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View Full Version : Legality of 5 mm Remington Rimfire Magnum "AR" Rifle with PG and Detachable Mag?


oaklander
10-25-2010, 1:50 AM
I actually know it's legal, at least if I am reading this right:

12276.1. (a) Notwithstanding Section 12276, "assault weapon" shall also mean any of the following:
(1) A semiautomatic, centerfire rifle that has the capacity to accept a detachable magazine and any one of the following:
(A) A pistol grip that protrudes conspicuously beneath the action of the weapon.
(B) A thumbhole stock.
(C) A folding or telescoping stock.
(D) A grenade launcher or flare launcher.
(E) A flash suppressor.
(F) A forward pistol grip.
(2) A semiautomatic, centerfire rifle that has a fixed magazine with the capacity to accept more than 10 rounds.
(3) A semiautomatic, centerfire rifle that has an overall length of less than 30 inches.

So. . .

What I am wondering is whether any of the folks who make "AR-style" uppers/barrels and bolts have even *thought* about making parts for a 5 mm Remington Rimfire Magnum?

This would actually be pretty awesome, since it would result in an AR style rifle which shoots a round having more power than some 9mm loads, waaay more power than a .380, and which would be able to use detachable magazines and have evil features here in California.

For those of you who are not familiar with the "5 mm Remington Rimfire Magnum" - its ballistics appear to be pretty good.

Bullet - 38 gr (2.5 g) Lead
Velocity - 2,100 ft/s (640 m/s)
Energy - 372 ft·lbf (504 J)

I guess it was out of production for a while, but is now being made in Mexico, and sells for about .32 per round.

http://www.midwayusa.com/viewproduct/?productnumber=525113&cm_mmc=Froogle-_-Ammunition%20-%20Rimfire%20-%20Varmint-_-PriceCompListing-_-525113

Perhaps the most interesting part about having a rifle like this would be that it would point out how stupid California's AW laws really are. For example, a (detachable mag with PG) "AR" with potentially worse ballistics would totally be illegal, if it was in 9mm, since 9mm is a centerfire cartridge.

BUT something with up to 50 more foot pounds of energy would be perfectly legal, since it is rimfire.

Even more interesting, since the 5mm is only about 7/10ths of an inch shorter than a .223, it seems to me that it would be a simple matter to tweak a standard AR magazine to function with the shorter round (thus ensuring that those of us who have pre-bans could run our 30's).

jtmkinsd
10-25-2010, 2:01 AM
.22 WMR has similar ballistics and there's "AR" type rimfires out there already.

oaklander
10-25-2010, 2:54 AM
You appear to be incorrect on both counts:

1) I could not find a current manufacturer of .22 WMR "AR" conversion kits or complete rifles. Do you have a link?

2) WMR ballistics are not that great (this appears to be the hottest load):

40 gr (2.6 g) JHP
1,910 ft/s (580 m/s)
324 ft·lbf (439 J)

They are back down into .380 level, instead of up in 9mm level. Given that MOST people consider something with 9mm ballistics to be the bottom of what can realistically be used for HD/SD, I'm still thinking the 5mm would be a useful alternative to a 9mm AR.

I would be happy to change my opinion of the correctness of your post if you can give me a link to someone who currently makes a WMR conversion kit or rifle -- AND a link to some WMR ballistics that match or exceed the 5mm.

.22 WMR has similar ballistics and there's "AR" type rimfires out there already.

If by the bolded portion of your post, you are referring to "AR-type" rifles that shoot 22LR, I know about those already. Perhaps you missed the gist of my post, which was simply that there is a rimfire cartridge with centerfire ballistics which would make a neat alternative to a neutered, maglocked (or spade-gripped) 9mm AR?

Please clarify.

MrPlutonium
10-25-2010, 5:18 AM
Well, if you wave enough money at somebody they'll certainly do it for you. I like the idea! Shove the logical errors back into the anti's faces.

bwiese
10-25-2010, 10:13 AM
I know of no availability, but 'rimfire' means exactly what the word means and is in no way restricted to 22short, 22Long, or 22LongRifle calibers.

