ammo flying off the shelf

[josephmrtn]

Verm, find me one example where this actually occured? They were worried how the extra casing pushed up againsn't the rifling could cause a catasptopic failure because of the increased pressure even though the tolerances of rifles are well with in the capability of handling it. The problem you sometimes see is a blown primer that scolds the bolt face and leaves pitting

if your reloading you could trim the case....

[ants]

So the case is longer on the 5.56?

Edited January 6, 2013 by ants

[josephmrtn]

Verm, find me one example where this actually occured? They were worried how the extra casing pushed up againsn't the rifling could cause a catasptopic failure because of the increased pressure even though the tolerances of rifles are well with in the capability of handling it. The problem you sometimes see is a blown primer that scolds the bolt face and leaves pitting

i guess...... so ^^^he^^^ says

EDIT copied off wiki:

5.56x45 NATO Case length 44.70 mm (1.760 in)

.223 Remington Case length 1.76 in (45 mm)

they "seem" the same... anyone help me out on this one

EDIT again

The 5.56 mm NATO chambering, known as a NATO or mil-spec chamber, has a longer leade, which is the distance between the mouth of the cartridge and the point at which the rifling engages the bullet. The .223 Remington chambering, known as SAAMI chamber, is allowed to have a shorter leade, and is only required to be proof tested to the lower SAAMI chamber pressure. To address these issues, various proprietary chambers exist, such as the Wylde chamber (Rock River Arms)^[33] or the ArmaLite chamber, which are designed to handle both 5.56 mm NATO and .223 Remington equally well. The dimensions and leade of the .223 Remington minimum C.I.P. chamber also differ from the 5.56 mm NATO chamber specification.

Using commercial .223 Remington cartridges in a 5.56 mm NATO chambered rifle should work reliably, but generally will not be as accurate as when fired from a .223 Remington chambered gun due to the longer leade.^[34] Using 5.56 mm NATO mil-spec cartridges (such as the M855) in a .223 Remington chambered rifle can lead to excessive wear and stress on the rifle and even be unsafe, and SAAMI recommends against the practice.^[35][36] Some commercial rifles marked as ".223 Remington" are in fact suited for 5.56 mm NATO, such as many commercial AR-15 variants and the Ruger Mini-14 (marked ".223 cal"), but the manufacturer should always be consulted to verify that this is acceptable before attempting it, and signs of excessive pressure (such as flattening or gas staining of the primers) should be looked for in the initial testing with 5.56 mm NATO ammunition.^[37]

ALSO

In more practical terms, as of 2010 most AR-15 parts suppliers engineer their complete upper assemblies (not to be confused with stripped uppers where the barrel is not included) to support both calibers in order to protect their customers from injuries and to protect their businesses from resultant litigation.

Edited January 6, 2013 by josephmrtn

[covert]

Regarding the 7.62x51 vs .308 and 5.56x45 vs .223 discussions here is an email exchange I had in 2005 with Federal Cartridges. The names have been removed to protect the innocent.

From: Prodserv [mailto:[email protected]]

Sent: Friday, October 07, 2005 9:52 AM

To: Me

Subject: RE: Ammo Inquiry from Federal Web Site

Greetings

The two are military designations which mean how/where the military tests pressures etc is different.Case thickness can also be an issue as well as type of primers etc.

The 308 & 7.62x51 are quite interchangeable without an issue.

In 5.56 SAAMI reccommends to not use 5.56 in a .223 chamber as it might be tighter.You can use .223 in a 5.56 chamber.

From: Me

Sent: Thursday, October 06, 2005 9:34 PM

To: Prodserv

Subject: Ammo Inquiry from Federal Web Site

Dear Sir or Madam:

Could you please settle an argument for me? Is there ANY appreciable difference between 7.62x51 NATO and .308 Winchester? I would also like the same question answered about 5.56x45 and .223 Remington. I have heard so many different opinions from people on headspace, pressures, OAL, etc. that I don’t know who to believe, if anyone. I figured if anyone could give me a credible answer it’d be the people who do it for a living!

Thank you,

"Me"

p.s. Please start making .450 Marlin soon. Nothing against Hornady, it’s just that I have always liked Federal ammo.

Edited January 6, 2013 by covert

[silent death]

I found a few boxes on line for my mini 30 {7.62X39} but man it sure was hard as no one has them in stock . Nothing local at all around here. Guys are really ripping fellow shooters off on line for guns, the prices are double what they should be. Its a shame all around.

walmart in glenmont has 7.62 just figured id give you a heads up they has 6 or 7 boxes on the shelf as of yesterday

[sbuff]

FMJ or hunting rounds ? thanks for the heads up.

[Guns&ReligionCop]

If you have a match chamber where the case sits against the rifling you wouldn't be able to close the bolt with out forcing it at which point you should realize theres a problem but most factory rifles don't come with match chambers that bullet just starts to seat in the rifling. If you reload you trim the brass anyway so there is absloutely no difference