Straight through, no choke.
They were designed for use as proper Muskets: smoothbore military shoulder firearms firing a single Ball. As such, they were the Last Musket to see military service anywhere in the world.
Originally they were an offshoot of the I.P. (India Pattern) single-shot Lee-Enfild rifles, which were regular rifles converted to single-shot and issued for 2 purposes: (1) to native troops regarded as unreliable in battle, and (2) for standing guard duty at the gate of an encampment. If the rifle fell into hostile hands (or was taken via a blow to the sentry's head with a blunt instrument), all the enemy would get would be a single-shot and a handful of rounds.
The Musket went this road a step farther by offering the enemy merely a 40-yard weapon with very little powr and miserable accuracy. As a sentry piece, though, it would make noise enough to summon a flying squad of a dozen men, each with 9 in the mag and one up the spout. In addition, the ammunition was controlled AT SOURCE (the factory) because NOTHING else used a straight .303 case.... and the people most likly to steal the gun did not have an ammunition factory at their disposal. It worked: sentry assaults for the purpose of gathering weapons fell off drastically, the gunmakers up in Darra became busy little beavers and the army was happy.
But the Indian Prison Service recognised the fact that a low-velocity round Ball is much less lethal in a riot situation. After all, if you have people screaming at you, 40 deep, you only want to incapacitate the ringleaders, not kill the first dozen ranks. And for this, the Musket was eminently suited.
A small quantity of Muskets came to Canada about 25 years go and were gobbled up pretty quickly. Far too many were butchered immediately into minimal .410 shotguns and sold on the open market, reblued and slicked-up just a bit but still recognisable for what they really were.
A few, I am afraid the minority, remained unaltered and made it into private gun collections to the great exultation of Milsurp addicts. Many of these were NOT in the best condition, the butchers apparantly having hd first pick. I have $54 invested in mine and, believe me, for the condition it was FAR too much! But I own a copy of the Last Musket..... and it's a Lee-Enfield, so I am happy with the sad old thing and it has a special place in my collection.
A lot of fun to shoot, though, and a wonderful chunk of History.