5.45 Bolt Question

[TerryW]

Ok, so I bought a dedicated complete 5.45 upper from Smith and Wesson. Took it out yesterday and could not get it into battery. I noticed the bolt wasn't fully seating. So I pulled the bolt out of the carrier and grabbed a few 556 rounds and a few 545 rounds. The 556 rounds would seat completely flat inside the bolt. The 545 rounds wouldn't. The "lip"(the part the extractor grabs to throw the hull out) of the 545 cartridge would not go in at all, it's bigger in diameter. Is there a 'special' bolt or do I have several thousand rounds of 545 I can't shoot because it's not made for a "AR" style 545 upper?

I am out of ideas. I have pulled every bolt I own out of their hosts and can't find any that will accept the 545 cartridge.

Thanks for your help...

[R1100R]

I have a 5.45 upper from S&W also. I have had no issues. I would call S&W. There warranty is second to none.

The bolts on a 5.45 are different than a 5.56. You could also take the extractor apart and make sure it is clean and has the proper spring and insert in it.

Edited June 12, 2011 by R1100R

[Karnage]

The bolts on a 5.45 are different than a 5.56.

I also have a 5.45 upper from S&W also. I also have had no issues.

You may have inadvertently received a 5.56 bolt instead of a 5.45 bolt. If it is a 5.45 bolt it will have 5.45 x 39 stamped on it. A 5.45 cartridge should seat completely in the bolt. If your bolt does not have any markings it is likely a 5.56 bolt.

Edited June 12, 2011 by Karnage

[Dolomite_supafly]

I would also verify the barrel is 5.45x39 as well.

Dolomite

[TerryW]

Thanks guys for all the help. Right after I got the 545 I painted the flash hider so I would put the wrong ammo in it. Plus, I have gone over and over every bolt I own and I don't have one that is marked 5.45.

OK, at least I'm not crazy.

Karnage, My 556's will seat like that but the 545's won't. That's exactly the picture I needed.

Thank you soooo much. You guys take the rest of the day off with pay! LOL

[Dolomite_supafly]

Thanks guys for all the help.

Thank you soooo much. You guys take the rest of the day off with pay! LOL

I've been off all day.

Actually not, been at the doctors. On my way home now and will be in bed for a few days now.

Dolomite

[TerryW]

Dolomite, I hope everything is going to be ok.

I certainly don't like being at the doctors......

Tw

[TnShooter83]

Ok, I gotta ask.

But all the affordable 5.45 ammo I've found is corrosive.

And the AR being a "DI" gas system. I'm not sure I'm willing to clean it that good every time I shoot it.

Are S&W Bolt Carriers Group internals chromed?

Maybe I would if it were a piston system.

But by that time, I'm at AK prices.

Take no offence, I'm not downing your system.

I guess, I admitting the being to lazy to have to do a full strip down after every shooting.

Unless I pay more (about the same price as 5.56) for noncorrosive ammo.

[R1100R]

I have shot a lot of surplus ammo through mine. The S &W is chrome lined. The only step you add is some water. I then blow out mine with some air then clean as normal. I don't even take the hand guards off. I use to clean my black powder rifle in the bath tub. Hot soap and water.

I have Guy's I know that shoot these uppers on a full auto lower. They have shot the barrel out before any corrosion has set in.