Martini cadet .310

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Martini cadet .310

Post by Obie73 » 10 Feb 2026, 8:06 am

With the uncertainty of possible new laws in Qld re mag capacity and all that I started thinking of single shot rifles. Some say there will be no changes, but that's another story. So anyway, I was in a shop the other day and asked if they had a Martini cadet rifle I could look at. I fell in love with it as soon as I held it up and sighted through the old open sights. I bought it. It didn't cost much.

Now, I'm wondering, what is the accuracy like of the old .310 cadet round. Does anyone here have experience shooting and/or reloading it? My interest is completely in target shooting at the range, just for fun. I like vintage style, old firearm designs and I'm not really into bolt actions, so I like things like single shot rifles and lever actions (but lever actions often have large mag capacity).

I could get the rifle rebored and rechambered, or rebarreled, to .357 mag. My question is, what is likely to get me smaller groups at 50 and 100m, the .310 cadet round, or the .357 magnum, or would there be no real difference between the two? I know that .357 would be much easier to reload for. I've read that the .310 cadet was considered to be a highly accurate little round.
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Re: Martini cadet .310

Post by No1Mk3 » 10 Feb 2026, 12:38 pm

310 Cadet at 100 is capable of MoA in a good barrel. 1 1/2 to 2 MoA is not uncommon. The 357 has more power at all ranges and is a good hunting choice, as is 222R. Reloading for the 310 is a journey, seldom will any 2 rifles will be the same and you need to play around with bullet diameter, style and powder choice to get the best from your Cadet which is all part of the fun in shooting them. We have a couple of people in the club who shoot comps out to 300m with their Cadets and do fairly well. Many of these rifles were converted by Mick Smith in Sydney to 32-20, not all were stamped with the new calibre, and some originals will accept 32-20 (one of mine does) and shoot OK at shorter ranges but the 32-20 bullet is a little undersize. CBE make several bullet moulds and have a 310 relading article that makes good reading. I would start with a .316" 122g bullet and a medium powder, 2205 was the most popular choice but when that became hard to find many people tried 2207 with some good results.
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Re: Martini cadet .310

Post by Obie73 » 10 Feb 2026, 1:07 pm

Thank you No1Mk3, that is very helpful. A big appeal for me of.310 cadet is the quieter report, and softer recoil. So if I can I might try and keep it as a .310. I reload .357 mag for lever action rifles and I use AR2207 for that. Some bits of unburned powder stay in the barrel after firing so maybe it's not the best powder but hopefully it would work for .310 cadet. I will look into CBE bullet moulds.

Would you personally prefer a Martini cadet in .310, or in .357 mag?
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Re: Martini cadet .310

Post by Obie73 » 12 Feb 2026, 8:36 am

I've decided to keep it as .310 and not convert to .357. Then I can compete in combined services discipline with SSAA. Also have made contact with a local expert on .310 and he's told me which range has Martini cadet events. Looking forward to the learning journey on how to get good results with .310.
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Re: Martini cadet .310

Post by cadet » 12 Feb 2026, 9:56 am

BSA 4b .310s are great, simple, fun little rifles. I love 'em.

Although long-obsolete, dies (lee and others), cases (bertram) and moulds (CBE) are readily available, and handloading modest charges under cast scrap lead is very economical. I've used AR 2205 and AP70N in mine; I settled on AP70, as 2205 seemed to leave a lot of unburned powder. I imagine APS 650 is readily adaptable, but haven't seen verified data for it yet. Others have used as fast as AS30, but I don't like the risk of double charging.
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Re: Martini cadet .310

Post by NickRigby » 12 Feb 2026, 3:21 pm

I love the old 310 Martini, especially in an unadulterated state, they are just classic. Also light to carry and accurate. I used to load 120 gr Hawkesbury River hard cast projectiles to 1600 fps with AR2205, can't remember the load now.....16 gr maybe..?

It's not a reliable killer on anything bigger the a fox, I'd suggest. I shot a couple of smaller pigs with it at about 50 m and they went down, but tbh a 22 mag will do that.

If it's a single shot you're after for hunting, there's lots of better options, like the Bergara BA13. Scopeable, short and handy, good range of calibres and they take down. A cheaper option is the CVA Scout. I've owned both.
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Re: Martini cadet .310

Post by Obie73 » 21 Feb 2026, 8:59 am

Thanks for all the advice and anecdotes. PTA has come through, just got to get to the shop sometime to pick up. Will report my progress with loads etc.
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