Salt bathing (nitriding) a Garand receiver

[Huckleberry]

I am building two Garands using Krieger stainless barrels. I am going to send them off and have them salt dipped and was wondering what you guys think about having the receivers and all metal parts done at the same time.

Batch price is $100 plus $60 per barrel. I have not asked about costs on the rest of the parts.

Both will have McCann gas plugs and I will be using 208 and 210 grain bullets. One will be in 308 and the other in 30-06.

 

[butchlambert]

Re: Salt dipping a Garand receiver

Are you speaking of the QPQ nitriding?
Butch

 

[Huckleberry]

Re: Salt dipping a Garand receiver

Yes if that is the Trutec process.

I have changed the title to reflect that.

 

[butchlambert]

Huckleberry,
I would contact Joel Kendrick about it. I have had barrels, bolts and dies treated. I am very happy with the process.
Butch

 

[Robert]

Huckleberry,
I would contact Joel Kendrick about it. I have had barrels, bolts and dies treated. I am very happy with the process.
Butch

Butch,

I would not recommend salt bath nitriding of a part whose metal is not know and certainly have been already heat treated under the right process by the maufacturer as were the Garands no doubt...

In this case, it would certainly be better to recommend CrN PVD-coating (silver colour, coefficient of friction 0,3), or better TriboBond (Me-DLC=Metal-Diamond Like Coating) blaack in colour, 2300 Vickers hardness, C.o.F=0,1...

For barrels, time will tell the value of salt bath nitriding (Melonite)...... Do not forget nitriding happens naturally in barrels during firing, and is one of the main causes of erosion.. I have not been able to find anywhere the exact C.o.F of parts treated with Melonite..Documentation says it improvs it, but no exact data. Woulld be interested to know?
R.G.C

 

[Huckleberry]

I sent an e-mail to Joel yesterday but have not received word back yet.

 

[butchlambert]

Robert,
If you have followed the QPQ as Joel does, He also stresses that we need to let him know the type alloy. My barrels are 416R and so are the dies that I have made.
Butch

 

[Huckleberry]

My biggest concern is due to stress relieving and possible dimension changes in the receiver itself. The metal to the rear is somewhat thin in areas but I am willing to try it if Joel wants to tackle it. I do not think the process will build up enough heat to bother anything that is hardened using a heat treat process already.

 

[blawton]

Most of them run the salt baths at around 1200 degs. Which for most types of stainless that have been heat treated will weaken the core of the metal. As far as cause problems it may not for most apps but big high pressure rounds you may want to stay away from SS and use 4140 or 4350. If you getting a barrel done then its not going to harm anything. I have got SS and CM done at the same time and never taken apart. It came out great and has had many many rounds ran through it. Im about to do my 338/408 ST in it soon. Cant wait to see what that things gonna do. I have seen MV's increase because of this process almost 300 fps.

 

[blawton]

My biggest concern is due to stress relieving and possible dimension changes in the receiver itself. The metal to the rear is somewhat thin in areas but I am willing to try it if Joel wants to tackle it. I do not think the process will build up enough heat to bother anything that is hardened using a heat treat process already.

I have noticed no change at all in all the pieces i have had done.

 

[butchlambert]

Joel's QPQ is done at 980Deg.
Butch

 

[blawton]

It just depends on how hot the heat treat company made them when drawing it back. That in turn can affect the core material. There is a window that you can hit that wont harm the internal material of stainless. I cant be for sure but from what i have heard/learned that when done at lower temp it doesnt get the treatment as deep. its kinda a give or take when your talking about doing stainless. I always recomend using CM while doing it. Doing this also increases the corrosion resistance as well.

 

[Huckleberry]

I know that most of the benefits apply to CM, but stainless is already pretty corrosion resistant.

I would like to see results of stainless and CM barrels after the process is done to both type steels. It may be that CM will out-perform stainless in all areas. The most important area to me is wear.

I had not heard that there is a possibility of velocity increase with the process. Makes sense with the increased lubricity of the hardened metal.

 

[Robert]

Robert,
If you have followed the QPQ as Joel does, He also stresses that we need to let him know the type alloy. My barrels are 416R and so are the dies that I have made.
Butch

Butch,
I have followed the thread closely, and my point was about Garand receivers, already treated otherwise, not newly manufactured goods of know specifications and untreated...

I still do not know the exact CoF of the Melonite QPQ treatmnt.
The term used ''improves friction' does not satisfy my metalurgy logic.
Sincerely

R.G.C.

 

[blawton]

Robert,
The reduced fricton is a byproduct of the process. The process fills in pores in the metals and if i didnt see how much FPS you do really gain every time i wouldn't believe it myself.

bobby

 

[blawton]

It is also best to do the stainless and CM in different baths. They are done at a different temp.

 

[Huckleberry]

Just talked to Joel on the phone. The batch temp is done at 980 degrees at the Arkansas facility. The Tennessee facility uses a hotter quench.

I need to find out what the core hardness of the Garand receiver and bolt is. If it was hardened at a temp higher than 980 degrees, I'm good.

Anyone know offhand?

 

[Huckleberry]

Found this.

Receiver: Treatment: Carburize 0.012" to 0.018" at 1600° F.; oil quench temper 1 hour at 480°. Rockwell D 59 to D 67.

Bolt: Treatment: Normalize before machining. Carburize 0.015" to 0.020" at 1600° F.; oil quench. Temper 1 hour at 325°. Rockwell C 35 to C 59 on locking lugs and rear end of bolt.

I am guessing that since the heat treat was performed at 1600 degrees, 980 should be good. Correct?

 

[wapiti25]

Huckleberry, I think the 1600 is the heat treat but it may be drawn back at a lower temp. Most heat treatments use a draw back temp. I think you may have only part of the process.

 

[wwbrown]

Have you shot the barrels you had treated Butch? If so was there any change in accuracy and have you shotten the barrel enough to see if it extends life?

Thanks

wade