There's even a 41Remington rimfire that was used in old derringers ;)

Peter.Steele
10-25-2010, 10:21 AM
Hm.

How 'bout something like a .44 Henry cartridge, stretched a little bit, and necked down to accept a 5.56 or 7.62 round? That'd be fun, too ... :D

bjl333
10-25-2010, 10:27 AM
So we have to contact Hornady and make a new cartridge for us, the 5.56 CGN rimfire. The only thing we'll have to change is the BCG and we are good to go !!! :thumbsup:

wash
10-25-2010, 10:28 AM
I'm pretty sure I've seen a .22 WMR AR but it may have been a dedicated upper type.

The magazine idea sounds nice but I'm sure the rim would screw it up.

ptoguy2002
10-25-2010, 10:34 AM
How common are 5mm Barrel blanks and chamber reamers?

dexterbase
10-25-2010, 11:01 AM
So we have to contact Hornady and make a new cartridge for us, the 5.56 CGN rimfire. The only thing we'll have to change is the BCG and we are good to go !!! :thumbsup:

I.....LOVE.... this idea. I would buy one today.

Wherryj
10-25-2010, 11:08 AM
I actually know it's legal, at least if I am reading this right:



So. . .

What I am wondering is whether any of the folks who make "AR-style" uppers/barrels and bolts have even *thought* about making parts for a 5 mm Remington Rimfire Magnum?

This would actually be pretty awesome, since it would result in an AR style rifle which shoots a round having more power than some 9mm loads, waaay more power than a .380, and which would be able to use detachable magazines and have evil features here in California.

For those of you who are not familiar with the "5 mm Remington Rimfire Magnum" - its ballistics appear to be pretty good.

Bullet - 38 gr (2.5 g) Lead
Velocity - 2,100 ft/s (640 m/s)
Energy - 372 ft·lbf (504 J)

I guess it was out of production for a while, but is now being made in Mexico, and sells for about .32 per round.

http://www.midwayusa.com/viewproduct/?productnumber=525113&cm_mmc=Froogle-_-Ammunition%20-%20Rimfire%20-%20Varmint-_-PriceCompListing-_-525113

Perhaps the most interesting part about having a rifle like this would be that it would point out how stupid California's AW laws really are. For example, a (detachable mag with PG) "AR" with potentially worse ballistics would totally be illegal, if it was in 9mm, since 9mm is a centerfire cartridge.

BUT something with up to 50 more foot pounds of energy would be perfectly legal, since it is rimfire.

Even more interesting, since the 5mm is only about 7/10ths of an inch shorter than a .223, it seems to me that it would be a simple matter to tweak a standard AR magazine to function with the shorter round (thus ensuring that those of us who have pre-bans could run our 30's).


Franklin Armory in Morgan Hill makes ARs in 25 Winchester Supper Short Magnum , 243 WSSM , 223 WSSM as well as 5.56 NATO, 450 Bushmaster, 7.62x39, 6.8 Rem, 6.5 Grendel, 204 Ruger, & 22LR. If those don't fit your needs, perhaps giving them a call about a "special special order"?

http://www.franklinarmory.com/PRODUCTS.html

If nothing else, this indicates that parts for these calibers are available...(I know that the point was rimfire, but this shows that there are a few more choices than most people realize AND that this company might work with you on your project.)

oaklander
10-25-2010, 12:11 PM
7.62x54R can be shot out of a semi-automatic box fed magazine (Dragonov, SVT-40, PSL, etc.).

It's "rimmed" - just like a rimfire.

You just have to load them a certain way.

I'm pretty sure I've seen a .22 WMR AR but it may have been a dedicated upper type.

The magazine idea sounds nice but I'm sure the rim would screw it up.

oaklander
10-25-2010, 12:17 PM
I'm liking where this thread is heading!!!!!

