221 Fireball - what twist rate?
 

My search for a .22 caliber centerfire barrel for my Encore pistol has caused me to research several promising cartridges. First was the 5.7x28mm, which I decided against due to a lack of brass availability. Second, the 22 Hornet, rejected due to its thin brass. Finally, I looked at the 223 Remington, which (and this will sound silly) is a bit too much gun for what I want. Now, I've settled on a 221 Remington Fireball barrel. I've decided on an MGM 12" blued heavy taper barrel, but I'm unsure of what twist rate I need. I'd like to be able to fire 55 grain FMJ bullets as cheap target fodder, along with similarly weighted V-Max and A-Max bullets for more precise shooting.

What twist rate should I go with, and what would be the upper range of bullet weights that twist could handle at Fireball velocities?

Blast from tha past!!! Boy did you pick a love child!! I never got into the "long pistol" craze like you did Wolf but I did some experimenting with that cartridge LONG LONG ago in a rifle. Don't quote me on this cuzz it was probably 45-50 years ago but I seem to remember that barrel being 5 groove 1:18 and it handled 55gr Sierra's like a champ. One thing, actually the only thing, I liked about it over the .22-250 was it was a dang site quieter! You ever shoot a .22-250 and you will get my drift. Dang things are LOUD!! But in pistol lengths, I think you may have thought up a dandy little critter gitter there buddy.

I used to have a 22-250 years ago. You're right about that sucker being loud. I wish I still had it - it would stack bullets on top of each other at 100 yards, even with me shooting.

This build is going to be more of a target/practice rig. You've seen the potent handguns I shoot. Needless to say feeding them gets expensive after a while. I've done the math, and I can reload it for far more cheaply than my other Encore handgun chamberings. Maybe it'll be a fair bit quieter than most of them, too.

Well you certainly wont have to brake it so that's a plus on the noise factor. And I'd say you will be in around the half range of your other loads price wise for reloading. Even buying good bullets you will come in WAY under the monsters you load for now. And honestly, I think that would be a dandy little cartridge to get out there and nail some pesky ground hogs and Yotes with!

That should make for a sweet little shooter.
-Jake

I haven't had one in a TC, but have had 3 of "the original 221 Fireballs," the XP-100's. They initially came out with a 1:14" twist, then with the advent of the XP-100R, they updated to a 1:12" twist, both of which were aimed at shooting 35-50grn bullets, and the change being driven by the fact the 1:14" didn't run the 50's all so well.

You should be able to kick up over 2550fps with the 55grn pills in a 12" TC. You'd do fine with a 1:10" if you only ever shot the 55 FMJ's at that speed, but the tipped bullets are too long to be stabilized by the 1:10", I'd personally go with a 1:9" if I were planning 0-200yrd shooting, 1:8" if I were planning any farther. The 55 V-max needs a 1:9" to stabilize "confidently" according to Berger's stability simulator, and is on the ragged edge with a 1:10". The 55TTSX assuredly needs a 1:9" to stabilize, as I'd assume any of the other tipped monometals would.

Otherwise, remind yourself the 221 Fireball was never meant to be a "baby 223rem." It was designed to shoot the lighter 22cal pills, and it does so very well. If I were going to plan a longer range 221 Fireball barrel, I'd be hard pressed to talk myself out of a 1:7" twist barrel, crowned at 14", throated for the 69 SMK - it's hard for me to remind myself "it's not a baby 223rem" too. Reason would win out and I'd go back to a standard 1:12" with a 40grn Blitzking, which is why I haven't ever rebarreled my 221FB XP100's.

I went with a 1-9" twist when I ordered the barrel. I figure that ought to keep the 55 grain bullets stable out to 200 yards at least.

Just got an email today. It'll be here Tuesday.

How did that rate of 1:9 twist work out for you. I am thinking of a 221 fireball build in a Remington SPS and was looking into the 1:12 twist or maybe a 1:10 twist.

You do know the op was over 3 years ago, I doubt the op is checking the thread anymore.

He's still active- this is a valid question.

Why does it bother you so much?

-Jake

yeah I know the threads old, but for the newer guys,

maybe because Im an engineer
but have you ever considered using precision measuring tools on the bullets you want to use and available math?
links to calculators





https://bergerbullets.com/twist-rate-calculator/

https://thebarreloutlet.com/twist-calculator/

http://bulletin.accurateshooter.com/...el-twist-rate/

Because it does!

Here we see a post that is on topic, a good question, a follow up to the OP, asking for personal experience from somebody who has now owned a firearm for several years.

Exactly what forums like this were intended to do.


Here we see a post that's not on topic, not a good question or addition to the thread, not adding anything useful in the slightest.

I don't know how i can make it any more simpler for you (and others who do this)

Your posts don't disappear three days after posting them. They show up in google searches all the time. That's what brings allot of people to the site. They Google ".221 fireball twist rate" and they end up here.

The information that was useful and valid in 2017 is still valid and useful today.

Pick a new thing to be bothered by.

-Jake

Sorry for the delay! Been off the site for a little while. I can't say for certain whether the 1:9 twist was the reason for it, but the build turned out very well. I developed an accurate load using what I consider "economy" components, which is to say, bulk Hornady 55 grain SP bullets and relatively easy-to-find IMR 4227. My best handgun group to date was this 0.589" 3-shot group at 100 yards. I know the 3-shot group isn't the best indicator of a gun's accuracy, but even with 5-shot groups, it'll shoot under 1 MOA.



Was the 1:9 twist strictly necessary? According to Berger's Twist Rate Stability Calculator, this load would be "marginally stable" with a 1:12 twist. However, with the higher velocities produced by a rifle length barrel, I don't think a 1:12 twist would be a handicap.

I honestly haven't tested many other loads since this one does exactly what I want it to do. That's going to change soon, though, as I've just taken possession of a 24" barrel, also with a 1:9 twist. While the standard 1:12 would likely shoot these same loads just fine, I wanted the option to try some 69 grain BTHP bullets with slower burning powders that will likely be more accurate than my "economy" loads. I'll make a thread once I get started testing it.