General question poly or aluminum lower for the wimpy .556?
I've always wondered if it really matters.
I've always wondered if it really matters.
Poly or Alum?
- Thread starter medium187mph
- Start date
For firing, it doesn't matter.
For rough service and dropping or what some may call abuse, forged aluminum.
I've seen cast aluminum lowers break at the buffer tube when falling over.
For rough service and dropping or what some may call abuse, forged aluminum.
I've seen cast aluminum lowers break at the buffer tube when falling over.
I've read the forged vs. cast arguments too many times.
I have designed repairs for many airplanes and I will tell you that forged only gets a small increase in strength vs. a billet part. Casting has inherent problems that are hard to overcome without a post casting heat treat/stress relief process.
The most important thing for strength, as far as aluminum is concerned, its the composition of the material. 6061-T6 is the crap hole of aluminum material. 7075-T6 is freaking awesome- literally double the yield strength of the 6061 stuff. The "T-number" after the first four digits refers to the heat treat of the material. -O "plain" is the worst. -T43/-T6/-T63 all vary in their properties as far as the material is concerned.
I have designed repairs for many airplanes and I will tell you that forged only gets a small increase in strength vs. a billet part. Casting has inherent problems that are hard to overcome without a post casting heat treat/stress relief process.
The most important thing for strength, as far as aluminum is concerned, its the composition of the material. 6061-T6 is the crap hole of aluminum material. 7075-T6 is freaking awesome- literally double the yield strength of the 6061 stuff. The "T-number" after the first four digits refers to the heat treat of the material. -O "plain" is the worst. -T43/-T6/-T63 all vary in their properties as far as the material is concerned.
A .556MM rifle would be very wimpy indeed...if it existed.
Or were you talking about a .556 inch caliber beast? Probably not a wimp at all!
For 5.56MM rifles, I prefer the strength of metal to prevent wear and slop at the pin holes.
where on earth are you guys finding cast aluminum lowers and not forged or billet?
Honestly, the new plastic lowers are pretty damn durable, they just dont have the resale value because people want the metal because they've always used the metal.
If going polymer, pick up a TNarms lower. they even make AR10 lowers.
Honestly, the new plastic lowers are pretty damn durable, they just dont have the resale value because people want the metal because they've always used the metal.
If going polymer, pick up a TNarms lower. they even make AR10 lowers.
Not really. The one's I've seen are actually more $$$
If they were $15-20 I'd try one, otherwise I'll pass.
Absolutely no reason to buy a poly AR lower with the current price of forged ones so low.
I have had one and it sucked ass. Fit was way to tight. Very rough and just didnt seem very robust.
...and then there is this from a couple years ago:
http://www.ar15.com/forums/t_1_5/16...ass_Lowers___Anyone_else_buy_one___PICS_.html
I have had one and it sucked ass. Fit was way to tight. Very rough and just didnt seem very robust.
...and then there is this from a couple years ago:
http://www.ar15.com/forums/t_1_5/16...ass_Lowers___Anyone_else_buy_one___PICS_.html
I had a poly at one point. I think I purchased a complete new frontier for $109 back around the same time a LRB forged lower was the cheapest option at $79. It even had a poly trigger and hammer. I mated it to a CMMG 22 upper but never shot it much. The trigger was actually smoother most milspec trigger groups.
I sold it after sandy hook for $350.
I sold it after sandy hook for $350.