5.45 AR

AR/M4 AR General Discussion
1

This is a quote from member “Hebrew Battle Rifle” of the Falfiles…

LINK

SUCCESS!!! Well, it is running anyway. I was going to build it as a mid length, but Rock River Arms* is not being co-operative, so since I already had the parts for it, I built it as a carbine.

I got the barrel** and all of the other parts that I had to make machined and as blind luck would have it, they all fit. I got the upper assembled and attached to my lower. My 30 rd AR mags that I bought from Brownells will hold 29 rounds of 545 just like it was made for them. YEAH!

I measured the existing gas port and the closest reading that I could get was .076.( I was using number drill shanks as feeler gauges) Since I was setting the gas block back about 4 inches closer to the chamber, I deducted 25% (this is a SWAG figure)from the measurement and the closest reamer that I had to that figure was .059.

With this gas port size, the cartridges would fire and eject, but the bolt would not strip a new round from the mag. I opened the port up to .076 and I got about 50% eject/feed. So, I opened the port to .082 and out of 29 rounds, I had one Failure to extract about half way through the mag. A quick pull on the CH and I ran through the rest of the mag in about 10 seconds or so. So, I am going to run it like this for a while and see things loosen up a bit.

Actually, for a training only rifle, having 1 round out of 29 Fail to extract is not a bad thing. Quick reaction drills would be a regular thing. Regular enough that they would become automatic I suspect. The extractor is not modified and is for 223. It has not failed to grip the rim nor has it failed to pull an empty from the chamber. I set the bolt face back about .010 so that the extractor would fully seat every time. So far, it has.

I am not sure why the port needed to be bigger when the gas port is closer to the chamber than the original. It may have to do with the volume of gas needed to operate the DI gas system VS a gas piston. It could also be that my measurment is off and the FSB is partially obstructing the gas port. I just thought of that so I will give that look tommorow.
I am planning to do some accuracy tests tomorrow. I’ll post the results if I do.

Some of you may be thinking, Well big fat hairy deal. Who Gives a Fat Rats Eyelash about shooting 545 ammo. It is corrosive and made by communists.
Well, here are a couple of reasons that it is a big fat hairy deal. While the prices of our beloved calibers of ammo are currently racing each other into freakin orbit, the price of 545 ammo is insanely cheap. The former Warsaw Pact countries are dumping their stores of this caliber on our shores and it is raining 545 ammo. While the current ammo market is a barren desert, the flood of 545 ammo is like manna from GOD.

The ballistics are comparible to 223 and the cases are made of steel. So, when my range time is o’r, I quick sweep with a speaker magnet on a string and my mess is cleaned up. And all of this for the silly sum of .11c per round delivered. Um, yeah, I consider that a big fat hairy deal.

  • Rock River Arms has been very disappointing. This is the first time that I have attempted to do business with them and I am underwhelmed so far.

** I bought a NIW AK74 barrel from K-VAR out of Las Vegas NV. It is chrome lined bore and chamber.

2

Here is someone claiming to sell a S&W M&P with 5.45x39 upper

http://www.militarygunsupply.com/shop2/index.php?main_page=product_info&cPath=37&products_id=381

I have no clue on this except for a posting in a different forum advertising.

Sounds intriguing. I would like to get a 5.45x39 AR barrel as I have an MGI upper and would like to try it out…

Chad

3

I recall having read that particular website didn’t have the best rep. I’d be a bit leery of ordering from them. If Grant get get me one of these, I’d buy it from him.

That ad claims 27 rd capacity in a standard AR mag. I can’t get more than 19 rds in a regular AR mag (green follower, aluminum body) nor more than 10 rds in a PMag. In the PMag the rds nosedive so much that I have to fish them out of the mag, no way they would feed.

I am all over this when it comes out, but part of the deal has to be a relatively easy changeover in magazines. I don’t know if a follower swap will do the trick though, because of the different taper of the 5.45 case vs a 5.56 case.

4

I’d be all over a quality 5.45 upper (not some Olympic POS)…would be great for inexpensive training!

5

I would like one but the only bad thing is I would have to clean my weapon soon after shooting it with surplus 5.45.:wink:

6

I’ve purchased from Military Gun Supply and haven’t had any problems. However, I can drive to there store and pick thru what they have. Have found numerous AKs that had noticeably canted front sights as well as rear sight blocks.

7

YOu cant blame that on them if they are simply retailing weapons made by Century etc.

8

I don’t blame them. However, I will check them in person before I buy from them because they either do not check or don’t care.