223R With 90gr Bullets?

[ThunderDownUnder]

I did a forum search and found very little load data for the high BC 90gr bullets.

The 90gr long range, high BC bullets have been around for a while now and I was hoping someone might be able to post some load data.

I am curious about what velocity and accuracy can be achieved with the 90 grainers and if they perform better than the widely used 80gr bullets.

 

[memilanuk]

Lots of load data on nationalmatch.us, and probably some on long-range.com.

The short version... the .223 Rem lacks the punch to push them fast enough to make it worth the effort over a good 80gr load. It can push them, and they will fly,though a lot of them blew up early on too), but the benefit realized down range on target ain't much,1/2 moa or so, if that). Thats the synopsis of what I read as well as saw trying them out of a 20' AR Service Rifle.

Jerry Tierney did some testing recently with long-barreled .223 Rem, since its now a legal Palma cartridge in the US. I don't recall specifically how the 90gr bullets fared, but you can probably find the thread easy enough on long-range.com - it was in the last couple weeks I think.

YMMV,

Monte

 

[JERRYHM]

Barnard Action 223 Palma Rifle completed on May 5, 2009
Krieger barrel 32” 7.7 Twist.




June 23, 2009 Sacramento 100 yard chronograph testing, Temperature = 72 to 75 degrees.
Bullet --- Powder --- Charge --- MV --- ES --- SD --- Group size --- Comments

B90VLD –RL15 – 24.3 ------ 2892 ---- 29 --- 11 ----- 0.571” ------- in 10
B90VLD –RL15 – 24.3 ------ 2881 ---- 30 --- 14 ----- 0.471” ------- jump 20
B90VLD –RL15 – 24.3 ------ 2879 ---- 13 --- 05 ----- 0.642” ------- jump 40
B90VLD –RL15 – 24.3 ------ 2878 ---- 28 --- 12 ----- 0.430” ------- jump 60
B90VLD –RL15 – 24.3 ------ 2874 ---- 28 --- 11 ----- 0.648” ------- jump 80

 

[tenring]

Savage LRPV 1-7' twist. Tried the 90 gr. Berger, but it did not shoot as well as the 80 gr. VLD. Don't remember my load.

 

[ThunderDownUnder]

Thanks for the input!

Here's my plan, buy a 32' Krieger barrel in 7 twist and attach to my Barnard action. I had a reamer made by PT&G with 0.085' freebore for the 80gr Amax's that I currently shoot. The 90gr Sierra bullets at 1.171' long are almost the same length as the 80gr Amax at 1.162'. I'm hoping the chamber will suit both.

From what I have seen of JERRYHM's post I will need about 24.5gr of Varget to be at approx 2900fps. At 2900fps with the much better BC of the 90gr bullet I should have a good f-class rifle for 300-600yd matches. Thats providing the accuracy is as good as the 80gr Amax bullets I currently use in my 30', 8 twist barrel. For the longer ranges of 700-1000yd I'll use the 6.5x47L.

When the barrel turns up I will start the load testing. I might even run a few through my current 8 twist barrel just to get some idea of velocity and max loads.

 

[JERRYHM]

I would not use a barrel length over 30' for the 223. When I cut the barrel from 32 to 30 inches some loads increased in MV.

Summary after cutting barrel from 32” to 30” and to 28”
19 five shot groups for each length.

MV average
32” --------- 30” ---------28”
2989 ------- 2983 ------- 2963

ES average
32” --------- 30” ---------28”
25 ---------- 23 ---------- 30

Group size average
32” --------- 30” ---------28”
0.539” ----- 0.501” ----- 0.502”

 

[ronemus]

Thanks for the input!

...buy a 32' Krieger barrel in 7 twist

You'll do much better with a 1:6 twist if you plan to use the 90 gr bullets; they are barely stable from a 1:7 on a warm day, and will be unstable at low temperatures. A 1:6.5 will work, but the stability factor is still low.

 

[JERRYHM]

A 6 twist? You got to be kidding.
I think the problem that shooters have in getting the 90 grain bullets to shoot in a 223 is that they are spinning them too fast.
I have NO problem getting the Berger 90 VLDs and BTs to stabilize in a 7.7 twist, 50 degrees and elevation of 200'. I have gotten the 15 shots,Palma irons) sub X ring elevation at 1000 yards.

 

[Rtheurer]

I personally would not go to a faster than 1:7 twist in a Bolt Gun with a Barrel longer than 24' No need to go crazy there.

