77TMK 1:9 Twist

[FSB12B]

May be a dumb question, but is anyone having success with 70+ grain 223 bullets in a 1:9 twist? Specifically the 77TMK?

Not sure if this is the correct forum, but a 223 fell into my lap for roughly $200. Will 1:9 stabilize the 77 enough for decent results? If not, what’s my best option for 60-70 gr bullets on big game? Sub 400 yards.

Thanks!

 

[KJ_ND]

I haven't had an issue with 73 eldm stabilizing in a 223 savage 1:9. I can throw some 77 tmk through it this weekend and report back.

 

[S-3 ranch]

For god’s sakes use your search feature on here
This subject has been beaten to death

P

Thread '.223 for bear, mountain goat, deer, elk, and moose.'

Jun 3, 2019

DON'T HAVE TIME TO READ 176 PAGES? HERE'S THE CHEAT SHEET.

---

“Bullets matter more than headstamps.”

“Spent primers offer the supreme tutorial”.

I’ve read it here and elsewhere online. It got my attention. I started digging and asking questions and listened.

The 77gr TMK delivered by a .223 is where I ended up after many discussions and objective data regarding bullet performance and numerous pics of field results.

Now for the delivery system. Accurate. Repeatable. Reliable. Reasonable weight to afford steady shot placement and the ability to spot my own impacts...

• PNWGATOR
• Replies: 11,138
• Forum: Firearms

• 
• 
• 

 

[h2so4]

You could also try the 69gr TMK.

 

[Steve300xcw]

Ammo's cheap enough. Pick up a couple boxes and find out. You might be surprised....

 

[JackButler]

For god’s sakes use your search feature on here
This subject has been beaten to death

P

Thread '.223 for bear, mountain goat, deer, elk, and moose.'

Jun 3, 2019

DON'T HAVE TIME TO READ 176 PAGES? HERE'S THE CHEAT SHEET.

---

“Bullets matter more than headstamps.”

“Spent primers offer the supreme tutorial”.

I’ve read it here and elsewhere online. It got my attention. I started digging and asking questions and listened.

The 77gr TMK delivered by a .223 is where I ended up after many discussions and objective data regarding bullet performance and numerous pics of field results.

Now for the delivery system. Accurate. Repeatable. Reliable. Reasonable weight to afford steady shot placement and the ability to spot my own impacts...

• PNWGATOR
• Replies: 11,138
• Forum: Firearms

• 
• 
• 

What you quoted showed nothing about 77tmk in a 9 twist.

 

[JackButler]

Out to 200 yards, my 9 twist AR shoots the 77tmk great. Bullets not tumbling at that range at least. Need to shoot paper at 500 to verify it holds.

 

[Rockpicker]

You’ll be fine with a 9 twist. My Ruger Hawkeye is a true 9 twist (I ran a rod and patch through it to verify) and shoots the 77 TMK a hair over MOA at 350 yards for 5 shots. If I got rid of the craptastic trigger I’d probably do a bit better.

If you bought a Savage/Stevens with a 9 twist it’s more of 8.75-8.625 twist which is plenty.

 

[NDhunter88]

Believe it or not I have a 1-10” twist 223 barrel for my Blaser that shoots the 77tmk great out to 700yds. I tried the 77s since I had them for my tikka and I was surprised at how good they shot.

I did verify the barrel is a 10” twist with a cleaning rod.

 

[1000yards]

For everyone with a 9 twist or slower that stabilizes the 77 tmk, what's your elevation?

 

[JackButler]

For everyone with a 9 twist or slower that stabilizes the 77 tmk, what's your elevation?

I'm at 3300

 

[flyfisher117]

I can shoot them with reasonable accuracy at 100 yards. Somewhere a little past 300 yards they will start to keyhole a bit. That’s from a 20” bolt gun with a 9 twist.

Edit to add I guess I don’t have the pics of the 77 grain targets but they were similar to this group. Red center is 1”

 

[Jordan Smith]

I can shoot them with reasonable accuracy at 100 yards. Somewhere a little past 300 yards they will start to keyhole a bit. That’s from a 20” bolt gun with a 9 twist.

That doesn’t make much sense. Bullets get more stable as they slow down over distance, not less.

 

[flyfisher117]

That doesn’t make much sense. Bullets get more stable as they slow down over distance, not less.

If you can tell me why my paper targets are wrong then I’m all ears.

 

[Jordan Smith]

If you can tell me why my paper targets are wrong then I’m all ears.

Well, that's why I said that it makes no sense. Have you verified this observation repeatedly with a meaningful sample size?

Stability is a function of rotational speed and translational velocity. Rotational speed is approximately constant as the bullet flies downrange, but the translational (forward) velocity is quadratically decreasing. The result is that the ratio of rotational speed to translational velocity is increasing as the bullet flies downrange, which increases stablility.

The only explanation I can think of would be that the bullet is marginally stable before encountering a significant destabilizing force somewhere downrange, though I can't think of what that would be.

 

[flyfisher117]

Well, that's why I said that it makes no sense. Have you verified this observation repeatedly with a meaningful sample size?

Stability is a function of rotational speed and translational velocity. Rotational speed is approximately constant as the bullet flies downrange, but the translational (forward) velocity is quadratically decreasing. The result is that the ratio of rotational speed to translational velocity is increasing as the bullet flies downrange, which increases stablility.

The only explanation I can think of would be that the bullet is marginally stable before encountering a significant destabilizing force somewhere downrange, though I can't think of what that would be.

I shot 1 box of 100 of the 77s. And after not having a single round bullet hole at range I scrapped the idea of trying to shoot them from the gun.

The 75s I shot above was just for giggles as I had a partial box on the shelf. I shot roughly 10 of them at distance on steel and all seemed OK but I didn’t verify them much.

 

[Steve300xcw]

I shot 1 box of 100 of the 77s. And after not having a single round bullet hole at range I scrapped the idea of trying to shoot them from the gun.

The 75s I shot above was just for giggles as I had a partial box on the shelf. I shot roughly 10 of them at distance on steel and all seemed OK but I didn’t verify them much.

the shorter length of that bthp helps a bit when you are right on the edge of stuff not working.

 

[Jordan Smith]

I shot 1 box of 100 of the 77s. And after not having a single round bullet hole at range I scrapped the idea of trying to shoot them from the gun.

The 75s I shot above was just for giggles as I had a partial box on the shelf. I shot roughly 10 of them at distance on steel and all seemed OK but I didn’t verify them much.

Thanks for the info. How much did you shoot the 77s at 100 yards? Another thought I had was that the bullets fired at long range might appear to be less stable because of asymmetric holes in the paper due to their steep angle of attack when hitting paper.

 

[flyfisher117]

the shorter length of that bthp helps a bit when you are right on the edge of stuff not working.

Yeah that’s have also seen reports of others having luck with the 75 BTHP in 9 twists. I’ve been tempted to try more but the 68’s just shoot so much better in this gun.

Thanks for the info. How much did you shoot the 77s at 100 yards? Another thought I had was that the bullets fired at long range might appear to be less stable because of asymmetric holes in the paper due to their steep angle of attack when hitting paper.

I shot tue 77s about 50/50 100 yards and beyond. Probably shot a few more at 100 yards to get a rough zero. But I was trying to sample them both near and far just to see what happened.

I wondered about the angle of the dangle as they hit the further targets but when shooting my usual 68 grain bullets I’ve always had round holes at the 500 yard berm.