Hi all,

I dropped by a couple of gun dealers near me and had a look at their shotguns to see if there was anything that might make a good donor gun for a DR conversion. I found a really nice little .410 Bernadelli S/S (snap underlever) which I might buy anyway. However its one of those typical .410's that hinges at the hinge pin to fold almost in half, i.e. you cant remove the barrels from the action without driving out the hinge pin. So do you know if it would be suitable for a conversion to .22 LR or .22 Hornet?

The other action is a "Belgian Manufacture" 20 gauge S/S, no makers name although it has the made in Belgium engraved on the barrels. The engraving looks pretty good, it has side clips, Greener cross bolt, reinforced fences/root and the action still shows traces of colour casing. Seems like it was a nice gun in its day although the woodwork has def looked better. It seems to me to still be on face and locks up tightly though. The barrels however are quite badly pitted. What do you think the most suitable calibre would be for this action? Could I get a .303 Brit or 6.5x53R out of it or would a less intense calibre be reccomended like 30-30?

I have Ellis Browns book but he doesnt cover these questions, unless I missed it.

Any input appreciated, thanks!

You are on the right thinking track; and if the 20 has double bites which it probably does, then it would work for a 303. I don't know what pressures are for a 6.5x53r. Those little bores can raise pressures fast so watch out for them. More importantly is the size of the firing pin holes/ bushings.

Thanks for the reply dpcd, it has double bites but the firing pins will need to be bushed. Its difficult to find pressure info on some cartridges but if I could get a .303 out of it I'd be well pleased!

Maybe I am missing something, but with an action that locks with two underlugs and a third crossbolt you may be able to go bigger if the standing breach is substantial. The only limiting factor is case head size versus the width of the action. We use a minimum of .200" wall thickness at the chambers. As long as you can acheive a correct weighing gun for the caliber you are good to go.

Thanks for the reply Aaron. Actually I'm looking for a small bore double, something relatively light and quick pointing that's not going to have a lot of recoil. I chose the 20 gauge action size as it should make for a slim and trim rifle but I dont want to punish myself with recoil, hence the .303 Brit or 6.5x53R query. I have a CZ 16 gauge gun that should make a fine donor for a 9.3x74R and will turn out a bit heavier.

Would you have any pressure info for those three cartridges by any chance? i.e. the 215gr .303 load @ 2100 fps, 160gr 6.5x53R load at about 2300 fps and a standard factory 286gr 9.3x74R??

Why didn't you say it was just the 256 Mannlicher? Pressure for that is 48K psi, 303 is around 49, as is the 9.3, but most loads I use for that don't go that high; the ones I use are in the mid to high 30s. With bushed firing pins, you will be fine.

Thanks for the pressure info dpcd!! I went back to the gun dealer to have another look at the Bernadelli .410. As you can see its only got a single bite and firing pins are not bushed. What would you guys say, no go on the .22 Hornet, maybe .22 Magnum would be a better bet?

Here's the lockup of the .410...

It won't take much to hold the thrust of a 22 Hornet. I will calculate it later but it will be low.