Savage Model 12 LRPV 1/9 Bullets

[qec]

I recently picked up a used model 12. Based on the serial number its from 2008. I used a bore brush to get the twist rate and it appears to be 1/9. I was hoping it would shoot 55 - 77gr bullets however the Hornady 55 BT I have don't group well (over 2"). 69 SMK shoot great as do 77gr. I'm surprised by this. Has anyone else had a similar experience with 1/9 twist barrels?

 

[NZ_Fclass]

I guess that most would have the same experience - It's likely that you will need to set the 55g nearer to the lands, so flat base bullets will be a problem, but some boat tails will set out far enough. I have had success with Sierra 55g = you will need to see which your rifle likes. 69g is the what the barrel was desniged for - and I have shot 69g Berger quite well in my old Savage. Some 77's will shoot, but high BC 75g will be unstable. 8 twist would have been a better choice - but at least Savage recognised the need for a faster twist while other makers were only offering 12's.

 

[Turkeytider]

Congrats on the LRPV. Hope you enjoy yours as much as I do mine. Mine is 1:7 and shoots everything 68grains and up VERY well. Throws 55 grain bullets all over the lot, though. I think the 69 SMKs might be one of the best bullets ever built!

 

[jpx2rk]

I've had several Cabela's Savage FV12 rifles in 223, with the 9T 26" barrel. I've gotten every one to shoot the 50-55g varmint bullets well enough for pdogs and sage rats out to 400yds. The Nosler 55g Varmegeddons, both tipped and HP's will shoot to the same POI with the same powder charge, etc. I've even gotten the Hornady 55g sp's, (the real cheap one's with cannelure) to shoot well at 100 yds but have not shot this load at pdogs/rats yet. I'm curious to see what reactions i get with these sp's. LOL

 

[marchboom]

I have the same gun and get very good accuracy with Hornady 55gr V-Max bullets and Sierra 53's. Powder was Varget.

 

[Charlie-NY]

I have a BVSS .223. The specs say that it has a 9 twist, but after several careful tests, the barrel is actually an 8.5 twist. The rifle shoots 69 & 77gr bullets distinctly better than 50-55gr bullets.

 

[qec]

@Charlie-NY
Interesting that you mentioned that. Mine actually measures 8.5 as well but I assumed that was poor measuring on my part.. The Hornady's are boat tail with a cannelure so I was trying to crimp at that length. I will try seating them longer

 

[fkimble@charter.net]

Don't crimp .Hornady 55's, both the cheap FMJ and the BTHP, shoot very good in my AR15s 8 twist barrels loaded to mag length or less. And don't try to for max velocity. And they shoot even better in 12 twist.

Frank

 

[JB10]

Mine likes the 73 eldm

 

[Ned Ludd]

Although pushing a 77 SMK through a 9-twist barrel is often said to be a no-no, the reality of the gyroscopic stability for that bullet/twist rate combo is not that unfavorable based on stability calculator predictions.

Berger 77 OTM, Berger Twist Rate Calculator, 2750 fps, 1000 ft elev., 70 degrees





Sierra 77 Matchking, JBM Stability Calculator, 2750 fps, 70 degrees, 29.95" Hg



When predicted gyroscopic stability coefficients are close to 1.4, the primary effect should be a slight loss of effective BC rather than gross instability issues. I used to own an older Sig 556 that had a heavy contour 10-twist barrel and shot 77 gr commercial .223 Rem loads just fine. Although I wouldn't recommend a 9-twist barrel for a rifle intended to be used primarily with 77s for someone starting a new build, with a pre-existing rifle setup we don't always get the twist rate we'd like to have. Unless the 77s somehow start showing obvious signs of gyroscopic instability such as oblong holes in the targets or even keyholing (which I doubt will happen), the 9-twist barrel should work just fine.

 

[dusterdave173]

My 9 twist BVSS LOVES 53 g Vmax--with N133 less than half MOA or half when things are perfect
It will also shoot very small groups with 40 vmax
It was less happy with 50 or 55 Vmax for sure

 

[lawman29]

70 grain Berger for mine.

 

[Txhillbilly]

My old Savage 12 FLVSS 223 1-9 twist absolutely loves to shoot 75gr BTHP and 77gr BTHP bullets. It will shoot 55-60gr varmint bullets pretty good, but not like the heavier bullets.
It will not shoot the 75gr AMax or ELD-M bullet's. They're too long to stabilize for my barrel.

 

[Laurie]

Although pushing a 77 SMK through a 9-twist barrel is often said to be a no-no, the reality of the gyroscopic stability for that bullet/twist rate combo is not that unfavorable based on stability calculator predictions.

Berger 77 OTM, Berger Twist Rate Calculator, 2750 fps, 1000 ft elev., 70 degrees

View attachment 1506565



Sierra 77 Matchking, JBM Stability Calculator, 2750 fps, 70 degrees, 29.95" Hg

View attachment 1506566

When predicted gyroscopic stability coefficients are close to 1.4, the primary effect should be a slight loss of effective BC rather than gross instability issues. I used to own an older Sig 556 that had a heavy contour 10-twist barrel and shot 77 gr commercial .223 Rem loads just fine. Although I wouldn't recommend a 9-twist barrel for a rifle intended to be used primarily with 77s for someone starting a new build, with a pre-existing rifle setup we don't always get the twist rate we'd like to have. Unless the 77s somehow start showing obvious signs of gyroscopic instability such as oblong holes in the targets or even keyholing (which I doubt will happen), the 9-twist barrel should work just fine.

