ARC Prefit Cross-Compatibility?

[KnowNothing256]

I’m sure this info’s out there somewhere but I haven’t seen it yet, sorry if I missed an obvious thread with the answer, but:

I’m interested in an ARC Archimedes, but it’s important to me to be able to snag cheap/discounted prefits here or elsewhere. ARC prefits, labeled as such, almost never come up in SH WTS posts, as opposed to say Impacts or Origins. Does anyone know what actions share the same headspace dimensions as the ARC actions, or can just use a shim to work with an ARC? I know there are headspace conversion spacers out there, for instance the PVA Origin to TL3 ring.

Actually what would be amazing would be a chart that compared headspace dimensions (shoulder to bolt face i’m guessing?) across the different actions that take prefits, even if it was just baselined off of the action with the shortest dimension and everything else was like “Baseline + 0.100” or whatever.

Thanks for any info folks can provide.

ETA: Whoops, this probably should be in the Bolt Action forum, mods please relocate if appropriate. Thanks!

 

[Midpack]

All the current arc actions share the same headspace. The ones you will see listed most often will be for a nucleus. Also if I recall pva actually makes a shim that allows you to use a tl3 barrel on arc actions but I would call Josh to verify that.

 

[Eagle1899]

The shim made by PVA is a "maybe" for ARC actions. PVA does not endorse its use as such.

TL3's and ARC actions have different bolt protrusion. Depending on how the barrel was cut, a ARC action bolt may rub or hit the barrel face with the shim and a TL3 barrel (or even some Savage prefit barrels may do this). You will have to measure carefully to know.

I've had the shim on my short list to try with a left over TL3 barrel I have kicking around that I've measured a few time to verify it is possible.

 

[Steel head]

Arc only has one barrel print for all its actions at this point.
My nuke measured well within the tolerance on that print.

 

[KnowNothing256]

I may not have explained this very well, sorry. I know all ARC prefits are good for all ARC actions; I’m asking what OTHER prefits will work with ARC actions, if any, including ones that need a shim/spacer.

For example, would a TL3 prefit fit an ARC action? Would it fit with a 0.050” or 0.100” spacer ring? Etc.

 

[Steel head]

That’s asking a lot
You’d need compatible threads, headspace, tenon length and bolt nose geometry.
Yea you could get lucky with a spacer, or you may get burned.

 

[Midpack]

That’s asking a lot
You’d need compatible threads, headspace, tenon length and bolt nose geometry.
Yea you could get lucky with a spacer, or you may get burned.

Not to mention you better not want the markings to line up. Even between actions from arc. The makings on a mausingfield barrel don't line up on my archemedias for example but it headspace the same

 

[KnowNothing256]

Thanks for the replies. Definitely don’t care about the markings, and I understand that many prefits won’t fly.

If anyone knows of ones that might, lemme know!

 

[FisherT&C]

The easiest thing would be to use savage barrel nut prefits. You can get the Bar-Loc nut from ARC and swap barrels out like shouldered prefits. You'll need headspace gauges.

 

[KnowNothing256]

The easiest thing would be to use savage barrel nut prefits. You can get the Bar-Loc nut from ARC and swap barrels out like shouldered prefits. You'll need headspace gauges.

Appreciate the feedback. I currently use barrel nuts on my Bergara setup, but anticipate going to an Archimedes later this year. However, prefits seem to be available anywhere from $100-200 less than a custom cut barrel, even at MSRP, and it'd be nice to save that cash if possible. ARC prefits seem much less popular than some others, though, which is a bummer, leaves me looking for workarounds.

Savage setups aren't a huge headache in my mind, I'm not running five different calibers on a given day at the range. They're slightly less convenient, but honestly it takes me longer to get the action wrenched up using an external wrench than it does to fiddle with the headspace. I'll get an internal wrench if I pick up an ARC, but I'll have to come up with some sort of setup to lock the wrench down if I use a barrel nut setup (or just use the external wrench).

Anyway, thanks!

 

[FisherT&C]

I can do ARC prefits and have a fair price depending on how exotic you get with twist and caliber

 

[KnowNothing256]

Haha good to know, you’re on my short list! Do you typically have them in stock, or have to order and be subject to these long lead times we’re seeing?

 

[srt-4_uk]

That’s asking a lot
You’d need compatible threads, headspace, tenon length and bolt nose geometry.
Yea you could get lucky with a spacer, or you may get burned.

Is it really though? You buy a Savage prefit, put it in your TL3 and set the shoulder with a nut. You buy a Savage prefit for your ARC and set the shoulder with a nut. Only difference is where you set that barrel nut. I just did that with a second hand barrel I bought.

a spacer with a shouldered barrel will do the same thing. You can go TL3 to ARC but not the other way around.

 

[KnowNothing256]

Is it really though? You buy a Savage prefit, put it in your TL3 and set the shoulder with a nut. You buy a Savage prefit for your ARC and set the shoulder with a nut. Only difference is where you set that barrel nut. I just did that with a second hand barrel I bought.

a spacer with a shouldered barrel will do the same thing. You can go TL3 to ARC but not the other way around.

What spacer do you use for the TL3 to go to ARC?

 

[srt-4_uk]

Sorry if that wasn't clear. I took a prefit Savage barrel and nut that was set to a TL3 and set it to an Archimedes.

