Loading for a .223 1 in 7 Twist Barrel

[X - Man]

I need some advice on finding "the" accurate load for my .223 rifle with 1 in 7 twist barrel. I've been handloading for just over one year, and have got the essence of the process. But I can't seem to get below a certain point of target accuracy.

I use IMR 4895 powder. I want to try and stay with this powder as it's usable for the M1 and other gas operated rifles. I shoot at 100 yards; it's the longest distance at the Club range.

Best to date; at 100 yards, 1.33 MOA using 69 gr SMK, 24.0 gr of 4895, five round group; and 1.446 MOA using 77 gr SMK, 23.0 gr of 4895, seven round group.

I'd like to get this down a bit more. I load to the max length of 2.26, so I can use the rifle magazine. The length of chamber freebore is .200"(which is deep), measured using a RCBS freebore micrometer tool.. I've tried various powder charges. It's a gas operated mag fed rifle, with a 3 x 9 variable scope.

So I thought I'd ask for suggestions on the next direction to try. And I will confess it might just be that my shooting skills that need improving.

 

[subsonic]

X-Man, are you using a bipod, sandbag or rest? What make of rifle do you have? What is the purpose of this rifle? The IMR 4895 powder is very usable, but when it comes to accuracy from your gun, your barrel will tell you when you got it right. All barrels like different combinations of components. My two cents and a little experience told me that "69gr SMK's" were best used in my slower twist barrels and my 8 twist barrels ( I don't own a 7 twist ) like most bullets that are one inch or longer. Here's another two cents, I think you might want to try some 80gr and heavier bullets that will stabilize better with a 7 twist. Check out the Don Miller Twist Rule formula, you can find it under accurateshooter.com bulletin as article "Calculating bullet RPM - Spin Rates and Stability" posted June 3rd 2008. Hope this helps.

 

[X - Man]

8Ball, Thanks for the input.

I'm shooting off a sandbag rest. But it doesn't work as well as I'd like it to. The bench at the range bugs me, as it's narrow and its planks of oak are uneven. So that's the next item I've got to improve. I've got to get a proper bench rest.

I've found that the 77gr SMK is the longest bullet that can be fitted into the magazine.

I've just found the Powely computer, and have been analyzing my loads. " http://www.kwk.us/powley.html ".

And the rifle is a general purpose varmit/coyote gun, used out to 75 to 100 y. Definitely not a target piece.

 

[subsonic]

X-Man, are you shooting a bolt gun or a semi auto? Which make and model?
I feel what you're saying about that bench, a good stable platform always works best when trying to develop an accurate load.
I use Varget and Benchmark with my 223 loads in my AR, boltgun and my 308 & 30-06 M1 Garands. I will be testing IMR 8208 XBR this spring in my AR. I shoot out to 200 yards and on occasion to 600 yards.
Even though you will be using your magazine when shooting normally, try loading to single feed your rounds, just to prove a point to yourself. Try seating your bullets at the lands and grooves, then backing off about .005" at a time until you find a point where your groups reduce to under one MOA at 100 yards.
This is some advice that was given to me when I first started reloading. Remember reloading is like a science project, sometimes you have to think outside the box (magazine) to reach your goal. Whatever you decide to do, BE SAFE.

 

[X - Man]

I follow the concept of loading to just off the lands. That would require the coal to be at 2.40, about .005 off the lands. Might try that next time I make up some loads. But they are going to have to be hand fed, for sure. I suspect that the amount the bullet has to jump to engage the lands may be part of the issue.

But a proper bench rest would also help.

Now the rifle; it's a Mini 14 Ranch in S/S #188 series. While it may not be well liked in some circles, I have invested a lot of effort in its performance. Many of its manufactured shortcomings have been addressed using a number of up grades and improvements.

I want to continue to try out a number of loads. And then determine the next step once a good load is found.

 

[subsonic]

X-Man, I do understand your reluctance to reveal that particular gun. And you're right in some circles it is not liked. But I do own Ruger products too. The Mini 14 was my first semi auto just a little over ten years ago. I did not have to patience with it that you have, plus I was not reloading. So I traded in for an 20" barreled varmint AR. I was baffled at first at the difference in accuracy between the two rifles. And today I'm still baffled as to why the accuracy is still as poor as it is in the Mini 14. It seems to me that Ruger is not concerned with accuracy, in the Mini series of rifles, as much as they are with reliability or maybe liability issues. All I know is that I found it very frustrating to not be able to shoot under 2 MOA at 100 yards with a good rest on a flat concrete bench. Please keep us informed with your project.

 

[whiskey08]

not to sure about the mini 14, but .223 in ar's are usually very easy to shoot accurately. If it was me I would change powders. 4895 has provided some great groups in different calibers but it always seemed more temperamental than it needed to be. Tac is also interchangeable with other 30 cal rounds.

