I have a Stevens 200 in 223. It has a very long throat in it. It might be a 5.56 chamber. I have tried searching for and answer to the question, How to tell the difference between them?
I seated a flat based bullet nose first in a resized case. Just enough to stay in place. I then inserted this cartridge in the rifle and closed the bolt. The flat base of the bullet hits the rifling and gets pushed into the case.
I then opened the action removed the cartridge and measured the overall length of this cartridge,
It came out to 1.967.
Is this a 223 length or a 5.56 length?
Leo

I don't know if this is relevant, but I had a Savage 24V in 223/20 gauge that did not fire surplus 5.56x45mm ammunition reliably.
It was most likely a chamber issue as a Mini-14 did not have the problem.

The 5.56 chamber will have the longer leade. Here is a good article on it. The rifling is also smoother and longer in the 5.56 in order to handle the pressure difference.

223 vs 5.56

Tom P---The Savage 24V is .222 Rem/ 20 gauge I would hope it did not fire 5.56x45 reliably.

The 223 has a .025 freebore and a 2.5 deg leade angle, while most of the other 223 hybrids and 556 have throat much longer- .0619 for the Wylde if I recall , the 556 is .0566 and both/most all hybrids have leade angle of 1.25 to 1.5 deg. A Holliger throat designed for 90 SMKs is longer than .100

1.967 sounds close to either a 556 or Wylde-but it ain't exact science unless you pull a chamber cast.

quote:

Originally posted by carpetman1:
Tom P---The Savage 24V is .222 Rem/ 20 gauge I would hope it did not fire 5.56x45 reliably.

Yes, there was a 223/20 gauge version. It's now a 6x45mm, and it fires that very reliably. It did fire 223 just fine, but not 5.56x45mm.

Tom P--Thanks for the update, my older reference material only listed the .222.

Thanks for all the responses.
I have read a lot of articles about the differences between the two cartridges, but most of what I read was about pressure and accuracy. Mostly differences in the ammo, not much of anything told how to tell one chamber from another.
I finally found links to the specs but they still didn't help much.
I often pass up on ammo for a real good price because it is marked 5.56. Sometimes as cheap as I can reload for.
I pass on it because I don't want to risk anything.
I do load longer than factory specs. The magazine allows for a COAL longer than what the chamber can hold. The model 200 uses a 308 length action blocked off for the shorter round.
If this extra length means I can shoot 5.56 ammo safely, I won't pass on the next good deal.
Leo
I thought there had to be an easy way to tell, like inverting a bullet and measuring.

44mag
.

223 shooters can load as long as they want provided the throat allows an extend seating depth/COAL.

High Power service rifle shooters routinely load 80 grain bullets to well over 2.5" and singly load these rounds manually ( slow fire prone at 600 yards requires single loading anyway). An80 grain vld by Siera, Nosler Berger or Hornady and a stout charge of appropriate powder in a Wylde chamber gets about 2700 fs from a 20 inch bbl. A bolt gun with action length to spare and a deep throated chamber like a Wylde or 556 can get more.

556 ammo can be fired w/o regard in an of these hybrid chambers, but they say that in a 223 SAAMI chamber pressure can get up to 75k psi.

I shoot the 5.56 in AR's.
I shoot the 223 in my bolt guns.
I reload all of the brass using 223 dies, for what it's worth; and every thing works. So far...

This article

223 vs 5.56

is good, but it left me wanting to know specifics. I have referred to Dave Kiff's chamber reamer specs.
There is more than just a difference in throats here:

5.56 Nato: Tight base and loose throat.
Mainly the throat is sloppy wide in diameter, only slightly longer in parallel-sided free-bore, and with a common gradual leade angle.



.223 Remington: Loose base and tighter throat, mostly a more abrupt leade angle.



And other "hybrid" chambers galore, eh?

Each small square on this graph paper represents 0.001", a thousandth of an inch, in the drawing below.

Two pieces of this graph paper taped end-to-end are not long enough to show where the 5.56 NATO throat finally has its leade come to bore diameter.

The first drawing is continued to the right of the drawing, shown in the second image below the first:





5.56 NATO free-bore diameter is 2.5 thou bigger than bullet diameter.
.223 Remington free-bore diameter is SAME AS BULLET DIAMETER!


Both cartridges have identical locations and measurements for the end of the chamber's cartridge case mouth or neck-2 location,
right where it begins to chamfer down at a 45-degree angle into the throat.

If the chamber throat is counted as the total length of the run of the chamfer plus parallel-sided free-bore plus the entire run of the leade to the start of fully rifled barrel:

5.56 NATO full throat length = 0.2458"

.223 Remington full throat length = 0.0852"



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The non-milspec ammunition produced by most commercial companies for 5.56 and .223 is identical except for label. "Paramilitarist" shooters like to buy the 5.56 label for their rat-tat-tat plastic-and-aluminum spray guns because they've been told it is "more powerful". Your Stevens will safely shoot anything you can buy. Don't sweat it.

The simple fact is, 2,000psi difference is moot, BUT, the throat differences pose a real problem, as 5.56 ammo IS loaded longer. This is where the problem lies, as pressure can spike due to this.

Hope this helps.

Cheers.

quote:

the throat differences pose a real problem, as 5.56 ammo IS loaded longer

I show them as both 2.26" OAL

quote:

Originally posted by 416RigbyHunter:
The simple fact is, 2,000psi difference is moot, BUT, the throat differences pose a real problem, as 5.56 ammo IS loaded longer. This is where the problem lies, as pressure can spike due to this.

Hope this helps.

Cheers.

I've found I can consistently load my .223 ammo, for use in my Stevens 200, longer than the ammo I load for my AR, mainly because of the AR's magazine.

Life as been getting in the way of my shooting interest lately. Thanks for all the responses. I feel assured that my Stevens can handle most anything I can buy.
Being it has a fairly long magazine, longer than I can load the chamber with, I can load to just short of the rifling and be fine.
I have not loaded to more than about mid levels in the books, I will have to work a bit higher to see how it shoots.
Leo

This may be easier to see:

The top of the drawing shows the NATO chamber/throat and the bottom the 223