dumb .223 and rifle/shotgun questions

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Could anyone elaborate on the differences between M193, M855, and SS109 and .223 "hunting" or "sporting" ammunition? Just the basics, I don't need an encyclopedia. Mostly concerned with compatibility, accuracy, power type of info.

I also read on "wikipedia" that "The only difference between 5.56 NATO and .223 Remington is that 5.56 rounds contain more powder leading to more powerful rounds and higher pressures when firing."; but I thought there was also a slight difference in diameters, where one couldn't be fired in, for example, the Ruger Mini.



Second one is, after looking at: KAC Masterkey, would something like this be illegal in the civilian market on a non-auto? I know there are over/under rifle/shotgun combos now, but not on an AR type platform. Just curious is all.
 
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I also read on "wikipedia" that "The only difference between 5.56 NATO and .223 Remington is that 5.56 rounds contain more powder leading to more powerful rounds and higher pressures when firing."; but I thought there was also a slight difference in diameters, where one couldn't be fired in, for example, the Ruger Mini.

I've been told and have read about this as well. Both are correct (loads and diameters are different). The head diameters are slightly different (don't have the data in front of me). I also believe that you can always shoot guns that specify 5.56 with .223 but not the other way around.
 
The only difference that I know of in the ammunition is that military ammo is loaded to higher pressures. They get away with this because the chambers are throated long in a NATO chamber and the bullet has lots of jump into the rifling and they tend to be much more generous in the size of the chamber. The cases also tend to be a lot stronger than commercial cases.

SAMMI .223 chambers have the origin of the rifling much closer to the bullet. I do not believe there is any difference in case dimensions.

Like was said, don’t shoot military ammo out of commercial rifles marked .223.

If you go to this URL

http://www.ar15barrels.com/tech.shtml

You can download a picture of the 5.56 chamber and the .223 chamber and see the difference for yourself.

B
 
I've been told and have read about this as well. Both are correct (loads and diameters are different). The head diameters are slightly different (don't have the data in front of me). I also believe that you can always shoot guns that specify 5.56 with .223 but not the other way around.

Not an issue for me right now, but this sounds like an important one for those who need it.


Also, was just reading about the Valmet RK62. What a nice gun. Too bad there isn't a civilian version we could get here. I wonder what the "best" "improved" version of an AK47 is which is available here. I know the AK47 was improved in 1974 into the AK74, but I'm talking minute of arc accuracy and build quality like in the Valmet. Something for a "keeper".



...Like was said, don’t shoot military ammo out of commercial rifles marked .223. ...

I thought cheaper military ammo was one of the draws of going to this caliber in the first place. That said, it makes the .204 Ruger or the .17 Remington or the wildcat .19 Calhoun or .19 Badger sound better and better.



Oh, and a big thank you for all the good info. Keep it coming!
 
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"The only difference between 5.56 NATO and .223 Remington is that 5.56 rounds contain more powder leading to more powerful rounds and higher pressures when firing."

That's contrary to information in Barnes.
M193 ball -- 55 grain FMJ-BT. 3250 fps with 1325 ft. lbs. energy
M855 ball (SS-109) -- 62 grain FMJ-BT. 3100 fps, 1325 ft. lbs.

5.56x45 military chambers and throats differ from .223 Remington sporting rifle chambers. Military ball ammo. may produce high chamber pressures in sporting rifles, according to SAAMI.

JT
 
Glad I asked. Maybe the questions aren't so dumb after all. How about the other questions? Thanks again.
 
I thought cheaper military ammo was one of the draws of going to this caliber in the first place. That said, it makes the .204 Ruger or the .17 Remington or the wildcat .19 Calhoun or .19 Badger sound better and better.

I think the cheap ammo is only really relevant if you do a lot of blasting with military type rifles. Most of those rifles will be chambered with a 5.56mm NATO chamber anyways, so it shouldn’t be a problem.

If you are looking at a .204 Ruger or looking to do handloading, you most likely wouldn’t be all that excited by the accuracy potential of ball ammo. The military stuff is basically crap. There are some exceptions but in general it is not the best for accuracy work.

If you have a rifle built, you can get it chambered with the Wilde match chamber, which will shoot both commercial ammo and military ball pretty well at resonably safe pressures.
 
There's some more good info, including exploded diagrams of the different types of ammo here ...

