*** September 2007 Purchases ***

[stencollector]

Inserts are .22 cal. The early boys manual of 1937 talked about a 303 subcal, but by 1939 there was an amendment to scratch that and insert .22 .
The subcal rounds are rifled and have a small adapter to convert the center fire to rimfire. The adapter is usually missing...I have only one of the adapters.

[Warren]

.22 LR sub cal unit.....They were discontinued as hard on the .55 bore. They found evidence of gas cutting in the barrel.

[stencollector]

Another Boys rifle owner told me that he had enough of these subcals to fill the mags. His kids would fire it, but he warned that the bullets would tumble down the barrel.
I just had a Kreiger match barrel installed on mine in 50 cal, so these wouldn't work anyway, and if they did fit, I wouldn't use them.