OK, This may sound like a dumb question and maybe it is.
But I was cleaning my Sig and my XD, one has a forged alloy frame, the other a polymer frame.

I had them stripped and had the polymer frame in one hand and the alloy in the other.

To my surprise the polymer frame was not lighter. It should not be stronger.  They are both corrosion and heat resistant.


So what's the big deal with polymer? What are the advantages if not weight and strength?

If it's just because polymer is trendy and cheaper to make, that's not enough, because the cost savings are obviously not passed on the consumer, and I am not into trends. I like my XD, but not any better than my Sigs.

Not trying to start a fight, really would like to know what the deal is.

Please help me understand why I should like a polymer framed gun over an alloy framed one.

beretta just came out with a polymer framed 92 called the 90two.... it's a whopping 1 ounce lighter unloaded than a regular 92.  It features modular grips and some updated styling, but I see no real improvement over my regular old M9.....


I'm with you.... i dont see a benefit to polymer most of the time

The polymer is actually stronger than alloy. Alloy, while strong, can be quite brittle.  A blow that could crack the alloy wouldn't damage the polymer. Generally, with an alloy frame pistol, the frame is the first thing to go. The stronger steel slide often causes cracking at stress points in the alloy frame where the two parts contact. Even steel frame pistol are more likely to crack than polymer which has some flex to it. Think about some of the GLOCKs that have over 100,000 rounds on them, some even far more than that. Some manufacturer's list the life of thier alloy frames at 30,000 rounds.

Polymer pistols also do not take on the extreme tempatures of their environment like metal frames.

Polymer can also be formed into shapes and designs that would be much more difficult or impossible with alloy.

That is all I can think of right now.

It is indeed a cost issue.  The production rate on polymer is also much higher.  Cavalry arms is capable of producing 3K lowers with fixed stocks in one day.  Colt can't do that.  Similar arguments can be made in the old Glock versus 1911 debate.

A machined metal frame such as a SIG or 1911 will start as a block of material, and probably two thirds of it will be removed in about 12 hours of machining in several setups (this means that 2/3 of the material purchased will be scrapped).  It then has to be deburred, surface prepped and finished (annodized, parked, chromed, etc.)  

A polymer frame such as an XD or Glock can be injection molded in about 90 seconds.  After the flashing is removed (similar to deburring) it goes to final assembly.  Hardly any material is wasted.  This gives polymer framed guns a tremendous cost advantage.

Furthermore, polymer is more corrosion resistant than AL or steel.  Saltwater will corrode AL and steel.

put both guns on the ground and run em over erpeatedly. which 1 ya think is less likely to be bent or damaged?

injection molding is cheap

Molded plastic frames are WAY cheaper than machined metal frames.

There is no other reason for them.

OF COURSE the savings aren't passed on to the consumer! It's called PROFIT!

Glock realized there was a product with an expected retail price of $500 or so, realized he could manufacture it for a few hundred dollars less than everyone else, and pocket the rest.

It's called smart business.

Quoted: injection molding is cheap

Sure, once the $100,000 mold is paid off.

Quoted: Molded plastic frames are WAY cheaper than machined metal frames. There is no other reason for them. OF COURSE the savings aren't passed on to the consumer! It's called PROFIT! Glock realized there was a product with an expected retail price of $500 or so, realized he could manufacture it for a few hundred dollars less than everyone else, and pocket the rest. It's called smart business.

+1

polymer being just as durable, lighter, more/less recoiling sensitive, etc is all just advertising to push the cheaper to make product

Quoted: Quoted: injection molding is cheap Sure, once the $100,000 mold is paid off.

I think Glock and the other companies sold enough plastic guns to justify it

Quoted: Quoted: Molded plastic frames are WAY cheaper than machined metal frames. There is no other reason for them. OF COURSE the savings aren't passed on to the consumer! It's called PROFIT! Glock realized there was a product with an expected retail price of $500 or so, realized he could manufacture it for a few hundred dollars less than everyone else, and pocket the rest. It's called smart business. +1 polymer being just as durable, lighter, more/less recoiling sensitive, etc is all just advertising to push the cheaper to make product

Try taking an alloy frame and a polymer frame and giving them both a few smacks with a hammer. They alloy frame will crack long before the polymer frame.

Quoted: Quoted: injection molding is cheap Sure, once the $100,000 mold is paid off.

Ditto.

