Twist Rate for Varmints - 223/6mm CM

[85MikeTPI]

Regarding bullet weight/twist rate:

• less than 50 gr -- 1:12, or even 1:14
• 50-60 gr -- 1:9 or maybe 1:8
• Heavier than 60 gr -- 1:8/1:7

That's kind of what I'm getting from what I've read so far.

Bringing this back around to my situation, wanting specifically a varmint rifle for small varmints inside of 400 yards with a 223 using bullets of 50 grains or less, I'm specifically looking at finding a rifle and/or barrel with a 1:12 twist. It's either that, or relegate myself to using bullets that are 55 grains or heavier. Now the question is, which rifle?

I've gotten 1 MOA out of two ARs I have with 1:7 with 55 gr reloads, so it's doable, but not quite where I'd like it to be.

All pretty much spot on. As in the "Precision 223" thread in reloading section, the bullet weights above agree with twist and I've been testing 50gr, 53gr, 55gr, 60gr, 75gr, 77gr rounds in various twists and confirming.

I think you should stick with your AR, use 55gr V-max, and find a load that your rifle loves (http://www.65guys.com/10-round-load-development-ladder-test/) and get on with the serious biz of varmint hunting..

 

[Rockzilla]

The 788 in 223 shoots 40-55 gr bullets just fine 1/12 twist
Some of the old AR barrels 1/12 twist work fine with those weights.
even the bullets made from 22 cases shoot decent. In the above
45-53 gr.
The Sierra Blitz bullets work great.
Have 1/14, 1/12, and faster

-Rock

 

[KRC]

It has been a few years, but I've shot p-dog towns that were MILES wide and deep. Start with a 22LR, work through the .224's, then bring out the heavier stuff (.243 Ackley). Crazy. Downside - yes - handloading is required for BR's and Ackley's.

But nothing wrong with an AR based .223 with 55 gr. VMaxes or Blitzkings (25.4gr. H4895) for shorter (<300 yds.) distances, again, just be mindful of heat and throat erosion when p-doggin. I came back from one Wyoming trip with no rifling left 6" down the bore of a beautiful Hart barrel.

 

[John from MD]

It has been a few years, but I've shot p-dog towns that were MILES wide and deep. Start with a 22LR, work through the .224's, then bring out the heavier stuff (.243 Ackley). Crazy. Downside - yes - handloading is required for BR's and Ackley's.

But nothing wrong with an AR based .223 with 55 gr. VMaxes or Blitzkings (25.4gr. H4895) for shorter (<300 yds.) distances, again, just be mindful of heat and throat erosion when p-doggin. I came back from one Wyoming trip with no rifling left 6" down the bore of a beautiful Hart barrel.

That is the biggest issue with overbored calibers. The flame comes out of the case like a blow torch and erodes the throat and barrel. There has been lots of material written about calibers and powders when making varmint rifles much that I have forgotten.

I would suggest reading up on varmint rifle throat erosion before you make the final choice of what rifle to buy or build. That said, if you choose to use a easily replaceable barrel, then I would worry about it as the fix is easy.

 

[Uncle Duke]

I'd want a 17hmr or a 22wmr along too. Rotate in to keep centerfire cooler, and fun themselves if shots available inside 125 or so.

 

[Rockzilla]

I'd want a 17hmr or a 22wmr along too. Rotate in to keep centerfire cooler, and fun themselves if shots available inside 125 or so.

yes sir..good point.
I don't take the Swift out to often, but shoot it let it cool down
then the triple duece comes in.

-Rock

 

[Biggfoot44]

It's a slippery slope to chase just a little flatter , or just a little more wind bucking , balanced against recoil and bbl wear .

Nothing wrong with Wildcatting for the sake of Wildcatting , or recreating once popular historical chamberings on purpose . But almost imeadately upon its introduction circa 1950 , the .222 Remington dominated as the sweet spot, eventually .223 inheriting due to cheap brass.

 

[trickg]

It's a slippery slope to chase just a little flatter , or just a little more wind bucking , balanced against recoil and bbl wear .

Nothing wrong with wildcatting for the sake of wildcatting, or recreating once popular historical chamberings on purpose, but almost immediately upon its introduction circa 1950, the .222 Remington dominated as the sweet spot, eventually .223 inheriting due to cheap brass.

That's really what it's boiling down to for me - .223 brass is super easy to come by and I already have enough of it that if I really wanted to, I could sort it for consistency. (Currently I just process and trim it all to a certain spec, and load it from there, regardless of headstamp)

I suppose if I wanted to, I could do .243 the same way by necking down 308, which is also plentiful.

We live in strange times - I can't believe how much of almost everything is out of stock everywhere. At this point I'll just have to have a list of possibilities, and keep my eyes peeled for if/when something becomes available at a price I'm comfortable paying.

 

[DanGuy48]

So this is kind of interesting. It would seem that even the manufacturers are going to faster twist rates on the rifles they are marketing as "varminters" for their 223s, and 1:9 seems to be the common twist - they seem to expect everyone to use bullets that are 55 grains or heavier, which I suppose is ok - a typical 22 LR is a 40 grain bullet - but it takes lighter, quicker bullets off the table.

Here's an interesting rifle review of the Howa 1500 "mini" action in 223. Rifle seems to be pretty danged accurate.

[YT]3CmQypK8eBo[/YT]

Unless I’m misunderstanding something, that makes sense to me. You need to have a twist rate sufficient to stabilize the longest bullet you will be shooting. Shorter (lighter) bullets should do just fine in the same twist barrel designed for the longer bullets. This was why the .244 Remington magnum failed. They sold it as a varmint round, with bullets to match, while the .243 Winchester came out intended for medium game. The faster twist of the .243 rifles stabilized both types of bullets, the .244 did not. Hence the switch to the 6mm Remington designation which now matches the twist of the .243 rifles. Too late though for the (excellent IMO) 6mm, the damage had already been done.