Only reason to even shoot a 1:6.5 is because of a short Barrel of the service rifle AR15. In Anything longer a 1:7 works just fine as Jerry Pointed out.
And since Mr Thunder is from Australia I doubt he is shooting any Semi auto 20' barrel anything,, just a guess).

Right Now Jerry is leading the way on this research. You would be well advised to pick his brain on all such matters of shooting 90's out of a Bolt gun at Long Range. He has alot of data on 80's as well. Judging by the amount of data he has collected and charted I would say he is buring up barrels for our digestion of information on the subject.

Jerry where do find all this time to do that??

RussT

 

[flatlander]

From several years' experience shooting JLK 90VLDs out of 6.5-tw AR service rifles, I agree with Jerry's assessment of the problems many shooters have had with 90s in the past. My 1st 6.5-tw was a PacNor 3-groove AR SR, and it was absolutely a hammer. The next three 6.5s were not-so-hot, varying from mediocre to a downright disaster that blew up everything I shot through it except S77s. I finally gave up on 90s at about the same time I gave up on 6.5-tw. 223 bbls., in the belief that 90s wouldn't work with anything slower than a 6.5 twist.

However, after reading Jerry's post on LRTargetShooting, I just had to try some left-over 90 ammo through the 7.5-tw PacNor on a M70 - they shot great at 600, and middlin' good at 1000. Haven't shoot enough of the Berger 90 VLDs through this barrel yet to have much of an opinion on them, but there's no doubt that the 7.5-tw is plenty fast enough to stabilize a 90. I'm not getting quite as much velocity as Jerry is, but my bbl. is 27' long.

 

[Travelor]

The Dominion of Canada Rifle Association, Winter/Spring 2008 newsletter, called 'The Marksman' has a very extensive article on shooting heavy bullets in the 223 Remington out to 1000 yards. The article on heavy bullets in a 223 begins on page 16 and you need Adobe Reader to view it. Well worth the read!

Enjoy: http://www.dcra.ca/Marksman/Winter%20Spring%202008%20Edition.pdf

I have begun testing these loads mentioned and have had very good results, but I am still in load developement. I am using a Savage 12 LRPV with a 1:7 twist barrel that has been massaged by Larry Racine. Hope I am not giving up the secret Holy Grail to 223 loads.

 

[1000yardstare]

Was shooting with my buddy on our club`s 300 metre range last Spring, getting ready for the ORA F Class season. I was having good luck with 75 gr AMax molys which I was trying for the first time in my MacLennon 30 inch 8 twist barrel.

He was trying 90 gr MKings in a Savage LRPV 7 twist. Can`t remember his load. He would usually put 4 shots into moa but there would be a 5th shot flier. The flier happened at anytime during the firing sequence. Now and then there would only be 4 shots on the paper. After reading the above mentioned DCRA article, we didn`t know if the flier was so wide it missed the paper or if it had blown up before reaching the target. Anyway, he sticks with 80 gr Berger or MKing now.

 

[ThunderDownUnder]

There is much discussion about bullet stability in relation to the 90gr bullets. It seems everyone is happy with 8 twist for the 80gr bullets as most use this with great accuracy and stability out to maximum ranges.

Lets get technical and do some stability calculations using Bryan Litz's software from his new book. We will look at 2 bullets and 2 twist rates.

Sierra MK 90gr are 1.171' long with a G7 BC of 0.256
Berger VLD 90gr are 1.263' long with a G7 BC of 0.281
Twist rates used will be 7.7 and 7.0

Bryan Litz suggests a stability factor higher than Sg = 1.4 to allow a margin of safety for adequate stability. Anything under Sg = 1.0 is unstable.,Sg is the gyroscopic stability factor)

Sierra Bullet
MV = 2900fps 7.7 twist for a Sg = 1.39
MV = 2900fps 7.0 twist for a Sg = 1.68
Berger VLD Bullet
MV = 2900fps 7.7 twist for a Sg = 1.11
MV = 2900fps 7.0 twist for a Sg = 1.35

Sierra Bullet
MV = 2800fps 7.7 twist for a Sg = 1.38
MV = 2800fps 7.0 twist for a Sg = 1.67
Berger VLD Bullet
MV = 2800fps 7.7 twist for a Sg = 1.10
MV = 2800fps 7.0 twist for a Sg = 1.33

Its interesting to note that the Berger bullet is longer than the Sierra bullet and therefore requires more stabilization,more twist) but has the higher BC.