I worked for a company that had $250,000 in a mold and it was not finished yet. Plastic can be better or worse depending on the plastic and the process. Sometimes flex is good and sometimes it is bad (Watch the wings next time you fly). A quality made polymer pistol is as good as a metal framed pistol. Cost is an issue as well and after the mold is paid for the cost for making the product is cheaper. The guys that work at the factories that make them have to eat too. Some plastic parts are cheap though in my opinion. I hated to see Beretta go so so many plastic parts that used to be metal on thier pistols. Plastic guide rods are something I do not like because most of them I have seen are not made that great in my opinion. I will take a Glock over a HiPoint any day. I think Glock, Steyer and the XDs are all great pistols and still have to say a well machined metal pistol is one of the best feeling things you will ever shoot just like a well made wheel gun. It just depends what you want. To say that the poymer framed pistols are the answere for everything is an over statement and to say they are junk because they are polymer is just an uneducated wrong answere. Shoot what you like and enjoy it. If you do not like polymer framed pistols that do not get one. I will say that my metal CZs, 1911s, Sig and Beretta are all more accurate than my polymer framed guns even the Hk USP I had.

Quoted: The polymer is actually stronger than alloy. Alloy, while strong, can be quite brittle.  A blow that could crack the alloy wouldn't damage the polymer. Generally, with an alloy frame pistol, the frame is the first thing to go. The stronger steel slide often causes cracking at stress points in the alloy frame where the two parts contact. Even steel frame pistol are more likely to crack than polymer which has some flex to it. Think about some of the GLOCKs that have over 100,000 rounds on them, some even far more than that. Some manufacturer's list the life of thier alloy frames at 30,000 rounds. Polymer pistols also do not take on the extreme tempatures of their environment like metal frames. Polymer can also be formed into shapes and designs that would be much more difficult or impossible with alloy. That is all I can think of right now.

Yep and by using polymer, you avoid the risk of improper heat treating.  Besides, polymer-framed pistols are reinforced with steel inserts inside the frame.  The polymers used are nothing like the ABS and PVC plastics we're all familliar with.  About the only things they have in common are the appearance and the fact that they're not metal.  The different polymers are completely different animals from one another.  

OK, some good responses.

So far the consensus is:

1. Cheaper to make once expensive molds are paid for.
2. Stronger than Forged alloy/aluminum
3. Easier to make difficult shapes
4. Resistant to temperature extremes.

No I would like to create a bit of controversy and challenge #2.
I hear this claimed, but I have yet to see any evidence. Are there any studies of torture tests that shoe this to be the case (Polymer stonger than Forged Aluminum)?

In AR15 variants and the G36 Polymer has consistently shown itself to be weaker. I had an H&K SL8 that cracked the polymer trigger group housing, threads get stripped easier, pin holes enlarged and in the case of some CAV arms lowers, receivers and stocks break(defective units). Even the MagPul M93A had to be reinforced with forged alloy inserts to keep the butt from cracking when used in clearance drills.

I could likely break both with a 5 pound sledgehammer hit in the right place, so that's not really a good argument.

I know there have been many manufacturing issues also. Taurus has a lot of problem with the back end of their polymer frame breaking off under recoil on their early polymer models, so it seems the process must be done so to have the same strength as a forged alloy frame.

I suppose what I am saying is is there and empirical (concrete) evidence or test results showing that Polymer frames are in fact stronger, or is all the evidence just anecdotal.

BigBore's test of running over his Glock with a car tire is impressive, but I have seen the same done with Steel/alloy pistols and survive just fine. I have seen anecdotal evidence of Sig alloy frames from range rental guns lasting 250,000 rounds until the rails fell off, the frame never failed. So you can argue this both ways.

So where's the beef? If you say polymer is stronger than say 7075 forged aircraft grade aluminium, where is the evidence of this?

Thanks.

Cav Arms .45 lower cracks in half

Quoted: OK, some good responses. So far the consensus is: 1. Cheaper to make once expensive molds are paid for. 2. Stronger than Forged alloy/aluminum 3. Easier to make difficult shapes 4. Resistant to temperature extremes. No I would like to create a bit of controversy and challenge #2. I hear this claimed, but I have yet to see any evidence. Are there any studies of torture tests that shoe this to be the case (Polymer stonger than Forged Aluminum)? In AR15 variants and the G36 Polymer has consistently shown itself to be weaker. I had an H&K SL8 that cracked the polymer trigger group housing, threads get stripped easier, pin holes enlarged and in the case of some CAV arms lowers, receivers and stocks break(defective units). Even the MagPul M93A had to be reinforced with forged alloy inserts to keep the butt from cracking when used in clearance drills. I could likely break both with a 5 pound sledgehammer hit in the right place, so that's not really a good argument. I know there have been many manufacturing issues also. Taurus has a lot of problem with the back end of their polymer frame breaking off under recoil on their early polymer models, so it seems the process must be done so to have the same strength as a forged alloy frame. I suppose what I am saying is is there and empirical (concrete) evidence or test results showing that Polymer frames are in fact stronger, or is all the evidence just anecdotal. BigBore's test of running over his Glock with a car tire is impressive, but I have seen the same done with Steel/alloy pistols and survive just fine. I have seen anecdotal evidence of Sig alloy frames from range rental guns lasting 250,000 rounds until the rails fell off, the frame never failed. So you can argue this both ways. So where's the beef? If you say polymer is stronger than say 7075 forged aircraft grade aluminium, where is the evidence of this? Thanks. Cav Arms .45 lower cracks in half img.photobucket.com/albums/v408/darowden/cavarms.jpg

wow!
Not knowing any details about that it looks like faulty plastic processing or poor design or both.

