ARC Archimedes Bolt Stop: PITA

[KnowNothing256]

So, love most things about this action so far, but the bolt stop is quite difficult to operate, especially since my scope ring (ARC M10) happens to park right on top of it.

Anybody figure out how to make this a little easier to operate? My first thoughts include either replacing or clipping the spring under the 3mm ball bearing, or perhaps putting a little "feed ramp," so to speak, on the detent in the bolt stop. Probably I'd do the spring first, it being a much cheaper part I expect.

Anyone else frustrated by this?

 

[paulrem308]

Yes. Mine is the same way. Rear scope ring is right above bolt stop. About only negative about this action.

 

[scott5456]

Can't you just use an Allen wrench to turn it?

 

[Pvt.Donut]

Mine is tough to remove but honestly, when do you need to remove your bolt in a hurry. I'm usually removing it while cleaning and while its a hassle, its really not that bad. Takes about an extra 5 seconds of wiggling the bolt to find the sweet spot to get the stop turned vs. my Tikka or Zermatt. I'd prefer to have a rock solid bolt stop than a QD bolt stop, which is why I bought the Arch.

 

[Northernjets]

My Nucleus 1.1 had a hard to turn bolt stop. I removed it, polished it and cleanedup the edges around the divot for the ball bearing. Made it feel a lot better.

 

[KnowNothing256]

Ok, so judging by the responses, I'm not alone here. Just called ARC, since they have a rep for being responsive, and was able to talk to a nice lady who chatted with me about it. She (unprompted) suggested clipping a coil or two off the spring, so I'll try that first.

I did mention to her that I might alter the detent profile a bit to make it smoother and more gradual; I also suggested to her that if they ever revisit this design, they could even make the detent more shallow. It doesn't need to withstand a nuclear blast, there's not really a scenario where unintentional torque is applied to the bolt stop sufficient to overcome even a mild detent setup. She said both ideas sounded solid, and they could sent me a replacement if I screwed it up lol.

I don't know why I always end up with a dremel in my hand every time an action comes my way, but it sure seems to be a pattern...at least this time I'm working on a replaceable part, versus notching the receiver on my Bergara B14 lol.

 

[KnowNothing256]

Ah, and to respond to a couple comments:

- Requiring a tool to remove the bolt? Come now, people gripe about needing tools to zero a scope, who wants to need to carry a wrench to get their bolt out?
- It's semi-fair that the bolt doesn't have to come out that often, but I remove mine when casing/transporting the rifle, and right now I'm doing a ground-up load development so the bolt's in and out quite a bit. It just seems like a silly complaint to live with, when several potential fixes are immediately evident and cheap/easy to try. But I take your point in general; just wanted to find out if my action was an outlier, or if there were well-known fixes for the issue.

 

[2aBaC̶a̶]

my only gripe with ARC actions. both my Nuke and Arch have this issue. why ARC didnt just make it push button instead of twist is beyond me.

Can't you just use an Allen wrench to turn it?

it's a torx but yes you can but who really wants to have to carry a tool just to remove the bolt? At the very least they could have made it the same tool required to disassemble the bolt once you get it out but no that requires another set of tools.

 

[KnowNothing256]

my only gripe with ARC actions. both my Nuke and Arch have this issue. why ARC didnt just make it push button instead of twist is beyond me.


it's a torx but yes you can but who really wants to have to carry a tool just to remove the bolt? At the very least they could have made it the same tool required to disassemble the bolt once you get it out but no that requires another set of tools.

I think they went with the rotary bolt stop because it's more resistant to breakage when you run the bolt like a gorilla, which I can understand. On the other hand, because of the ejector design (of which I am a big fan, having had my B14 dribble cases at my feet during comp stages) would launch my empties into the next county if I was running the bolt hard enough to break a decent bolt stop pin.

Anyway, I'm honestly totally fine with the premise, I just think the detent portion needs a bit of a rethink.

 

[st1650]

Wouldn’t be surprised if the next version of the Archimedes is like the Nuke 2.0 with the right side bolt stop.

