Home Forums Hunting & Shooting Ask The Gunwriters Metallurgy, Ruger Investment Casting, Action Strength?

In the case of the REmington 700 the barrel at one point was a casting and then heat treated and then hammerforged. The action is a blank of SS or CM and then heatreated, there is no forging.

Investment casting orients the grain structure in to the shape of the finished object and results in enormous strength.

The 'investment castings' (lost wax process) that Ruger and others use to make products are strong and well engineered.

I bought those and other castings and have toured Ruger's Pine Tree Investment castings foundry in N.H.

In the case of the 700 barrel there are a few stages besides heat treat between casting and hammer forging.

All steel starts out as a molten metal soup...that's how steel is made...then it's poured into some type of a mold to await it's final form...that's the basic process for making all steel.

Once you have a blob of steel, it's steel, with very different properties from the iron from whence it came.

When casting methods were primitive, forging used to have some advantages in some applications, but for some applications casting is stronger.

Now-a-days, casting technology is computer controlled to fractions of a degree, as is heat-treatment...that is also digitally controlled and the process is precisely optimized to favor the alloy being used.

It's high tech stuff...

Today, it's an extremely precise manufacturing process compared to the heavily bearded and muscled blacksmiths of olden days beating lumps of steel into primitive shapes...most guys alive now don't remember those days anyway.

But cast it or forge it...it's still steel...the rest of the story is all about engineering.

All things being equal, its the heat treat that makes the difference.

It's difficult to discuss something this complex in off the shelf , cryptic sound bites, and vague generalizations.

Example:


not at all sure just what you're trying to say,...

GTC

Heat treat makes a big difference, but if it's got impurities or casting voids, that's a problem.

Lots of critical items are still forged, even in the modern age.

Not that difficult to understand. All starts as soup. Some is cast as bar stock some is cast as something specific. All the same.

Machining which tears the grain during the process.

Keep in mind that the billet or bar that is machined or forged was also once "soup".

Castings get a bad reputation because the alloying elements used to increase fluidity (generally silicon and carbon) make the material brittle and reduce its impact strength.

A very high degree of process development and process control means that steel castings can be made with standard alloys and without inclusions, voids or other casting flaws. It can be done, but you are not going to buy those castings for $2 a pound.

Even with high silicon and carbon, tiny amounts of alloying elements can be added that make the graphite inclusions spherical. Given proper annealing, these cast irons (called nodular irons) are suitable for automotive suspension applications, like steering knuckles, that are high shock applications.

Not really true. Yes, it all comes from the furnace as molten steel, but bar stock is not "cast as bar stock..." Bar stock is rolled which results in aligning and refining the grain structure.

One of the more interesting parts of Stuart Ottesons book on bolt action rifles was the part where he describes craftsman taking Ruger 77 actions out of the mold, placing them in a jig with dial indicators and then beating the hell out of them until they are straight.
I never really cared for the brick of steel look, the crude unfinished action rails or the wacky bottom metel, but reading about the actions being pounded on sealed the deal for me.

TRW made the best M14 of all time. Receiver was cast if I remember correctly.

I recall reading where the purpling of parts is due to a high silicon content. Have seen this on Rugers, Weatherby's, some Kimber parts etc.

I think the silicon makes the metal easier to mold.

Cheers, Chris

8620 steel

....The stuff's a DREAM to work with, and smiles back at you as you weld it.

GTC

I believe Ruger Investment Casting also manufactures the Montana 1999 action which seems to be heald in high regard on the fire.I own one Hawkeye and one Montana, both work just fine and are strong. I am a designer in the fishing industry and work mainly with aluminum of various types and they all work. We also use different types of steel and titanium for guide frames. It all depends on applications. I am no expert on investment casting steel but back when Ruger developed the process they are using I think it was pretty new( I could be wrong). I may be wrong here but I think the tolerances on some fully machined actions are a bit tighter.

Glad you're bringing this up,...it's more catch phrase vagueness, with no basis in reality.
Closest thing I can buy as "cast bar stock" is some specialty CONTINUOUS POUR FE ( PURE IRON) that's specific to making quality magnets, and such.
Outside of that, there is no such thing,..."bar stock" by industry definition is a ROLLED material.
Simplistic generalizations may not be be "difficult to understand".
....that doesn't make em' RIGHT, either.

GTC

GTC

Here is Ruger's Pine Tree Investment Casting co's site:

Rugers Pine Tree Foundry

Here is a pic. from their site:

The bottom line......... no rifle (or revolver) is any stronger overall than its weakest point functionally. Rugers are anything but flawed when it comes to weak points. In fact, some have complained about them being overbuilt.

Certainly, if I was stranded some place out in the wild parts of Alaska and my only source of supply was a single fly-over via SuperCub dropping 50 pounds of stuff, my Ruger stainless M77 223 and a hundred rounds of ammo would give me more confidence than any of the Winchester, Marlin, or Remington rifles and equal weights of ammo that my safe might hold.

The fella' that wrote this knows more than a wee bit about making quality steel parts and pieces.

There's a good reason he chose the word bolded above.

Ruger and his team started scratching around on this process with SLIDE RULES, and vacuum tube based process equipment,....the staggering advances forward from that base in the last 40 years sees investment casting an industry byword, and reliable material qualities they were only DREAMING of at the beginning.

GTC