All we do is find the following:

1) an obsolete rimfire cartridge that is about the same length and base diameter as a .223.

2) Someone who knows how to load those old cartridges.

3) Someone with access to a CNC to machine a bolt and barrel (chamber).

Do we have any volunteers?

I can't imagine this costing more than a few thousand dollars to accomplish, and I will even finance it, if I get a percentage of the resulting rifle sales.

;)

Who here has contact with any people who manufacture gun parts and/or ammo?????


I know of no availability, but 'rimfire' means exactly what the word means and is in no way restricted to 22short, 22Long, or 22LongRifle calibers.

There's even a 41Remington rimfire that was used in old derringers ;)

Chatterbox
10-25-2010, 12:33 PM
7.62x54R can be shot out of a semi-automatic box fed magazine (Dragonov, SVT-40, PSL, etc.).

It's "rimmed" - just like a rimfire.

You just have to load them a certain way.

7.62x54 is rimmed, but is not a rimfire catridge. It's very much centerfire.

supersonic
10-25-2010, 1:27 PM
Great thinking "outside the box" Kevin. Bravo!:)

383green
10-25-2010, 1:42 PM
Interesting. If tooling would need to be made for a suitable rimfire round anyway, I wonder if it would be practical to design a "rimlessfire" round in which the OD of the rolled rim was about the same as the OD of the rest of the cartridge case, with a recessed groove for the extractor. Basically, a modified rimfire design which provides improved feed from box magazines and which headspaces on a shoulder or the case mouth rather than on the rim. I think that the toughest design challenge would be simultaneously making the rim soft/thin enough to be crushed by the firing pin, making the extractor groove area strong enough to not balloon out under chamber pressure, and getting low-end centerfire performance out of a round that needs to operate at lower rimfire-compatible pressure.

Does anybody know if such a case design has been attempted before? If the technical challenges have already been worked out but there simply wasn't a market for such a beast before, then resurrecting an old design might be beneficial.

Whatever the round ends up being, it would be particularly interesting if it'd feed properly from an unmodified STANAG magazine, so our stockpiles of pre-ban AR mags could be used with the rimfire uppers!

I also wonder whether CGF/etc. expect to take down the AW laws in a short enough timeframe to make this venture pointless, but the brainstorming part is fun anyway!

IrishPirate
10-25-2010, 1:46 PM
I'm lost on what the question is......

sreiter
10-25-2010, 2:11 PM
Oak. A friend works at a machine shop in ny state that make gun parts. Call in bound to him

oaklander
10-25-2010, 2:41 PM
You mean that the 5000 rounds of 54r that I have shot in the last five years or so are not rimfire?

:)

I was wondering what this little berdanny looking thing in the middle was.

They sure make more of a fireball than my 22LRs - thanks for straightening me out.

Seriously - it appears that you missed the simple point of my post:

Cartridges that are SHAPED like a rimfire will work in a box-fed magazine semi-auto. Even LARGE ones.

I will work on making my posts easier to understand. I typically write for other lawyers, I need to remember my audience.

7.62x54 is rimmed, but is not a rimfire catridge. It's very much centerfire.

oaklander
10-25-2010, 2:45 PM
No question. Only a solution. Move along.

I'm lost on what the question is......

oaklander
10-25-2010, 2:46 PM
Sweet! Thanks!

Oak. A friend works at a machine shop in ny state that make gun parts. Call in bound to him

oaklander
10-25-2010, 2:47 PM
That might be the solution.

Scratch the "new ammo" idea for now and use something that is being produced, and is fairly cheap. Since it's close to being the size of .223 anyways - many things get easier.

But the idea with the 5mm remington rimfire is very tempting. There, the biggest problem (ammo availability) is taken care of.

Peter.Steele
10-25-2010, 2:48 PM
Hm.

Safety concerns are obviously an issue here. We don't want a large rimfire round that will detonate if you bump the magazine the wrong way.

So, what sort of feasability issues might be encountered with a middle ground?

It's not rimfire, it's not centerfire, it's ringfire.

