Thoughts on chambering

[XTR]

I’m curious to know if anyone has ever put together a list of the BPCR chamberings and the uses for them. The thought has occurred to me since I have acquired my third 45-70 and I’m pondering the idea of ordering an 1877 at some point but I’m not sure what chamber I’d want.

I get that of the straight wall 45s the 2.1 and the 2.4 are the most common and practical for a lot of hunting and target shooting. The rest seem more trouble than they are worth.

I think I understand that the 40-90bn is a thumper, and the impression I get is that it’s hard to get to shoot but it can be good at about anything if you can manage the recoil.

What about the rest of the list. I know some are great silhouette guns. Thoughts here?

[Don McDowell]

The 40-90 bn is not hard to get to shooting at all. It does consume a huge amount of powder 90-94 grs every time it goes off, the recoil can be a bit punishing if shooting a 30 round or more match. But would make a slam-dunk hunting rifle.

[bpcr shooter]

Well when you only had one powder, being black powder, the only way to get more speed with the same size bullet, was to put more powder in it.
Here is some readings for you about cartridges.
https://www.chuckhawks.com/buffalo_cartridges.htm

[bruce m]

xtr,
it is my understanding that the 77 was developed with long range target shooting in mind.
they wanted a heavier barrel, and to keep under 10lb wt the only way to achieve that was to lighten the action.
creedmoor shooting required a single trigger.
sharps introduced the 45 2.6" case for creedmoor type shooting, but quickly reduced the case length to 2.4".
i cannot say for sure, but i have read that in the day, 100 gns powder was considered all that was needed.
this is borne out by the fact that tese rounds were called the 45 100 2.6. and the 45 100 2.4.
sometimes the bullet wt of 550 was tacked on as well.
shortening the case meant that the bullet was barely in the case of the 2.4, a thing we know to be beneficial to accuracy.
if you really want a 77 that cuts to the core, you would have to consider the 45 2.4 in what shiloh calls an orville chamber.
this suits bore diameter bullets only, and all you will have to do is finger seat a bore diameter pp bullet into a recharged case.
of course later on the borchardt became considered the bet creedmoor rifle, and guys started going back to the 2.6" case to get more powder in, some preferring to breech seat the bullet in front of a full case of powder.
if only shiloh made a borchardt with a single target trigger.
bruce.

[XTR]

Thanks guys. As I wrote above, I’m up to three 45-70s now, and 2 never see anything but BP. I’ve experimented with GG and PP shooting to some extent but that all got kind of put on hold a few yrs back when I really dedicated myself to long range F class shooting. I’ve had some success with that, and I’m on the US team so I kinda figured that out. (And the OCD is strong). In any case I’m really feeling the need to get back into shooting my BPCRs.

I appreciate the thoughts on the 40-90bn. I thought it was harder to get shooting.

I’ve read that Chuck Hawks article.

Any thoughts here about some of the other chambers, like the various 40 straights or the other BN chambers.

I’m particularly interested in the 40s and maybe the 44s. Do any of them offer a real world advantage over the 45s?

I understand that there is a world of difference between shooting a black powder cartridge and a smokeless bottleneck cartridge. I’ve done a little bit of casting. Not much compared to some of the folks here but more than a few pounds of lead. I get that the ballistics of a cast lead bullets traveling Transonic at the muzzle is somewhat different than that of a long range boat tail that I can keep supersonic past 1000 yds.

Can the big 40s or 44s be tuned to take advantage of their ballistics, which I would assume to be better, on paper, compared to the 45s.

I know that what looks good on paper may not on the target. I routinely shoot 308 to 1000 yards in FTR. Over the last 10 to 11 years We have moved from 155s and 185s to 200 grain bullets in our 308s. Up to 200 grain bullets the heavy bullets pay dividends. In the last decade the Scores are higher across-the-board, but those people who have tried to drive bullets that are heavier than 200 that that on paper should have better ballistics for what ever reasons have typically been unable to put up the scores that they can put up with a 200 grain bullet.

So that’s one thought about the possibility of dabbling in competition shooting.

The other thought is in a hunting application looking for a round that has possibly less recoil or similar recoil and somewhat flatter shooting out to reasonable hunting distances. Is that a thing or just an unexperienced musing.

