cast bullet sealing

[barnabus]

as a general rule do you try to seat the bullet out to seal off the lands in a single shot/bolt action? Have you noticed best accuracy by doing so or does it just depend on the rifle? im working on a 38-55 Hi-Wall

[big bore 99]

I stay about .010 off the lands worked best for me in my single shot 45-70.

[uscra112]

The Schuetzen types actually shove their soft cast bullets entirely into the throat (leade if you prefer) and load the case with powder charge behind it. Called breech seating. They get some pretty impressive accuracy this way.

For fixed ammo, most cast bullet loaders (myself included) like to have the bullet engraved at least one band by the lands. This centers the bullet up so it enters the bore as straight as possible. Think of .22 rimfire target chambers, which all do this, without exception.

Exactly the opposite of jacketed bullet loading, where jamming that hard, stiff bullet into the lands leads to excessive pressures.

[JBinMN]

Some related reading which helps answer your question is on pages 353 -356 of this book by Naramore in E-book .PDF file form:
https://ia800205.us.archive.org/1/items/Handloaders_Manual_Naramore1943/Handloaders_Manual_Naramore1943.pdf

Note - Use the actual pages of the book & not the .PDF file page numbers if you do go look.
:)

I do not have much to add since the previous posts cover most of what I think, but I will add that since you are using a single shot you do not have to worry about magazines & the overall length of cartridges fitting in the magazine, & still feed into the chamber, so that is what will usually be the maximum OAL for magazine fed firearms, thus one of the advantages of single shot bolt action rifles.



Anyway, Hope that helped even just a little bit.

G'Luck!
:)

P.S. - that E-book is a really good read, even if some of it is dated( 1940s era)

[uscra112]

With lead bullets you can push them as far into the rifling as you want. As I posted above, breech seating method actually pushes them all the way in, with a special tool, so that the seating depth is actually a negative number. This has been proven for over 130 years to be the most accurate loading method of all when shooting cast bullets, whether with black powder or smokeless. It guarantees the best possible alignment, and if the bullets are correctly sized, the best possible sealing. A bit impractical in the field, but pretty easy at the bench when you have the right tool.

Do not look at reloading manuals covering jacketed bullets for advice. Look to the Lyman Cast Bullet Handbook and like publications. Cast bullets are a whole different animal.

One idea that works well with bolt guns is to seat the bullet very long, with no crimp, and let the bolt closing push the bullet back into the case. I've used the same trick with Stevens Model 44s, which can push the cartridge in against resistance by a good 3/16" if necessary. Ballards do the same thing, although the range of motion is less, as does the Stevens 44 1/2 action.

No matter how you do it, lead bullets should be in firm contact with the rifling to get the best accuracy.

[JBinMN]

You will have no argument from me. I agree & understood both your posts. I see that you mention & "specified " the word "Lead" as in cast boolits. The OP did not.

As you pointed out, there "is" a difference in whether or not you can do the same with cast or jacketed/plated. That is something that must be understood.

Also, the "tool" used to insert the cast boolit into the rifling does the work that otherwise would have to be done by the expanding gases, and that lack of "jump" will certainly keep the boolit more on it's longitudinal axis, (center of mass/gravity) as well as reducing any possible deformation caused to the boolit by any "jump" trying to get itself centered in the bore which would certainly affect performance/accuracy. Not likely able to do that with a jacketed, tool or not, I would reckon...

Like I said, no argument from me.

BTW, I may as well mention that the Narramore book covers both cast & jacketed, for those who did not know.

[uscra112]

Yeah, Naramore is mixing both types together, which is confusing.

[Gunlaker]

I do as uscra112 suggests. Breech seating works extremely well, but when I shoot fixed ammo it's almost always with a bullet that is being engraved by the lands. Your highwall action is good for this, although less good than a Stevens 44 or 4-1/2.

Chris.

[marlinman93]

Usually a bullet touching the lands shoots the most accurately. But don't just set it up that way without doing some accuracy testing. I've found occasionally that for whatever reason, a particular gun likes a little space or "jump" into the rifling to shoot better. So try it touching, and make up some loads with various mounts of space to see what shoots best in your gun.

[MT Chambers]

With cast boolits I like to get the bullet as far into the rifling as possible, even though you can get a bullet stuck in the barrel if you remove a loaded round.