Twist rate/bullet weight .223

[Handsome Rob]

Yeah, I know it's been done to death.
And as much as it has, I can't find the actual answer, anywhere, that I'm after.

I have a 1:8 twist .223
I know it will stabilise pretty much any bullet weight from 40gn to 80gn but I really want to know what weight it will stabilise best.
My brain is saying sound 62-64gn, but I don't trust my brain. The sneaky bastard's let me down before.
I'm limited to factory ammo right now & I'm looking at premium stuff, not green tip/fmj surplus.

Oh, barrel length is 16½" in a bolt gun. Edited May 11, 2015 by robtattoo

[samson7x]

This is just one sample, but my Ruger American likes my 60gr vmax handloads the best.  It does not group well with anything 70gr or heavier.  

[Hozzie]

I would personally say in the 70-75gr range would be best suited, but I suppose it depend on what you are looking for.  I think 40's would be way too low.  I think 60's for a 1/9, and 80's for a 1/7.  

 

I suspect you are looking for the heaviest bullet with the most accuracy for your hog hunt?  

 

Edit: And as soon as I post, someone with direct experience opposite what I would have went with :pleased: .  The hard part is each gun seems to act so different.  Wish I had some heavier bullets for you to try out beforehand..

Edited May 11, 2015 by Hozzie

[Handsome Rob]

You got me!

Yeah, that's pretty much my line of thought.

I was just trying to figure out what I need to buy, before I plunk down a load of hard-earned. I'm as interested in accuracy as I am in weight.

[Dolomite_supafly]

You want the heaviest bullet the barrel will reliably stabilize. The faster the twist for a given bullet the more the groups will open up but how much it bothers you will depend on you. The best groups I even shot consistently were out of a 9 twist barrel shooting 69 grain bullets. Same bullets in a 7 twist resulted in larger groups even after working up the best possible load. For an 8 twist I would say you want at least a 73 grain but ideally probably 77-80.

 

Think of it like an out of balance tire. The faster it spins the more off center it becomes. Every bullet is out of balance to some degree and the faster you spin then the more off center they become. There are some bullet makers who even suggest that bullets will not truly settle down for several hundred yards. I have read about people having smaller 200 yard groups than their 100 yard groups so there might be some truth to what is being said by the maker.

[Tempest455]

Ditto on above.

 

My 1-9 .223 loves the Berger 70 VLD's. Best that gun has ever shot at mid range.

[Jct1911]

Lots of opinion here as it relates to personal experience. Rightfully so. Every barrel is different. My most accurate barrel is a Odin Rifle Works 18" 3gun barrel with intermediate gas system. It groups my well proven 75gr HPBT over Varget load around .8(10shot group)and this load has shot .6 in 2 other rifles. This rifle will group .5 with 55gr Speer flat based HP varmint bullets and 25.6grs TAC. Long story short, load development and testing is necessary otherwise it's just a guess. Of all my barrels, the 1:8 twist barrels are consistently more accurate across the weight range from 52-77grs.

[Trekbike]

It groups my well proven 75gr HPBT over Varget load around .8(10shot group)and this load has shot .6 in 2 other rifles.

If you don't mind me asking, how much powder are you using in that load?

[Jct1911]

If you don't mind me asking, how much powder are you using in that load?

I won't post details but it is a few tenths of a grain over max published .223 data with the Hornady 75gr HPBT match bullet loaded to mag length, it is a compressed load. I only load it in Winchester brass as it is most consistent.

[Handsome Rob]

Well, either my GSR sucks like a $2 hooker, it's SUPER picky about ammo, or I just flat out can't shoot anymore.
I tried Hornady & Armscor 55gn, green tip & Federal Fusion 62gn & Prvi 75gn match.

My best 100yd 5 shot group out of that lot was 2½"

I've tried other factory loads in the past & I've not found anything yet that this damn thing likes :(

[RED333]

Well with all the info given by robtatto it is still not enough.

Chamber specs? Not "printed or factory" but actual, meaning a chamber cast or a pound cast.

My bet there is a possible chamber issue.

Also the barrel crown just might not be right.

You could have a bastard rifle that the chamber is not in line and square with the bore.

Have you check a spent case for specs?

[Dolomite_supafly]

Take a look at the crown, if there is an issue let me know.

A couple of things I would try.

