Bullet Sizing for GG 45/90

[sccadu]

Being a newbie to BP cartridge reloading, could someone tell me what the cast bullet needs to be sized to. I'm trying to get my reloading setup done before the rifle arrives. I'll be using a lease groove bullet Thank you

[sccadu]

I meant GREASE GROOVE.

[sccadu]

I meant GREASE GROOVE.

[Don McDowell]

458 in a Shiloh

[sccadu]

Don,
Thank you. I reload presently but this is a new deal for me, fun too.

[gunlaker]

Ideally you don't want to size the bullet in my opinion. Get a quality mold ( like Buffalo Arms ) and order it to drop a .458" or .459" bullet. With a .458" you'll likely want a little bit of neck tension. With a .459" it'll likely be a perfect slip fit so you can go that way or add neck tension. Both diameters and techniques shoot very well in my Shiloh's.

Chris.

[desert deuce]

What Chris wrote

Anecdotal, I was at the range shooting groups at 200 yards doing load development for several rifles.
I inadvertently chambered a 44-90 cartridge with a .446 bullet in a 45-90 with a .4575 groove diameter.
I fired the shot (it sounded different) at the 200 yard repair center and the bullet struck point on six o'clock in the 8 Ring.
I believe Paul Mathews once wrote he fired a .455 bullet in a 45-70 because it was more accurate.

Some bullets from some moulds do require a little excess smoothed in irregular places and a sizing die that fits or is slightly over size to the shank can perform this task.

[Kirk]

Size it to .458" and make sure your nose diameter is .450" or less.

Kirk

[sccadu]

Thanks Kirk

[sccadu]

Thank you all, I'm sure I'll be back many times tapping the collective. LOL

[mdeland]

Slug your bore then you will know for sure and then get a bullet as close to groove diameter as possible.Better a thousands over than under.

[bruce m]

sccadu,
you need to ask, what happens to a lead alloy bullet when you fire it.
here is what happens.
the bang causes the bullet to expand to fill any space available.
some even suspect that the nose of the bullet even goes backward as part of this process, before the bullet starts to move forward.
we know this happens in part from the fact that bore diameter pp bullets bump up approx. 0.008" to fill the rifling.
so what space does the alloy have to fill? with a gg bullet a lot of this process happens in the case.
the case also expands to fill any space, which means it obturates to fill the chamber.
as this happens, the bullet is also expanding.
when all space is full, the bullet has nowhere to go but forward and it starts to move.
the fired case will have about 0.001 or thereabouts springback after pressure is released.
here is the place to establish bullet diameter of the shank.
the bullet which will slide into a fired case is optimum diameter.
it will easily allow chambering a loaded round, but bump up minimumaly.
the fact that there is hardly any alloy movement is a benefit to accuracy.
here is where chambers are important.
loose chambers allow the bullet to bump up excessively, then needing to swage down again as they enter the bore.
never fall for the trap that a fired bullet will look like an unfired new one.
most of the so called bore riders are not such, and more so with softer alloys.
they bump into the rifling too and being unlubed are an excellent source of leading.
how you deal with this is a subject in itself.
what chris (gunlaker) said is the best answer to your question for this reason.
bruce.

[Kenny Wasserburger]

With a Shiloh,

No need to slug the bore, the owner and president of Shiloh gave you all you need to know. I have owned Shilohs since 1994, never slugged a single one of them. From 38, 40, 45 calibers.


Chris and Bruce also gave you good advice. Enjoy the sickness. These rifles are addictive.
Their chambers work equally well with GG or PP bullets.

Kenny Wasserburger.

[gunlaker]

I agree with Kenny on not needing to slug the bore on a Shiloh. I have a number of them and they all like the same bullets and loading techniques. They are also the easiest rifles to develop a load for due to their consistency. I have only one exception and it is an early Bryan built Long Range Express in .45-70 which has a little tighter bore/groove. The bull barrel guns will also have a very slightly reduced bore diameter. In that case I can't use a .459" bullet but have to use the .458" one. I mostly shoot patched bullets in that gun anyway.

Chris.

[mdeland]

One learns from gunsmith school and over many years of gun work ,to check for your self if you want to know the truth about any barrel dimension, no matter who makes it! No two are exactly the same in the best of them and a properly made and measured slug tells the tale.