“The 22 Creedmoor Project”

[huntnful]

Probably a dumb question, but is this a thing? What’s happening here? Do all powders do this or just some of them?

Not a dumb question at all man. Yes certain powders much more destructive to the barrel.

 

[waspocrew]

Not a dumb question at all man. Yes certain powders much more destructive to the barrel.

I've got 10lbs of N570 - not sure I want to torch a barrel with it, but I'm sure I'd have fun in the process! haha

 

[mxgsfmdpx]

I've got 10lbs of N570 - not sure I want to torch a barrel with it, but I'm sure I'd have fun in the process! haha

You’ll have fun! Haha.

 

[Axlrod]

In the cartridges I've used N570 in, it always gave top velocity and good accuracy. It's magical.
As far as barrel life I look at it this way: The cost of all the components to wear out a barrel is more than the cost of a new barrel. The barrel isn't here for a long time, it's here for a good time!

 

[Okie_Poke]

Okay, so this is a “powder x wearing the throat/barrel” thing and not a “switching from powder x to powder y screws everything up” thing, right? Are double-based powders more prone to this than single-based or is it just certain powders? Thanks!

 

[HighUintas]

Okay, so this is a “powder x wearing the throat/barrel” thing and not a “switching from powder x to powder y screws everything up” thing, right? Are double-based powders more prone to this than single-based or is it just certain powders? Thanks!

Yes, at least that's what has been said by many for a long time. I don't know if there is any actual data to back that up.

This chart is what is often referenced. Lower heat number powders are supposedly easier on barrels.

 

[HighUintas]

I’ll measure some brass for you for sure!! I have virgin, once fired, and twice fired pieces. I’ll get back to you!

It also has to do with whether or not your die is actually sizing the base of the case enough. Or is the chamber design allows the base of the case to get fat enough for your die to adequately size it for multiple firings

Yes I learned the lessons of chamber design, mfg cartridge dimensions, and sizing die dimensions over the last couple of years with the 284 case. It was a huge pain and a valuable lesson. I just wish that money was spent on a either different caliber or case! Although I now have the solution to that specific problem, I no longer wish to dump money into that cartridge haha

 

[TaperPin]

What a fun project - thanks for writing everything up.

Your barrel will be lucky to make it to next fall - that’s a good sign it’s extra fun.

 

[huntnful]

In the cartridges I've used N570 in, it always gave top velocity and good accuracy. It's magical.
As far as barrel life I look at it this way: The cost of all the components to wear out a barrel is more than the cost of a new barrel. The barrel isn't here for a long time, it's here for a good time!

N570 is seriously legit. Top speeds, top accuracy, top consistency in every gun I’ve tested it in. Its excellent. Its just spicy haha.

A 300 NMI was damn near made for it it feels like. The throat wear isn’t terrible, and the case fill is excellent with every big 30 cal bullet and it shoots them fast with low ES. I’ve had 4 of them and they all hammered with N570 and multiple bullets.

 

[huntnful]

What a fun project - thanks for writing everything up.

Your barrel will be lucky to make it to next fall - that’s a good sign it’s extra fun.

Haha funny you mention that. New barrel en route to the gunsmith tomorrow!

 

[huntnful]

Along with the functional data tracking you do for all your rifles, do you also keep track of anything related to the brass if it's a cartridge you're reloading the same cases for?

Something I've been trying to figure out is how much impact the change of the case typically has on a given load's poi and speed. If you only reload a case 3-4 times, I'd expect it to not matter. But I like to stretch my case cost as far as possible, so things like web growth and case volume eventually come into play but I don't know if it really makes a difference. I think the web growth can impact pressure, or at least pressure signs. With one load, it functioned great with no pressure signs until I hit 3-4 reloads, then I got intermittent ejector swipe and bolt lift. The only difference I could find was web diameter growth.

If case "drift" can influence poi and speed, I may opt for the cheapest brass and discard it after 3 reloads.

@huntnful maybe you can track web diameter of some of your cases with speed/poi? I'm guessing with your super hard brass you may not see much. Peterson has a tendency to grow, which is what I experienced that with

Here are the measurements from all the different pieces of brass I currently have from this 22CM.

 

[gotlag1789]

Damn - I feel like all the potential of 22cm is in reloading.

Loving this info

 

[huntnful]

Damn - I feel like all the potential of 22cm is in reloading.

Loving this info

I definitely have more testing planned. But I really wanted to just start shooting gun in various scenarios to get better as a shooter, instead of just group shooting.

I’ll get back to testing and sharing info soon enough