Burn temps and rates

[TAJ45]

I inquired/commented abt RL17 being hard on a bbl of a wildcat being tested.
Had a reply saying a post was found of reverse findings and to check how far down the bbl I could feel the heat.
Made me go "Hmmmm".
Now my idea is to use the colored heat strips mid bbl or further as well as at chamber end to add another "reading" to the best load chase if two powders are very similar in performance.
Thoughts?

 

[WyleWD]

I've seen them being used by a fellow shooter during matches. I suppose they might be somewhat useful if barrel heat is a consideration of load development. WD

 

[kvd]

Get yourself one of these:

https://www.amazon.com/gp/product/B00DMI632G/?tag=accuratescom-20

Maybe not the world standard for accuracy, but it will be in the ballpark and you can scan the entire barrel if you feel the need.

Ken

 

[MagnumManiac]

You do understand that burn rates and heat produced are governed by the bore size and case shape/size?
Burn rates are not constant, all powders burn faster and hotter as pressure increases, no getting away from that, so, if RE17 gives good barrel life in one cartridge, isn't necessarily true in another cartridge.

Cheers.

 

[rifleman700]

QL shows RL17 to have a heat of explosion of 3990 kJ/kg.

For comparison - H4350 3760, H1000 3630, RL26 3905 and RL25 3810

 

[ASbobcat]

I inquired/commented abt RL17 being hard on a bbl of a wildcat being tested.
Had a reply saying a post was found of reverse findings and to check how far down the bbl I could feel the heat.
Made me go "Hmmmm".
Now my idea is to use the colored heat strips mid bbl or further as well as at chamber end to add another "reading" to the best load chase if two powders are very similar in performance.
Thoughts?

That was me.
I discovered this quite by accident. I always feel my barrels while shooting so I don't over heat them. I was astonished at the different location of peak temperature vs other powders. I admit that hand feel is quite subjective and I think the temp strip idea is great. I would love to hear from someone trying this method about their more objective findings.

 

[ASbobcat]

QL shows RL17 to have a heat of explosion of 3990 kJ/kg.

For comparison - H4350 3760, H1000 3630, RL26 3905 and RL25 3810

That number is the TOTAL heat released by a given quantity of propellant. Notice that it is given as "per kg". It does not say how FAST the heat is released. That's what deterrent additives are designed for, to control the RATE of release.
RL17's deterrent application process is very different from that used in any other commercially available powder and it's energy is released over a much longer time.
I speculate that this means barrel wear is probably distributed over a longer section of the bore rather than being concentrated in the throat.
I searched the internet under "RL17 barrel wear" and found a post on www.rifleshooter.com from April, 2012 where an author posted the results of a comparison between RL17 and H4350 in a .243. He bore scoped the barrel every 200-300 rounds and found significantly less throat wear using RL17.

 

[rifleman700]

The good people at Neco told me this is what to look at when determining the powders affect on throat wear when it comes to heat.

 

[TAJ45]

The good people at Neco told me this is what to look at when determining the powders affect on throat wear when it comes to heat.

I can see where total heat available would be the first stepping stone on this path but WHEN they occur as the area affected lengthens seems extremely relative.

Using a Lyman reloading manual, I started with a nut cracker 310 Tool in 1966 with a spoon, scale, pound of powder, box of bullets and primers + two boxes of factory 243....and have found out there is more to reloading than what Lyman mentioned. It wasn't erroneous - it just scratched the surface. I'm thinking the same for the Neco response.