In the above example the Sierra bullet is better suited to the 7.7 twist barrel and the 7.0 twist only just gets to Bryan's recommended Sg >= 1.4 for both bullets.

Using Bryan Litz's 'Point Mass Ballistics Solver' software has given a better insight into how to determine the stabilty needed for the 223R 90gr high BC bullets. Now I just have to go out and shoot it and find out for myself how well my choice of 7 twist barrel will perform!

Edit: I just found JBM now have a stability calculator, do your own calculations here: http://www.jbmballistics.com/~jbm/cgi-bin/jbmstab-5.0.cgi

Ian

 

[mysticplayer]

Since reading the Litz book and seeing how high the BC of the 90gr Berger VLD's are, I decided to see what would happen in a 8 twist Shilen 223 at 22' long.

Using a standard 223 chamber, the VLD is seated well into the case. Kind of looks neat cause only the point is sticking out.

Not expecting much, I made up a couple of loads based on what I am using with 80gr Amax and Varget.

One load put 2 shots 1/4' apart in gusty winds,only shot 2rds cause was expecting them to go in sideways). All holes nice and round.

So I loaded up a some more of this load and headed out to 1035yds,swarovski LRS). Temp around 7C, elevation approx 3000ft.

NO issue making this distance at a chronied speed of only 2600fps. Bullets did land with good accuracy,plinking at rocks).

Out to 1175yds, no problem at all. Bullets dropping into a target about the size of a milk jug.

Again, only a few rds fired at each distance cause I was fully expecting the bullets to tumble.

I am very surprised but this bullet handles the 8 twist just fine and is very easy to set up. It is well off the lands and is working just fine.

Very interested in how this will work as either an F T/R in 223 or as a 22/250 in F Open.

Jerry

 

[ThunderDownUnder]

Interesting post Jerry!
I just ran 2600fps with the Berger 90gr VLDs thru the calculator with an 8 twist barrel and the result was 0.99Sg, which is borderline stable.

I shot a few Sierra 90gr thru my 8 twist 30' barrel at 2722fps and got pretty good accuracy. I am going to load it up a bit and maybe get around 2850-2900fps and see how it performs.

Ian

 

[mysticplayer]

Agreed, the numbers certainly do not support the type of performance the bullet did at 1200yds.

As time allows, I will try shooting some more and try to get a feeling for the accuracy of this set up.

I wonder if some of the problems some shooters have reported could be due in part by too much spin/stability.

Still lots to try.

Jerry

 

[ThunderDownUnder]

I completed load testing with the 80gr Amax bullets in my 8 twist barrel and couldn't resist putting a few more 90gr MKs thru as well.

90gr Sierra MKs,pointed) with 25.2gr of Varget has bumped the velocity up to 2800fps and the 3 shot group at 100yds was 0.23 moa. Thats it for testing till I get my 7 twist barrel chambered. When the barrel turns up I'll up the load to 25.5gr of Varget and see how it goes. Its one accurate bullet and might be like a mini 6BR if the velocity can get into the 2850-2900fps region.

 

[Rtheurer]

Ian

Good report so far Im glad your keeping us posted. What kind of ES and SD are you getting with the SMK..

.23 MOA looks promising, Id like to see a 10 or 15 shot group to see if it holds good accuracy and ES as the barrel and chamber heat up.

I may have missed the post but what is the type of shooting this rifle is intended to do? Target rifle Fullbore? Benchrest? or just for fun paper punchin.

Cant wait to see if your results mirror Jerry's with the 1:7

RussT

 

[ThunderDownUnder]

Russ, I going to use it in f-class. The Amax 80gr will be used in f-std,restricted to 308W, 155gr and 223R, 80gr)and the 90gr MKs I'll use in f-open,unrestricted caliber upto 8mm)out to 500yds.

ES 14, SD 7.6, for the 3 shot group I shot, not much data collected yet.

It all depends on how well the Sierra's shoot if I will use it in f-open. Interestingly a 7 twist barrel on paper appears to be a better proposition than the 8 twist even with the 80gr Amax. The Amax being a VLD type bullet is quite long and while the 8 twist does the job, maybe the 7 will do it just as well or better. I'll know soon enough!

Ian

 

[JERRYHM]

Ian,

Have you seen this five shot group on the 600 yard Bench Rest target. It was shot with the 80 grain amax bullets, the amax is grouping the best of the 80 grain bullets I've shot. Had a Nightforce scope and front block on the prone rifle to shoot bench rest. The X ring is about 1.2 inches.

Jerry Tierney