David Greene
Member
Here is my story to start this discussion and I promise to answer and fill in any gaps you find.
I am just beginning reloading rounds for a new Uberti .45-60 Centennial with 28" Barrel. I couldn't find it in any reloading manual going back to 2005. I wanted to check with the experts at Hodgdon to see if any validated load data or recommendations could be made for powder type and projectile weight. The new Uberti's are proof tested and rated to 28,000 CUP. I wanted to use Reloder7 or H4198 but had only anecdotal data submitted by our members in various threads. In most respects our member inputs are usually spot on, but being the rifle cost me 1400.00 I wanted to be absolutely sure without having to risk experimenting on it. I needed to conduct a limited but valid test on another rifle and somehow obtain actual data sets for RL7 pressure and velocity that could be normalized and set against a reasonable confidence level.
Now a crazy thought germinated that got me thinking I could not only get good loading data if I did this right ($$$$ dont tell wife), I might just be able to address once and for all the weak toggle action debate and help put it to rest. This I couldn't let go by folks. The burr under my bonnet about the assertion that old toggle links are not able to be consistently/repeatedly fired over SAAMI specifications without extreme risk to user. I just had to try to put this rest while I waited for Hodgdon to try to address my .45-60 inquiry at least. Thank God our fellow members have built a tremendous body of data for RL7 in .44-40. But to do the analysis justice would have taken months for me to extract, compile, and correlate all of the data and observations our members have submitted online (its a lot). So, the only viable alternative was for me to conduct a limited but repeatable test that would generate velocity and pressure with confirmed standard deviation on a known load with a statistical confidence level.
So I fell back on member submitted load data of .44-40 with Reloder7. I selected a reasonably set maximum charge of 25grains under a 215 grain soft cast lead RNFP bullet. I conducted the test on the weakest toggle link system available to me, my own Uberti Model 1860 Henry in .44-40. If this rifle could stand up safely to full RL7 charges and I could measure and obtain valid velocity and pressure data; I could answer or at least inform the toggle link debate and maybe correlate this baseline to help guide me on .45-60 RL7 loads. I still wanted the Hodgdon's H4198 data but I wasn't about to play around with charges and bullets that might destroy an otherwise beautiful testament to the old west.
Velocity readings were taken with a Caldwell Chronograph. Desired confidence levels are usually at a minimum of 95% and the gold standard sought is 99% confidence. Lord, that would require a cart load of .44-40 rounds I would have to prep and fire which exceeded my time and $$$ budget both.
So...I configured my Uberti 1860 Henry with a strain gauge and fired 100 .44-40 rounds loaded with 25 grains of Reloder7 topped with a 215gn RNFB cast lead projectile (BRN of 12) using WInchester brass and CCI Large Magnum primers. The results from the 10 ten round strings yielded the following:
Chamber Pressure in PSI (not CUP) Confidence Interval (CI): PSI 16864 +/- 0.02% [16,859.827 to 16,868.173] . Ok...good, we know the PSI level variance (SD) at the 75% confidence level.
Accuracy of velocity readings with the Caldwell made me a little nervous. I arbitrarily lowered the confidence level for velocity to 70%. The test yielded a sample mean velocity of 1573fps with a SD of 56.14. At 70% Confidence Level I obtained a CI of:1573 =/- 0.4% [1567.181 to 1578.819]
The test CP mean of 16864 PSI is way above SAAMI recommended 13000 CUP even without me doing a conversion to normalize. The question in my mind remained: "Is 16000+ PSI damaging to the toggle link and brass receiver mount point"? Does continuous fire at these pressures degrade/weaken the receiver toggle rear mount interface (resulting from excessive axial pressure, which I didn't test for). I broke the rifle down and examined the reciver interface and all toggle parts and linkages under a scope at 100x mag. If I was at work we would have done an X-ray scan for micro-fractures. So all I have is a visual inspection which is not conclusive because of the low number of rounds fired and inability to deep scan the materiel.
On a promising note my inspection of the toggle action showed no deformation of the brass securing ring that joins with the toggle rear linkage. The brass looks strong, the mount circle concentric and aligned. I guess after all this more testing to test article failure is needed. that is something I am not doing. I wish Uberti would on a randomly selected production article. I will continue to fire 25grains of RL7 because it makes the Henry a great little deer hunting rifle inside 100 yards. Long story short if 25 grains under a 215grain bullet produced 16000+PSI in the Henry, can we reasonably extrapolate that 15 additional (40) grains of RL7 under a 325grain gas-checked, cast lead RNFP in a cut down .45-70 to .45-60 be well under 28,000 CUP? That is a test I don't want to run on my girl. I am willing to bet it is under 28,000CUP and that toggle link will be just fine and out live me. Using smokeless we should be able to use the .45-60 and equate it to the .45-70 much the same as we do a hot .44special to the .44mag.
Anyway my part of the story is told. Do you have any load data for .45-60? I appreciate any advice you can give me.