Instead of having a primer located dead center of the cartridge, have a ring-shaped primer concentric to the center. The center remains solid brass, and inert. The firing pin would be somewhat like a rimfire, in that it would be offset somewhat from the centerline of the bore.

Not being an ammunition manufacturer, I don't know how feasible this would be ...

oaklander
10-25-2010, 2:50 PM
The fact that you could make a rimfire rifle with centerfire ballistics could be used in argument in a legal case to illustrate how lame and pointless the existing laws are.

Not only that, but it would just be kind of cool. . .

:D

I also wonder whether CGF/etc. expect to take down the AW laws in a short enough timeframe to make this venture pointless, but the brainstorming part is fun anyway!

wash
10-25-2010, 2:51 PM
The fact that you can make rimmed cartridges feed out of a box magazine does not make it easy.

Look at how hard it is to find a Saiga-12 magazine that doesn't have some negative issue.

I've had that idea of a rebated rim rimfire for a few years, mostly to get rid of the magazine issue. Beyond the brass strength issue, you would have to strike the rim at the extractor and I'm not sure if that is practical.

oaklander
10-25-2010, 3:08 PM
Good point.

Maybe we stick with 5mm?

I do not know anything about engineering, but it seems to me that if you can make a 10/22 work, you can make an "AR-22" in 5mm work.

I think there was actually a semi-auto that was made for 5mm back in the day - I think it was made by CZ. Would be interesting to see how they made it work.

The magazine feeding issue seems to be moot by the fact that 10/22's work with a cartridge that is functionally similar (just shorter and not bottlenecked).

Here, you would not even need a gas system - just use straight blowback with a strong enough recoil spring - since it's a RIFLE, you can have a strong spring (since you would have something large to grab, unlike a straight blowback pistol in 9mm for example).

The fact that you can make rimmed cartridges feed out of a box magazine does not make it easy.

Look at how hard it is to find a Saiga-12 magazine that doesn't have some negative issue.

I've had that idea of a rebated rim rimfire for a few years, mostly to get rid of the magazine issue. Beyond the brass strength issue, you would have to strike the rim at the extractor and I'm not sure if that is practical.

Ksmash01
10-25-2010, 3:16 PM
7.62x54 is rimmed, but is not a rimfire catridge. It's very much centerfire.

I'm sure he knows that. He wasn't really talking about priming or anything, just the fact that the 7.62x54r is rimmed, like a rimfire cartridge.

Purple K
10-25-2010, 3:43 PM
Kevin, I like the way you're thinking.

http://www.gunknowledge.com/Ammunition/Calibers/5mm_RMR.html

dfletcher
10-25-2010, 4:18 PM
The fact that you could make a rimfire rifle with centerfire ballistics could be used in argument in a legal case to illustrate how lame and pointless the existing laws are.


:D

Or, could be used by our legislators as an opportunity to apply centerfire AW resrictions to rimfire as well? :(

When you or I hear "an AW is no different than any other semi auto" we mean to say the AW should be treated no differently than the semi auto "hunting rifle". Antigunners hear that and say "well then, the semi auto hunting rifle is just as bad as the AW" and should be as restricted. Witness the whole Korean Garand affair.

I think there is a rimfire 223 out there somewhere - patented, maybe existing on paper only?

bwiese
10-25-2010, 4:31 PM
The fact that you can make rimmed cartridges feed out of a box magazine does not make it easy.

There's no need for a rimfire cartridge to have an actual exposed, non-flush, non-rebated rim. That rim is a legacy from revolver days.

You could indeed have, say, a new "22RimfireImproved" cartridge that has identical-to-22LR but with no exposed rim, and yet the outer annulus of the rear case surface is the firing area.

Another interesting technique - likely unfruitful - would be to try to operate "vigorous rimfire" on a centerfire rifle cartridge - that is, a damned hard strike on the brass ring surrounding the primer actually detonates.

