Shiloh Rifle Forums

Above are two chamber casts I made from my Shiloh .44-90 2-5/8 BN. The top is the Shiloh reamer with their 45 degree chamber end and the bottom cast is a reamer I had cloned from a original .44-2-5/8 long range that was in new unused condition in a wooden case with all tools and some PP bullets. I Had PT&G make me a reamer from this cast and I had Kirk use this reamer for my rifle.
I think there some confuse the free bore with the original long throat chambers used before the jacketed bullets came about when the long tapered lead was changed to a sharper chamber end like the now used .45 degree.
I made one slight change with this reamer and this was from a 3-5 degree taper to a 4 degree' 1/5 degree compound and it turned out being a fine shooter.
I call this type of throat a lead bullet chamber and not a PP chamber only because it works very good for a PP or a GG

I have looked at a lot of old original chambers and casts and to this day I have never seen a cylinder type of free bore like the early Shiloh farmers or the chamber I thing Pedersoli copied from the early Wolfgang's sharps.

So if I may be allowed to summarize, what I’m reading so far essentially confirms my understanding and belief that patching to groove works and may be the preferred technique if the rifle has a significant amount of freebore. If not than patching to bore diameter is the way to go if an adequate amount of powder is required for silhouette or long-range competition.

I’ve got a couple of reasons I started this thread which was not mention in my initial post. One is I’ve been informed many times by PP shooters over the years that patching to bore is the only way to go for good accuracy, which I always struggled accepting. The 2nd reason is, as many of you know and until late last year when I acquired a Shiloh Sharps Sporter #1 in .40-65, I had been a "dyed in the wool" 100% Browning shooter. Although I have Browning’s in .45-70 & .45-90, my preferred chambering is the .40-65. The Browning .40-65 has about 0.180” of what I call “effective freebore” and I’ve considered trying PP bullets in it.

BTW, as semtav noted, the Browning .45-90 Creedmoor also has a good bit of freebore. I’ve made chamber casts of several which average approximately 0.260”. Also, for what it’s worth, the freebore diameters in both the Browning .40-65 and .45-90 Creedmoore are 0.002” to 0.003” over groove diameter & the leade angle in both is 1.5 degrees which I would expect to be favorable for PP’ing unless I’m mistaken. This leads me to a final assumption.

Even if reduced loads were acceptable, patching to groove diameter for a rifle with no freebore and a 45 degree chamber to throat transition step or leade angle would be a bad idea since it would tend to destroy the patch.

Fire away guys.
Wayne

Brent,
I'll try and a chamber drawing and some cartridge pics this evening, but basically - the paper has nowhere to go but down the barrel.
Actually, your reaction would also apply even more to the bore-dia. bullet: why doesn't the paper stick, and it actually should split or at least unravel when the bullet is upsetting. Still, it does work, and work well.
Same with that groove-dia bullet: the bullet only needs/gets minimal upset, so less deformation. Why doesn't the paper strip? No idea, but it doesn't.
All theory of course, but it works....

Here a pic illustrating the difference for my rifle:


And the chamber looks like this:


And for the moment, the groove-diameter bullet does just a bit better than the bore diameter bullet.

And no, it doesn't destroy the patch... ohterwise it wouldn't shoot that well.

The bottom chamber cast looks like my Roller's original 40-70 Remington chamber circa 1877.

TexasMac wrote:
Even if reduced loads were acceptable, patching to groove diameter for a rifle with no freebore and a 45 degree chamber to throat transition step or leade angle would be a bad idea since it would tend to destroy the patch.

Fire away guys.
Wayne

Again, I do not find this to be the case when the bullet's paper is cammed into the rifling before shooting.
But it may very well be the case if you try to jump the patch to the rifling.

Geologist wrote:The bottom chamber cast looks like my Roller's original 40-70 Remington chamber circa 1877.

I think that they used one closer to 15 or 16 degrees.

I started in 2007, patched to bore, Brent was and back then so was Dan. I used too small a diameter bullet, with too thick of paper, had some good accuracy. But at Phoenix had a dirt digger 2 in every 10 record shots. Went to a bigger diameter bullet very think Vellum. Haven't looked back since.

Kenny

My Patched to Groove Dia loads

40-65 (Browning chamber)
40-82 (Crossno Chamber)
42-85 (custom Chamber)
45-70 (standard Shiloh Chamber)
45-90 (Browning chamber)
45-2.6 (custom chamber)

That's a hugely instructive photo! Looks about like I would expect too.

semtav wrote:PP Bullets.jpg


My Patched to Groove Dia loads

40-65 (Browning chamber)
40-82 (Crossno Chamber)
42-85 (custom Chamber)
45-70 (standard Shiloh Chamber)
45-90 (Browning chamber)
45-2.6 (custom chamber)

Could you also state bullet wts for these loads.
Thanks,
Gus

40 Cal is right at 400 grn and 45 Cal is about 535 I think. . I'll weigh a couple when I get back. Dia of the unpatched bullets are .404, .424, and .454. Patched dia are about .410, .430, and .460.

One misconception I think some are making is the difference between the leade and the transition from chamber to throat.
All these rifles have a 45 deg transition and a very shallow leade. Some have freebore and some don't.

semtav wrote:40 Cal is right at 400 grn and 45 Cal is about 535 I think. . I'll weigh a couple when I get back. Dia of the unpatched bullets are .404, .424, and .454. Patched dia are about .410, .430, and .460.

One misconception I think some are making is the difference between the leade and the transition from chamber to throat.
All these rifles have a 45 deg transition and a very shallow leade. Some have freebore and some don't.

Brian,

All the Browning BPCRs (.40-65, .45-70 & .45-90) have 12.75 degree transition steps from chamber to throat. The leade angle for the .40-65 and .45-90 is 1.5 degrees, both of which have freebore. The leade angle for the .45-70 is the same as the transition step angle of 12.75 degrees since it does not have freebore (the transition step angle continues to the top of the lands).

Wayne

Okay thanks. Should have looked at my chamber castings before I posted that. Haven't done much with my Browning for 4570, it'll be interesting to see how it compares to the Shiloh 4570