 

[KnowNothing256]

Sorry if that wasn't clear. I took a prefit Savage barrel and nut that was set to a TL3 and set it to an Archimedes.

Ah, ok, so it can be done is what you're saying, but it's not clear what thickness spacer would be required? Got it, thanks!

 

[HOLLYW00D]

Does this help?

American Rifle Company Black Friday and Cyber Week Sale

I was thinking it was just a .100" spacer used with the stock Nuke lug. Without pulling my Nuke down I'm thinking it's .187" thick like a factory M700, so maybe a 287" thick lug? One piece would be much better than two IMO. I would try that. Does anyone sell these lugs? Mine mics out at...

www.snipershide.com

 

[srt-4_uk]

Get Zermatt prints
Compare to ARC prints
Do some math
????
PROFIT

 

[KnowNothing256]

Does this help?

American Rifle Company Black Friday and Cyber Week Sale

I was thinking it was just a .100" spacer used with the stock Nuke lug. Without pulling my Nuke down I'm thinking it's .187" thick like a factory M700, so maybe a 287" thick lug? One piece would be much better than two IMO. I would try that. Does anyone sell these lugs? Mine mics out at...

www.snipershide.com

Looks like this here is the quote of interest:

American Rifle Company Black Friday and Cyber Week Sale

With a Archimedes bolt in 223, what mags would you run? Will the action fit into a standard Manners mini chassis without the need for additional in-letting or a stock specific for the Archimedes? The new MDT DSSF 10 rounds.

www.snipershide.com

Says that you need a 0.100" spacer to get from TL3 to ARC. If you add that thickness to the thickness of this fella, then you can go Origin to ARC:

Origin to TL3 Headspace Conversion Ring

[email protected]

patriotvalleyarms.com

So, my thought is have two spacers spun up, one to get from TL3 to ARC and the other to get from Origin to ARC (not really interested in stacking spacers). Anybody have an idea what the Origin to TL3 spacer thickness is? Is it also 0.100"?

We're getting somewhere...

 

[FisherT&C]

Haha good to know, you’re on my short list! Do you typically have them in stock, or have to order and be subject to these long lead times we’re seeing?

I try to keep .223, 6&6.5mm blanks handy. I do have some .257 7.5 twist blanks right now. I thread and chamber them as ordered. I usually run 4 weeks for a prefit if I have the blank.

 

[Steel head]

Sorry if that wasn't clear. I took a prefit Savage barrel and nut that was set to a TL3 and set it to an Archimedes.

And I yanked a barrel out of my savage and put it in my Nuke.
A few actions can do that, ARC, Zermatt and the new Aero are some.
OP kinda wanted shouldered barrel compatibility and that’s a far different requirement.

 

[KnowNothing256]

And I yanked a barrel out of my savage and put it in my Nuke.
A few actions can do that, ARC, Zermatt and the new Aero are some.
OP kinda wanted shouldered barrel compatibility and that’s a far different requirement.

I was definitely talking shouldered, yessir. But very open to shouldered + spacer, since the spacers would be reusable, and are a lot cheaper than the difference between a prefit and a custom barrel.

If I can confirm that I can make Origin and ZL3 prefits both work with an ARC action, even if the two options require different spacers, then that puts me in a much better place than having to order a $600+ barrel each time.

 

[b6graham]

I was definitely talking shouldered, yessir. But very open to shouldered + spacer, since the spacers would be reusable, and are a lot cheaper than the difference between a prefit and a custom barrel.

If I can confirm that I can make Origin and ZL3 prefits both work with an ARC action, even if the two options require different spacers, then that puts me in a much better place than having to order a $600+ barrel each time.

@POI_Shift looked into this for me before i decided to just run all Origins/RimX

 

[larryh128]

I’m sure this info’s out there somewhere but I haven’t seen it yet, sorry if I missed an obvious thread with the answer, but:

I’m interested in an ARC Archimedes, but it’s important to me to be able to snag cheap/discounted prefits here or elsewhere. ARC prefits, labeled as such, almost never come up in SH WTS posts, as opposed to say Impacts or Origins. Does anyone know what actions share the same headspace dimensions as the ARC actions, or can just use a shim to work with an ARC? I know there are headspace conversion spacers out there, for instance the PVA Origin to TL3 ring.

Actually what would be amazing would be a chart that compared headspace dimensions (shoulder to bolt face i’m guessing?) across the different actions that take prefits, even if it was just baselined off of the action with the shortest dimension and everything else was like “Baseline + 0.100” or whatever.

Thanks for any info folks can provide.

ETA: Whoops, this probably should be in the Bolt Action forum, mods please relocate if appropriate. Thanks!

Any small ring savage and a barrel nut.

 

[b6graham]

Any small ring savage and a barrel nut.

way to read the thread before making a comment...

also small shank. these arent mausers

 

[larryh128]

way to read the thread before making a comment...

also small shank. these arent mausers

I read it , made a mistake on my reply and really don't know why anyone would want to use a shim.

 

[b6graham]

I read it , made a mistake on my reply and really don't know why anyone would want to use a shim.

they work well with origin/TL3 barrels

same as the HLR lug to run TL3 barrels on origins

 

[spife7980]

I read it , made a mistake on my reply and really don't know why anyone would want to use a shim.

So you didn’t read it then. Thanks for the valuable contribution.