Although when it’s cold at the range and I want to pull the bolt out on my 1.1 it’s certainly a pain, it’s still worth it for a bomb proof bolt stop.

 

[KnowNothing256]

The nice lady at ARC mentioned that they're generally trending towards the side bolt stop, but I didn't ask specifically what that meant; I expect we'll see more of the kind we're used to in future designs.

I'd be perfectly content with the rotary style if I could turn the damn thing without pliers lol

 

[2aBaC̶a̶]

FYI if you take the bolt stop out be very careful. that fucking bearing is small and easily falls out.

 

[2aBaC̶a̶]

The nice lady at ARC mentioned that they're generally trending towards the side bolt stop, but I didn't ask specifically what that meant; I expect we'll see more of the kind we're used to in future designs.

I'd be perfectly content with the rotary style if I could turn the damn thing without pliers lol

ive been thinking of how to make it a lever switch like the safety selector on an AR.

 

[KnowNothing256]

FYI if you take the bolt stop out be very careful. that fucking bearing is small and easily falls out.

Yep! Fished the little fucker out of my carpet last night, lesson learned the hard way. And it didn't fall out, it LAUNCHED. Luckily I heard it hit the ceiling, then the bookshelf, then the foot of the tripod last. The tripod foot impact narrowed down the search considerably.

ive been thinking of how to make it a lever switch like the safety selector on an AR.

View attachment 7866328

I thought about something similar, but it's a 180 degree throw, and anything that would give me enough leverage would also hit the base of the scope ring, or the receiver itself. I guess, looking at it, you could put the lever on the ejection port side, replacing the retaining screw there with something that stood proud enough off that it wouldn't hit the receiver when rotated, but that's on my gun-running-hand side and I'd like minimal junk over there.

We've had many of the same thoughts on this, it'd seem haha

 

[2aBaC̶a̶]

or something like this.

 

[st1650]

ive been thinking of how to make it a lever switch like the safety selector on an AR.

View attachment 7866328

Pretty smart actually

 

[308pirate]

So, love most things about this action so far, but the bolt stop is quite difficult to operate, especially since my scope ring (ARC M10) happens to park right on top of it.

Anybody figure out how to make this a little easier to operate? My first thoughts include either replacing or clipping the spring under the 3mm ball bearing, or perhaps putting a little "feed ramp," so to speak, on the detent in the bolt stop. Probably I'd do the spring first, it being a much cheaper part I expect.

Anyone else frustrated by this?

$50 to take the rifle off your hands and ease the frustration?

 

[KnowNothing256]

$50 to take the rifle off your hands and ease the frustration?

I'll send you the bolt stop for $50, sure; it's the only part that's frustrating so far

 

[TxAg93]

I actually don't mind the rotating design of it, just wish that the window of operation was longer. When putting the bolt back in it'd be nice to just throw it in, even if its like halfway closed, and rotate locked rather than find that sweet spot first.

 

[atomic41]

All this time I thought I was the only one with this gripe. That is the only thing that bugs me about my Nuke, I've cussed a few times.

 

[Simonsza1]

All this gripe I guess makes me lucky that both of mine I can turn no problem. I do have mechanics hands though which act like human pliers most the time.

 

[D_Lamz]

I believe initially on the release pictures years ago it was a tear drop design, why they went to a round one is beyond me

 

[Chesapeake]

When I have the bolt in where the bolt head is directly in front of the bolt stop it turns very easily for me. It took me a few tries to figure this out but has been easy to use ever since I found the “sweet spot.” Hope this helps

 

[KnowNothing256]

When I have the bolt in where the bolt head is directly in front of the bolt stop it turns very easily for me. It took me a few tries to figure this out but has been easy to use ever since I found the “sweet spot.” Hope this helps

This is actually a separate issue I've noticed that is frustrating, but I'm willing to live with it: if the bolt's all the way back, it's even harder to operate the bolt stop (although it can be done). The geometry of the two contact surfaces (bolt stop and top bolt lug) are such that the bolt actually has to be just slightly forward of the fully back position for the stop to rotate; this is evident if one places the bolt all the way back and turns the bolt stop with a wrench or by hand, the bolt will scoot forward just a bit when the stop turns.

