Will a 9 twist 223 stabilize a 75 grain bullet or do you need an 8?

Just curious.

Thanks

Okay, I'll take a stab at this. There are many who have much better insight but I'll tell you what I believe.

I'm not sure what bullet you're talking about but It's more about the length of the bullet than the weight. I would suspect you'll have better success using an 8" twist.

Factory Hornady HP

I'm no expert but I do believe bullet speed,length of barrel,and even altitude can have an effect as well.

A 9" will spin the 75gr BTHP, and sometimes will spin a 75 gr A-Max but an 8" is the best option for Amaxs and other similar bullets.

Thanks Bret

If I was building I'd go 8 but it's a factory rifle.
CZ Carbine with 18.5" barrel to be specific.
Their magazine is pretty short so I doubt I could load the VLD's.
I really don't want to reload anyway, just thinking about a no muss/no fuss handy little truck gun/camp carbine/plinker/small to medium sized game rig.




And before everyone starts....I'm NOT looking for suggestions. It's CZ or nothing.

Starts? When did anyone here ever start anything?

You must have this nice place confused with some other board.

BTW, shortactionsmoker has some 8" .22/250 Tikkas coming in.😜

Bastard......

What was it Wabigoon said the other day.....oh yea.....ask the 24hr what time it is and someone will try to sell you a watch.....

^^^^^^^^^


This

Thanks ingwe......I was hoping you would chime in.

are you off your meds? nobody 'hopes ingwe will chime in'..... he just does anyway.




wanna buy a watch? to go with that tikka?

A one in 9 must be borderline for a 75 A Max...

in mine with that twist, the BTHP version is no issue...

The A Max version seems to do fine if I pump the velocity up and run it close to hot...

locally that translate to about 2800 fps MV.. couple thousand feet altitude...since JB mentioned altitude can play into it...

The 68BTHP is a good alternative... shoots as flat in my rifles as the 75s... and the 1 in 9 is no issue...

I had a savage LRP 1:9 twist and it shot 75gr Bergers in the .2-.3s. Sold it because it is a heavy accurate POS

The BTHP shouldn't be a problem. The Amax I wouldn't even bother with.

^^^^^^^^^^^^^

It took Steelie a long time to convince me on the 8 twist, but once one goes to it, "issues" seem to disappear.....

You know I'm always here for you Don...

But I will go away if you give me Finn.....

Yup

Tonto, our work here is done!

FieldGrade,

My experience is that 75-grain bullets will stabilize fine in MOST 1-9 twist barrels, at least in my part of the west, around 4000 feet above sea level.

This includes 75 A-Maxes, because plastic-tipped bullets actually stabilize easier than non-tipped bullets of the same length and weight. Apparently this is because plastic tips not only weigh considerably less than lead and jackets, but are usually more streamlined than even the sharpest hollow-points, reducing air pressure on the front end of the bullet, a major part of stability.

The JBM stability program takes into consideration the plastic tip, and predicts 75 A-Maxes will stabilize easily in a 1-9. The Berger program is based on the same basic formula, but doesn't have any provision for plastic tips, probably because Berger doesn't make any plastic-tipped bullets. It predicts the 75 A-Max as marginal in a 1-9, but that is not my experience.

That said, one of the 1-9 twist .224's I've owned, an AR-15 carbine, hated them. But so did a 1-8 twist .22/6mm Remington (.224 Texas Trophy Hunter) which happened to shoot 80-grain Berger VLD's very well--which are slightly longer than 75 A-Max's.

All of this leads me to suspect that something about the geometry of 75 A-Max's doesn't agree with certain throats, crowns or whatever. But in 1-9 twist rifles that "like" them, they will indeed shoot very well. So you never know until you try.