I load to mag length with Tac and 77smk's and it easily shoots .5 moa with a red dot scope.

 

[whiskey08]

quick question, have you tried quality factory ammo, what kind of groups do you get with that?

 

[X - Man]

Changing to another powder is a good suggestion. I've been watching the use of the new 8202(?) powder. It looks like that powder would also work when reloading for a M1 Garand.

No, never tried really good match grade commercial ammo, simply because it's hard to find locally.

While I can't provide the answer as to why the Mini behaves so, I have ruled out a number of possible cause. Less likely to be of a mechanical issue, more of a challenge to match the load and pressure to the barrel (I think). It's a process of working through all the variables. Hope I live long enough! My Mini actually shoots quite nicely, considering. Just want to see what more can be done. It's consistent, no POI wandering or stringing of shots, reliable, with smooth recoil.

Have thought about have a 'smith cut back the shoulder of the barrel (and the other tasks related), and have the chamber recut. But there are still several ideas using load techniques that can be tried.

 

[subsonic]

If you do decide to go to a gunsmith, ask him about a custom barrel with a slower twist, bedding the action and free floating the barrel, if I still had mine that's one thing I would consider or maybe call Ruger and ask them what ammunition they recommend for the Mini to shoot within 1 MOA.

 

[mattt]

You can load 2.40 if you load onlt 1 round in the mag at a time.The bullit tip will ride just on top of the mag.The best thing you could do to your mini is get the asi adjustable gas block. It turns the gas on ,off or anywhere you find works best.

 

[subsonic]

X-Man, I did some research on Ruger's site and found they don't make a Ranch with a 1:7 twist rate. The correct twist rate is 1:9, so that changes everything. Hornady make a large selection of great bullets between 50 - 60grs which I think will stabilize and give you better groups. Remember, the slower the twist, the lighter (and shorter length) the bullets.

 

[mattt]

Ruger made mini 14,s in the past with 1 in 7. I dont remember if they were from the 1980,s but I think thats the era

 

[subsonic]

Thanks mattt, I didn't know that. Maybe that's why mine didn't shoot for me, I purchased it used sometime in the late 90's, I was using 55gr factory and military surplus ammo.

 

[X - Man]

Ahhh, the nuances of Ruger's Mini. There's something about the Mini's 1 in 7 barrel that makes it a challenge to load for.

I'd like to try and load to the 2.40 length. Will be shopping for more bullets shortly.

Matt; I've installed a reduced size gas port. It helps a lot to tame the recoil. And now the Mini only throws the brass a mere 10 feet (instead of the county!).

 

[jonbearman]

What about h335 or blc-2.I get great performance and super good accuracy with it.

 

[X - Man]

Jon, I've doing some reading , relating to my issue. And I've concluded that a different powder is the next thing to try. So, you have the right idea.

I've been using IMR 4895, listed as #114 on the list of powder burn rate. H335 is #108; blc-2 is #105. 4895 is great for the M1 Garand, but it seems to be a bit too slow for the Mini.

Today, I just purchased a pound of IMR 3031, # 94 on the list. A faster powder than what you use. Using the Powley computer, 3031 is what is recommended for the bullet/barrel/cartridge combination that I use.

We are getting better weather here. Range time is in the cards.

 

[Taildrag15X]

Did some reading on the old Mini's, I've owned many though the years and wasn't aware of all the barrel twist rate changes.

Looking at the book, Ruger and his Guns, I found that the twist rate of the Mini-14 started out at 1-in-10" in 1975. It then changed to 1-in-7" in 1989 and then finally to the current 1-in-9" starting in mid-1994.

The serial numbers are approximately:
1989: 185-56000 or for the Ranch Rifle: 187-84000
1994: 186-35000 or for the Ranch Rifle: 188-75000

Hope this helps.........

 

[X - Man]

I did get out to the range, and wanted to pass on the best result.

Used the 100 yard range, shooting off the bench. Load was a 62 gr FMJBT bullet from IMI, 3031 IMR powder and a charge of 24.0 gr. COAL was 2.26"

Shot seven rounds at a 2.18 MOA. OK, but I'd like to see it group under 2". This is a load and powder I'll continue to develop.

What I did note were problems with the bench. It's simply poorly designed. The bench seat is too high, one can't plant their feet on the ground. The table top is even higher, and is covered with a sheet of plexiglass. ??? The combination makes it very difficult to get a consistent cheek weld. Even with the sand bags I used it was tough to keep the butt of the stock in my shoulder pocket. I'm fairly certain these poor bench conditions are a large part of my problem.

I've ordered a new shooting rest, and I hope it will help. I suspect that particular load will do well if I could get a better set up on the bench.