25/303,what powder and how much

[felix]

Length becomes less and less important for twist requirements as the boolit nose becomes sharper and sharper. Always remember, twist is for overcoming dynamic projectile resistance to outside disturbances. Outer space requires very little twist; just under the ocean waves requires a lot of twist should stabilizers (variable wings) not be used. ... felix

[koehn,jim]

I use 18 grains of 2400 behind a 90 grain soupcan in my 25-06 works very well and cheap to load

[303Guy]

Just when I though I had it sussed! OK, so the long, sharp point displaces the shockwave that would otherwise disturb the bullet from the ogive on? But that would be applying a destabilizing moment right up front or is the larger base area self-compensating in air at supersonic velocities? High speed gas flow is a tricky science and is not something one can easily visualise.

[swheeler]

Certaindeaf, you're right - that's what the maker says about H110. Then they list loads for 32 - 40. I only know that a friend has been using it since the early '60s, and that I've shot upwards of 20 lb of it without incident and with good results in 30 30, 30 40, 308, 30 06, 303 Brit, 6.5x55 and 257 roberts, always with fairly light loads. For what it's worth, it didn't show much promise in 45 70.
Grouch

I have tried H110 in 223 with 55 gr cast bullets without a filler(as a published load in the RCBS cast manual) I fired 10 rounds over the chrono, took the other 40 home and pulled them. I was getting extreme spread of 179fps for 10 rounds, definate delayed ignition(click bangs)-Dec 2005. I later found an article about multiple ringed chambers in 308 with cast and H110(big thing to use in 1980's), author attributed the ringed chambers to this powder. I now have the data marked in pink hilighter in my notes with DANGER. I'll save it for the 357 mag and heavy cast, that's where it works for me.

[303Guy]

I've had signs of high lateral pressure in the neck with mild pressure signs on the primer using shotgun powder and a light boolit. No chamber ringing but the cases were locked in the chamber by just the neck. That was with filler.

[runfiverun]

that's from the filler shoving up to the base before the boolit moves.
maybe from the primer shooting it there then the fast pressure rise finishing it being jammed in there.
fast powder is well,,,, fast.
i always think of it like spitting.
the big pressure right at the start and then the let down.

anyways the pointy part on the front makes a smaller point to break through the shockwave, when going supersonic.
it works for jets too.

[303Guy]

One of the cases that produced that tight neck still had filler in it with channels through it like it hadn't formed the suspected piston. Don't know, but it's strange that the boolit base is unaffected.

So if that pointy bit in front is a bit off centre, would that have much effect on accuracy?

Ok, so with all this 25 cast talk, I'm getting more and more interested in trying plain cast in mine. I am interested in top end cast loads though - it's not like the 25 is a massive calibre so I'd like a little speed. After all, there needs to be some justification in shooting rabbits and hares with a 25 when a 22rf works just fine. So range is that justification for me (read excuse). If I settle on a 100gr cast as a workable boolit weight, what boolit styles would be recommended? Same as for the 12 twist? Or would I be better served with a 120gr? I do have a vague idea of the throat shape and size as I've made paper patch boolits for it but I'll get a better measurement just the same.

I currently have and use AR2209/H4350 and W748. I'm thinking the W748 might be a good starting point followed by the H4350.

My requirements might be exactly the same as PAT303's.

[Al_sway]

Just a quick question, why would we want a light plinking load from a small calibre such as the 25/303? Nothing wrong with it in principle but the calibre has the potential for a pretty reasonable velocity with a pretty heavy for calibre boolit with a slow powder load. I'm not sure what would work well in the 25 but I do know what works well in the 303. I would like to transpose that sort of performance across to the 25. I was getting in the region of 1800fps with heavy cast in the 303 using AR2208 (Varget). I'd like a load something like that but with a filler that forms a wad behind the boolit. I know paper patching can do magic but these are getting on to the rather small side for greater than teenage fingers to patch! Don't get me wrong, I'm still pretty young but I do have trouble operating these new fan-dangled gadgets called cell phones! (Designed by youngsters with feminine little fingers ... mutter mutter ... !)

Anyway, velocity limitations would be the same with heavies and lights so why not go with the heavies? They're actually still pretty light at 25 calibre.

(One more question, why in heck does my spell checker flag me when I try to spell caliber the right way?)

Since I am the guy who talked about light plinking loads, I should explain a bit more.
I use a nice 120 grain jacketed bullet most of the time for deer hunting at a good velocity of around 2800 fps. Works very well on deer.
I had the 100 grain mould and I decided to use it. To keep life simple I keep the velocity down and I have no problems shooting them around 1100-1200 fps. Makes for a great practice load, and I take the rifle out rabbit hunting sometimes. The gas check mould gets loaded up a bit faster for longer range practice, out to 100 metres or so. Allows me to practice hunting positions without worrying about the barrel warming up (firing 20 rounds of jacketed hunting ammunition during summer practice really heats up the barrel). I have never considered trying to speed up the 117 grain cast bullet to make it into a deer round, as I have lots of the jacketed bullets and I know they work. If I want to use a cast bullet for deer, I use a .30-30.
Hope this helps explain a bit. By the way, in general terms I have found that the round acts like a .257 Roberts for reloading and velocity.