Every bore is an entity unto itself.
I have a Tikka T3, 6.5x55 which just doesn't seem to be affected by jacket or propellant fouling. I will confidently let this rifle go from the beginning of the hunting season to the end, with several shooting sessions, for practice and "just to make sure" nothing has changed dramatically for whatever reason over this period.
Last year, it had close to 150 rounds down the bore before I cleaned it, for winter storage. This rifle needs ONE fouling shot to settle down. It's Gem, almost in the Unicorn class.
I also have a 7x57 Mauser (aka 275 Rigby) which I put together from surplus parts in the bins, including a NOS Brazilian 1908 barrel, made in Oberndorf, with the unusual Brazilian twist rate of 1-8.66, for the 140 grain bullets, which were loaded to 2900fps.
This rifle loves the Barnes TTSX 120 grain bullets, just like your Rigby.
Barnes jackets tend to foul bores quite fast, as do Nosler products. The faster they're pushed the more they foul.
My load for the 7x57 is not "hot" but it's stout and not suggested for use in pre 98 Mauser type actions.
50 grains of W760 over CCI250 primers = 2860fps average with appx 25fps extreme spread at 20C 1300ft of elevation.
Sub moa groups are the norm and pressure signs are not obvious.
The length of the monolithic TTSX 120 grain bullets are very similar to cup and core 139 grain Hornady FBSP Interlock offerings, but the TTSX have grooves to keep down friction and maybe fouling.
I took out the Remington 700 Classic I picked up because it was chambered for the 280 Remington (aka Rem 7mm Express).
I loaded it with a stout load of H100V, a powder I haven't used before and an article by John Barsness convinced me it was a good choice with the Barnes TTSX.
H100V by any other name would appear to be RL19, but I haven't used it enough to see how close the loads are. When they're put side by side, they are physically identical in shape, color and size. It will be interesting to check speeds of identical weight charges behind identical bullets/primers in the same cartridge. It should give good results in strong 7x57, 7-08 cartridges with bullet weights from 120-150 grains
The load for the 280 Remington was 59.0grns H100V over CCI 250 primers = 3170 fps avg from a 22 inch bbl.
Speed was checked with a Garmin C1 and extreme spread was 28fps over the 30 rounds clocked.
Sorry for wandering off Super Cub, but I felt you may like a bit more detail than both of these rifles saw 50 rounds each today, being allowed to cool after every three shots to ambient temperatures.
The rifles had been cleaned with Wipe Out, back to the bare steel before the shooting started.
Both rifles used the TTSX 120 Barnes bullets and fouling did not enlarge the groups after the first three shot group was fired by each rifle.
Maybe it's the light bullets?? which are keeping the fouling down??
It's interesting to say the least and in my limited experience, very unusual.
Most bores, no matter what the bullet weights or bore condition, need to be cleaned after 20-30 rounds, or accuracy becomes unacceptable
I have a Tikka T3, 6.5x55 which just doesn't seem to be affected by jacket or propellant fouling. I will confidently let this rifle go from the beginning of the hunting season to the end, with several shooting sessions, for practice and "just to make sure" nothing has changed dramatically for whatever reason over this period.
Last year, it had close to 150 rounds down the bore before I cleaned it, for winter storage. This rifle needs ONE fouling shot to settle down. It's Gem, almost in the Unicorn class.
I also have a 7x57 Mauser (aka 275 Rigby) which I put together from surplus parts in the bins, including a NOS Brazilian 1908 barrel, made in Oberndorf, with the unusual Brazilian twist rate of 1-8.66, for the 140 grain bullets, which were loaded to 2900fps.
This rifle loves the Barnes TTSX 120 grain bullets, just like your Rigby.
Barnes jackets tend to foul bores quite fast, as do Nosler products. The faster they're pushed the more they foul.
My load for the 7x57 is not "hot" but it's stout and not suggested for use in pre 98 Mauser type actions.
50 grains of W760 over CCI250 primers = 2860fps average with appx 25fps extreme spread at 20C 1300ft of elevation.
Sub moa groups are the norm and pressure signs are not obvious.
The length of the monolithic TTSX 120 grain bullets are very similar to cup and core 139 grain Hornady FBSP Interlock offerings, but the TTSX have grooves to keep down friction and maybe fouling.
I took out the Remington 700 Classic I picked up because it was chambered for the 280 Remington (aka Rem 7mm Express).
I loaded it with a stout load of H100V, a powder I haven't used before and an article by John Barsness convinced me it was a good choice with the Barnes TTSX.
H100V by any other name would appear to be RL19, but I haven't used it enough to see how close the loads are. When they're put side by side, they are physically identical in shape, color and size. It will be interesting to check speeds of identical weight charges behind identical bullets/primers in the same cartridge. It should give good results in strong 7x57, 7-08 cartridges with bullet weights from 120-150 grains
The load for the 280 Remington was 59.0grns H100V over CCI 250 primers = 3170 fps avg from a 22 inch bbl.
Speed was checked with a Garmin C1 and extreme spread was 28fps over the 30 rounds clocked.
Sorry for wandering off Super Cub, but I felt you may like a bit more detail than both of these rifles saw 50 rounds each today, being allowed to cool after every three shots to ambient temperatures.
The rifles had been cleaned with Wipe Out, back to the bare steel before the shooting started.
Both rifles used the TTSX 120 Barnes bullets and fouling did not enlarge the groups after the first three shot group was fired by each rifle.
Maybe it's the light bullets?? which are keeping the fouling down??
It's interesting to say the least and in my limited experience, very unusual.
Most bores, no matter what the bullet weights or bore condition, need to be cleaned after 20-30 rounds, or accuracy becomes unacceptable
