Different loads for different twist rates

Let me try to explain what I am trying to ask,
I have some .223 to load. I have rifles with different twist rates. A 1/12, 1/9, and I need to check the third one for it's twist.
I have several different Hodgdon brand powders. When looking at the data center only gives data for 1/12 twist rate.
So does the twist rate of the barrel call for different load data like is does for bullet weight?

gjgalligan said:

Let me try to explain what I am trying to ask,
I have some .223 to load. I have rifles with different twist rates. A 1/12, 1/9, and I need to check the third one for it's twist.
I have several different Hodgdon brand powders. When looking at the data center only gives data for 1/12 twist rate.
So does the twist rate of the barrel call for different load data like is does for bullet weight?

Click to expand...

Simple answer is NO. Twist rate relates to bullet length/weight, longer bullets require a faster twist rate. Any velocity within a reasonable range of the cartridges design velocity will shoot reasonably well. For .22 caliber and bullets up to 50 grains the normal twist rate is 1:16" For heavy bullets, 60 grains+, the required twist rate is 1:12" to 1:9" with longer spitzer bullets needing the 1:9". Round nose bullets usually work well at the 1:12 RATE.

In general terms, lighter bullets can be pushed faster than heavier ones. A faster powder may be better for a lighter bullet, slower powder for heavier. There is a wide amount of overlap in what powder works for what bullet.

A slower twist for a faster, lighter bullet, a faster twist for a slower heavier bullet. The forward speed of the bullet is directly tied to the RPM imparted to it by the rifling twist to keep the RPM in the correct stabilizing range.

I think Protocall Design stated it well. The best accuracy in a 22 caliber (like 223) is around 35,000 RPM. That is hard to maintain in a semi auto like AR's and be inside pressure limits but for most other action types The limit is your powder capacity.

I have a 223 with a 1:9 twist, I have to seat the 75/77 grain bullets beyond normal AR Magazine length to get enough Varget in to get enough velocity to get that RPM. So my over length and over charged rounds are not over pressure. BUT They need single loaded in any chamber with enough lead to accept the round. The end result is a load for that gun (and a number of other rifles) in a GUN/Scope/Stock/& Load combination that is phenomenally accurate! 3" at 1000 yards! Change the stock and it drops to 5" at 1000.

With the exception of that one special rifle, I prefer all my ammo of a cartridge to safely fit and fire in any gun so chambered. So, my other 223 rifles will eat any ammo for my other 223 rifles. So, I Full Length Size all my reloads! (My best AR-15 55 gr FMJBT ammo, shoots 1/4" groups in the AR and even better groups in my Cooper 21. The Best Cooper 21 load is below 1/10" at 100, and around 1/8 to 3/16" in the AR.

The problem is this is not universally true. Your guns may not like my ammos.

Also, The primer and the powder you choose may not like each other! So, when you read an accuracy load in a manual be sure to use that exact brand and model primer. Rem 7 1/2 primers are very common in High Pressure Bench Rest loads. But with the same powder in a low pressure load they suck big time, switch to Rem 6 1/2 and usually the accuracy returns.

Different brands of the same weight and profile bullet will often give radically different results. In most 22 Center Fire cartridges, I use a 50 grain polymer tipped boat tail bullet. (everything but 22 Hornet) There are 4 major brands of that bullet on the market. Hornady V-Ma, Nosler Ballistic Tip, Sierra Blitzking, & Combined Technologies Ballistic Silver Tip. I use whatever I have the most of to develop a load for a gun. when I get as good as that bullet gets, I use the same load data with a 10-round sample of the other three. Of the 4 brands of bullets a specific gun will like one brand of bullet more than all the others. (I once had a 223-bolt gun that liked Sierra and Hornady the same, but that is super rare!)

In these days of shortages, just getting ammo that shoots reasonably accurate is often difficult! But if you have the resources, why not go for as perfect as possible?

