Cast/mim parts

[edwardyoung]

I know cast/mim parts are here to stay; but on critical parts like extractors and sears, how much money can manufacturers save using them when you add in return shipping and warranty repair? If I am missing the obviuos answer, please be gentle.

 

[Jim Watson]

The manufacturers have already done the arithmetic. They are selling way more than they are fixing. You read the complaints on the internet and don't get the favorable or neutral reports. There are a lot of guns running well with the cost cutting parts. Or well enough. A lot of people think 99% is pretty good. And a lot of guns aren't shot enough to expose flaws.

 

[edwardyoung]

Of course, you are right. I guess we do get somewhat of a skewed perspective on gun boards like these. I should have just thought about it for 2 minutes before posting. Thanks. As a matter of fact, I am in the 99%. I've never had any gun part break. Of course, 90% of my guns have been Rugers and Marlins.

 

[steveno]

here we go again

 

[edwardyoung]

Sorry, steveno.

 

[1911Tuner]

Cost vs Cost

Howdy Edward! When ya comin' to see us again?

Cost of MIM vs cost of real steel...On a piecemeal basis, probably not a lot.
Check Brownells catalog for the difference in cost between the two Ed Brown Hardcore hammers...one cast and the other machined barstock. There's not a great difference. But when you order 50,000 sears from a vendor who makes'em via the MIM process, it can make a helluva difference in the bottom line. Bean counters don't look at cost savings per unit so much as they study
cost savings per hundred thousand units over a period of years.

Also agree with Jim Watson. I have MIM sear and disconnects in two of my Colts that I beat on heavily at the range, and haven't had a problem. Two others that have had over 125,000 rounds netted me one cracked disconnect.
The sears in one was machined...the other was MIM. So, evidently Colt has a pretty good manufacturer lined up.

On the other hand, I've seen MIM parts in other brands fail with only light to moderate use...and other guns of the same brand hold up very well.

I tested a Colt MIM sear once in a completely scientific manner by beating on it with a 16-ounce ball-peen hammer and couldn't break it. I did get the feet to bend, and did get a slight crack when I laid it cupped side up...after 5-6
fairly heavy blows...but that was it. Another sear from another manufacturer that was likewise tested broke off just below the nose on the third blow. The feet bent, but didn't break. Neither brand of disconnect fared as well, but given the thickness of the cross-section in the beam and spade, that wasn't a surprise. Tougher than I expected. Castings from an old Thompson Auto Ordnance pistol snapped like glass on the first whack.

 

[45auto]

As mentioned, I've had over 30,000 on Colt MIM sear and disconnector with no problems.

I have no problem with MIM trigger parts...at this time anyway. Recently bought a Nowlin hammer and sear that dropped right in, look well finished and gave a very good trigger pull for @ $36 I think. Time will tell on this set.

Pass on MIM for most other parts however.

 

[NMshooter]

Only MIM part I have had trouble with so far was a slide stop, and that was after 15K rounds.

 

[pcf]

If the average firearm fell apart after 51 rounds, manufacturers would still hear relatively few complaints. The overwhelming majority of firearms are lucky to see 50rds in their lifetime.

You are missing the obvious answer, most firearms will never be fired enough to break parts or discover defective ones. Whether the parts are MIM, cast, forged, plastic or old moldy noodles doesn't matter most of the time.

 

[jungle]

Parts can be made poorly or perfectly in many different ways. Some of the the most highly stressed parts, thermally and mechanically, in current aerospace applications are cast.
MIM is fairly new and it's apparent that some makers are better and some applications are better.
Ruger may not make the most eye pleasing firearms, but they run one of the most modern casting facilities in the world and make many types of castings used in critical applications. Very few complaints.

 

[Old Fuff]

There are a number of issues in play here. For example in the original Browning 1911 design the exrtractor was literally a leaf spring. It was machined from "real" high carbon spring steel, and heat-treated. Some of today's makers use a similar part, but made using MIM technology. So what's the problem? The problem is that the MIM part can't be spring tempered, and over time (or between 800 to 2000 rounds on average) will no longer have the proper tension to work right. The result? Possibly life-threatening malfuctions.

In another instance a manufacturer switched from a steel hammer strut to one made using MIM. In this particular application MIM was a bad choice, as the part was stressed and started breaking. When one did break the pistol was totally disabled.

Problems most often happen when a manufacturer tries to duplicate a part that was previously made by some other method, or out of some other material, rather then design a part where its design and application match the chosen manufacturing method. This is why MIM (or for that matter, investment castings) work well in some guns, but not in others. Ruger’s firearms are designed around investment casting technology, and work very well. Browning’s pistols were not designed around MIM technology, and when parts are simply duplicated using this method they may, or may not prove to be reliable – in a context where the end user may stake his or her life on that reliability.

Quality control also plays a part. In the aircraft and aerospace industry precision castings and MIM parts often go through 100% x-ray or magna-flux inspections. I question if many gun parts go through any inspection at all. Cost factors and questionable inspection procedures that drive the gun-makers often don't apply in the aircraft & aerospace industry.

Those that depend on the reliability of a particular firearm to protect themselves or others should keep in mind that: (1) New technologies usually work well when the parts are correctly designed to take advantage of the method, and the part has the characteristics that are necessary to insure it will work within a particular application. (2). When new technologies are used primarily to reduce production costs of an existing part, without regard as to possible consequences trouble should be expected.

 

[jungle]

Very good points Old Fuff. Not too many are aware that Ruger makes castings for many other gun makers. They would also be surprised that late Government spec. allowed cast frames and slides for our beloved 1911A1.
Quality depends very much on who is doing the MIM, casting or forging.