Very Respectfully,
Dave Greene
I am just beginning reloading rounds for a new Uberti .45-60 Centennial with 28" Barrel. I couldn't find it in any reloading manual going back to 2005. I wanted to check with the experts at Hodgdon to see if any validated load data or recommendations could be made for powder type and projectile weight. The new Uberti's are proof tested and rated to 28,000 CUP. I wanted to use Reloder7 or H4198 but had only anecdotal data submitted by our members in various threads. In most respects our member inputs are usually spot on, but being the rifle cost me 1400.00 I wanted to be absolutely sure without having to risk experimenting on it. I needed to conduct a limited but valid test on another rifle and somehow obtain actual data sets for RL7 pressure and velocity that could be normalized and set against a reasonable confidence level.
Now a crazy thought germinated that got me thinking I could not only get good loading data if I did this right ($$$$ dont tell wife), I might just be able to address once and for all the weak toggle action debate and help put it to rest. This I couldn't let go by folks. The burr under my bonnet about the assertion that old toggle links are not able to be consistently/repeatedly fired over SAAMI specifications without extreme risk to user. I just had to try to put this rest while I waited for Hodgdon to try to address my .45-60 inquiry at least. Thank God our fellow members have built a tremendous body of data for RL7 in .44-40. But to do the analysis justice would have taken months for me to extract, compile, and correlate all of the data and observations our members have submitted online (its a lot). So, the only viable alternative was for me to conduct a limited but repeatable test that would generate velocity and pressure with confirmed standard deviation on a known load with a statistical confidence level.
So I fell back on member submitted load data of .44-40 with Reloder7. I selected a reasonably set maximum charge of 25grains under a 215 grain soft cast lead RNFP bullet. I conducted the test on the weakest toggle link system available to me, my own Uberti Model 1860 Henry in .44-40. If this rifle could stand up safely to full RL7 charges and I could measure and obtain valid velocity and pressure data; I could answer or at least inform the toggle link debate and maybe correlate this baseline to help guide me on .45-60 RL7 loads. I still wanted the Hodgdon's H4198 data but I wasn't about to play around with charges and bullets that might destroy an otherwise beautiful testament to the old west.
Velocity readings were taken with a Caldwell Chronograph. Desired confidence levels are usually at a minimum of 95% and the gold standard sought is 99% confidence. Lord, that would require a cart load of .44-40 rounds I would have to prep and fire which exceeded my time and $$$ budget both.
So...I configured my Uberti 1860 Henry with a strain gauge and fired 100 .44-40 rounds loaded with 25 grains of Reloder7 topped with a 215gn RNFB cast lead projectile (BRN of 12) using WInchester brass and CCI Large Magnum primers. The results from the 10 ten round strings yielded the following:
Chamber Pressure in PSI (not CUP) Confidence Interval (CI): PSI 16864 +/- 0.02% [16,859.827 to 16,868.173] . Ok...good, we know the PSI level variance (SD) at the 75% confidence level.
Accuracy of velocity readings with the Caldwell made me a little nervous. I arbitrarily lowered the confidence level for velocity to 70%. The test yielded a sample mean velocity of 1573fps with a SD of 56.14. At 70% Confidence Level I obtained a CI of:1573 =/- 0.4% [1567.181 to 1578.819]
The test CP mean of 16864 PSI is way above SAAMI recommended 13000 CUP even without me doing a conversion to normalize. The question in my mind remained: "Is 16000+ PSI damaging to the toggle link and brass receiver mount point"? Does continuous fire at these pressures degrade/weaken the receiver toggle rear mount interface (resulting from excessive axial pressure, which I didn't test for). I broke the rifle down and examined the reciver interface and all toggle parts and linkages under a scope at 100x mag. If I was at work we would have done an X-ray scan for micro-fractures. So all I have is a visual inspection which is not conclusive because of the low number of rounds fired and inability to deep scan the materiel.
On a promising note my inspection of the toggle action showed no deformation of the brass securing ring that joins with the toggle rear linkage. The brass looks strong, the mount circle concentric and aligned. I guess after all this more testing to test article failure is needed. that is something I am not doing. I wish Uberti would on a randomly selected production article. I will continue to fire 25grains of RL7 because it makes the Henry a great little deer hunting rifle inside 100 yards. Long story short if 25 grains under a 215grain bullet produced 16000+PSI in the Henry, can we reasonably extrapolate that 15 additional (40) grains of RL7 under a 325grain gas-checked, cast lead RNFP in a cut down .45-70 to .45-60 be well under 28,000 CUP? That is a test I don't want to run on my girl. I am willing to bet it is under 28,000CUP and that toggle link will be just fine and out live me. Using smokeless we should be able to use the .45-60 and equate it to the .45-70 much the same as we do a hot .44special to the .44mag.
Anyway my part of the story is told. Do you have any load data for .45-60? I appreciate any advice you can give me.
Very Respectfully,
Dave Greene
