Stabilizing 69gr .223 in 1:9 twist barrel

[fhsjrm]

This topic has been covered extensively but I have a specific question that I haven't seen answered anywhere. I know that slower twist rifles often won't stabilize the heavier and longer .223 bullets. I have a Savage Axis with a 1:9 twist and yesterday I shot a couple groups at 25 yards with 69 grain Federal GMM and it grouped wonderfully. So I thought that was that...my rifle stabilizes 69gr bullets just fine. But then I started wondering, if a bullet isn't stable when does its instability start to manifest itself? In other words, if I shoot a tiny group at 25 yards, is it safe to assume that my groups will still be good at 100, 200, 300 yards assuming all other factors are equal or is it possible my bullets weren't actually stabilized, it just didn't "show" at 25 yards?


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[darrenk75b]

You may have a difficult time perceiving it at that distance. However, you should have no issue stabilizing the 69 bthp bullet out of your 1:9 barrel. You could likely stabilize the 75 bthp as well.

 

[Steel head]

69's should be no problem as far as you'd want to shoot 69's.

I have a few AR carbine 1-9 barrels the toss 75/77's very well past 500 yards.
That not the norm maybe but it's not that uncommon either.

 

[steve123]

9 twist has been the recommended twist for 69's so that should remove doubt. I shot them in my HBAR exclusively for years which had that twist.

 

[308pirate]

If they're stable at 100 they'll be stable all the way to 500 - 600.

Now, don't confuse lack of accuracy with lack of stability if your groups open up at distance. Once a bullet is stable enough, barrel twist has no discernible effect on accuracy.

 

[Iamero]

I have always had better results with lighter bullets out of my 1:9 so I never bothered with the 68-69gr stuff until recently. Seems a bit more picky than the lighter 50-55gr vmax, but once you get a load done it is pretty straight forward.

 

[VegasHKShooter]

First, the 69gr is often recommended as the choice in heavier bullets in the 1/9 twist. It's kind of "recognized" as the one to run. Secondly, I know it's often said the 1/9 won't stabilize the heavies: 75-77. That has not been what I have seen with my own eyes.
Min a full time instructor for a very large Sheriff's dept. we have an SPR (special purpose rifle) program that allows Officers to use low power variable scopes, after sufficient training in their use. Our ammo is the Speer 75gr Gold Dot. Popular theory is that it won't stabilize in 1/9 twists. I have seen it in multiple rifles be very stable and accurate to at least 400-500yds. I was surprised, because it's not "supposed" to, but it has in the ones I've seen.
So, shoot 69's all day, you're gtg, and , try some 75/77gr. You might be pleasantly surprised.

 

[Mordamer]

I have fired thousands of 75 A-Max from 1:9 twist barrels. They surely had a lower stability factor than your 69 grain bullets, but they have always been accurate out all the way to 1000 yards. I have had first round hits on 1.5 MOA steel targets at over 800 yards multiple times. I am at a relatively high altitude of 3000 ft and that helps.

 

[fhsjrm]

Back from the range and I have my answer. I'm my barrel at least the 69gr FGMM shoots lights out, but the 75gr Hornday Match is all over the place.

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[Steel head]

Back from the range and I have my answer. I'm my barrel at least the 69gr FGMM shoots lights out, but the 75gr Hornday Match is all over the place.

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I’’d also try 77 FGGM.

I’’ve had good success with the 75bthp’s but not in factory loads.

 

[EJ1001]

I have a Savage 1:9, 26" barrel. No real measurable difference in my rifle between the Sierra 69gr and the 77gr to date.

 

[308pirate]

There are two reasons why 1-9 barrels sometimes stabilize 75+ gr bullets and sometimes don't

1. Some barrels, due to normal process variation, are a little bit faster than the nominal 1-9. They may be 1-8.75 or something like that. They will likely stabilize 75s and 77s, particularly in combination with #2 below

2. Barrel rifling rate (aka twist) is only one variable in bullet stability. Bullet speed is the other. The basic formula is rifling rate in rev/inch x bullet speed in inch/min. Longer 1-9 barrels typically yield faster muzzle velocity, so they impart a higher rotational rate (revs/min) to the bullet and typically will stabilize bullets that a shorter barrel will not.