Legally, I believe the "centerfire" definition of the rifle should refer to the "nature of firing of the rifle" and its internal architectre - not the nature of the round that might be chambered. I believe this term is not defined in regulation nor statute, so I believe we could fill the room with experts affirming the above.

CHS
10-25-2010, 4:35 PM
Alexander Arms was working on a .17HMR AR conversion kit a while back. No idea where that idea went.

They are California-friendly.

Someone should call them :)

CHS
10-25-2010, 4:37 PM
Another idea:

What about caseless?

The law bans semi-automatic centerfire rifles with certain features only.

It doesn't make an exemption for rimfires. It simply chooses ONE type of rifle to regulate.

So rather than think about it in terms of rimfire vs centerfire, we should think about it in terms of "anything other than centerfire".

The earlier bit about "ringfire" makes sense. There's plenty of caseless ammo out there (but would require new tooling and firearm designs).

What about an offset primer? Similar to the ringfire.

wash
10-25-2010, 4:46 PM
There's no need for a rimfire cartridge to have an actual exposed, non-flush, non-rebated rim. That rim is a legacy from revolver days.

You could indeed have, say, a new "22RimfireImproved" cartridge that has identical-to-22LR but with no exposed rim, and yet the outer annulus of the rear case surface is the firing area.

Another interesting technique - likely unfruitful - would be to try to operate "vigorous rimfire" on a centerfire rifle cartridge - that is, a damned hard strike on the brass ring surrounding the primer actually detonates.

Legally, I believe the "centerfire" definition of the rifle should refer to the "nature of firing of the rifle" and its internal architectre - not the nature of the round that might be chambered. I believe this term is not defined in regulation nor statute, so I believe we could fill the room with experts affirming the above.
I would love to be wrong but I thought that rimfire required that folded over rim for the priming compound and also to sandwich the priming compound between the firing pin and an un-moving barrel breach.

If the firing pin can just push the case deeper in to the chamber, I'm thinking it wouldn't ignite reliably and removing a stuck unfired case might be really dangerous.

Other than that, it sounds like a great idea.

oaklander
10-25-2010, 4:51 PM
Possibly - the current gun law politics tenor is leaning towards increasing gun rights.

A group of us actually talked about this the other night at my BBQ.

Basically, the internet has allowed a true grass roots of gun owners to organize and fight the gun grabbers. Since gun grabbers are NOT grass roots, sheer numbers are now starting to overpower them. They have no true recourse, since they can't mobilize additional troops like we can.

Also - we now have a political climate in which being against gun rights is dangerous to someone's political career (in MOST parts of the country - even the state).

We also have some nice precedent setting cases lined up - and this does not even count McDonald/Heller.

In sum - the gun banners are outnumbered, and politically awkward vestiges of an old political paradigm that no longer applies, now that we can use our sheer numbers to formulate coherent opposition.

Or, could be used by our legislators as an opportunity to apply centerfire AW resrictions to rimfire as well? :(

383green
10-25-2010, 4:56 PM
Another idea:

What about caseless?

Hmm, that's even more intriguing.

In any case, I would hope that the rounds could feed from a standard AR magazine, such that we could use the Large Capacity Ammunition Feeding Devices that we stockpiled before the ban. If the rounds require a magazine that didn't exist back in the day, then we have features and a mag-drop button, but we're still stuck with 10-round magazines.

oaklander
10-25-2010, 4:57 PM
Also - there appears to be some doubt that there's technology available to make a semi-automatic 5mm rifle. That simply is not true.

As I have mentioned before, a 10/22 semi works just fine - same with a 54r semi. The rim does not prevent feeding, it just makes it a little more tricky sometimes.

383green
10-25-2010, 5:15 PM
I would love to be wrong but I thought that rimfire required that folded over rim for the priming compound and also to sandwich the priming compound between the firing pin and an un-moving barrel breach.

