Martini Cadet small or large firing pin ? 25-35W

[Bill]

So I've had a 25-35 Win reamer slip into my 256 Win Cadet recently to give it myself an extra 100yd of useable energy..

The cadet has a smaller bushed 22 Hornet firing pin and now that I'm running the larger 30/30 based case with large primers should I upgrade and run a larger 310 cadet firing pin ? thoughts

[Larry]

If it works dont touch it. Smaller is better in firing pin and bolt hole dimensions

[Bill]

thats the thing Larry the bushing is a bit average and depressed and needs to be redone, its catching primers just. I have a spare 310 block and the firing pin protrusion is similar so I can swap it over if the head space matches and looks ok.

Anyway i need to chase Bertram up for brass as I'm struggling forming 30-30 brass into 25-35, seems to be a smidge too thick in the case head area. If any one is sitting on a stache of Winchester or Hornady 25-35 brass hit me up

[bigrich]

25-35 interesting build-up bill . post on how you go

[Bill]

Hey bigrich only fired a dozen rounds thru it yesterday and it got a bit of sharp little kick, also throwing a fair bit of flame out the barrel which is pretty funny.

Accuracy from when it was a 256 is stil there with it putting 3 bullets into a 1 cm at 50m, Ill throw up some pics when I get some more brass going

[in2anity]

Just reading about 25-35 - good velocities. Reminds me of the 223 - it'd go good out to 300

[LawrenceA]

If it works dont touch it. Smaller is better in firing pin and bolt hole dimensions

What Larry said.
It has more to do with pressures and the gaps between the primer face and breech face.

[gunnnie]

Certainly interested in this one Bill!
I've got two single shot projects on the future cards; a 25-35 on a Cadet action with 24" octagonal bbl & a 32-40 on a Martini Henry action with a 24" bbl.

[Bill]

Hey gunnie Im almost certainly going to build a 2nd one I enjoyed shooting this so much, Ive been sitting on a mint Tikka 25-06 Varmint barrel for a few years which I think will now get screwed onto a spare cadet.

I dropped off my breech block and the crappy silver soldered bush is get removed and laser welded back up, will need to get the face machined and firing pin hole redrilled and I was lucky enough to find a bag of Winchester 25-35 brass in QLD yesterday.

[Bill]

quick turn around from the Laser weld dude, cant believe how good the breech face turned out.

I'll be dropping into a local gunsmith to get the firing pin hole redrilled. I'd give it a crack if I had a drill press but I dont and a wobbly handheld drill just wasnt going to cut it.

[LawrenceA]

Noice

[Bill]

So Ive run into a issue with the thicker and harder CCI 200 primers in the winchester 25-35 cases, only 70% of rounds went off last week.

Primer striker seems a bit weak so I decided to improve the firing pin protrusion, was borderline at only 47 thou anyway. I got the Laser welder dude to build up 2 firing pins ( same cost) and Ive got about 80 thou protrusion now. So what's the a safe max/ minimum length ?? seems to be quite a few opinions online

[Bill]

the drill and a diamond file got a work out this arvo, two firing pins knocked back to 60 thou protrusion ( Frank de Hass recommended 55 thou) and a nice hemisphere shape tip.