The 22 creedmoor thread

[Pickettpuncher]

Damn! My 18" is gonna top around 3000k with a 77tmk using 4831sc. At 3100ish, I saw decent pressure. I might need to grab some N560

I stayed right at 3k. Had some neck tension issues and they went up to 3040-3080. Huge swings. But I had a .29 moa group at 300. Hard to argue with how it shoots, but I’m burning alot of powder to be at arc speeds

 

[ChrisAU]

I’m at 3065 out of a 16.5 with 77 TMKs. N555, can’t remember charge off the top of my head but it was walked back a fair amount from first pressure signs. In testing I got up to 3200 with light ejector swipes IIRC.

 

[The Guide]

Curious, what is your dial for the 420y shot at 4000 DA? What did Shooter say it was at -170?

The drops and drifts aren't that mud of a difference, generally 0.5 MOA or less but the velocity drop is what is more important to me. On a 6.5 PRC with a 156 Berger the drop in velocity was only around 70 fps. On my 223 with the 77tmk, the drop is about 145 fps. While it isn't that much, I'm not trying to see what the lowest velocity is that will still kill an elk. When temperatures start chasing close to negative temperatures I will continue to use cartridges that use large rifle and large rifle magnum primers due to personal preference.

Jay

 

[Matt5266]

The drops and drifts aren't that mud of a difference, generally 0.5 MOA or less but the velocity drop is what is more important to me. On a 6.5 PRC with a 156 Berger the drop in velocity was only around 70 fps. On my 223 with the 77tmk, the drop is about 145 fps. While it isn't that much, I'm not trying to see what the lowest velocity is that will still kill an elk. When temperatures start chasing close to negative temperatures I will continue to use cartridges that use large rifle and large rifle magnum primers due to personal preference.

Jay

Just throwing my data out there shooting my 223 with 77 tmk im at 3700 elevation, and sighted in at 50ish degrees. Shot my elk this year at 410 yards at 8500 feet in 11 degrees temp steep uphill. Hit spot on all 3 shots same as my practice earlier in the year. No issues with dope or my small primers in once fired LC brass. Just my experience.

 

[Grizzle]

Hunting sea level at -5 Celsius is why I went 7 twist on my 22cm and have great results so far. Given the choice of 7.5 I'm sure I would of been fine but I'm definitely in the category of user that would likley have had issues with an 8 twist and 88s

 

[Split toe]

Been trying out the 62ELDVTs. No runners yet.

 

[TimberHunter]

With 45 gr of N560 and a 77 grTMK I’m getting 3414 with a 24” tube.

That will indeed, smoke a yote


Sent from my iPhone using Tapatalk

 

[TimberHunter]

Damn! My 18" is gonna top around 3000 fps* with a 77tmk using 4831sc. At 3100ish, I saw decent pressure. I might need to grab some N560

Dang… I’m 2740 fps with the 77 in a 16” 223 barrel. Let’s us know how 560 goes if you try it


Sent from my iPhone using Tapatalk

 

[43.6N]

Damn! My 18" is gonna top around 3000 fps* with a 77tmk using 4831sc. At 3100ish, I saw decent pressure. I might need to grab some N560

What type of barrel and freebore? What is your coal? And what charge was showing pressure?

I hit pressure way early in my barrel when seating at sierras recommended book length. I checked my lands by making a dummy cartridge, and found out I was 60 thousands jammed.

I seated deeper, pressure normalized, and I was able to get a load that shoots.

16.5” barrel. Saami chamber and freebore (80 thou). 77tmk at 3068 using 42gr N555.

 

[HuntHarder]

What type of barrel and freebore? What is your coal? And what charge was showing pressure?

I hit pressure way early in my barrel when seating at sierras recommended book length. I checked my lands by making a dummy cartridge, and found out I was 60 thousands jammed.

I seated deeper, pressure normalized, and I was able to get a load that shoots.

16.5” barrel. Saami chamber and freebore (80 thou). 77tmk at 3068 using 42gr N555.

.081 free bore. PBB 42 grains of 4831sc was 3050 fps average on new brass. Slightly heavy bolt lift on 1 of my shots and start of an ejector marks on another. That's on virgin brass, so I know I need to back down a little because once fired is going to be worse. I do not recall my CBTO but I know it's not in the lands, iirc I am jumping .040. I am hoping the barrel speeds up. It has just shy of a hundred rds on it right now. H1000 produced almost the same exact pressure signs and velocity.

 

[43.6N]

.081 free bore. PBB 42 grains of 4831sc was 3050 fps average on new brass. Slightly heavy bolt lift on 1 of my shots and start of an ejector marks on another. That's on virgin brass, so I know I need to back down a little because once fired is going to be worse. I do not recall my CBTO but I know it's not in the lands, iirc I am jumping .040. I am hoping the barrel speeds up. It has just shy of a hundred rds on it right now. H1000 produced almost the same exact pressure signs and velocity.

Yeah, I agree. Your numbers look squared away. At least according to Hodgdon 41.2gr H4831 with the TMK made 60.6kpsi as their max charge.

You add in brass with thicker walls or a magnum primer, and I could see you being above 65kpsi at 42gr.

Good luck with the N560 when you get it. Sorry I couldn’t solve your pressure problem tonight