22 WMR keyholeing

[Ojaileveraction]

Went to the range this afternoon to sighting my Octagon 22mag using Hornady's 45gr thx Critical Defence.
Hoping to use it for Pistol Caliber Silhouette.
At 25 yrds They keyholed every shot.

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This is not the fisrt time. Some lead free CCI ammo did the same thing.
The only thing to add is the base of the expended shell looks bulged or rounded.

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That's the best shot I could get.
I have ideas why the keyholeing is occurring, bullet length my first thought, but the odd looking spent shells add another variable I can't explain.

[Abnermal]

If you can pull a bullet from the box of ammo and measure it. My first instinct tells me improper bullet diameter. Try some "old fashioned" SuperX or equivalent ammo and see if the same thing happens. If the problem persists I'd suspect a barrel issue. Just my two cents worth.

[North Country Gal]

My guess is that it's that particular ammo. The Critical defense 22 mag is one of several 22 mag loads now on the market that are specifically designed for shooting in short barreled self-defense handguns to get the velocity up fast in very short barrels. It's essentially a 22 mag load for handguns. As Abermal suggests, go to standard 22 mag ammo and see if the problem disappears.

[PT7]

Ojaileveraction,

NCG's "guess" is spot-on about the Hornaday CD ammo you used. I have the same ammo, and bought it specifically for HD use in my 3" Ruger LCR .22 magnum revolver. Hornady specifies the best use for this ammo round, but it's quite well "hidden" on their web site at https://www.hornady.com/support/duty-de ... ifferences The heading it is posted under would not be where a Henry .22 magnum rifle owner might search: "Personal Protection / Concealed Carry." Almost at the bottom of this web page is the info you needed to know:

Critical Defense® ammunition IS optimized for short barreled, concealed carry style handguns and will not deliver excessive recoil and associated muzzle flip.

At the same time, it is odd to me that on my ammo box of these Hornady 45gr FTX CD rounds, they publish the ballistics for both a handgun with a 1-7/8" Bbl, and a rifle with a 24" barrel. Seems to me a disconnect from their recommended use for the round.

If you find a better ammo for your Henry and don't shoot the Hornady CD stuff, you can always send me any of the unused .45gr FTX rounds!
PT7

Went to the range this afternoon to sighting my Octagon 22mag using Hornady's 45gr thx Critical Defence.
Hoping to use it for Pistol Caliber Silhouette.
At 25 yrds They keyholed every shot.

My guess is that it's that particular ammo. The Critical defense 22 mag is one of several 22 mag loads now on the market that are specifically designed for shooting in short barreled self-defense handguns to get the velocity up fast in very short barrels. It's essentially a 22 mag load for handguns. As Abermal suggests, go to standard 22 mag ammo and see if the problem disappears.

[Ojaileveraction]

CCI Maxi-mag 40gr HP and TMJ listed at 1875fps didn't keyhole but were disapointing accuracy wise. 6 to 8 MOA spread at 50 yards. Maxi-mag HP-V and Hornady Vmax at 30gr and 2200 were similarly disappointing.
Only the CCI TNT green 30 grain at 2050fps and the Hornady CD have keyhole.

[Sir Henry]

I'm surprised a 45 grain bullet in .22WMR would keyhole with the Henry twist rate.

[Ojaileveraction]

I'm surprised a 45 grain bullet in .22WMR would keyhole with the Henry twist rate.

Kind of shook me up.
Put the rifle in the safe till I have time to figure it out or get rid of it.

[roddy]

I shoot the C.D. 45 grain rounds in my H003TM, and have noticed no keyholing at 25 yards. My little pump likes them. The groups do open up (and raise) with the CCI V-Max and HP+V 30 grain rounds. Both the cheap Federal Champion 40 grain round nose, and the Aguila semi-jacketed soft point shoot well too (at 25yds).

[220]

If you can find any S&B 22mag ammo it shoots exceptionally well in most rifles.
Out of my sako quad it is a genuine moa load, used it last year in a 200y rimfire match against mainly HMR's but the odd target grade 22lr as well. Kids & I finished 1st 2nd & 3rd.

A keen CLAS shooter here in Aus started disassembling 22mag ammo and increasing the powder charge for rams when federals 50gr load was unobtainable. He found the S&B ammo by far the most consistent with powder weights.
(I wouldn't recommend doing what he did, his 22mag is a marlin, same action as marlin's centrefire pistol chambering so could safely handle a bit more pressure)

[BigAl52]

I'm surprised a 45 grain bullet in .22WMR would keyhole with the Henry twist rate.

Kind of shook me up.
Put the rifle in the safe till I have time to figure it out or get rid of it.

Have you thought about giving Henry a call and tell them what is going on sounds to me like you might very well have a barrel issue. Al