 

[Old Fuff]

They would also be surprised that late Government spec. allowed cast frames and slides for our beloved 1911A1.

They might be more shocked to find out that in 1939 Colt was experimenting with two-piece frames where the two sides were brazed together, and with die cast Brastil (81.5% copper. 14.5% zinc and 4% Silicon) frames and slides. A 1936 era prototype passed a 5000 round shooting test.


Edited to correct typo.

 

[1911Tuner]

re:

Fuff noted:

>Quality control also plays a part. In the aircraft and aerospace industry precision castings and MIM parts often go through 100% x-ray or magna-flux inspections.<
*******************

Not to mention that the materials and casting/sintering process used with small parts destined for service in a 500-dollar pistol probably aren't even in the same league with the materials and casting/sintering process used with high-stress parts manufactured for the aerospace industry...one would tend to think...

Sorta like comparing the tire composition on an Indy car and a stock '67 GTO.

 

[jungle]

It is interesting that some of the highest quality 1911 frames built today are cast and the maker reports they are more trouble free than his own machined from bar stock products.
Non destructive testing is common as a QC control step with parts in modern US military weapons. Look for a stamp with the letters MP on barrels and bolts. It denotes use of penetrant type inspections for cracks or other flaws. These types of inspections may also be conducted as a part of maintenance.

 

[Old Fuff]

Non destructive testing is common as a QC control step with parts in modern US military weapons. Look for a stamp with the letters MP on barrels and bolts. It denotes use of penetrant type inspections for cracks or other flaws. These types of inspections may also be conducted as a part of maintenance.

While this is sometimes true within a military establishment – that is rarely driven by a profit motive – the same can’t be said about commercial makers, who seldom use such inspection systems. It was recently reported on another thread that a popular maker of 1911 clones not only doesn’t test guns that they repair, but also as a rule don’t fire them when they are first assembled. Why? Because they don’t have an in-house range, and the use of an available public range is subject to weather conditions.

On another current thread we learn that a sear pin in a new pistol was actually bent, apparently because the “precision close-tolerance” disconector that was made using MIM technology was too long. Of course this was not discovered through the part maker’s inspection system (if there was any), nor by the gun manufacturer (after all the gun did make it out the door).

Judging from the threads posted on this forum alone concerning functional and part failures, it should be clear that government mandated aerospace and military inspection procedures are rarely found within the firearms industry – which is all too often driven by cost considerations, and not a quality control department. Economics may make this necessary, but never the less, it’s a fact of life that must be recognized.

 

[jungle]

One can easily do penetrant testing on almost any part, but is serves only as a verification that the heat treat and machining haven't caused flaws.
If the material being tested is out of spec. with regard to metal or heat treat, then all the testing in the world won't make it better or serve as a reliable indicator of failure potential.

The Military isn't profit driven, but the firms that sell to them surely are, and the testing serves as a safeguard to both parties.

 

[jungle]

Just one more point for those of you who are careful about the quality of the weapons you buy.
Take a look at which makers are winning large government contracts. You may not care for the specific firearm, but you can be sure that endurance and quality was tested carefully. Just winning such a contract takes such a high degree of quality control, technical excellence and accountability(not to mention a mountain of paper proving it) that few can compete and fewer make the grade. Some names in the industry with a very good reputation have not fared well in this arena.

As a side note, one maker who is big in this market goes so far as to laser engrave each slide with a fairly lengthy coding to ensure any problems are directly traceable to process or supplier. This is helpful if problems start to crop up and it beats the often heard "we don't know, that came from an outside supplier".

 

[Old Fuff]

Many years ago I worked in the military equipment part of a company that also made similar products for the automotive and aircraft industry. The products themselves were the same, but the military and aircraft contracts involved all kinds of special specifications, inspections, and red tape. In some cases this was justified, in others not. But in every case the company made money.

Because Uncle Sam paid anywhere from 3 to 8 times as much as General Motors did for what amounted to the same thing.

Your tax dollars at work... :banghead:

Also rest assured that because a certain company has a government contract for a firearm, this doesn't mean ZIP when it comes to the quality of its commercial products. The same quality assurance programs and material specifications don't apply, and it's not unheard of to find that rejected military parts were recycled back into commercial arms.

Some years ago Beretta got into a bit of trouble in the M-9 pistol program when it was discovered that some of the parts used to build them were coming from Taurus. The parts were O.K., but not what the contract required.

 

[1911Tuner]

Military

When my company went to Vietnam to join the regiment, I was told:

"Never forget that your equipment was supplied by the lowest bidder."

 

[jungle]

The lowest bidder always wins, but you can bet the ranch they met the specifications.

There are lots of reasons El Toro and others don't win contracts and they are valid and numerous.

The idea that SIG and Beretta are running two different lines for the same product is amusing though.

 

[Old Fuff]

The idea that SIG and Beretta are running two different lines for the same product is amusing though.

Amusing...??

 

[gamachinist]

Not really two different lines,just one time span of contract stuff and then a run of commercial stuff with the leftover (and possible contract reject) and newly made parts.
Happens all the time in the gun business and commercial ventues too.
The contract may not make a pofit,but if it breaks even and there is a market for the item,the tooling and whatever training is in place for a more profitable run.

 

[jungle]

So, after slagging my ideas on how to buy a new, high quality, well built and designed firearm that has been used by units around the world; perhaps some members of the forum have a better idea to share?

Which makers give a buyer the best bang for the buck in a new pistol?

 

[Old Fuff]

gamachinist:

If the contract is really big having two lines going is possible, but more often what happens is that one line is kept running with alternating production runs between government and commercial production. This presumes that the principal difference (besides specifications, quality assurance, and red tape) is the roll-marked stampings and serial numbers.