That's one way to solve the problem of there needing to be some sort of anvil for the firing pin to hammer the priming compound against, and it's the easiest/cheapest way to do it in a case that doesn't have a separate primer. It should be solvable in other ways, too, though. Maybe those ways are trickier to implement and more expensive to manufacture than a simple drawn rimfire round, but the AW laws introduce unnatural constraints that can affect design decisions enough to make us consider things that would seem absurd otherwise (like bullet buttons or non-pistol-gripped ARs, for example!). What if the drawn metal case didn't have the rim rolled over, and instead had a separate metal piece placed in the case against the priming compound to act as an anvil? Ok, there would still need to be some provision for extraction and some way to define headspace, but I'm just throwing it out there as an example of another way to give the firing pin something hard to beat the priming compound against.

Ok, so it's been pointed out that it's not important that the rifle be rimfire; rather, it's important that it not be center-fire. It just so happens that rimfire is the only non-centerfire option in production at this time. Those aren't the only possibilities, though. There used to be pinfire rounds until better ideas came along. There also used to be external ignition (i.e., muzzle-loaders). "Ring-fire" was mentioned; that sounds to me like an option that could be implemented with cases manufactured just like modern centerfire rifle cases, but with modified primer and primer pocket designs. The rifle would need to have a bolt with an off-center firing pin that would not be able to ignite a normal small or large centerfire primer, but the chamber, case dimensions, magazine, etc. could still potentially have the same dimensions as some existing centerfire round. The rounds might be loadable on regular loading presses with priming systems modified to accept a larger primer. Or maybe somebody could figure out an ingenious way to manufacture primers with the same dimensions as common centerfire primers, but which require an off-center strike, and some means of insuring that the firing pin of their matching rifle cannot ignite a standard centerfire primer.

supersonic
10-25-2010, 5:38 PM
The fact that you could make a rimfire rifle with centerfire ballistics could be used in argument in a legal case to illustrate how lame and pointless the existing laws are.

Not only that, but it would just be kind of cool. . .

:D

I think that the "cool" factor would be about the only thing we'd gain in our favor. As optimistic as I'd like to be about this, just look at how much the (already) proven absurdity of AW laws - and CA firearms laws in general -has done to change not only the laws themselves, but opinions of John Q. Public.

The magazine feeding issue seems to be moot by the fact that 10/22's work with a cartridge that is functionally similar (just shorter and not bottlenecked).

Actually, the semi-auto Remington 597 is chambered in .22LR/.17HMR/.17HM2, so the rimfire, bottleneck cartridge is already proven in a SA action. I bought a 597 for my son a few years ago, and the actual blowback/twin guide rod & spring action is very well-designed. The only weak point in the system is the magazines, which IIAC, were redesigned and function flawlessly.

slappomatt
10-25-2010, 8:50 PM
Another idea:

What about caseless?

The law bans semi-automatic centerfire rifles with certain features only.

It doesn't make an exemption for rimfires. It simply chooses ONE type of rifle to regulate.

So rather than think about it in terms of rimfire vs centerfire, we should think about it in terms of "anything other than centerfire".

The earlier bit about "ringfire" makes sense. There's plenty of caseless ammo out there (but would require new tooling and firearm designs).

What about an offset primer? Similar to the ringfire.

This is exactly what I was thinking. The law doesn't state rimfire we just need NOT CENTERFIRE. what about using something with a very large primer and having the firing pin off set to hit the edge of the primer. it would be offsetfire. might even be legal to keep using .223 and just move the firing pin over .050 or so.....

Bhobbs
10-25-2010, 8:59 PM
It may be legal but I know how well it will operate. I remember when .17 HMR semi autos were recalled because the fouling would build up in the chamber and cause OOBDs. Hornady even has a newsletter on their site about .17 HRM semi autos being dangerous. This round might have the same issues because it is bottle necked. It may be fixed using some other operation than blow back.

383green
10-25-2010, 8:59 PM
might even be legal to keep using .223 and just move the firing pin over .050 or so.....

I'd say that if it'll fire ordinary 5.56 rounds, it's still centerfire.

hoffmang
10-25-2010, 9:13 PM
I'd buy a 5mm Remington Rimfire AR upper and put it on a featureful lower!

