I see lots of people making their own receivers from 4140 or 4340. When making a home made rifle action I think it is important to overcompensate for any possible error by using the strongest metal available. When designing your own action or scaling up an existing design you definitely want the ultimate strength to minimize any chance of failure. I think 17-4 steel is a really great material with tensile strength around 200,000 psi. Another great advantage 17-4 has is it is "precipitation hardening" meaning it hardens at a much lower temperature than other steels, about 950 degrees F. This eliminates any scaling so there is no need to wrap the material. It does not need a quench you just let it air cool. It hardly moves at all from the heat so you can machine your part complete then heat treat, maybe leave your most critical dimensions for a light skim after heat treating. ANYWAY I JUST "DISCOVERED" AN EVEN BETTER MATERIAL: It is called Maraging 300 (Vascomax C300). It heat treats at low temperature like 17-4 and has a heat treated tensile strength of nearly 300,000 pounds. The data sheet also says compressive yield strength 317,000 psi and notch tensile 420,000 psi. It hardens to 50 to 55 Rockwell. Now usually too hard is no good but in the case of this metal the numbers look real good from my limited understanding. It is crazy expensive by the way. Does anyone with better knowledge of metals have any input on this? Does anyone know of any other great materials for receiver making?
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Ultimate best steel for home made building a bolt action receiver
- Thread starter Helix
- Start date
- Replies 94
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Winterfalke
Stainless
- Joined
- Mar 26, 2011
- Location
- Huron
I've heard of numerous superalloys with numbers like that, but they were all super expensive and difficult to machine, and many had serious drawbacks. Such as, Aermet 100, a managing steel with a tensile strength around 280kpsi, but it cannot handle any exposure to moisture. The stuff sounds great, but what's the rest of the story?
Not sure that's why I am putting it out there for discussion. If it is prone to corrosion there are coatings for that. Many firearms are made from steel that will rust if not treated properly. I have milled and turned it, machines fairly easily with un-heat treated Rockwell around 30 to 32.
Really interesting. Maybe try a small caliber first and put 100 rounds through then inspect under microscope. Post pictures of your build sounds fascinating.
paracongo308
Banned
- Joined
- Jan 16, 2014
- Location
- Green Lane, Pa.
Nails can also be made from D2 for the ultimate strength, but what's the purpose. 4140 steel is more then strong enough for receivers and machines well in a preheat treated state of 28-32 Rc. I have made several receivers in single shot and repeater from 4140 chambered in 6.5x47, 260 Rem, 284 Win. Several 308's and 3 50bmg's currently making 5 more 50 bmg's all the bolts receivers and barrel extensions are made of 4140. Some of them were shot many 1,000's of times already. If your looking for corrosion resistants you can gas nitride or ion plasma nitride them. Just as important as the receiver configuration is the bolt.
SteveF
Titanium
- Joined
- Jul 4, 2004
- Location
- central NC
Hitting nails almost perfectly square and still having them bend over, I would like some nails made of D2.
Steve
paracongo308
Banned
- Joined
- Jan 16, 2014
- Location
- Green Lane, Pa.
Hitting nails almost perfectly square and still having them bend over, I would like some nails made of D2.
Steve
No problem Steve, their $4 each how many pounds
Its not about if 4140 is good enough. Its about a search for stronger and safer materials. If I am going to put many hours of time into a project it would be nice to use the best possible metal available. A much stronger metal can also be thinner and have the same strength so designs can be changed to make a lighter part. 4140 has its disadvantages too like requiring high heat which creates scaling and distortion. It also has a zone of temperature where it should not be tempered.
WILLEO6709
Diamond
- Joined
- Nov 6, 2001
- Location
- WAPELLO, IA USA
I would go 8620 case hardened. strong stable, soft core will bend before it fragements....
paracongo308
Banned
- Joined
- Jan 16, 2014
- Location
- Green Lane, Pa.
Sounds like you have little knowledge on heat treating of metals, when my bolts and receivers are heat treated at 1,500+F degrees there is no scale and no discoloration. There dropped off at the heat treaters looking like shiny bright steel and their picked up looking the same way. The 2nd stage there ion plasma nitrided to 60+ Rc and there returned bright with no scale and there more rust resistant then hard chrome. You can make your receiver out of what ever you choose in the quest for a stronger receiver, but don't believe its explosion proof.
They look very nice. There is no reason to assume I "have little knowledge of heat treating". I own a kiln and heat treat many different metals. I would guess the place you have heat treating them uses the vacuum heat treating process or inert atmosphere furnace. Heat treating at that temperature in normal air does cause scale. Even when wrapping in stainless heat treating foil if there are any leaks it can cause scale. Also this thread is about finding new hi tech materials not singing the praises of the old materials that have been the standard even though they work quite well.
magneticanomaly
Titanium
- Joined
- Mar 22, 2007
- Location
- On Elk Mountain, West Virginia, USA
You quote ultimate tensile strengths, but far more imotant to any engineered structure are yield strengths, fatigue limits, toughness, and elongation. Particularly for a firearm, where loads are applied over milliseconds, and where accidental overloads must be considered, the toughness of the standard, properly tempered not-too-hard alloys is essential.
As far as taking advantage of extreme strength to design thinner. lighter sections, the stiffness of all ferous alloys is similar, and does not change with increased hardness, So an action might not itself "fail" if loaded to a stress of 200,000PSI instead of a conservative 50,000, but it will temporarily, elastically stretch four times as much. Do you know what this might do to thread engagement, headspace, or a common old brass cartridge case?
You also want an alloy not subject to stress-corrosion, or low temperature brittleness.
Go slow, learn from hundreds of years of firearms design experience, learn the importance and interrelation of ALL the properties of materials.
As far as taking advantage of extreme strength to design thinner. lighter sections, the stiffness of all ferous alloys is similar, and does not change with increased hardness, So an action might not itself "fail" if loaded to a stress of 200,000PSI instead of a conservative 50,000, but it will temporarily, elastically stretch four times as much. Do you know what this might do to thread engagement, headspace, or a common old brass cartridge case?
You also want an alloy not subject to stress-corrosion, or low temperature brittleness.
Go slow, learn from hundreds of years of firearms design experience, learn the importance and interrelation of ALL the properties of materials.
300sniper
Hot Rolled
- Joined
- Nov 14, 2006
- Location
- Greenwood, Ca
I machine mine out of highly compressed unicorn turd billets. It's far better than what everyone else uses.
GGaskill
Titanium
- Joined
- Feb 14, 2001
- Location
- Central AZ
It's my understanding that AR15 bolts are made from a maraging steel, although which one I do not know. Probably why AR builders don't make their own bolts.
Butch Lambert
Titanium
- Joined
- Oct 30, 2002
- Location
- Poetry Texas USA
I suspect it is to say you did it. Why not make it out of 4140 and you could tell them it was made from a dinosaur dick and nobody would know.
ulav8r
Cast Iron
- Joined
- Feb 21, 2003
- Location
- Russellville
It is better to rely on superior design than superior material. The brass is the weakest link. If it lets go, then you need a design that handles the gas well.
WILLEO6709
Diamond
- Joined
- Nov 6, 2001
- Location
- WAPELLO, IA USA
I know the alloy, and no...... its not maraging
Butch Lambert
Titanium
- Joined
- Oct 30, 2002
- Location
- Poetry Texas USA
A lot of competition receivers are made from aluminum. We use pretty high pressures in our BR loads.