I've basically had a lot of the same questions as you have as I just recently bought my first AR. A couple things I've learned during my quest to find surplus military ammo to feed it ... XM193 is probably the best surplus ammo to find, and is also the most scarce and expensive since all of the supply is going to the troops ... M855 is another very good option, and I've had better luck finding this, and it's been cheaper than the XM193 by a lot ... SS109 is basically the same as M855 BUT is often loaded light to help the weapons of some European countries cycle better. This can cause short stroking in the AR platform in some cases (but not necessarily all). I've read that it feeds perfectly in one persons rifle, but completely fails to feed in another's. SS109 loaded to M855 spec should be fine.
 
If you have a rifle built, you can get it chambered with the Wilde match chamber, which will shoot both commercial ammo and military ball pretty well at resonably safe pressures.
Anybody can comment on the above statement?
I'm on the market for a AR15 and haven't made any decision on the chamber choice.
 
Derek, thank you.
I'm just not sure if Wilde is a good choice if I will go with M4 carbine, RRA may not even have this option available for M4.
 
The stainless match & varmint barrels have wylde chambers and the chrome moly 20" heavy barrels do as well. All the others have NATO as far as the website goes.

B
 
I'm on the market for a AR15 and haven't made any decision on the chamber choice.

Is this a serious gun, or a play gun? Do you anticipate shooting it a LOT?

John Farnam has commented on these chamber issues a number of times over the years. I keep a small file with selected tidbits for reference. Here it is.

John Farnam said:
22 Jan 02

I just completed a two-day Patrol rifle Course with a large PD on the West Coast. Everyone in the class used an AR-15, mostly Colts, a few Bushmasters.

Ammunition was generic Winchester. Each student expended nearly one thousand rounds.

We had a few failures to feed which were quickly reduced by the student, but no catastrophic breakdowns, save one. One student, a gunsmith no less, brought a tight-chambered (SAAMI), heavy-barreled, target rifle that started life as an AR-15, although it was difficult to tell by looking at it. It heated up and seized during the first hour of the class. We had to pull it off the line and give him a military surplus M-16, which worked fine for the duration. Any serious, autoloading rifle needs a NATO chamber. Only bolt guns should have SAAMI chambers.

A great contributor to AR-15 reliability is the chronic habits of:
(1) keeping the dust cover closed, and (2) keeping a magazine continuously in the magazine well. Those processes, in concert, plug all the holes and keep blowing grit and dirt out of the weapon. It should be standard procedure.

/John

DPMS AR-15s are manufactured nearby, and we had several in the course. All functioned well, except for the ones that had their triggers "customized." All of them experienced continuous functional distress One went down completely.

Lesson: PLAY GUNS CANNOT DOUBLE AS SERIOUS GUNS. Military rifles are pretty well set up for serious fighting as the come from the factory. Attempts to "customize" triggers and "accurize" the system are ill advised if the weapon is to be put to serious use. Increases in accuracy from such modifications are negligible, but compromises in reliability are disastrous, as we saw this weekend.

/John

13 Aug 02

Sage rifle comments from a friend in the Philippines:

"AR15's have always been popular here. They were made locally from 1983-1987 under license from Colt. Most are still in active service. The black market is the ONLY source for these rifles, as none can be transferred legally.

Connected (‘qualified') civilians are allowed to possess and even carry them
outside their homes. Many are thus ditching their MP5s and UZIs. Pent up demand, coupled with news photos of US soldiers armed with M4s during their local exercises, has driven the cost of these black-market ARs through the roof.

In the last few months, among my friends I've seen every conceivable permutation of this rifle! Anything from an eight-inch barrel to a twenty-four inch, heavy barrel, with every imaginable gimmick glued, screwed, taped, or pinned onto them.

You Americans are not the only gimmick-happy race in the world! Most folks here too just can't seem to be content with any species of ‘stock' rifle. They
predictably load them up with widgets until they weigh more than an M-14.

‘Accuracy' jobs are just as common. Like you, I've seen nearly all of these
modified guns malfunction with monotonous regularity. Curiously, their
demonstrated unreliability is usually lost on their naive owners. Some things
never change!

Standing in stark contrast are full-time military people I know whose lives
literally depend on the reliability of their individual weapons every time they
go on an operation. Most of my military friends have been on many. Their M-16s are all stock, ‘plain vanilla' as you would say. These men have survived
numerous, live contacts with the enemy. Their rifles work, every time. Those
with unreliable rifles are no longer with us!"

