Chamber Impact impression.

[CaptnJack]

Howdy, all.
I want to make a chamber impact impression of my 45-110 chamber to size the brass. it calles for a fireformed case to use. I don' have any fireformed cases. In fact all I have right now is 45 basic brass nothing done to them. I have some CerroSafe I could go that way and get a close measurement, load it and get a fireformed cast that way. I will be shooting a 540gr PP bullet. Anyother suggestions.
Thanks.

[Michael Johnson]

So, I seem to be missing something here. Why not just firearm a case? Hell of a lot easier.If you want a sizing die, RCBS and others make standard dies for Shiloh chambers.

[desert deuce]

Cerrosafe is what I do, get a rough idea of over all length, then trim to length then fire form with white powder and cornmeal.
A case that is a little bit short works a lot better than a case that is a little bit long.

[Kurt]

You can also use paraffin canning wax or melt down a candle. Just use a little WD-40 on a cotton patch and lightly oil the chamber and bore plug the barrel with a patch a 1/2" or so past the chamber heat the barrel a little with your Wife's hair dryer and pour the wax. Wax shrinks on the inside and it holds the outside well of the cast and the out side will be close enough to measure the depth of the chamber.
Here is a wax cast of one of my .44-2.6 chambers. The camera did not pick up the details but everything is very sharp and clear.

.44-100 wax cast .JPG

[Coltsmoke]

Take one case and cut it to the standard length for your caliber, and then fire form it. Now use it to do your chamber cast and you will find out what the length needs to be. I have found that new brass will shorten around .005 after it is fireformed. So, don't cut all your brass to the length the chamber cast shows you it needs to be, then when you fire form it you come up .005 short. Cut one case to standard length, do the chamber cast and get the actual length you need, cut one case .005 longer than the chamber cast calls for, fire form it and then see what you have. Now you can make an informed decision on exactly what your rifle wants.

I like the wax cast Kurt, thanks for that idea.

[bobw]

Norma 2.9"? Trim to 2.883" 45 degree chamfer outside, VLD chamfer inside. lube the whole case but not excessively. Full length size till it chambers completely and if it don't, take off another .001" till it does. You didn't mention your bullet dia. if .442" use 9lb onion skin, if .444" use the thin paper for a .449-.450" patched dia. Get the Lyman LONG 45 cal taper crimp die to size down the case mouth to hold the ppb. Not every 2.875" chamber is exactly 2.875" so DON"T trim the cases short, up front before you have fireformed them and fit them for length fireformed. bobw

[CaptnJack]

Thanks all for the Ideas. Will look into them.

[CaptnJack]

Norma 2.9"? Trim to 2.883" 45 degree chamfer outside, VLD chamfer inside. lube the whole case but not excessively. Full length size till it chambers completely and if it don't, take off another .001" till it does. You didn't mention your bullet dia. if .442" use 9lb onion skin, if .444" use the thin paper for a .449-.450" patched dia. Get the Lyman LONG 45 cal taper crimp die to size down the case mouth to hold the ppb. Not every 2.875" chamber is exactly 2.875" so DON"T trim the cases short, up front before you have fireformed them and fit them for length fireformed. bobw

I have the 540gr money .443 mold from BA. with 9lb onion paper. I came apon two rcbs 3 die sets one for the 45-110 and another for 45-70 A few years ago at a gun show cheap. And I have a lee universal crimp die for the 45-70.

[CaptnJack]

I finally got around making my case length impact impression for my 45-70 chamber. It came out to be 2.175" Like I said this is all kind of new to me. I have 200- 47-70 cases they been fired but not from my rifle. There measuring right around 2.092 are the cases to short to be used? Do I need to stretch them some to get to where I need be? I will be shooting a 540 gr PP bullet. Suggestions. Or which way to go from here?

[Coltsmoke]

They are short, but you have measured too far. You need to measure to the point where the leade angle starts, not where it ends.

[Trigger1212]

Can someone explain what an impact impression is and how it should be done?

I THINK I know what it is just not sure on the idea of how to do it in a proper fashion.

Why this instead of a normal chamber cast?

Cheers!

Wade

[rebsr52339]

Texas Mac's has a very good article on impact chamber impressions as well as others. Go to the articles section and read. Have used the impact method and it is very accurate.

http://texas-mac.com/index.html

[CaptnJack]

Can someone explain what an impact impression is and how it should be done?

I THINK I know what it is just not sure on the idea of how to do it in a proper fashion.

Why this instead of a normal chamber cast?

Cheers!

Wade

I made some slugs out of a hardwood mold and pure lead. Instead of pouring lead down the barrel. Read over Texas Mac's way and also watch this Video I kind of followed both. [urhttps://www.youtube.com/watch?v=GswRfrW5xV0l][/url]