table, spray it with rem oil, then work the outside of the extractor back and forth for a while. Then take a piece of 2000 grit paper, and do the same thing. Trust me, if what your talking about is what I'm thinking, by doing what I've said, it is impossible to bind a nucleus on the forward bolt stroke no matter what angle u apply pressure to the handle. If what you're feeling on the bolt close, then u need to start applying forward pressure on the handle when closing the bolt or get the gen 2 bolt head from ARC. Just got my .223 head for mine and it feels completely different. Much easier on bolt close.

 

[Steel head]

On mine if you push quite hard on the bolt handle downward while pushing the bolt forward mine will jam a bit of you just easi it forward.
I can run the bolt fast and aggressively and never have issues unless I actually try to jam it in an awkward manner.

 

[Skunkworx]

How many cycles has your action had? I know mine smoothed out quite a bit after 1000 cycles. Adding a little Lubriplate to the bolt body made it slick as snot. The only binding issue I ran into during matches has been a magazine binding issue with bottom pressure, but that’s not what you’re experiencing.

 

[Kadams1563]

The Nuc likes to be handled rough and fast but you have to learn how to throw the bolt.

I didn’t care for one that I had but that’s because it was side by side with a Impact and a Defiance.

I could throw it fast but I remember pushing the bolt slightly straight up as I pushed forward.

 

[BLKWLFK9]

Buy yourself some hornady one shot HD extreme lube. It will make a factory rem almost feel like an impact.



Almost

 

[lennyo3034]

You have to push all the way forward before rotating down. I think I know what bind you're talking about, and it revolves around the plunger on the bottom left side of the shroud. Take it out (not long term, just to test) and see if the bind goes away. It may break in some, but I cut a small chamfer on it in a lathe.

I have this same issue with my new Nucleus. My first Nucleus (first batch) does not have this issue. I can be pressing down on the bolt the entire way and it will close just fine.

 

[Triple D]

What trigger are you running?

I’m experiencing a similar issue, but not every time I cycle the bolt with a Tunney CE. I believe it’s due to the sear interface with the bolt based on wear marks.

Try removing the trigger and see if the problem magically disappears.

 

[JH54]

If it's not what Ledzep said, take the bolt apart. Remove the extractor. Get some 600 grit sand paper, lay it on a table, spray it with rem oil, then work the outside of the extractor back and forth for a while. Then take a piece of 2000 grit paper, and do the same thing. Trust me, if what your talking about is what I'm thinking, by doing what I've said, it is impossible to bind a nucleus on the forward bolt stroke no matter what angle u apply pressure to the handle. If what you're feeling on the bolt close, then u need to start applying forward pressure on the handle when closing the bolt or get the gen 2 bolt head from ARC. Just got my .223 head for mine and it feels completely different. Much easier on bolt close.

From what I can see it does look like the extractor dragging so I’ll pull it apart and have a look. Also I’m a big Hornady one shot fan. And as for not rotating it prior to full forward, I assure you I’m being very careful to not twist (rotate) the bolt while I diagnose the issue.
I’ll set down tomorrow and try to just cycle the action a few hundred times and see if that improves it any, maybe dry fire drills as well. I do appreciate everyone’s input!

 

[motofrog]

I get a little of the same binding when running hard.

When pushing tail of bolt to the right and running slow it appears there is a little contact between the ejector and groove in the bolt head at the beginning of the forward stroke. Almost like the grove in the bolt for the ejector isn’t deep enough.

I called ARC and they said it may need an exchange to the updated bolt head but have been waiting to see if it smooths out with break in, before sending my bolt heads in for the swap.

 

[chadrp]

I get a little of the same binding when running hard.

When pushing tail of bolt to the right and running slow it appears there is a little contact between the ejector and groove in the bolt head at the beginning of the forward stroke. Almost like the grove in the bolt for the ejector isn’t deep enough.

I called ARC and they said it may need an exchange to the updated bolt head but have been waiting to see if it smooths out with break in, before sending my bolt heads in for the swap.

This is the same way mine is and I have about 600 rds on it. With the bolt all the way back, if you put any right pressure on it, it will bind. With rightward movement on the bolt handle, the bolt head moves left, and you can see the ejector move right and pinch the front of the bolt face. I just make sure to keep left pressure on the bolt handle and it's not an issue. My new bolt head will be here today so I'm curious if it will make much of a difference.

 

[JH54]

This is the same way mine is and I have about 600 rds on it. With the bolt all the way back, if you put any right pressure on it, it will bind. With rightward movement on the bolt handle, the bolt head moves left, and you can see the ejector move right and pinch the front of the bolt face. I just make sure to keep left pressure on the bolt handle and it's not an issue. My new bolt head will be here today so I'm curious if it will make much of a difference.

Give us a update after you get it together! Mine should have the updated bolt head but it may have squeaked out just before the change over.

 

[Northernjets]

If it's not what Ledzep said, take the bolt apart. Remove the extractor. Get some 600 grit sand paper, lay it on a table, spray it with rem oil, then work the outside of the extractor back and forth for a while. Then take a piece of 2000 grit paper, and do the same thing. Trust me, if what your talking about is what I'm thinking, by doing what I've said, it is impossible to bind a nucleus on the forward bolt stroke no matter what angle u apply pressure to the handle. If what you're feeling on the bolt close, then u need to start applying forward pressure on the handle when closing the bolt or get the gen 2 bolt head from ARC. Just got my .223 head for mine and it feels completely different. Much easier on bolt close.

Took a look at my action last night, and ended up with a similar observation. When bolt was pushed to the right, it had a familiar feel to a rough Savage bolt sleeve that I once had. Ended up polishing it real quick with a 7447 Scotchbrite pad that I had lying around. Makes a huge difference. Also noticed that the bottom of the recess for the bolthead pin can catch on the corner of one of the rails on the receiver when the bolt is moved with some downward pressure. I added some grease to the edge of the recess to help with any wear. Overall, not to overly worried as I don't run the bolt to the right anyway, but thought I'd share what I noticed.

*edit, highlighted the correct spot catching on the bolthead pin recess.