.22 Shorts in a .22lr Supermatic Trophy

Folks ,
My buddy inherited a Supermatic Trophy 106 with a 6 3/4” Fluted barrel. Also in the box was an aluminum slide , two 22 short mags and a shorter bull barrel and a small chamber brush . I knew his dad and at one time he did shoot the International dueling event , which is done with 22 shorts . I’m wondering if he used the shorter barrel for shorts . If he did would it hurt anything ? That’s probably why he kept a small chamber brush in his pistol box .
What’s your figuring gents ?
Soup

Lots of shorts shot in a long rifle barrel will leave a very hard to remove build up at the front of the chamber.  I have a LR space barrel that had only shorts through it.  It took many soaks and brushings to clear the crud ring.

Is your bull barrel marked for shorts?

No his barrel is clearly marked .22 long rifle.

Nice inheritance, but the Pistol Rapid Fire event is now shot with 22LR.

ALso was a 5.5” S&W model 41 in the box with 2 mags , screw driver &
manual sheet . The Trophy also had 2 short mags and 2 red bottom lr mags in the box with instruction sheets .
His father was a WWII vet . He gave his grandson a boxed .Colt 45 which the Army or Marine armorers put together while he was in a pistol shooting clinic at Perry for 1 or 2 weeks. I think it was in the late 60s or early 70 . He told me what the pistol cost it was about 95 or 129 .
They paid the military’s price.
Imagine if they offered that today ?

The slide, 2 magazines & barrel are a 22 short kit. Used to fire the old ISU  rapid fire event in the 1970. The barrel has a different twist rate for the short.   Mine had a removable muzzle brake, in the kit. 

Firing shorts in a LR  barrel is not  very accurate.

The dueling was center fire.  I used a S&W M 28 , shooting 38 specials.

Photos-  Kit link