New rifle

[Ian]

I haven't run them yet, still having nightmares over the week-long decoppering project from the break-in (and I cleaned after every shot with copper solvent). Maybe the 380-400 rounds of PC cast at full-bore load levels has smoothed it out some. I was mainly remarking about the care Sierra and some others seem to be taking toward throat fit with cartridge-specific bullets, and I'm glad to see it.

Here's the bullet that shot one-hole groups in my 30XCB having the standard 3° included-angle ball seat......https://www.midwayusa.com/product/1...r-150-grain-hollow-point-flat-base-box-of-100

 

[fiver]

I can see the striations in the jacket on that one it's a dual purpose bullet for varmints too.
I got a couple of 800 count buckets of Berger J-4 Jackets and I still haven't messed with them other than forming a hands on game plan on getting them core seated and point formed properly.
I want to make some 165-168gr hunting loads with them, but just ain't spent the time figuring out what they need to make that happen.
or what rifle I want to make that happen in.
and no I don't need another rifle...LOL

 

[Ian]

I didn't section one but I imagine most of the nose is full of air, including where the swaging striations are. I did the sharpie test for jam length and got a lot of scuff from the ball seat taper area so it snuggled up pretty well to the barrel steel. The positive stop made jam -.010" an easy adjustment.

I'm still trying to sort out exactly what "ideal" bullet fit looks like, but am getting a much better idea these days and with new, un-worn throats it can mean different things.

Who wants to take on the project of designing a throating reamer to cut the normal, universal wear pattern that rifle throats eventually achieve si we can use the same cast bullet to good effect from new to setback/rechamber time? The SAAMI .375 H&H isn't too far off.

 

[35 Whelen]

Maybe this will help:

View attachment 6729

Thanks Ian...I just found your articles ( #4 Fit is King ) relating to this subject. Thanks....I think I have a better handle on what you are talking about now. Getting the cast bullet to be as close to the walls of the throat as possible aids greatly in accuracy of cast bullets. Like I said, I guess I have just been lucky with all the nose ride bullet molds I have ordered. Each bullet would be very lightly engraved with the rifling making for a pretty accurate load in all of my rifles so far. I will read more of your Artful bullet articles and see if I can get a more thorough understanding of the casting and loading of cast bullets. Thank you , all of you for all the input and knowledge..you have made this journey of cast boolits a most enjoyable one. Please don't ever let my wife know how much I have invested in molds....I think it's more than my most expensive rifle.....Hahahahaaaaaa