[semtav]

Lots of 40's to choose from, but the 40-82 silhouette is hard to beat for ease of load development..

[XTR]

What bullet do you run in the 40-82?

[Don McDowell]

I prefer the 44's over the 45's. It seems to me like any of the 40's are more prone to having trouble in the wind. The 40-90 bn isn't bothered as bad by the wind, for a long range gun the 40-90bn would be pretty good in a 16 lb gun.

[DAG4570]

XTR

For hunting and a little less recoil you could try a 50-70 with light weight bullets.

Dave

[bruce m]

xtr,
having been an fclass shooter for years, it was natural for me to gravitate a black powder interest in the direction of long range.
my first rifle was a 45/2.4, and it taught me a lot.
it shoots well with a 540 gn greaser and 90 gns powder as well as similar wt pp bullets and 98 to 100 gns powder.
this rifle taught me a lot about long range black powder shooting, but i always wondered how a 40 would stack up.
i built a 40/72 using 405 win brass, and it proved to be as good in the wind as the 45 with less recoil.
it uses about a 440 gn bullet with 85 to 90 gns powder depending on the lot, so the major recoil reduction comes from bullet wt.
many guys claim the 40s are more prone to wind deflection than the 45s, and in general terms they are right.
this is because twists generally available in 40s are too slow to handle bullets with as high a b.c. as the 45s.
my rifle has a 1:13" twist, and after exhaustive tests i found that 1.5" long bullets were optimum performance.
it will handle 1.55" long bullets, but they have a little wobble at 600 to 700 yds then go back to sleep.
a 1:12 would handle 1.55 long bullets.
i have often wondered how a bigger case would go and the 40/90 bn sharps, as well as the 40/90 ballard look interesting.
you would not go wrong with the 40/82 either.
long range allows up to 15 lb i believe? (someone might correct this), so either calibre is manageable.
the important thing with this shooting as with any shooting is follow through.
it helps you handle recoil, as well as manage the longer barrel time of black powder bullets.
if you are in the us fclass team you will understand the relationship between b.c., bullet length, and twist.
back in the old days, there was very little difference between 44 and 45 cals.
many 44s were such only in groove diameter, being 44 only in bore diameter.
you can easily put a twist on a modern 44 cal that will shoot a bullet as good in the wind as a modern 45 cal.
i believe kurt has tried a few different twists in 44 and might offer advice here.
from memory a 17 twist 44 with bullets to suit might come close to an 18 twist 45 similarly bulleted.
as you have seen with your ftr rifle, speed does little to avoid deflection compared to b.c.
bruce.

[Don McDowell]

long range allows up to 15 lb i believe? (someone might correct this)

Tollefson class in NRA are rifles between 15 and 25 lbs. BPTRA allows rifles to 24 lbs.

[semtav]

What bullet do you run in the 40-82?

40-82 bullet.jpg

its sitting on a 40-65 case there, but I had it made for the 40-82.
shoot it behind 80 gr Swiss 1.5

Steve Brooks made it.
Strictly for target.

[bruce m]

long range allows up to 15 lb i believe? (someone might correct this)

Tollefson class in NRA are rifles between 15 and 25 lbs. BPTRA allows rifles to 24 lbs.

thanks don.
my own rifles are just under max allowable for silhouette to offer more versatility, and i find that manageable.
however shooting the 45/2.4 with 100 gns is hard work doing scheutzen, but not too bad prone.
weight is your friend in these matters.
bruce.

[bruce m]

semtav,
how much swiss powder can you droptube into a 40/82 case so that a wad is level with the case mouth?
bruce.

[XTR]

Bruce, I definitely get the whole twist rate bullet length stability relationships. I’ve experimented with long bullets in twists as high as 1:8 in a 308.

There are some pretty reliable stability calculators out there. Don’t know about cast but a little extra usually doesn’t hurt that is until you cross the 300,000 rpm boundary, then jacket bullets start to get into the zone where they go *poof* at 75 yards.

Hope the conversation continues. Appreciate the input here.

I’ll keep noodling this one for a while. I’m not in a hurry, this is just the start of my thinking about this. I’m still dedicated to F class at least till we finally get to have the worlds whenever that happens. It was supposed to be in Bloemfontein next month but that got the flu, currently scheduled for early ‘22. Keeping my fingers crossed it happens.