I've been seeing several threads where guys are able to achieve 2800fps in the rigby with the 350gr TSX... and several recommendations to work to get to that velocity. I'm getting substantially less than that at max published loads.

The rifle is a CZ with a 23" barrel.

105 grains of H4831sc = 2585fps
99 grains of H4350 = 2575fps

Do these loads seem like what I should be expecting?

And to get 2800, is the trick to load well into 416 weatherby territory?

I spoke to one of the Barnes tech guys when working up loads with their 400 Gr. bullets in my 416 Rigby. He told me you often takes more powder to achieve the desired velocity with TSX bullets.

quote:

Originally posted by mrjulian_1970:
I've been seeing several threads where guys are able to achieve 2800fps in the rigby with the 350gr TSX... and several recommendations to work to get to that velocity. I'm getting substantially less than that at max published loads.

The rifle is a CZ with a 23" barrel.

105 grains of H4831sc = 2585fps
99 grains of H4350 = 2575fps

Do these loads seem like what I should be expecting?

And to get 2800, is the trick to load well into 416 weatherby territory?

Your loads and results look about right.

And yes, 350 grains at 2800fps is edging into 416 Weatherby territory. Basically, when loading the 416 Rigby carytridge for a CZ rifle, a person needs to decide whether they want to duplicate the under-pressure 1912 loads, or to conservatively load to the capacity of the cartridge and rifle, essentially producing a wildcat, or in other words crossing into Weatherby territory. I am one of the posters who reminds people that the 416 Rigby in a strong bolt acton is capable of far more than the published loads. Those published loads are kept in the 40000-50000 psi range, while the CZ rifles are capable of 60000 psi, and then some, in the Rigby casehead. For comparison, the 30-06 is typically loaded to a 60000 max, while the 270 is allowed to run to 65000 psi. This may reflect the wider production background and longer history of used rifles circulating in 30-06. Of course, not everything in big bore should be run up to 60000 psi. On the Gibbs casehead (.640", close to 20$ more area than the Rigby) someone has posted that CZ recommends a 55000psi ceiling. In any case, below is a picture from a recent buffalo hunt with two Rigby cases and one bullet from a 2825fps loads. The loads were 101.5 R-17 with the 350 gn TTSX. The TTSX and TSX loads are not interchangeable, with the TTSX needing to reduce the charge by 1-2 grains. (The case on the right is from a 338WinMag also at 2838 (225 TTSX).)


Notice the 'cool primers' on the Rigby cases. The buffalo approved. It was on the longish side, 110 yards. The bullet blew its petals, dropped to 258 grains, but then formed a secondary mushroom. The Rigby works well, of course, at lesser velocities. However, if you want a flatshooting dangerous game calibre, the 416 Rigby will provide and is basically a 416 Weatherby with about 3-4 grains less capacity because of body taper. The Rigby is a great calibre, however one runs it.

PS: I am not the first to recommend such use of a 416 Rigby beyond traditional loads. I remember Jack O'Connor writing on the cartridge and talking about acheiving 2600fps with a 400 grain bullet without too much problem. He didn't like the recoil. While it snaps a bit, it is quite manageable. I don't get a chance to shoot it much. Once a load is established I mostly just do sightins and hunting shots.

You may have seen my thread - 350 gr TSX with AR2209 (H4350) - 102 gr gave me 2850 fps. I dropped it to 98 grs & got 2630 fps. 100 gr may give around 2750 fps I think. My rifle may have a slightly faster barrel compared to yours.

I found the heavier charge booted me a fair bit. I am a lot more comfortable shooting the milder load. Good accuracy too with the milder load. I also prefer the 2400 fps load for the 400 gr bullet.

I think you will find H4350 give less felt recoil for same velocity compared to H4831 - 6 grains less powder.

A word of caution - Saeed's loads on the AR load data pages were developed long ago & have much higher powder charges for similar velocity. Different powder lots (15+ years) & different components.

Compare that to the 404 Jeffery or the 450/400 and you are still ahead on velocity, energy, TKO or thunderbolt that you may need!

Guys

Thanks for the input. I would not have expected to see that much additional velocity from a (relatively) small change in load.

Naki, you are seeing ~8% increase velocity from a 4% increase in powder charge. Clearly there is more room to run in my case (no pun intended).

When seated to the last (first?) groove, I am essentially out of room in the case with the H4831. I may need to focus my attention on the H4350 and see what I can build up to (safely).

quote:

When seated to the last (first?) groove, I am essentially out of room in the case with the H4831. I may need to focus my attention on the H4350 and see what I can build up to (safely).