-Gene

the_quark
10-25-2010, 9:22 PM
I had this idea (with regard to rimfire) back in the heady early days of thinking about stuff like the bullet button.

My research at the time was that it would be difficult and expensive, and might not work that well.

I think something non-rimfire and non-centerfire is a really good idea, but it'll be a race between getting that developed and us overturning the laws.

My thought on it at the time was, "Hey, I'll put my effort into trying to fix the laws, and keep that in my back pocket as a last line of defense."

jimx
10-25-2010, 9:30 PM
Before oll's a member here was trying to get a 5mm rimfire project going. I think his name was 44 something. If anyone knows who I am talking about they are probably mad at me for reminding them.

Purple K
10-25-2010, 9:31 PM
Remington designed a new case that was very similar to the older .22 Mag, but stronger to handle the higher pressure of the 5 mm at 33,000 PSI.[5] It uses a 5mm (.20 caliber) bullet that measure 0.2045 inches (5.19 mm), the same as the more recent .204 Ruger cartridge.For a brief time, Thompson Center Arms offered firearms in 5 mm Mag.[3] From 1982 until 2008, no ammunition manufacturers manufactured rounds for this cartridge, but some firearms manufacturers are creating conversion kits to allow the existing 5 mm guns to shoot other more-common cartridges.[3]

At the 2008 SHOT show, Taurus International introduced the first handgun chambered for the 5mm Remington Magnum rimfire.[6] Concurrent with the announcement from Taurus, Aguila Ammunition announced they would begin producing 5mm RMR ammunition in 2008.

As of January 2010, Taurus has not yet imported nor produced their Tracker in 5mm Remington rimfire. They have stated that it will be manufactured and imported pending production demand in the second half of 2010.

command_liner
10-25-2010, 9:36 PM
So we need a non-centerfire cartridge that we can call rimfire. No use thinking
small. Think big.

Start with the base of the 50 BMG. There can be a good solid rebate for extraction,
and still be plenty of area for crushable pocket as needed for the rim fire mechanics.
Call it the 458 CalGuns cartridge.

The funny thing is you can probably use a ring of percussion caps seated in the
base of this new non-centerfire cartridge. Heck, let us start with the 14mm
Vulcan case necked down to 12mm out front, and a ring of 8 #11 percussion
caps recessed 1 mm on the back side. You need a 2-part bolt instead of a bolt
and firing pin.

I can make this bolt and striker on my lathe in my garage. Quick! Somebody
send me some patent applications! I already have the steel barrel blank in
my carport.

oaklander
10-25-2010, 9:46 PM
I'm liking the way this is going!!!

Even setting aside California's lame gun laws - I think that an "AR-style" rifle in 5mm would totally sell nationwide. It's a relatively cheap round, and I imagine that there is little recoil, and not too much noise.

bwiese
10-25-2010, 11:49 PM
So, is an electronically detonated round (like Remington's E-Tronics primer) considered centerfire? :)

383green
10-25-2010, 11:54 PM
So, is an electronically detonated round (like Remington's E-Tronics primer) considered centerfire? :)

I could see that going either way... unless the electrical contact is ring-shaped, with an insulated portion in the center, that is. :43:

For added fun, make the flash hole(s) off-center, like in a Berdan-primed case, so there's just not much going on at the center of the case head.

Eric Mayer
10-26-2010, 2:50 PM
This is the original 5mm Remington rimfire magnum (comparison):
http://www.varminter.com/images/rimfirecomp.jpg

Here are some old stories about the Remington release:
Classic Calibers - 5mm Remington Rimfire Magnum (http://5mmforums.com/forums/index.php/topic,15.0.html)

Lastly, here is the article about the re-release of the cartridge by Centurion:
Centurion 5mmRRM (http://www.varminter.com/2008/5mmrrm.html)

Oaklander, shoot me a PM if you have any questions, or need some samples of this ammo.

Eric :cool: