Chromoly or Stainless?

[shortgrass]

Have you ever had your barrels cut and tested for bore nitride penetration depth?
I arranged with a local heat treater in the Portland area to do the tests, but been so darned busy have not had time to make it over.
When I find the time, I'll bring him some dead 416R and CrMo barrels to nitrocarburize and test. He had his doubts about the efficacy on barrels in an atmospheric furnace because it still requires flow of the atmosphere through the barrel and the heat/diffusion time is much longer. Plasma is strictly line of sight, so is ineffective.
Salt baths are the best and fastest. There aren't too many places that still do a fluidized bed of nitrogen rich salts, or at least I had a hard time finding anyone in the PNW. Back when I designed heat treating equipment, we used to do it with NaCN if it wasn't an ammonia atmosphere furnace.

CTT uses the salt bath nitride process

 

[26Reload]

Hey Gwine......while living at Florence Oregon bought a ss t3 tikka lite at cabelas....had it two years....traded it away...but that ss DIDNOT resist the elements.....
Had a cm shilen put on another rifle..never a hint of rust....started as a 260..rechambered to 65284...a couple thousand rounds thru it...recently replaced with ss proof...
I wonder if theres a weight difference between ss and cm of same barrel dimensions....had to send this proof 24" to LRI for major body work.....spiral fluted....

 

[ntsqd]

The density difference between CM and SS is negligible.

4140 CM: .284 lbs per cubic inch

416 SS: .282 lbs per cubic inch

 

[65WSM]

I have been using Controlled Thermal Technologies in Phoenix. I send a 'batch', meaning more than 3 to make the cost worthwhile. CM and SS are not treated at the same time. Different temps, I think. Barrels need to be new, freshly chambered with only a few rounds fired. They need to be 'squeaky' clean , also, with all traces of fouling removed. I sent two batches of barrels to Controlled Thermal Technologies. I sent a Pelican Case with slots for 6 barrels. I got some friends involved. Shipping insured Fed-Ex costs more than the treatment. Three of those barrels were unfired. The rest were used and many purchased second hand. Clean means more than two patches with Hoppes. A bore scope is recommended. I live an hour and a half North of Shortgrass, Cowlitz drainage, so I am anxious to learn what he come up with. I have more "thoroughly tested" barrels in case you need some.​