No.  That cavarms thing was the result of some dumb dumb running .45acp without using a pistol buffer, IIRC.

Quoted: No.  That cavarms thing was the result of some dumb dumb running .45acp without using a pistol buffer, IIRC.

Who runs the wrong ammo........nevermind

Quoted: No.  That cavarms thing was the result of some dumb dumb running .45acp without using a pistol buffer, IIRC.

I think CavArms also admitted there was a defective lot of receivers. They replaced it free of charge with no questions asked. It seems there are many pitfalls in polymer frame/receiver production, and unlike metal, it seems harder to detect flaws in the moldings. Taurus had a similar issue with their Millenium line of pistol frames.

My point is, you rarely see this sort of thing happen with a quality forged aluminum lower.
That's why I wanted hard evidence that polymer is stronger than steel, because I have not seen any that proves this beyond any doubt.

I just don't see it so far.

"OK, some good responses.

So far the consensus is:

1. Cheaper to make once expensive molds are paid for.
2. Stronger than Forged alloy/aluminum
3. Easier to make difficult shapes
4. Resistant to temperature extremes.

No I would like to create a bit of controversy and challenge #2.I hear this claimed, but I have yet to see any evidence. Are there any studies of torture tests that shoe this to be the case (Polymer stonger than Forged Aluminum)?"


In some ways it can be stronger and in other ways it might not be. You have tensil streangth and shear streangth blah blah blah ect. The polymer can withstand some impact better than the alloy for sure and some steel as I said before the ability of the polymer to flex instead of crack or break makes it stronger in some instances at the same time I personaly believe that the flex is why most metal framed guns are more accurate then most of the poymer ones I have shot.  Every one likes to show pictures of polymer pistols that have broken frames and for some reason think that no metal framed pistol has ever came apart. I wish I had some pictures I have seen to post and show. If a casting process is screwed up or heat treatment done wrong or even if something milled from a billet is done wrong it can crack and break especialy if it is real hard. So I am not going to say the polymer is better or worse. If I was shooting a bullseye match I would prefer a tricked out 1911 or a custom CZ 97B(First choice) and when I am camping I prefer my Glock and XD and for home defense and carry I prefer either. This is all of course just my opinion and folks can "Believe it or Not".

I dont think the beretta 901two is polymer framed.

Quoted: I dont think the beretta 901two is polymer framed.

It isn't, just the grips

Quoted: The polymer is actually stronger than alloy. Alloy, while strong, can be quite brittle.  A blow that could crack the alloy wouldn't damage the polymer. Generally, with an alloy frame pistol, the frame is the first thing to go. The stronger steel slide often causes cracking at stress points in the alloy frame where the two parts contact. Even steel frame pistol are more likely to crack than polymer which has some flex to it. Think about some of the GLOCKs that have over 100,000 rounds on them, some even far more than that. Some manufacturer's list the life of thier alloy frames at 30,000 rounds. Polymer pistols also do not take on the extreme tempatures of their environment like metal frames. Polymer can also be formed into shapes and designs that would be much more difficult or impossible with alloy. That is all I can think of right now.

I personally know of first hand, a rental Glock 17 at the now closed Santa Anita Firing Range, Monrovia Calif(10 miles east of Los Angeles) that has gone 500,000 and breaking the slide which was replaced, the gun had 750,000 offical rounds on the clock when the range close.  The word official because the computer system automtically counts the number of rounds shot by each rental gun, because the owner told me that they know for certain that shooters have smuggled in ammo from Wall-Mart etc, so the number of rounds actually shot is much higher.

Quoted: Quoted: The polymer is actually stronger than alloy. Alloy, while strong, can be quite brittle.  A blow that could crack the alloy wouldn't damage the polymer. Generally, with an alloy frame pistol, the frame is the first thing to go. The stronger steel slide often causes cracking at stress points in the alloy frame where the two parts contact. Even steel frame pistol are more likely to crack than polymer which has some flex to it. Think about some of the GLOCKs that have over 100,000 rounds on them, some even far more than that. Some manufacturer's list the life of thier alloy frames at 30,000 rounds. Polymer pistols also do not take on the extreme tempatures of their environment like metal frames. Polymer can also be formed into shapes and designs that would be much more difficult or impossible with alloy. That is all I can think of right now. I personally know of first hand, a rental Glock 17 at the now closed Santa Anita Firing Range, Monrovia Calif(10 miles east of Los Angeles) that has gone 500,000 and breaking the slide which was replaced, the gun had 750,000 offical rounds on the clock when the range close.  The word official because the computer system automtically counts the number of rounds shot by each rental gun, because the owner told me that they know for certain that shooters have smuggled in ammo from Wall-Mart etc, so the number of rounds actually shot is much higher.