Yes, H4831 is too slow to reach max velocities in the 416 Rigby. Try Rel-17 if you can't reach your desire with H4350.

I've had very good results with W760 and my 416 RUM, actually a touch better than Re17.

You might want to try some IMR 4831. I ran a few test loads over the chrono with this powder and it achieved higher velocities than H 4831. 94 Grs. of the IMR version produced velocities comparable to 108 Gr. of the Hodgdon powder. Supposedly it's a little faster burning. This was with 400 Gr. TSX and Barnes solids. I stuck with the Hodgdon powder simply because I had a bunch of rounds already loaded and it produced good accuracy.

It would be interesting to regulate the iron sights with a 400 or 450gr load and zero the scope with a 350gr load.

Isn't Win760 a little too fast for the rigby?

quote:

Originally posted by mrjulian_1970:
Isn't Win760 a little too fast for the rigby?

A powder in the range of 4350/Rel-17/W760 is necessary if one wants to reach pressures of 60000psi and to make use of the Rigby pontential.

While the Rigby has a very large capacity, if one looks at its general shape it is closer to the straight-walled cases than to the 'overbore' types. It is closer to a 308 and 30-06 than a 7mmRM. Consequently, one may expect the medium-speed powders to be optimum. The main reason that the slower powders are used is to fill up the case without reaching a maximum potential velocity and without going over 50000psi.

I was surprised by that too. But that is exactly what I keep getting. Also compared this with some other people here and on Load data.

My explanation for that is that the pressure curve is not linear. So at low pressure you get big gains (& drops) while at high pressure the gains are much less.

I am sticking with AR 2209 (H4350) - shoots well and boots less! ....... Hey I should make that my signature!

quote:

Originally posted by mrjulian_1970:
Guys

Thanks for the input. I would not have expected to see that much additional velocity from a (relatively) small change in load.

Naki, you are seeing ~8% increase velocity from a 4% increase in powder charge. Clearly there is more room to run in my case (no pun intended).

When seated to the last (first?) groove, I am essentially out of room in the case with the H4831. I may need to focus my attention on the H4350 and see what I can build up to (safely).

quote:

Originally posted by 416Tanzan:
... The TTSX and TSX loads are not interchangeable, with the TTSX needing to reduce the charge by 1-2 grains. ...

I bought a bunch of 250 grain TTSX bullets at the SCI show for 375H&H, and emailed Barnes for load data. Their response was to send me pages from their book saying it was the same as TSX.

But, I gather you are talking specifically about the load you developed.

I'll need to take a look at working up the H4350 loads. I've some of that on hand, but a BUNCH of H4831.

The good news is the 4831 can get consumed pretty quickly with range practice... hah.

quote:

Originally posted by Nakihunter:
I was surprised by that too. But that is exactly what I keep getting. Also compared this with some other people here and on Load data.

My explanation for that is that the pressure curve is not linear. So at low pressure you get big gains (& drops) while at high pressure the gains are much less.

I am sticking with AR 2209 (H4350) - shoots well and boots less! ....... Hey I should make that my signature!

quote:

Originally posted by mrjulian_1970:
Guys

Thanks for the input. I would not have expected to see that much additional velocity from a (relatively) small change in load.

Naki, you are seeing ~8% increase velocity from a 4% increase in powder charge. Clearly there is more room to run in my case (no pun intended).

When seated to the last (first?) groove, I am essentially out of room in the case with the H4831. I may need to focus my attention on the H4350 and see what I can build up to (safely).

quote:

Originally posted by tanks:

quote:

Originally posted by 416Tanzan:
... The TTSX and TSX loads are not interchangeable, with the TTSX needing to reduce the charge by 1-2 grains. ...

I bought a bunch of 250 grain TTSX bullets at the SCI show for 375H&H, and emailed Barnes for load data. Their response was to send me pages from their book saying it was the same as TSX.

But, I gather you are talking specifically about the load you developed.

My take on the Barnes' advice is a little different. If they are not concerned about the difference between a TTSX and a TSX, sometimes .2" difference in length, then it may mean that they have a generous margin of error below a max pressure according to SAAMI spec. Their loads have already been "lawyer-approved". So they don't need to worry about a grain of powder.

With my 416 loads, we were getting about the same velocity with 102.5 grains of Rel-17 and the 350 TSX as with 101.5 grain of Rel-17 and the 350 TTSX. That is what we had expected, too.

2950 from my 416 Bee

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