First, use something to put a pressure pad back 1" from the tip of the stock. That will act like a bedded stock and should settle the groups down some. I have used cork, sponges and even foam ear plugs at times.

When tightening the stock into thd action do it this way. Loosen all screws but do not remove them. Pull the barrel away from the stock at the forearm. And while trying to hold the barrel away from the stock tighten the screw at the rear most position. Then do the next one, and the next one, until the action is tight in the stock. This ensures the recoil lug is firmly against the stock. This can help reduce harmonics. You would also want to add the pressure pad while doing this.

If that doesn't work then free float the barrel. Take the pressure pad and place it right in front of the recoil lug between the stock and barrel. Then tighten using the method above.

I would also verify that your optics are tight.

[gregintenn]

I'd try another scope before I dinked around with the rifle much. Also, try a box of factory Remington ammo.

[Handsome Rob]

Hmmm...

I removed the flash hider & tried the cotton ball test on the crown. A-ok there.
Removed the scope & checked the factory rail. Remounted the scope & I'll go try again on Saturday. I'll grab a couple more boxes of different factory ammo to try.
I bought a set of dies last night from Midsouth, so one I find which weight it groups best, I'll start messing with different loads & see if rolling my own tightens things up at all. Edited May 15, 2015 by robtattoo

[Dolomite_supafly]

There are some loads that are considered optimum loads. That is they work well in a wide variety of weapons. One of them is the Federal Gold Medal Match (FGMM). The same holds true for certain hand loaded ammunition. One load that seems to work really well across the board for a lot of people, with a wide variety of guns, is 24.5-24.7 grains of Varget and the 69 grain Sierra Match King. I was searching when I seen this recipe mentioned so I tried it and have stuck with that one if I am loading for accuracy. I have dozens of confirmed 1/2 MOA groups using that recipe in at least three different guns.

 

I think it has more to do with the powder charge than the bullet weight so you could try it with heavier bullets. That charge is on the low end of the recipe so there is plenty of room to increase the bullet weight.

 

Out of a 26" barrel 24.5 grains gives 2,950 fps with the 69 grain bullet. Out of a 16" barrel it is at a much more sedate 2,350 fps. So each inch of barrel length adds ~60 fps depending on the gun. I really do need to break out the 223 bolt gun and shoot it but it is boring shooting a gun at 100 yards that is capable of so much more.

 

BTW, I bet there are a few in this thread who use this same recipe.

[TN-popo]

I am not disagreeing with the conventional wisdom concerning bullet weights and rifle twists.

 

But, there is a bit of VooDoo involved too.

I've shot 1:7, 1:8, 1:9, and 1:12. 

I once had a 1:7 Colt that shot 55gr better than the heavier stuff (tested with multiple loads).  That shouldn't be, but it was.  Go figure.

I had a twin of that rifle (another Colt green lable, both were stock) that shot sub-MOA with Federal 69gr Match (and only that factory round...I don't handload).  Again, go figure.

 

I've always felt that the best all-around 5.56 / .223 twist rate was 1:8 (and I wish that it was more popular / standardized).

However, since all I ever shoot is 55gr stuff (both at work and personal / practice and SD rounds), all of my ARs are 1:9 (I know, I'm not MilSpec and Tacticool).

 

Anyway, the conventional wisdom is usually accurate and a good rule-of-thumb, just don't be completely married to it.

Just my opinion.

Edited May 17, 2015 by TN-popo

[Handsome Rob]

Well just finally managed to score some Varget. Had to buy 8 freaking pounds for just north of 2 freaking bills but...

I'll try Gordon's recipe (modified for the loss of 4gn bullet weigh) & report back tomorrow night...

[Handsome Rob]

Took it back to the range yesterday & problem solved!
65gn Gamekings over Varget cured the issue.
It shot well with everything from 25-26gn, increased in 0.2gn increments, but shot a 4 rounds cover leaf (maybe ½") with 1 called flyer with 25.8gn
The flyer I'm putting down to the trigger, which is akin to dragging a railroad tie over a corrugated tin sheet (#@$#*€ lawyers! :( )
A bit of a file & polish has fixed that issue ;)

Thanks for all the help guys!

[whiskey]

My hog killing buddy in Florida says he uses a Barnes Triple Shock for hogs with a 556. He's using a 55gr because that's what his gun shoots well. I think they offer it in a few weights.