223 remington ammo question

[agent00]

I am thinking of getting oberland arms ar 15 for target/fun shooting and for self defense.

The following question is more academical nature but I am still curious about it. Are the common commercially available 55 grain fmj bullets built the same way as the old military m193 rounds and then to behave the same when hitting a soft target (tumbling and fragmenting) In that case they maybe would be a viable option for a short range self defense scenario??

In the end I will gut some 55 grain jhp or jsp anyway and use the fmj just for the target/fun shooting.

At the end of the day a potential self defense situation is way too serious to leave anything to chance.

 

[murphydog]

Others will correct me if I am wrong (they always have in the past ), but I believe it was the combination of 55 gr bullets and the slower (1:12) barrel twist that tended to cause instability. The 1:7 to 1:9 modern barrels are not really known to do this in general, although depending on the exact gun you'll sometimes read it does.

In the scenario you describe (and good for the Austrian government to allow you to have a rifle for defense), using a expanding bullet that may fragment or penetrate less is a good idea.

 

[Nevada Ed]

A little 55gr will do great in a 1:14 barrel twist.
a 60 gr starts to wobble a little at 200 yards......

A 70 gr needs a 1:9 twist for best long distance shooting but will work at 25 yards
for SD work, if needed.

Depends on what you are doing with the bullet weights.

 

[HamHands]

There are much better choices for self defense than XM193 in either past or current loadings. Most AR barrels are 1/7 twist, lots are 1/8, and 1/9 is a very common twist rate. You want a grain loading of 64 or greater grains and preferably more... Like Gold Dot's 75 grain "Open-Tip-Match" or OTM's offerings, Hornady's 75 grain OTM's, IMI's heavy Mark 318 loads, or Privi Partizans OTM's in 69 or 75 grain loadings all expand the distance to fragmenting parameters. That said, the most destructive load I've ever seen fired into 20% Ballistic Gelatin was a 64 grain XM856 "Tracer" ball ammo. That particular bullet is so long in length that it tends to have a much greater "Yaw Effect" and takes much longer to stabilize than shorter and even heavier bullets do. Go to "BrassFetcher's" website I've linked below and look at the slow motion frame destruction of what that long pill does to ordinance gelatin for academic purposes. The second most destructive pills are Hornady's "TAP" 75 grain OTM and IMI's Mk 318 OTM's.

[ame="https://www.youtube.com/watch?v=-u5Uk0ae4p4"]https://www.youtube.com/watch?v=-u5Uk0ae4p4[/ame]

 

[agent00]

Thanks a lot for the replies. They were very helpful.

@murphydog Although it is quite complicated you can get a rifle in Austria. Besides the paperwork, there are not many semi Auto Rifles available. The semi Auto Rifles sold in Austria are required to be custom made, so the parts are not interchangeable with Military Rifles.

Luckily Oberland arms Overs such a custom ar type rilfe. The only other Rifles available would be a modified sig 550 and the styr aug z, the civilian Version of the Styr Aug, the Service rifle of our army.

Although I am familiar with the aug thanks to my Military Service I am more interested in owning a Ar 15 type rifle.


@all It seems that Oberland arms Ar 15 has a Barrel Twist of 1/8.

Would it be suitable for the heavier bullets or is it better to go just with lighter bullets?

 

[Engineer1911]

In a self defense situation, the target will not know the difference between a 50 grain or 75 grain bullet. In either case the pain will be significant.

 

[murphydog]

A 1:8 twist should be fine for heavier bullets.

 

[SMSgt]

My 1-12 twist .223 Rem 788 shoots wonderfully with 55-grain bullets. Faster twist rates are intended for heavier (longer actually) bullets. Once you go beyond 62-grain bullets, a 1-8 or 1-7 twist is better.

 

[alwslate]

If you buy true 5.56 M193 55 gr FMJ rather than .223 ammo the bullet
will tumble and fragment at SD distance regardless of the rate of twist
of the barrel it is fired in. Buy the rifle you want or can and don't worry
about effectiveness.