Shorter is Better

[ColColt]

I found that the chamber on my Browning 1885 B"PCR 45-70 was 2.125". So, I ordered some 45-90 cases and cut them back to properly fit that chamber. I seated the bullets to where I always did with the shorter W-W cases and by doing so, of course, the drive band was engraved by the lands. I thought that could be a plus but it wasn't. Three times I tried making it work thinking my glasses were at fault and got another pair after the checkup. It did no good. Groups were still not as good as with the shorter cases.

Apparently this rifle doesn't like it's bullets to be engraved so, I'm going back to the somewhat shorter W-W cases. I've seen no evidence of any problem in the leade area and groups are so much better. The target below was typical of what I got today with the longer, trimmed back cases. The target below that was the same load, same bullet but with W-W cases. That's four shots and a fouler. I can't ask for a better group than that. I wouldn't have thought it would make that much difference but pictures don't lie.





BTW-Thanks to Don McDowell for the recommendation of Olde Eynsford powder. I tried it today and it did almost as well as the Swiss 1.5 that bottom group shows and is cleaner than Swiss-not by a great margin but noticeable. I found as he mentioned, you have to increase your charge by about two grains to get to the same point on the target as I did with Swiss.

[rfd]

yer bottom pic tells the tale - good shootin'.

[ColColt]

Yep, I was happy about it. That particular bullet and the Lyman 457125 will shoot about as good as it gets in that rifle but, obviously it doesn't like to have a bullet shoved in the lands.

[Lead pot]

By changing from the thin wall Winchester brass to the thicker walled ???Starline????Jamison??? brass you changed the inside case dimensions and this changed your powder compression. You can get the accuracy back with the longer brass. You just have to change your load some.

[ColColt]

I had been using Winchester and bought some 45-90 Starline brass to trim. I don't know that a load change would do it or not. They rifle may just not like the bullet in the lands. With Winchester it's about .025" off the lands.

[rfd]

I had been using Winchester and bought some 45-90 Starline brass to trim. I don't know that a load change would do it or not. They rifle may just not like the bullet in the lands. With Winchester it's about .025" off the lands.

that really sounds like the issue - the oal - and ya sure fixed that.

[montana_charlie]

I seated the bullets to where I always did with the shorter W-W cases and by doing so, of course, the drive band was engraved by the lands.

So, your OAL was longer.
You have found a solution that pleases you, so it isn't important that you say...

But, why didn't you just seat the bullets deeper in the (new) case to maintain the original OAL?

CM

[.22-10-45]

Montana Charlie beat me as to why bullet wasn't simply seated deeper in case. However, short cases in long chambers when using black is not better..unless your bullets are cast from lino or some other very hard alloy the sudden kick from the black will upset unsuported bullet portion into that gap.

[ColColt]

I didn't seat them deeper because I didn't want to compress the charge anymore. I had established good groups with a certain compression and didn't want to change it.

[montana_charlie]

I didn't seat them deeper because I didn't want to compress the charge anymore. I had established good groups with a certain compression and didn't want to change it.

How much compression was used in your original load?
How much would have been required to seat the bullet to the 'good' OAL in the new case?

The questions are not aimed at proving you right or wrong, they are to determine how you 'measure' compression.

CM

[ColColt]

The trimmed 45-90 cases take .250" compression and the W-W cases take .100" to seat the bullet to the same place and in this case with the Postell bullet, both seated at the bottom of the first drive band. I try not to compress Swiss any more than necessary and the .250" for the longer cases apparently is too much in conjunction with the bullet engraving the lands. The targets show what it likes. It either doesn't like that much compression or it doesn't like the engraving...maybe both.

Apparently, even with the longer Starline 45-90 cases it takes more compression probably due to the brass being thicker. That charge I use is 64 gr of Swiss 1.5 with a .030" wad.

[montana_charlie]

Admittedly, that's quite a change in compression.
Press on ...

[MikeT]

For the compression to change from 0.100 to 0.250 would mean that your starline cases hold about 8 grains less powder.
I can tell you this, I do the same thing [cut down 45-90 brass] and it is not possible for the starline to hold even 4 grains less powder.
The "thicker brass" is a myth. Once, I cut down some 2.6 starline to 45-70 length and only gained .0005" wall thickness.

My guess would be that your problem is the chamber length is less that 2 1/8", so your brass is into the "lead".

Keep on hav'n fun!
MikeT

[country gent]

Winchester brass is some of the thinest / lightest brass on the market normally. Not real sure wheret the starline falls in at. I would try lightening the compression up on the starline to .100 and see if the load duplicates then

[ColColt]

My guess would be that your problem is the chamber length is less that 2 1/8", so your brass is into the "lead".

It is a little less than 2.125". I had to cut the brass back to 2.120" for it not to pinch the case mouth and that worked. With the cases being longer you'd assume it would hold more powder-it doesn't so, the brass would have to be thicker to some degree than Winchester and that's no myth it's a fact. There is no other explanation.

I would try lightening the compression up on the starline to .100 and see if the load duplicates then

If I do that the bullet would be too long to chamber.

Just for curiosities sake I filled both cases with Swiss and took a card and leveled the top of both. The Starline case held 77.5 gr and the W-W shorter case held 87.2 gr.

[Dan4570]

Nice shooting.
Something we found out, (my shooting buddies and I) we all shoot 45-70, they have trapdoors, and I have a #1 Rem. Rolling block (original action, new bbl) and one of the guys got his daughter a Browning Hi-Wall. We found that trim to min leangth, full leangth resize, and all the guns would shoot the ammo about as well as special loads made just for 1 rifle, shot in that 1 rifle. On occassion we do have loading/casting parties, and just build everything to US Gov. specs, and all the guns shoot well out 600 yds (my 22" bbl falls off after that, not enough velocity) I have found the 45-70 to be easy to be easy to load, and get it to work, the only finicky part of them I have found is the casings, PMC is all our guns is a no-go, besides they don't hold enough powder. Win prefered, Remington 2ndary choice. I have never had the opportunity to try Star Line, but I have heard good things about them.
Once again, nice shooting.
If your interested in not having the fouling shot flyer, or atleast drastically reducing it, give me a holler.

[ColColt]

The only thing I don't like about Starline, fine brass as they are, they hold typically 5-8 grains less than Winchester but who's seen Winchester 45-70 brass lately? Not me but I'm still looking.

[Don McDowell]

Good doin's on that bottom target. Once again it sort of goes to show how we can really bugger things up by trying to fix something that really wasn't broken. But we've all been there done that , bought the T shirt..

[ColColt]

Been there for sure. I don't have the T-shirt but bougth the hat. I've been working with O.E and have to tsay it's a toss of the coin between it and Swiss as to groups and it's a bit cleaner from what I've found to date.

[Don McDowell]

I've found the OE fouling to be softer than Swiss. The accuracy is so similar that I can't justify the added expense of the Swiss.