Recently I was trying out different weight bullets for my Ruger Rifle 223, starting with 53 grain and going up to 60. While shooting, a fellow next to me asked me what twist my barrel carried. I told him 1 in 9. He told me that the best weight bullet was 60 to 70 grains. He said that was the weight used by the professional shooters. I am new at rifle shooting, so I thought I'd ask for comments on that recommendation.
Personally, I found the lighter and heavier bullets, under and over 55 grain to be less accurate in my gun. Of course, I must admit that I didn't try different amounts of powder, nor was I using the powder the fellow shooter also recommended which is Varget. I have used Varget as my first reloading powder, but didn't do any tests with it using heavier bullets. I'm using Benchrest now since I was able to find 8 lbs at a good price.
1:9" twist would SUGGEST your gun would prefer 60-70 grain bullets, but I have to stress, all guns are different. They all have what they like and don't
yep thats right! Ive got a .223 with a 1 in 9 twist that absolutely loves 40 grain v-max's over a stiff charge of varget pushing around 3500 fps. one ragged hole at 100 yards.
Just like Deverge said, all guns are different from the factory. Professionals use premium grade barrels and throw away factory spec barrels. When reloading you get to see what works for your gun and know the exact best load from 40-70 gr and what powder.
Thanks fellows. I'll keep working on it. I'm thinking of sending my trigger assembly to Gundoc and have him work on it. It has one point on the squeeze that seems to have a rough spot. At 100 yards it tends to cause the scope to move off where I'm aiming. Right now, with Hogdon Benchrest I have found that the 55g BT Winchester with cannelure with 23.6 grains of powder does best. I'll keep experimenting though.
You better email him first. I just wrote him on some Mini-14 questions and a quote. He put me on a waiting list and he didn't say how long it was going to be.
Thanks. I did email him last week but haven't heard from him yet. I guess he has built such a good rep for himself that he is getting more than he can handle at this time, or he may just simply be taking a little R & R and needs to catch up.
I just found yesterday that Ramshot and Alliant have load data that is broken down by twist rate. For a 1:9 twist, the bullet weight ranges between 68 and 80 grains. I am beginning to explore this myself and I think I will be starting in to middle and working around about 75 gr. loads to start with.
But the twist rate formula variables are diameter and length, not weight.
The formula is:
150 x D x D = twist
length
So we would need to use that formula with each different bullet we load.
You got it. The common misconception is that twist rate determines bullet weight, but it actually determines bearing legnth. Just in the way the world works, heavier bullets tend to be longer than light bullets.
The only bullets that tend to not follow this rule are match bullets, and 100% copper bullets. Match bullets tend to have less lead in them compaired to traditional purpose bullets, so the bullets are longer for the same given weight. Leadless bullets are longer for the same reason. Eg. Barnes .284 dia 140gr. TSX is as long as a .284 dia Rem 175gr Core Lokt.
Bullets shape will come to play also in how your gun works. Guys were talking on another thread about the bearing surface between the Hornady 68 and Sierra 69 bthp's. The Sierra's usually shoot better because of thier greater bearing surface against the barrel. I love shooting the 65 gr spbt of Sierra in my mini 14. I do well with Hornady 60 vmax and Nosler 55 gr bt. I love reloading and seeing what works for my gun, my bolt Savage love just about anything I feed it.
Do you think either the Sierra or the Hornady SPBT would make a good SD load then, seeing as how it will definitely expand well and is the right weight for a 1:9 in a 580 series Mini-14?
Do you run into problems with the match bullets fitting in the chamber due to their length? Or do you seat them deeper and lower the powder charge to balance it out? What I was thinking was that the match bullet would, at some point, run into the rifling and cause problems. How do you overcome that?
Do you run into problems with the match bullets fitting in the chamber due to their length? Or do you seat them deeper and lower the powder charge to balance it out? What I was thinking was that the match bullet would, at some point, run into the rifling and cause problems. How do you overcome that?
I am assuming you are referring to your Mini-14. If you seat your bullets to fit the Mag, they will fit the chamber without any problems. The Ruger Mini has a very generous throat. If you are loading spire point bullets and they fit into the mag they will not be close to the lands(rifling) at all.
The best way to find out max COL for a specific rifle/bullet combo is to purchase a Stoney Point gauge. It will tell you within .001 of an inch were the bullet comes in contact with the rifling. I have one and use it all the time. I load for several different rifles and cartridges and I find it invaluable, but if I were loading for one or two long throated rifles like the Mini it would be a waist on $$. Keep it in the mag and you will be fine.
I don't shoot match bullet in my mini 14, I just use the same bullets for plinking and hunting. I think either Sierra or Hornady hp would be great for SD, but I lean more towards the Hornady Vmax or a ballistic tip for SD, less wall penetration and rapid expanding. For close quarters 50-55 gr would be enough in a ballistic tip. For loading I do like Steve mentioned, I load to fit the mag mostly but most of my loads do well with a col of 2.250, I think the farthest you can load to fit the mag is 2.265.
I would not use match bullets for SD. Most are designed with accuracy in mind. If they are designed to expand at all, they usually are designed for small varmint, eg: explosive expansion and frangibility for prarie dogs. You more than likely would not get enough penetration on a human to do any real damage.
I keep seeing this reference to bearing surface being the issue when it comes to rifling twist. I see a fundamental flaw with the reasoning.
The rotation required to stabilize a bullet depends on two things; velocity and rifling twist. If the bearing surface was playing by another rule, your bullet would clearly not be following the rifling and your recovered bullets would show this. I conject that the different sweet spots have nothing to do with bearing surface as demonstrated, but the difference that bearing surface plays is actually to do with the difference in drag and hence velocity. IE if a long ogive bullet has less drag, it will attain a higher speed, and thus be more tolerant of a slower twist barrel.
Am I missing something here?
Incidentally, I have both a 1 in 9 and a 1 in 10 mini, and my experience with the bullet weights in these two rifles is as such; The 1 in 10 cannot stabilize a 62 grain, but LOVES 55 grain bullets. The 1 in 9 Likes the 62's better, and shoots them more accurately than the 55's, but it takes careful scrutiny to catch the difference in accuracy. I load the 55's to the warm end of the spectrum, and the 62's are ss109's. My general experience with the 1 in 9's is that they are very forgiving of bullet weight. Fine tuning the charge to avoid negative effects of barrel resonance, I think may play a significant role.
Hey out there,
I am planing to start loading for my Stainless Mini 223. I have been trying to find the twist in order to find which weight and bullet may work best. I think I would be burning up supplies if don't first know the twist. The SR # on mine is 188-58008 and from what I have found it was made in 1992. I e mailed Ruger but they have not been back in touch yet. If any of you folks know of a site that I can locate the twist please let me know. Thank you.
Have Fun
Buckshot
Buckshot
Cleaning rod and a tight fitting patch.
Place a line along the length of the rod, insert the rod into the barrel, note where the line is and mark it at the muzzle. Push the rod into the barrel until the line makes 1 full turn, and again mark it at the muzzle.
Now, remove the rod and measure the distance between the marks.
I agree with Tailgunner's technique, but have had slightly better luck using a bore brush instead. My guess is you most likely have a 1 in 9. Another thing that works kind of well is to put a permanent marker on the side of the rod as you push it in. Then you can clearly see the twist marked on the rod. And you also can see if something slipped (straight line).
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