There seems to be some variation in Savage 9-twist barrels, Ned. One of the UK's top F/TR shooters started out with a BVSS given a bedding job and various other improvements, but it wouldn't shoot 77gn SMKs for toffee on a range 1,000 ft ASL. I agree it should have and I'm quite happy with Sg values around 1.4, but it just didn't for whatever reason. Lighter/shorter bullets grouped fine. The rifle was rebuilt in 308 with a non-Savage cut-rifled match barrel and did very well in GB F-Class Assoc. league rounds for a season or two back at the dawn of the F/TR discipline.

 

[waltk]

I had a Savage Model 12 BVSS with a SS barrel with a 1 in 9 twist. It was a tack driver with Black Hills remanufactured 77gr. ammo.

 

[Ned Ludd]

There seems to be some variation in Savage 9-twist barrels, Ned. One of the UK's top F/TR shooters started out with a BVSS given a bedding job and various other improvements, but it wouldn't shoot 77gn SMKs for toffee on a range 1,000 ft ASL. I agree it should have and I'm quite happy with Sg values around 1.4, but it just didn't for whatever reason. Lighter/shorter bullets grouped fine. The rifle was rebuilt in 308 with a non-Savage cut-rifled match barrel and did very well in GB F-Class Assoc. league rounds for a season or two back at the dawn of the F/TR discipline.

I would surmise the real reason that rifle wouldn't shoot the 77 SMKs was something other than bullet instability. My point was simply that a 9-twist barrel should provide ample gyroscopic stability for a 77 gr SMK or OTM style bullet, assuming sufficient velocity (i.e. not a really short barrel). We've probably all had barrels that wouldn't shoot a particular bullet very well for reasons that were often unclear, but in many cases was certainly not because of insufficient twist rate. A 9-twist barrel should sufficient to stabilize a 77 gr .224" bullet, even if it won't quite net an Sg of 1.5 or higher. But as you pointed out, sufficient gyroscopic stability doesn't necessarily equate to good precision.

 

[Laurie]

I would surmise the real reason that rifle wouldn't shoot the 77 SMKs was something other than bullet instability. My point was simply that a 9-twist barrel should provide ample gyroscopic stability for a 77 gr SMK or OTM style bullet, assuming sufficient velocity (i.e. not a really short barrel). We've probably all had barrels that wouldn't shoot a particular bullet very well for reasons that were often unclear, but in many cases was certainly not because of insufficient twist rate. A 9-twist barrel should sufficient to stabilize a 77 gr .224" bullet, even if it won't quite net an Sg of 1.5 or higher. But as you pointed out, sufficient gyroscopic stability doesn't necessarily equate to good precision.

This was obvious instability Ned. My surmise is that this Savage either didn't have a true 9-twist, or maybe suffered that button-rifling problem of the button slipping in the bore and causing a variable rate. It wasn't a case of poor groups with 77s, rather their producing oblong holes in the target at 600 yards. As the owner was a very knowledgeable gunsmith / rifle builder, I'd assume he did the classic twist measurement with a cleaning rod after the event, but I never followed up from the day by asking him what he found. This would have been maybe 15 years ago, and many factory rifles had a reputation back then of the stated twist rate being nominal, rather than precisely as stated, so that individual examples from different production periods sometimes behaved differently. Interesting that @Charlie-NY said in his post earlier that his BVSS barrel was 8.5 twist, for example.

 

[Ned Ludd]

This was obvious instability Ned. My surmise is that this Savage either didn't have a true 9-twist, or maybe suffered that button-rifling problem of the button slipping in the bore and causing a variable rate. It wasn't a case of poor groups with 77s, rather their producing oblong holes in the target at 600 yards. As the owner was a very knowledgeable gunsmith / rifle builder, I'd assume he did the classic twist measurement with a cleaning rod after the event, but I never followed up from the day by asking him what he found. This would have been maybe 15 years ago, and many factory rifles had a reputation back then of the stated twist rate being nominal, rather than precisely as stated, so that individual examples from different production periods sometimes behaved differently. Interesting that @Charlie-NY said in his post earlier that his BVSS barrel was 8.5 twist, for example.

Then something beyond the "norm" of a typical 9-twist barrel must have been at fault, because there is no good reason a true 9-twist barrel should have resulted in obvious signs of gyroscopic instability with a typical 77 gr .224" bullet. I generally tend to ignore such "outlier" situations when I am making fairly generalized statements about acceptable minimum twist rates because although they certainly occur, they cannot be predicted and often cannot be completely understood after the fact. I was merely offering the OP an explanation of why his 9-twist rifle seemed to work acceptably well with the 77s.

 

[jlshaw]

My own experience indicates that heavy (75-77 grain) bullets do best with 8 twist or better.
My LRPV with a 7 twist barrel shoots Berger 80.5 and 80 grain AMAX bullets into bug holes.
I don't wish to argue with anyone - just reporting my empirical evidence.

Good luck!

 

[Zero333]

You want to shoot lighter bullet in a 9" twist 223rem ???

26.6 gr W-748 & 52 gr SMK or 52 gr Sierra HP.
Or 25.5 gr H-335 with the same pills.