 

[SEMO Shooter]

I have a Remington XCR in 223 with 1:9 twist. It groups 77 SMK really well at 100-200 yards. At 300 the groups open up, and 400 or further is really bad. It just won't stabilize the 77's after 300 yards. With 69 SMK it's good to go.

 

[308pirate]

I have a Remington XCR in 223 with 1:9 twist. It groups 77 SMK really well at 100-200 yards. At 300 the groups open up, and 400 or further is really bad. It just won't stabilize the 77's after 300 yards. With 69 SMK it's good to go.

Are you seeing tumbling or just the groups opening up?

 

[308pirate]

OP if Hornady 75s don't stabilize in your rifle, there are a few modern high bc options between the old 69 SMK and the 75s and 77s

I'd try first of all the Nosler 70 RDF, it has an outstanding .416 G1 bc.

Also try the Berger 73 HPBT (Nosler recommends 1-9 or faster), the Sierra 69 TMK (Sierra recommends 1-10" or faster), and Hornady 73 ELD-M (this one might be iffy)

And don't forget the old Hornady 68 HPBT. It has a better bc than the 69 SMK, is sure to stabilize in any 1-9, and they are CHEAP

 

[SEMO Shooter]

Are you seeing tumbling or just the groups opening up?

I only saw groups open up with 77 SMK. I tried 80 grain once and they tumbled at 100 yards.

Keyhole would be a more accurate description of what the 80 grain did.

 

[ilmonster]

My 1:9 twist Remington 700 will stabilize 68 gr. and 75 gr. Hornady Match bullets out to 300 yards (both factory [Hornady and Black Hills] and handloads). Between the 68 and 75 grainers, I notice no difference in group size (1/4" - 1/2" MOA groups). I recently tried the new Hornady 73 gr. ELD bullets, and it shot them more like a shotgun pattern, so that's a no-go in my 1:9 barrel. I also chose the 68 gr. Hornady over the 69 gr. Sierra due to the slightly higher B.C. Good luck!

 

[308pirate]

I recently tried the new Hornady 73 gr. ELD bullets, and it shot them more like a shotgun pattern, so that's a no-go in my 1:9 barrel.

Did you try a few different loads or was it one and done?

 

[mrbig]

I shoot a bunch of69 SMKs from my CZ 527 V 9 twist and they shoot very well,but if I am shooting past 400 yards I really like the Berger 70 gr VLD,,

 

[Renofish]

You don't mention if these are factory loads. If factory loads a 1/9 twist is good for any non long range shooting. Say out to 500 yards or so. A faster twist say 1/7 will take you out to 1000 yards of so.

If you hand load, then the above will hold as long as your loads meet or exceeds factory ammo speeds of the same ball you mentioned and your barrel is not too short.

Figure bullet speed and twist and you will find the answer.

 

[Hunt]

I had a Savage 1/9 twist that would stabilize Hornady 75 gr HPBTs with no issue. However, a Howa 1500 .223 1/9 does not like the RMR 69 grainers.

 

[308pirate]

However, a Howa 1500 .223 1/9 does not like the RMR 69 grainers.

Mine is the same. Nothing over 60 grains works in it.

 

[supercorndogs]

OP if Hornady 75s don't stabilize in your rifle, there are a few modern high bc options between the old 69 SMK and the 75s and 77s

I'd try first of all the Nosler 70 RDF, it has an outstanding .416 G1 bc.

Also try the Berger 73 HPBT (Nosler recommends 1-9 or faster), the Sierra 69 TMK (Sierra recommends 1-10" or faster), and Hornady 73 ELD-M (this one might be iffy)

And don't forget the old Hornady 68 HPBT. It has a better bc than the 69 SMK, is sure to stabilize in any 1-9, and they are CHEAP

The 70RDF is a very long bullet. I would rule it out for 1 in 9 twist barrels. I even tried it at 22-250 velocities in a 9 twist. No love.

 

[RFutch]

The 70RDF is a very long bullet. I would rule it out for 1 in 9 twist barrels. I even tried it at 22-250 velocities in a 9 twist. No love.

I have a left over Savage 1/9 .223 barrel I throw on my Nuke every now and then. I have a 70 RDF/Varget load and a 77SMK/TAC load. Both shoot bugholes.

 

[spife7980]

70 rdfs didnt work for me in my 9 twist either. Its a gamble with it most likely not working.