Load data for 77 TMK in 223

[mustelid_master]

Howa Mini .223, factory barrel cut down to 16”.

LC once fired
F205 primers
2.004” CBTO
77TMK
Lever

23*f outside, loaded in 65* house

No signs of pressure other than slightest primer cratering at 27. No heavy or sticky bolt lift or ejector swipes or anything.

Shot groups of 5 at 25,25.5,26 and they started getting real interesting at 26g. Will load up 10 each at 26,26.3,26.5 for next range session.

View attachment 828317

Man that is haulig the mail

 

[KyleR1985]

Man that is haulig the mail

At 27g:

When I run it in quickload, with the default .223 case water capacity at 28.8, it shows 69,000psi, 2800fps

When I update it for my actual measured case capacity of 31.2, pressure drops below 55,000psi, 2650fps.


Load was not crunchy, but I’m certain is compressed.


Not sure what to make of it. Brass and bolt didn’t give me any sign.

But I liked what happened around 26g anyway

 

[Kaleb]

Not 77’s but 26.3 grains of lever under 75’s has been a good load for me for years. It’s also a great forming load for my 223AI’s.

 

[st1650]

New 20in IBI CFW. Defiance anTI HNT26
S&B ultra klassik 3-12x42 p3l mil/mil
Hawkins hunter 223 mags.
77TMK
2.475in coal (rem 223 match chamber with a lot of freebore)
Starline new 556 brass
25.0gr N540
CCI 450
2910FPS no pressure but probably a good 58K-60K psi load. Same load in new Lapua brass was 50FPS slower.
Doped to 500m
1.1 to 300
2.0 to 400
3.0 to 500


Staball match and varget also had very good accuracy but 50-80FPS less than N540


Spring bear coming up next week I’ll use this one as my primary because I’m curious how the 77 will do on a shoulder shot. I don’t plan to shoot further than 400m with it. For the long range stuff I’ll also have my 22Creed with 88 eldms in the truck.

 

[Matt5266]

Different ways to skin a cat. But middle of middle is definitely the preferred placement of all the bears we have killed. Their vitals sit different than say a deer or elk

 

[st1650]

Different ways to skin a cat. But middle of middle is definitely the preferred placement of all the bears we have killed. Their vitals sit different than say a deer or elk

Spring or fall bear ? I've only ever hunted fall bear and I was told that spring bears were easier to kill with a shoulder shot because when they're out of hibernation they could run off for a few hundred yards before collapsing.

 

[Matt5266]

Time of year doesnt change the anotamy of their organs. I / we dont hunt fall bears. Spring only for us unless a opportunity comes about that cant be passed up. Middle of middle is the go to for everyone I know. Most all bears I've seem lost guys were shooting them into the shoulder like deer and elk, lungs sit further back. A bear can go ALONG way on 3 legs.... ask me how I know

 

[ResearchinStuff]

Finally got ahold of some stick powder, and promptly shot the smallest group ever with my 223.

LC brass
Fed 205
2.40" coal, note that is longer than the factory mag can handle
20.8 gr Benchmark
77 tmk

Despite what the hogdgon site and get told me, I was catering primers at 21.3 gr, and pierced one at 22.2. Never had any bolt lift or ejector/ extractor markings, but I'm not going to load that high again.

 

[RockAndSage]

Finally got ahold of some stick powder, and promptly shot the smallest group ever with my 223.

LC brass
Fed 205
2.40" coal, note that is longer than the factory mag can handle
20.8 gr Benchmark
77 tmk

Despite what the hogdgon site and get told me, I was catering primers at 21.3 gr, and pierced one at 22.2. Never had any bolt lift or ejector/ extractor markings, but I'm not going to load that high again.

View attachment 896975

What kind of velocities were you getting with the Benchmark and that 77gr TMK?

 

[ResearchinStuff]

What kind of velocities were you getting with the Benchmark and that 77gr TMK?

Not sure, I still have a crappy optical chrono and didn't bother bringing it to the range. I am a bit concerned that it's slow, especially since my barrel is cut to 16"

 

[ResearchinStuff]

Finally got ahold of some stick powder, and promptly shot the smallest group ever with my 223.

LC brass
Fed 205
2.40" coal, note that is longer than the factory mag can handle
20.8 gr Benchmark
77 tmk

Despite what the hogdgon site and get told me, I was catering primers at 21.3 gr, and pierced one at 22.2. Never had any bolt lift or ejector/ extractor markings, but I'm not going to load that high again.

View attachment 896975

Did some more measuring and think I might have figured out the premature pressure. My distance off the land was less than the gap from my shoulder to the forward end of the chamber, so the firing pin was driving the bullet into the lands for me. This processed LC brass i got was sized very small.

 

[Schmo]

Nice catch, @ResearchinStuff! I could totally see that being the problem. Don’t overlook StaBall Match as a very viable temp stable option.

 

[ResearchinStuff]

Nice catch, @ResearchinStuff! I could totally see that being the problem. Don’t overlook StaBall Match as a very viable temp stable option.

Trying not to buy more powder for a while. Sitting on 11# of TAC and 7# of benchmark

 

[Schmo]

Trying not to buy more powder for a while. Sitting on 11# of TAC and 7# of benchmark

I hear ya! I’ve got around 8lbs of Tac. I need to play with Benchmark in my 223 since I have some.

 

[BigDog00]

Starline 5.56 brass
CCI 450
Varget 25.6
2.345 OAL
77 TMK

Shot just over 1/2" for 5 shots at 2925 fps in my 223 AI with 20" barrel.

 

[ResearchinStuff]

shortened my COAL by .005, bumped up to book max, and pressure signs vanished. pretty sure a combo of long COAL and shoulders bumped way back was the problem.

 

[Outdoorsman12b]

Anyone have some more info on Tac?

Using fed 205m, Hornady brass, 2.26. Hoping for 2800-2850 tikka barrel.

 

[ResearchinStuff]

I've shot up a lot of it, never with very good accuracy.

 

[Outdoorsman12b]

I've shot up a lot of it, never with very good accuracy.
View attachment 899169

What velocity are you getting?

 

[ResearchinStuff]

I think that load is around 2650 from my 16" barrel, but my chrono is junk, so who knows really