 

[trickg]

Unless I’m misunderstanding something, that makes sense to me. You need to have a twist rate sufficient to stabilize the longest bullet you will be shooting. Shorter (lighter) bullets should do just fine in the same twist barrel designed for the longer bullets. This was why the .244 Remington magnum failed. They sold it as a varmint round, with bullets to match, while the .243 Winchester came out intended for medium game. The faster twist of the .243 rifles stabilized both types of bullets, the .244 did not. Hence the switch to the 6mm Remington designation which now matches the twist of the .243 rifles. Too late though for the (excellent IMO) 6mm, the damage had already been done.

That all does make sense if you are looking for a rifle that's an all-around gun,but not so much if you want to build a gun for a specific purpose such as varminting.

From what I've read, (disclaimer: all of this is just theory for me because I don't have a lot of personal firsthand experience) shorter, lighter bullets tend to not be as accurate with faster twist rates because they the faster twist highlights imperfections in the bullet, and in the case of really small, thin jacketed bullets, can (supposedly) cause them to literally come apart due to spinning too fast.

I'm not entirely sure of my math here, so someone correct me if I'm wrong, but let's factor bullet spin based on bullet weight and speed out of a 1:7 twist barrel.

A 40 gr VMax has a velocity of 3,740 fps, and in a 1:7 twist, it gets a full rotation every .583 ft

So here's what we're looking at for spin based on twist rate for the VMax, assuming that the bullet maintains consistent velocity for a full second. (We know it doesn't, but I'm not a physicist, so work with me)\

40 gr VMax - 3740 fps
1:7 - 6,448 rps
1:8 - 5,615 rps
1:9 - 4,986 rps
1:10 - 4,489 rps
1:12 - 3740 rps

Here's spin based on a heavier, match grade bullet.

69 gr Sierra Matchking - 2,950 fps
1:7 - 5,060 rps
1:8 - 4,429 rps
1:9 - 3,933 rps
1:10 - 3,541 rps
1:12 - 2950 rps

The 40 gr VMax is already a bullet that's designed to expend all of it's energy suddenly, so ripping around at 6,500 rpms, I've read more than once that a fast twist causes those bullets to literally disintegrate once they leave the barrel - they just can't handle the internal stress. The longer, slower, heavier bullets do better with faster twists over distance.

Again, this is all theory to me because I don't actually have any experience firsthand.

 

[outrider58]

trickg, take a good look at Nosler Varmageddons. They are extremely accurate and are made for varmint perforating. They've been my most accurate .223 round I've loaded and I've tried all the others.

 

[steves1911]

The 55gr varmageddon are a favorite in my 22-250. Have taken multiple fox with them this one was at 280yds. None have ever taken a step after impact. On regards to bullets spinning apart due to high rpm the only time ive seen it was with 110gr 30 cal vmax i tried loading in a 300rum. Still have a couple of those 110gr vmax may have to try them in a 300 win mag with a 10twist and see what happens.

 

[outrider58]

The 55gr varmageddon are a favorite in my 22-250. Have taken multiple fox with them this one was at 280yds. None have ever taken a step after impact. On regards to bullets spinning apart due to high rpm the only time ive seen it was with 110gr 30 cal vmax i tried loading in a 300rum. Still have a couple of those 110gr vmax may have to try them in a 300 win mag with a 10twist and see what happens.

Definitely!

 

[teratos]

Why can’t you mean men with guns make friends with the doggies? Then you won’t have to shoot them.

 

[outrider58]

Why can’t you mean men with guns make friends with the doggies? Then you won’t have to shoot them.

Them's goood dogs. Good and day-id.

 

[calicojack]

9 is arguably your most common compromise twist in the .223 bolt rifles made today. Many AR's too.

If the older vintage bolt rifles of yesteryear appeal to you, you'll find a lot more in the way of 12 twist. Many of them can shoot lights out with the lighter bullets.

I think Tikka makes a 1 in 12 twist 223 Rem.

 

[steves1911]

Why can’t you mean men with guns make friends with the doggies? Then you won’t have to shoot them.

Chicken thiefs! They stay off my acreage we wont have any problems

 

[calicojack]

This Tikka is 1 in 12 twist:
https://grabagun.com/firearms/rifles/bolt-action-rifles/tikka-jrtx031-t3-lite-223-mossy-oak-fb.html

 

[John from MD]

This Tikka is 1 in 12 twist:
https://grabagun.com/firearms/rifles/bolt-action-rifles/tikka-jrtx031-t3-lite-223-mossy-oak-fb.html

That's great if you can find one. As the OP has said, there is a lot of OOS products in the firearms industry these days.

 

[trickg]

So here's a thought - would there be anything wrong with loading a 55 gr Varmageddon and running it through a barrel with say, a 1:8 or 1:9 twist? Seems to me that it would probably be a pretty solid round that way, especially if I worked it up for both powder and seating depth.

The Ruger Predator, which was my initial pick, uses 1:8 on the 223.

I'm not looking for silly accuracy - if I could realistically get just under 1 MOA, that would be great, and heck, a 55 gr would handle wind over distance better than a 40 gr bullet, although maybe not by much - when factoring the velocity difference, it would likely be a wash at point of impact.

The more I dig around and read on this idea, the more I'm beginning to think that I'm very likely drastically overthinking it.