Steel AR receivers

[TTSX]

I picked up a DPMS steel AR lower yesterday at a gun show. Weighs about 24oz, made in 1998. Didn't know these things existed and I'm assuming there's an upper out there to match? It was the same price as an aluminum model but for the "uniqueness" I couldn't pass it up. Does anyone have knowledge about these? A brief Internet search didn't yield a lot of solid info.

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[Nosferatu]

I vaugely remember them making their first rufles in 450 Bushmaster with those, but I think the uppers were still aluminum.

I don't think anyone knew why they made the lower out of steel except to perhaps to add some weight for recoil mitigation.

Cool find, nonetheless. I certainly haven't seen one.

 

[monkeybutler]

I have some vague recollection of non-bushhamster steel lowers. They were made by [not sure but non-confidence inspiring brand(s) like Olympia or DPMS], so I never looked too hard into them.

 

[TTSX]

I have some vague recollection of non-bushhamster steel lowers. They were made by [not sure but non-confidence inspiring brand(s) like Olympia or DPMS], so I never looked too hard into them.

I double checked, mine is marked DPMS. For whatever reason, that meant bushmaster in my mind. Looks like it's made from a cast iron skillet

 

[Ballardguy]

Seems odd to me. I'd think a steel upper would be more important since it sees more stress.

 

[TTSX]

Seems odd to me. I'd think a steel upper would be more important since it sees more stress.

The upper doesn't see much stress at all to my knowledge, comparatively. The stress on an AR is largely in the bolt/barrel lugs and the very rear of the lower where the "buffer tube" screws in.

 

[Will_White]

The upper doesn't see much stress at all to my knowledge, comparatively. The stress on an AR is largely in the bolt/barrel lugs and the very rear of the lower where the "buffer tube" screws in.

Yeah the majority of the stress is contained in the barrel, the stress points are on the reciever lugs/pin holes and the buffer tower.

If someone does find a steel upper I'd love to know about it, I have ideas for how to DIY one (not good ones but they're ideas) but I'd love to have a color case hardened reciever set.

 

[Stomper]

I picked up a DPMS steel AR lower yesterday at a gun show. Weighs about 24oz, made in 1998. Didn't know these things existed and I'm assuming there's an upper out there to match? It was the same price as an aluminum model but for the "uniqueness" I couldn't pass it up. Does anyone have knowledge about these? A brief Internet search didn't yield a lot of solid info.

I double checked, mine is marked DPMS. For whatever reason, that meant bushmaster in my mind. Looks like it's made from a cast iron skillet

 

[TTSX]

 

[Ballardguy]

The upper doesn't see much stress at all to my knowledge, comparatively. The stress on an AR is largely in the bolt/barrel lugs and the very rear of the lower where the "buffer tube" screws in.

Barrels, chambers, and breech bolts are always what sees the most pressure, and all those are in the upper. If a guy could figure a way to drop the firing pin with the whole lower removed you wouldn't even need the lower attached. Afraid I'll disagree with anyone who says there's more pressure on the lowers of an AR.

 

[TTSX]

Barrels, chambers, and breech bolts are always what sees the most pressure, and all those are in the upper. If a guy could figure a way to drop the firing pin with the whole lower removed you wouldn't even need the lower attached. Afraid I'll disagree with anyone who says there's more pressure on the lowers of an AR.

Weird hill to die on, but ok

 

[Will_White]

Barrels, chambers, and breech bolts are always what sees the most pressure, and all those are in the upper. If a guy could figure a way to drop the firing pin with the whole lower removed you wouldn't even need the lower attached. Afraid I'll disagree with anyone who says there's more pressure on the lowers of an AR.

Not pressure, stress, nearly all of the pressure is borne by the bolt, barrel and barrel extension. you can make a jig out of corn starch (pla) that holds the bolt locked and hits the firing pin and it will be just fine. The recoil force, and where things break, are the reciever lugs (upper and lower) and the buffer tower. The grip attachment is another weak point but that's mostly from misuse.

 

[VinnieBoomBah]

Weird hill to die on, but ok

Been a lot of weird hills going around lately

 

[Ballardguy]

Weird hill to die on, but ok

Take a look at any parts diagram blow up. The lower houses the trigger and hammer assembly, and the magazine well. Nothing else. The buffer tube gets a shot of gas to work the breech bolt, but that's very little pressure to do so. The gas tube under the barrel blows the bolt back and that pushes the buffer tube back. The gas tube also is part of the upper assembly, which sees all the chamber pressure, gas tube pressure, and more.

 

[Stomper]

View attachment 2272104

Fine, but I'd advise not to put your head between her knees.....

 

[Ballardguy]

Been a lot of weird hills going around lately

You might consider looking into some of those "hills" before calling them weird. Sounds like some people who own AR type rifles don't understand how they function.

 

[Will_White]

You might consider looking into some of those "hills" before calling them weird. Sounds like some people who own AR type rifles don't understand how they function.

again we're talking stress, not pressure.

 

[VinnieBoomBah]

You might consider looking into some of those "hills" before calling them weird. Sounds like some people who own AR type rifles don't understand how they function.

You think?

The gas tube under the barrel

 

[TTSX]

You might consider looking into some of those "hills" before calling them weird. Sounds like some people who own AR type rifles don't understand how they function.

Such as the man in your mirror?

 

[TTSX]

Take a look at any parts diagram blow up. The lower houses the trigger and hammer assembly, and the magazine well. Nothing else. The buffer tube gets a shot of gas to work the breech bolt, but that's very little pressure to do so. The gas tube under the barrel blows the bolt back and that pushes the buffer tube back. The gas tube also is part of the upper assembly, which sees all the chamber pressure, gas tube pressure, and more.

As far as ARs go, this is nearly all bad info. Looks like you're talking about a totally different rifle