.224" 40gr Vmax twist/velocity limit?

[dixiecricket]

Farmer asked me to kill all his jackrabbits and I dont have a 17hmr and dont want to deal with .22lr limits. Purchased some Hornady #22241 bullets to shoot in my hunting AR with a 7T barrel (all I have are fast twists). I understand that this bullet is really for 22 Hornet and is rather fragile. Loaded some uo at 2900fps with 19gr of AA5744 and dont have issues.


Here's my question: how fast can I push there in a 7T barrel before they blow up? I've blown up 55gr fbhp's before during service rifle practice. Some load data has them going 3600-3900fps.

 

[Zero333]

I found the lighter V-max tough enough not to have any issues with fast twists.

I've shot light V-max in fast twist barrels in the hot summer and never had any blow up. They are tough. Too tough for some small game in my opinion. Velocity will depend on barrel length and powder. Best accuracy with the 40 Vmax in the 223rem/5.56x45 will be with 4198 (H or IMR). If you prefer a ball powder H-335 will work as well.

The 40 Vmax will be a great choice. Not too tough to pencil right trough and not too soft to blow up in a fast twist.

At 2,900 fps it's sounds perfect.

I give you a Green Light.

Wish I could say the same with Bergers 6mm 80 gr Varmint bullets. They shoot so good when it's cold. Once it get warm outside and the barrel gets hot they don't group as well and at least 1 out of 4 blow up in the air.
In the freezing winter they always go in the same hole at 100 meters.

 

[Zero333]

If the Hornet can push them at 2,650+ from a 22" barrel there is no reason why 2,900 fps will blow them up.
If your semi-auto doesn't cycle properly and you have a adjustable gas block, then just close it and use it like a bolt rifle.

 

[DiRTY DOG]

Hornady 40gr Vmax is great. Hornady 35gr NTX (lead free) is also great! Both are very accurate for varmints. The 35gr lead free is long for it's weight. It's not solid copper, it's compressed metal powder of some sort and very explosive on varmints.

 

[rmeyerwy]

40gr vmax is rated to 2000-4400 fps, dont see anything on twist though. I use em in 223 and 22-250 in th 250 its a 1:12 and we around that 3950ish. If you are coming out of an AR, I think you will be fine as frogs hair

 

[Coyotefurharvester]

Have to watch seating depth on the 40 gr vmax and ballistic tips. The coal is right at mag length to stay in the bullets bearing surface. I have a few ammo cases of factory Nolser 40 bt, they are 2.260 coal, they are marked not recommended for AR use.

 

[dixiecricket]

Looks like I'm good to push them a lot harder. Will try AA2200 and imr4895 next. Not getting any powders I dont already use for something else.

 

[Fern]

Not vmax but the 40g noslers I send at 3600fps with great accuracy

 

[Coyotefurharvester]

Factory 223 rem Nosler 40 BT 3625 fps.

 

[JSH]

I never had any kind of good luck with the Hornady Hornet bullet.
The V max is a different story, one of my favorites.
I would advise not to load a large batch. Most hornets are 14-12 twist and I have seen some 16’s. The 7 twist may well eat them.

 

[HillbillyLongRifle]

Most bullets will Handle 295,000 rpms. Vmax ive ran over 300,000 rpms in 17 calibers with no issues. I would not run them over 300,000 rpms if i was you.

You are already almost 299,000 rpms at 2900 fps with a 7 twist barrel!

 

[Frankm]

RPM s regarding bullet blowups are important; but so it barrel length. We ve found long barrels 28”+ shooting bullets at same RPM (same fps and twist rate) are tougher on bullets than a 22” or so shorter barrel! Friction in bore matters!

Bore diameter and number of grooves matters too. It gets complicated real fast !!

 

[dixiecricket]

Shot a jackrabbit at the tree nursury, the 40gr at 2900fps pretty much split him in two. Probably dont need much more. It shoots MOA in two dofferent 16" ARs and has very low recoil. Just a mag change from 70gr copper monos for pigs to 40gr atom bombs for jackrabbits. Too easy.

 

[Ned Ludd]

As noted by @Frankm, there are quite a number of factors involved in bullet jacket failures that include (but are not limited to) barrel length, bore diameter, groove configuration, bullet jacket thickness/toughness, bullet bearing surface length, velocity, temperature, and so forth. Trying to predict an upper velocity limit as a potential "cutoff" to prevent or minimize jacket failure is going to require some testing, at a minimum. Even then, it may never be possible to know with certainty that a jacket failure won't occur if running a load that may still be too close to the margin.

IMO, it would be far better to work with the load you already know is producing good results at ~2900 fps. The difference in windage generated by an additional couple hundred fps velocity is not zero, but it is not huge, either. Likewise, the difference in the "flatness" of the trajectory will not be zero, but may not necessarily be huge, either. In other words, is the [very] slight increase in performance worth the risk of jacket failure? In the case of competition shooting, the answer is clearly "No" when a jacket failure typically means you're out of the running. For the purpose of shooting varmints, it may be possible to tolerate a few jacket failures here and there, but I can't really speak for anyone else on that. These are all considerations when dealing with the possibility of jacket failures.

 

[dixiecricket]

My only concern with jacket failure is one grenading in my supprressor. Im not shooting trophy big game or vying for 1st place at nationals, just shooting varmints.

 

[long40shot]

I have run the 40grn v-max up to 4150fps out of a 26", 1-14 twist barrel. No issues.

 

[dixiecricket]

I agree on the extra velocity not really effecting my hit probability at my target ranges, but going from 2900fps to 3800fps almost doubles kinetic energy from 747 to 1283fpe

 

[C.E.Smith043]

I blew apart the 40gr vmax out of a 12 twist savage 26" barrel going 4160fps out of a 22-250
At 4000fps they were fine

 

[SLAYIN'SWEDE]

I've shot them at 3850fps out of a 26" 7 twist and they stay together fine

 

[Coyotefurharvester]

I have these, shot from Rem,TC barrels. Only prairie dogs have blown up.