5.45x39 in an AR...

[Jay Cunningham]

I had to use the heavy hammer spring that came with my S&W upper. I tried without and it wouldn't detonate primers 80% of the time. With the heavy spring, no issues but the trigger is pretty stiff. Certainly not unworkable though.

[Chemsoldier]

Where are you seeing 5.45 for sale? My previous source sold out a month ago.

[Jay Cunningham]

Its available here and there.

http://www.ammunitiontogo.com/index....litary-surplus

[LittleLebowski]

Now accepting heckling and jeering..... Seriously, lemme know what I missed or screwed up.

http://rationalgun.blogspot.com/2013...5-article.html

[Kyle Reese]

Great article. I personally witnessed how accurate LL's 5.45mm AR was at Defoor's Carbine class at USTC in April of 2011. The guns are accurate with Soviet ammo, given the end user does his/her part.

[Jay Cunningham]

Nice article.

I would be wary of anyone jumping to the conclusion that they have a "bad" or "shot-out" barrel if they see rounds hitting sideways (keyholing). I believe it's a characteristic of the 5.45mm round, and is not very predictable.

My best guess is that *within a certain lot of ammo* you may have some that will have an early shift of the bullet internals. I believe this leads to 5.45 KHing, though I'm sure a shot-out barrel could contribute. One question: what was long-range accuracy like at the 12,000 round mark?

In regards to magazines, I personally replaced the weak, short springs with cut-down AK-74 mag springs. This has increased reliability. No I did not cannibalize actual AK-74 mags, I contacted a vendor and they sent me some springs.

[LittleLebowski]

Nice article.

I would be wary of anyone jumping to the conclusion that they have a "bad" or "shot-out" barrel if they see rounds hitting sideways (keyholing). I believe it's a characteristic of the 5.45mm round, and is not very predictable.

My best guess is that *within a certain lot of ammo* you may have some that will have an early shift of the bullet internals. I believe this leads to 5.45 KHing, though I'm sure a shot-out barrel could contribute. One question: what was long-range accuracy like at the 12,000 round mark?

In regards to magazines, I personally replaced the weak, short springs with cut-down AK-74 mag springs. This has increased reliability. No I did not cannibalize actual AK-74 mags, I contacted a vendor and they sent me some springs.

Good point. I'll edit it to point out that random keyholing can happen but mine was absolutely indicative of a shot out barrel. I tried three different types of ammo after I first noticed the keyholing (at a SoVA VMI-MO range day, no less).

I noticed no degradation in "long range" (300 yards and in due to my local geography) before the barrel got worn out. This was on torso sized targets; at least one forum member (keydet08) has shot next to me when I was using my 5.45 at 300 yards.

[Jay Cunningham]

Did you use the Hornady ammo, or did you use three different types with the "air pocket"?

[LittleLebowski]

Did you use the Hornady ammo, or did you use three different types with the "air pocket"?

Wolf, Hornady, and a different lot of Sov surp. The rounds spinning sideways hit the dirt in a most impressive manner

[LittleLebowski]

Great article. I personally witnessed how accurate LL's 5.45mm AR was at Defoor's Carbine class at USTC in April of 2011. The guns are accurate with Soviet ammo, given the end user does his/her part.

Aye but I believe your KAC SR15 had a slight edge in accuracy. That was a good class.