Lesson: Take this advice from the mouth of one who knows. You need to be serious about your "serious" weapons.

/John

27 Nov 02

On the AR-15/M-16/M-4/etc from a friend who manufacturers guns:

"As a result of heavy use, M-16 upper receiver aluminum forgings can begin
to 'oval out' where the barrel is installed. Accuracy suffers greatly, and the
weapon can come apart.

On the lower receiver (also an aluminum forging), the holes for the hammer pin are also famous for 'ovaling,' to the point pins walk out.

The M16 bolt also has problems. Locking lugs next to the extractor begin to
crack around 6,000 rounds, especially if the rifle is shot on full auto. The
other point of bolt weakness is the cam pin hole. The bolt breaks at the cam pin hole between 6,000 and 10,000 rounds.

Most civilians will never shoot their AR15s enough for any of these problems to develop. However, your students who attend course after course should be inspecting their arms regularly.

Our government, fully aware of the forgoing, has decided to get bids on (can you believe it?) shot counters, so they can know how many rounds have gone through each rifle. This is ridiculous! It is time for a long-overdue change."

/John

10 July 01

On urban rifles from a LEO friend in Wisconsin:

"A couple of our officers recently graduated of the Urban Rifle Course at Thunder Ranch. They both independently made the same observation:

Many of their fellow students showed up with bipods, various battery-operated sights, attached flashlights, lasers, and bewildering sling systems, all attached in miscellaneous ways to their rifles.

WITHOUT EXCEPTION, those people had taken all that junk off their rifle by the morning of the third day. All those gadgets had either broken, fallen off, ran out of juice, or made the rifle so heavy and unwieldily as to render it useless."

Lesson: Don't load up your guns with gimmicky junk. Instead, load up yourself with knowledge, righteousness, and experience. The latter will serve you far better than the former.

/John
Good friend, Giles Stock, made a wonderful and revealing presentation on 223/5.56 rifle chambers. Rifles can feature NATO or SAMMI specification chambers. As a rule, military rifles have NATO chambers, and recreational rifles have SAMMI chambers, but there is some overlap. For example, Ruger's Mini-14 has been made both ways!

NATO chambers have a long lead. SAMMI chambers are tighter and have a short lead. SAMMI chambers are designed for increased accuracy, but will yield dangerously high pressures in guns using military ammunition and/or which are subject to high volume shooting. Under such high pressures, primers will typically blow out backwards, fall down into the trigger mechanism, and cause the rifle to stop working. I've surely seen this on the range.

Bottom line: SAMMI chambers are for the kiddies. Any serious rifle needs a NATO chamber. Robinson Arms rifles come with NATO chambers, as do most of the others, but one needs to check.

Alex Robinson adds:

"If you use a SAMMI chamber in an autoloading rifle, you may overpressure it and blow it up when shooting rapidly. The tighter, shorter lead slows down the bullet substantially as it is trying to leave the case. When rifles are red hot from rapid shooting, the resultant pressures increase dramatically. In these situations, you need to get the bullet out of the case and down the barrel ASAP.

I never suggest using a SAMMI chamber on anything but a bolt action rifle. Anyone who tells you otherwise hasn't shot enough."

He ought to know!

More later.

/John

Regards
John

In God I Trust. Everyone else keep your hands where I can see them!
 
Is this a serious gun, or a play gun? Do you anticipate shooting it a LOT?

Most important question to ask on any project is what you want to do with it. The devil is in the details. If someone is using it as a serious rifle and can’t articulate exactly why they need something other than a NATO chamber, then they should stick with a NATO chamber.

I do disagree with some of the comments that Farnam et al posted though. Some of the conclusions they draw from their experiences are not necessarily correct in my opinion.

B
 
Also, was just reading about the Valmet RK62. What a nice gun. Too bad there isn't a civilian version we could get here. I wonder what the "best" "improved" version of an AK47 is which is available here. I know the AK47 was improved in 1974 into the AK74, but I'm talking minute of arc accuracy and build quality like in the Valmet. Something for a "keeper".

Probably the VEPR.

http://www.ak47.com/

Regards
John

In God I Trust. Everyone else keep your hands where I can see them!
 
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