While this makes it additionally difficult to turn the stop, the main issue is the geometry of the detent combined with the spring strength. I've got some Dremel polishing bits on the way, when they show up I'll polish down the side of the detent that sees the traffic and see how it feels; if I still don't love it I'll start clipping spring coils, probably a half coil at a time or so.

ETA: BTW, not here to just gripe about the action, I'm still stoked to run the thing. Getting to the range for the inaugural first rounds through the rig this week!

 

[paulrem308]

When I have the bolt in where the bolt head is directly in front of the bolt stop it turns very easily for me. It took me a few tries to figure this out but has been easy to use ever since I found the “sweet spot.” Hope this helps

 

[rydah]

It’s a giant pain in the ass but with that being said it’s the only bolt stop I haven’t broken, so there’s that. It’s good how it is, it just needs to turn a bit easier because it’s right where my rings are and you get no purchase on it.

 

[Txhillbilly]

My Nuke 1.0 bolt release has always been simple to operate. I love the new style on my Nuke 2.0. The bolt release on my Archimedes just plain SUCKS! It really needs to stick out at least another 1/2 inch in order for me to be able to operate it easily.
Ted needs to make an extended version of the knob!!!

 

[Mike_in_FL]

And I'm the opposite of above. My Nuke 1.0, that is my only complaint. Trying to find that window where it will turn to release it. 2.0 is a lot better IMO.

 

[Barelstroker]

I wonder, would drilling a small hole in the face of the round knob & tapping a S/Steel split roll pin which protrudes about 3/16" be of any help?
Would that give enough purchase to turn the knob under the scope mount?

 

[KnowNothing256]

I think you mean like giving the knob a handle? Anything that increases the effective diameter of the knob will just hit the receiver and/or the scope ring, unfortunately, since the knob rotates 180 degrees.

In any case, with some judicious Dremeling to notch a gentler ramp for the little ball bearing, some polishing of said ramp, and the clipping of one and a half spring coils, I'm happy to report that it's much easier to operate, and I'm good to stop here. I could probably keep going with the spring, and if I get frustrated with cold hands or something down the road it's still an option, but I'd consider it acceptable now.

 

[Barelstroker]

I think you mean like giving the knob a handle? Anything that increases the effective diameter of the knob will just hit the receiver and/or the scope ring, unfortunately, since the knob rotates 180 degrees.

In any case, with some judicious Dremeling to notch a gentler ramp for the little ball bearing, some polishing of said ramp, and the clipping of one and a half spring coils, I'm happy to report that it's much easier to operate, and I'm good to stop here. I could probably keep going with the spring, and if I get frustrated with cold hands or something down the road it's still an option, but I'd consider it acceptable now.

Anything that increases the effective diameter of the knob will just hit the receiver and/or the scope ring, unfortunately, since the knob rotates 180 degrees.

I don't mean the circumferential surface. I was referring to the circular face of the handle/knob.
A split roll pin would allow a protrusion on the side face to allow a finger to rotate without having to gain purchase on the serrated circumference.

 

[2aBaC̶a̶]

depending on how much clearance you could adapt a knob. if it was plastic you could just melt it on. maybe somone with a 3D printer could come up with something.

 

[Txhillbilly]

I fixed mine today while I had the gun apart swapping out barrel's. I just cut about 1.5 coils off the detent spring.
It turns pretty easy now, but still locks in place when the ball is in the detent.

 

[KnowNothing256]

I fixed mine today while I had the gun apart swapping out barrel's. I just cut about 1.5 coils off the detent spring.
It turns pretty easy now, but still locks in place when the ball is in the detent.

Nice, that’s how many I ended up clipping as well. Glad it worked out!