DAMN! I would like to see ANY other pistol stand up to that.

Quoted: Quoted: Quoted: The polymer is actually stronger than alloy. Alloy, while strong, can be quite brittle.  A blow that could crack the alloy wouldn't damage the polymer. Generally, with an alloy frame pistol, the frame is the first thing to go. The stronger steel slide often causes cracking at stress points in the alloy frame where the two parts contact. Even steel frame pistol are more likely to crack than polymer which has some flex to it. Think about some of the GLOCKs that have over 100,000 rounds on them, some even far more than that. Some manufacturer's list the life of thier alloy frames at 30,000 rounds. Polymer pistols also do not take on the extreme tempatures of their environment like metal frames. Polymer can also be formed into shapes and designs that would be much more difficult or impossible with alloy. That is all I can think of right now. I personally know of first hand, a rental Glock 17 at the now closed Santa Anita Firing Range, Monrovia Calif(10 miles east of Los Angeles) that has gone 500,000 and breaking the slide which was replaced, the gun had 750,000 offical rounds on the clock when the range close.  The word official because the computer system automtically counts the number of rounds shot by each rental gun, because the owner told me that they know for certain that shooters have smuggled in ammo from Wall-Mart etc, so the number of rounds actually shot is much higher. DAMN! I would like to see ANY other pistol stand up to that.

Still, you wouldn't know unless they were put under the same conditions side by side. That is impressive, though.

Quoted: Quoted: The polymer is actually stronger than alloy. Alloy, while strong, can be quite brittle.  A blow that could crack the alloy wouldn't damage the polymer. Generally, with an alloy frame pistol, the frame is the first thing to go. The stronger steel slide often causes cracking at stress points in the alloy frame where the two parts contact. Even steel frame pistol are more likely to crack than polymer which has some flex to it. Think about some of the GLOCKs that have over 100,000 rounds on them, some even far more than that. Some manufacturer's list the life of thier alloy frames at 30,000 rounds. Polymer pistols also do not take on the extreme tempatures of their environment like metal frames. Polymer can also be formed into shapes and designs that would be much more difficult or impossible with alloy. That is all I can think of right now. I personally know of first hand, a rental Glock 17 at the now closed Santa Anita Firing Range, Monrovia Calif(10 miles east of Los Angeles) that has gone 500,000 and breaking the slide which was replaced, the gun had 750,000 offical rounds on the clock when the range close.  The word official because the computer system automtically counts the number of rounds shot by each rental gun, because the owner told me that they know for certain that shooters have smuggled in ammo from Wall-Mart etc, so the number of rounds actually shot is much higher.

I shot at that range when it was still open and I can vouch for several hundred of those rounds through that pistol! It showed its age, but it functioned just as good as a NIB G17. No accuarcy problems either.

Every material has strengths and weaknesses.  Good engineering requires a designer to use the appropriate material for each application.  In the case of polymer, it can be molded into a near net shape very easily.  It's strong, corrosion resistant, inexpensive, and light.  However, it sucks at wear resistance, so steel frame rails are molded into the frame (steel has excellent wear resistance).  Aluminum is light, easy to machine, and inexpensive (not as cheap as plastic).  Aluminum does not do well in fatigue and it scratches easily.  Steel is a magnificent material: strong, durable, wear resistant, and fatigue resistant. However, it's heavy, oxidizes easily, it's difficult to machine, expensive and requires heat treating.

Each material has it's own quirks.   To make a blanket statement that one is the better ignores their strengths and weaknesses.  Use each appropriately.

Quoted: Every material has strengths and weaknesses.  Good engineering requires a designer to use the appropriate material for each application.  In the case of polymer, it can be molded into a near net shape very easily.  It's strong, corrosion resistant, inexpensive, and light.  However, it sucks at wear resistance, so steel frame rails are molded into the frame (steel has excellent wear resistance).  Aluminum is light, easy to machine, and inexpensive (not as cheap as plastic).  Aluminum does not do well in fatigue and it scratches easily.  Steel is a magnificent material: strong, durable, wear resistant, and fatigue resistant. However, it's heavy, oxidizes easily, it's difficult to machine, expensive and requires heat treating. Each material has it's own quirks.   To make a blanket statement that one is the better ignores their strengths and weaknesses.  Use each appropriately.

Well said.
Looks like there is a place for polymer, aluminum and steel frames depending on what you are looking for.