Accurate clone of Saeco #315

[L Ross]

Here is a photo of my "pound cast". The groove diameter is .3085". The case neck is .3345". The section between the case mouth and the rifling is .3325". I don't know what the correct name for this last section is. Is that the "throat"?

So with this information, what should be the diameter of the bands on this Accurate clone of Saeco #315 be when powder coating is going to add .002" to all the diameters?

View attachment 19278

I think what we are looking at with the .3325 section is what I dread as more chamber than brass. It really really is a nuisance with black powder rifles. I think the brass should be taking up that space for optimal cast bullet performance.

I can handle being told I'm wrong though. But I would prefer .005" of clearance after the case mouth.

 

[Ian]

I don't know why .30-30 chambers are cut that way and I can't think of a good reason. Usually the front part is just a fuzz too tight to fill with case neck even if one of sufficient length to reach the end were made.

So we have to span the gap with bullet. I'd still go with the 31-165W or 31-170F.

 

[L Ross]

I don't know why .30-30 chambers are cut that way and I can't think of a good reason. Usually the front part is just a fuzz too tight to fill with case neck even if one of sufficient length to reach the end were made.

So we have to span the gap with bullet. I'd still go with the 31-165W or 31-170F.

Are long chambers/short brass the reason we sometimes see a lead wash on the case mouth?

 

[fiver]

if you measure a jacketed 30-30 bullet they are tapered for pretty much the entire nose length that sticks out of the case.
it's severe enough on many of them you can see it from 5' away.

I don't know if you guy's have noticed, but IIRC Ben turns the case necks for one of his 30-30's.
I'm betting it is for his Ruger NO-1, and that slight chamber taper,,,? ya know.

 

[Rockydoc]

Everybody says the bullet has to fit the throat. Where is the throat on that pound cast?

 

[fiver]

right after that taper [leade] and before the rifling.

 

[Rockydoc]

That abrupt steep angle? How do you measure that?

 

[Ian]

In this case.....you don't. You shake your head and ignore it as much as you can, get a bullet that mimics the factory ogive curve Fiver just mentioned, and run with it.

 

[fiver]

airc this is a single shot rifle so your only other option is to use something like the 165-A it has that angle on the front of the front drive band.
it's meant for a 308 throat which is quite similar to the one here.
that angle will snuggle up to the one you have and the nose will push into the rifling, but you'll have to thumb seat the round, and you'll have to be very careful about your alloy selection to make the bullets dimensions not be too big.

miss it by .001 and you'll destroy the accuracy in the size die, miss it the other way and the nose will be of no use for guiding everything in place.

this is why the tapered designs do so well in a large variety of rifles, you can size the [rear] drive bands down, and you got no nose to fight with, you just move the bullet in and out to find the happy spot.