Trends in BPCR Long Range Shooting

[Don McDowell]

At the 1000 yd match last week at Alliance 3 of the top 10 were shooting paper patch. There was evidently another person shooting patched, as the range officer came back from painting targets and reported to us that he was finding bullets with twisted tails at the targets

[Don McDowell]

I was impressed by the performance of the .396 diameter 415 gr money bullet, wet patched in Seth Cole 55w in the Hyde manner, from the 40-90 bn #1 shiloh, using Olde Eynsford 1f.

[martinibelgian]

The theory regarding odd no.of grooves is that there is a groove opposite each land, meaning that there's room 'at the other side' for lead to go to when bumping up - in a linear fashion. That's the theory, at least...

[bruce m]

what gert said.
william metford was a great believer in this.
not sure about american barrels in the day.
the lead bullet guys over at assra feel that a min of 6 grooves, probably 6 to 8, lands less wide than the grooves is ideal.
the old pp barrels seem to have grooves about 0.003 deep, but by modern times wear might have affected this.
i have used canted land barrels by broughton and krieger in 6.5 and 7 mm barrels and they certainly shoot as well as square conventional rifling.
most of the better known custom barrel makers offer this kind of rifling under different names.
i have found one problem with it, and that is that you need sufficiently tight brushes or patches on jags to turn with the rifling.
if they are at all too loose they will skip over the rifling.
reports of this problem are not uncommon, with bad cases involving damage to the rifling.
this could suggest that fouling might do the same, i.e. blow straight out the barrel.
keep safe,
bruce.

[martinibelgian]

I believe the interior finish of the barrel (i.e. as smooth as possible) is far more important there. There's one form of rifling that would be pretty interesting though, judging from historical reports: Oval bore rifling, as advocated by Lancaster. According to contemporary reports (although with a ML rifle), it was possible to foul a barrel with a blank charge and the load/shoot it clean just by firing successive shots, the rifle getting easier to load with each shot... And there are other reports too of Charles Lancaster firing his rifles without any form of fouling management, and maintaining good accuracy. No angles at all in oval bore rifling...
As to Metford rifling, there are 2 types with the name - the one interesting for us would be his segmental rifling. And yes, both of these were used with PP bullet (successfully), despite missing sharp rifling angles for cutting the patch, as some claim is required for PP shooting...

[bruce m]

and the so called enfield rifling in the lee enfield 303 was designed by william metford.
5 groove.
keep safe,
bruce.

[Tomklinger]

Gentlemen,
Both of my Remington Creedmoor rifles have five lands and grooves, the Sharps has six with narrow lands...
Tom

[Woody]

My Springfield has three, and so does my sleeved 50-70 Sharps carbine. That Springfield is pretty accurate too.

Woody

[bruce m]

interesting about groove in various rifles.
suspected is that some hepburns even had gaintwist barrels.
orville's finding on alloys shows that you have to experiment.
one would expect that if any cartridge could bump up a bullet it would be the 40/90 bn, but in that rifle it was not so.
in the book "trajectories of american hunting rifles" (open library) alloys are mentioned with each cartridge.
the only cartridge to use pure lead is the 50/70.
could this relate to the low number of grooves in trapdoor barrels?
almost all the other rifle calibre cartridges used either 20:1 or 16:1, reflecting the modern trend.
almost every rifle manufacturer chambered a 40/70 straight, and often winchester ammo was used to test other brand rifles, suggesting that chamber dimensions were the same.
this cartridge used 20:1 bore dia pp bullets, and was commented upon for its accuracy.
orville, could harder bullets shoot better in that rifle with no grease wad?
keep safe,
bruce.

[Tomklinger]

Bruce m
You are correct, my Hepburn Creedmoor does have gain twist and a choke bore...
Tom

[alfajim]

Bruce m
Reading in Spence Wolfe's book on the trapdoor he indicated that the 3 groove barrel used in the trapdoor was adopted to allow the Troop's to be able to have a high shot count with a dirty barrel in combat conditions with out having to take a time out to wipe the thing clean so as not to get shot.
The original bullets .459/405gr used in arsenal ammo was a 16-1 swaged three deep gg with a hollow base required to get the harder allow to bump up to seal in the grooves. this was written by Spence also after a lot of research and obtaining and using original cartridges.
The later 500gr bullets didn't require the hollow base for bump up as being heaver it took more time to move so swelled up with the heat to seal.

Jim

[bruce m]

jim,
i was referring to the 50/70 cartridge and pure lead bullets.
was assuming that early trapdoors were in this calibre.
pure lead with the 45 cal govt bullets would virtually guarantee a leaded barrel with the long bore riding noses thy have.
they would cease to be bore riding the exact time the fire was lit.
with reagard the 45 cal bullets and hollow bases .
if the 500 gn bullet had a hollow base it would have had such length that the rifling twist woold have needed adjustment.
was the 16:1 alloy to minimive nose bumpup and leading that goes with, or to increase bullet penetration on horses?
in those days any military rifle had to be capable of disabling a horse.
keep safe,
bruce.

[Don McDowell]

According to the military manual on the Springfield rifle, the hollow in the base was to bring the weight of the 1.1 in slug to within weight specifications, but not so deep as to affect accuracy. The specified diameter was .458

[Orville]

I have also seen where .457 was the spec. for the diameter and lubed with Japan wax.

[Kenny Wasserburger]

Raton Target Rifle Nationals starts in just a few days.


I will shoot my Tolloffson rifle in both Mid-Range Prone and Creedmoor, shooting PP in both.


In a stunning turn of events, Scope rifles will run with Irons, for the chance to win it all.
Most interesting. This has never before been in our nationals programs.

Should prove to be interesting..


Kenny Wasserburger