my adventure in bore slugging

[treebeard]

I am worlking on increaseing the accruracy of my 1st model  1873 Trapdoor. So I decided to slug the bore which i have done with a number of modern rifles with no problem. Had the idea that i would use some of my store bought 405gr hollow base bullets not expecting any real effort to drive it down the bore. But had to drive it in with considerbal force and then it was very reluctant to go very far. so i left it overnight soaking in kroil and then went back to forcefully hitting it with a dowel and it gradually moved until about 12 or so inches at which time it became easier to drive and then the last few inches were easy. when i finally got the bullet out it measured .455 land to land. my bullets are .461 so i was going down 6 thousands. I was surprised at what appears to be a choke in the rifling from rear to muzzle.I think my next set of bullets will be .458 or .459. Also started reading Wolf"s book on shooting the trapdoors.

[Abilene]

I am kinda ignorant on this sort of thing, but that "taper" direction with the right bullet should be good for accuracy, right?

[treebeard]

I am kinda ignorant on this sort of thing, but that "taper" direction with the right bullet should be good for accuracy, right?

Yes i would think that may be one of the secrets to the good reputation for accruracy that trapdoors have. From what Wolf  is saying  you need to follow certain techniques in loading the cartridge to gain a high degree of accruracy. Sadly i will only be able to go out to 100yds as that is the longest range i have access to.

I might add BPCR is a new thing for me as i have spent 60 years shooting muzzleloading rifles or smokeless in cartridge firearms. I will be adding BP in my Spencer next!

[Dave T]

You said your .455" measurement was "from land to land". Isn't "groove diameter" the normal way of measuring a rifle's barrel? Particularly in determining the correct size of cast bullet to use.

Just wonderin',
Dave

[Reverend P. Babcock Chase]

It strikes me that measuring "land to land" on the slug in fact gives you groove diameter. I'm shooting .458-.459 405 gr. bullets in my Sharps and they work well out to 100 yds.

Rev. Chase