5.45 x 39 AR

[Malysh]

Malysh,

Good information. Thanks for taking the time to post it!

UPDATE...

Took the 5.45 upper to the local shooting range...a State owned Quarry.

Mounted the upper to my old Colt 7.62x39 lower which has performed flawlessly with both the original upper and a 2nd Bushy in 5.56 mm.

The two C-Products 30 rd mags performed flawlessly. Never an issue.

Took me about 5 three round groups at 50 yds to get it sighted in. The MWI BUIS rear sight is new to me and I had no idea what each click equated to. Also had to drop the groups and of course forget my frt sight adjuster...so a little more time fiddling around.

In the end I was pleasingly surprised by this cartridge. Plenty accurate with 1" groups at 50 yds when it all went right. My worse groups were 2-3 inches and each had a flyer that was my fault. I shot up about 240 rds, swabbed the barrel and checked the bolt, etc for lube and shot my last group at 100 yds and it was 5 shots into 3". Nicely centered on the bull. I'm sure optics would shrink it to 2" or maybe less.

I did notice the recoil is a bit less than a 5.56 and compared to my SIG 556 the REPORT seemed to be a bit quieter.

DID have several FTF's though due to the hammer not setting off the hard primers. The upper came with a S&W supplied stronger hammer spring so I'll install that and I'd wager it will take care of that issue.

After 300 rds the gun was dirty...but not excessively so. Had zero extraction problems or any signs of gunk in the chamber from the lacquered cases.

For fifteen cents a rd this is a fun plinker. So far it's all GOOD.

FN in MT

Frank, I'm happy to learn you are pleased with this set up and caliber!
If I can say this without raising any ire or anger - I noticed you are from Montana( a great state!).
I think somebody mentioned that they had experienced no corrossion problems even after deliberately not cleaning the rifle for a few days after shooting it with corrosive primer ammo. Although I realize every day can have different humidity and dew point figures, I think it would be best to clean these rifles after using corrossive mil ball ammo as soon as possible and not leaving them to later.
I am guessing that many areas of Montana historically enjoy lower average humidity than where I live, or that the elevation might make a difference?
I live in central PA. about 2 hrs. from the closest ocean beaches and our humidity levels are over 50% easily most days of the year.
I would clean an AR or an AK after I shot it with corrossive ammo as soon as I could, living where I do. High humidity levels will hasten rusting and act as a catalyst in conjunction with using corrossive primer ammo.

Also, if you were using military ball(corrossive) ammo - military ammo has harder primers than civilian ammo. As you have surmised you may need to change the hammer spring to something stronger if you start get a lot of non ignitions. I cannot tell you if 5.45 primers are harder to ignite than 5.56 ball ammo but I am sure if you ran an M-60 you have experience with mil spec ammo and cleaning proceedures.
Uncle Sam gave me one for two years. My M.O.S. was 0331.......

 

[Frank237]

Corrosive ammo....

Our humidity does generally run fairly LOW. And I agree (being the cleanliness FREAK that I am) one SHOULD really clean SOONER versus LATER. But when it comes to the AR's I seldom do as thorough a cleaning as Uncle Sugar taught us to. Maybe it's my post Service era way to rebel a little??

I seldom go more than a few days in summer (RH in single digits or maybe 20%) before at least breaking the bolt out, dropping it in soapy hot water, giving it a good cleaning, then blowing it out and setting it in the sun for an hour or so. The barrel will get a good scrubbing as well , then blown out and swabbed with a lightly oiled patch. Speaking about my Colt Sporter after firing Soviet or Chinese 7.62x39. My other uppers that fire US ammo WILL get set aside for weeks and months and I have never seen any rust or corrosion. I shoot far too many skunks, rattlers, etc to take the time to clean after each and every firing.

I've worked on hunting rifles out here that have NEVER been cleaned. The bore will have a dry, grey coating. I'll set them in the cleaning cradle, soak them down well and in a few days of soakings and scrubbings, they will come out clean. Most of the problem will be jacket fouling, more than powder fouling or carbon.

Seldom have I ever seen RUST in a bore, same for the outside of most rifles. Given a minor amount of care the low RH takes care of any rust.

I grew up in New Jersey. I've seen exposed metal show rust.....overnight. And when I worked for the PD in Jersey; I took out my blued M-19 at the end of each shift and wiped it down with a silicone rag. Otherwise you were in for an UGLY surprise when you took it out for inspection each quarter!!

FN in MT

 

[Malysh]

Good post, Frank.

I know what you mean about humidity NJ. I was a probation investigator for one of the northern counties in the mid 70s.

I also agree with you that a rigorous cleaning is not always necessary under all conditions. If the relative humidity usually doesn't hit 20% where are you have nothing to worry about as far as it affecting your firearms adversely.

The Green Machine reinforced firearms cleaning to me, that's for sure. I feel guilty if I leave a firearm dirty for 1 or 2 days after firing, even if it has no bad effects on the weapon.
With the hard chrome barrel extensions, barrels, bolt carriers and some bolts(ie: Colt Mod 601, early XM series also) on AR-15s, you have to work hard to ruin them. Likewise, excepting Yugoslavian AKs, all the rest have chrome barrels and chambers. Always did.

 

[dezir]

cleaning

I'm glad to get all this informantion about the corrosive ammo and cleaning. I live in miami which has a high humidity most of the time. Forty percent humidity would be a low number for us.

I do use black powder and clean them with soap and water but I have'nt cleaned my M&P 5.45 any different than any of my other rifles. I only use solvent on it and no water at all. I even let it sit for a few days and there are'nt any signs of corrosion at all.

I have an old AK47 that has shot only the worst ammo I can find and that one has no problems with corrosion either.

Might it be better for me to switch to soap and water when I use corrosive primer ammo?