Winchester(Mikoru) 1886 45-90-Hodgdon trail boss loads

[swifty]

My question is about bulk loading-similar to loading black powder- for the 45-90.
My latest issue of Double Gun Journal-Single Shot Journal has an article on Bulk Loading with Hodgdon's Trail Boss for Black Powder Express Rifles. The article stated to fill the case to the base of the bullet, weigh the charge and take 70%. My 1886 45-90 case will hold 23 grains of Trail Boss to the base of the bullet, and 70% is 16 grains.
I recently read a favorable report on using trail boss but I can't remember the article. The standard express bullet for the 45-90 was a 300 grain FN.
Do any of you have experience with reloading with Trail Boss for the 45-90 or the 45-70?

[Chuck 100 yd]

I load 14 gr. Trail Boss in the .45-70 under cast bullets of 325-350gr and they are very soft recoiling mild loads at 1130 fps or so.
The Hodgden annual manual,from I think 2007, said in one article to use the 70% figure you stated and I arrived at this load the same way.
I shoot 13 gr in the .444 under a cast bullet also. I can go look and see what that bullet actually weighs if you need.
Trail Boss is very fast burning and can build very high pressure so dont try to hot rod it. If you keep in the 1100-1150 fps range it will shoot tiny groups. These were from 50 yd with irons.


Have fun!!!
A 10 year old could shoot these loads all day long.

[1886]

I shoot 12grs of T.B. under a 400gr Bear Creek Supply soft cast ignited by Rem. 2 1/2 primers in Win. cases in my various .45-70 chambered rifles. Accuracy never disappoints and velocity runs between 950-975fps. With a 300gr bullet Hodgdon shows 14grs as a starting load and 16.5grs as Max. in the .45-70. They state the 16.5gr load produces 1285fps with 20,900 cup. This will obviously vary with different components. They list no .45-90 data. I shoot 13grs in my .45-90 with the above components for 950fps-975fps depending on the rifle. I have found that bullet does really well in that velocity range. I would think if you do not exceed 1300fps you would be fine with your 300gr bullet. I am sure you are aware but your Miroku will have a twist rate appropriate for heavier bullets, assuming it wears the factory barrel. Hope this helps, 1886.

[swifty]

Thanks folks, that is just he type of information I was looking for.
I really appreciated your photos and comments.
Swifty