Ivan

I believe that you should work up loads with rifles having different twist rates. If you want to shoot 35 gr and 77 gr bullets in rifles with 1 in 12, 1 in 9 and 1 in 7 twists you will be disappointed if you expect one load to work well in all of them.

several years ago bought a mint, used, Browning X bolt in 223. Scoped, found it just would not group well at all with my usual 62 or even 55 grain bullets. For some forgotten reason I thought it had a fast twist rate, and decided before I sold it to check with the Flag Test what twist it was. It is a 1/12 twist, I suspect for some sort of Varmit shooting.

So made up some 40 grain Hornady V max bullets, and it immediately became a very accurate rifle, with 335 powder, mid to upper load. So that is what I make on a single stage Redding press. I was talking to the gun shop guy, a good friend, and mentioned that my Browning is now a very accurate rifle. He mentioned that the former owner brought it back because it was not an accurate rifle.

I suspect that first owner just shot bought 55 grain ammo, and was disappointed. All my Browning needed was a lighter bullet to become what it is capable of.

When I let other shooters try my x Bolt, they are amazed at how accurate it is at 100 yards.

I suppose per the previous post I could further refine my rifle's accuracy with matching primers and lot number's of powders and such. But with my 78 year old eyes, and a slight shake, I just can't do any better. Plus, I am shooting my old stock of primers, and there just isn't much choice out there.

I have found the same for my now deceased Father-in-Laws, early Belgian Browning Bar. Checked the twist, and gave away some boxes of the heavier bullets which would not group, and now load and shoot lighter bullets, matching bullet wt and twist made that rifle much more accurate.

I think that for small caliber bullets, matching twist and bullet wt makes a lot more difference than in larger bores. A proportional thing? A 15 grain difference between 40 and 55 grain 223 is proportionally a lot more difference than the 20 grain 30 cal 130 and 160 grain difference.

I can only shoot out to 200 yards, so what happens beyond that is not important to me.

All the best... SF VET

My AR-15 rifles have fast twist rates, i.e. 1:7 and 1:8. They shoot the 75 gr. and 77 gr. bullets very well. I never cared for the run-of-the-mill 1:9 barrels. Those 1:12 barrels are often found on bolt action varmint rifles and they shoot the light bullets (under 55 gr.) well.

I know all this is confusing ... let me explain it in this way .

The rate of twist affects (effects) bullet Weight more than anything .
Some rates of twist will stabilize and accurately shoot Light bullets ...
other rates of twist will stabilize and accurately shoot Heavy bullets.

This seems to be more pronounced in the smaller calibers ... the ones belw 30 cal.

If you have a .223 that has a twist suited to light bullets ... you will never get super accuracy with Heavy Bullets ,

Pay attention to the twist rate of your rifle's barrel and use the weights reccomended.
Gary

Let me try to sort out the above advice. Some of which I learned the hard way.

1-12 twist, you're limited to the 50-55 gr bullets-or lighter- with a lead core. The various bullets that either have a non-lead core or are all copper are going to be too long to stabilize at any velocity you can safely reach. But, check your load manuals or the bullet manufacturers information on twist rate.

1-10 twist will stabilize up to and including the 69 gr Sierra Match King (SMK). Will not stabilize the non-lead core or all copper bullets.

1-9 twist will stabilize the Hornady 75 gr HPBT, but not the AMax or 77 gr SMK. Will handle some (most?) non lead core/monolithic copper bullets. In tests by American Rifleman staff, it appears to be the most consistently accurate twist rate.

1-7 twist was intended to stabilize a tracer round, will handle the AMax or the 77 gr SMK as well as the non lead core/monolithic copper bullets. HOWEVER, light bullets with thin jackets can be over spun and come apart on the way to the target.

A 1:12 twist will handle the lighter 55 gr bullets up to maybe a 63 gr bullet.

My 22-250 some how managed to get a Speer 70gr RN to group at 2" at 200 yards
but the 55gr or lighter bullet were much better at 300 yards, or longer !!

A 1:9 twist is made for bullets at 70 grains or heavier for 300 yard plus shooting.

We all know that WIND is the major factor with hits with the little .22 bullets.

Have fun.

Your .22-250 drives the bullet much faster than a .223 will, that's how you get those bullets stabilized. The bullet's spinning much faster.