Lil'Gun 357mag Chrono Data In My Rossis
Posted: 04 Sep 2018 12:00
I have both a 20" Rossi Carbine and 24" Rossi rifle chambered in 357mag. I got them NIB back in 2009 and they are my favorite range, plink, and woods walkin rifles, hands down. For 9 years I loaded them up with H110 and 158grn Zero JSP bullets with decently firm taper crimp as well as 158grn plated bullets with a slightly lighter crimp being careful on the crimp to avoid cutting through the plating. At 16.5grn H110 (slightly under max) with a magnum primer, I chrono'd the Zero bullets at 1,822fps for the rifle and 1,789fps for the carbine repeatedly at my range at 6,100ft asl on a mid 80's summer day.
I use my rifle with it's tang and globe sights to shoot at steel plates some 300yds down range. Surprisingly accurate and lots of fun. Anyway, about 1.5 years ago I decided I'd try a change of powder as my H110 charges in 357mag have a rep of being hard on brass and mine certainly proved it to be true. Hodgdon's Lil'Gun claimed significantly lower peak pressures with almost as high velocities in pistol length arms, with significantly less abuse of the brass, so I thought I give some a try. As the velocities in pistols were listed as slightly slower, I decided to load up some full charge weight loads (18.0grns Lil'Gun under my 158grn Zero Bullets) and see how they worked.
When I took them to the range early last May and gave them a go I noted that the recoil was stronger than with H110, but more of a stout push vs the sharper kick with the H110. That surprised me a bit until I thought about it some and realized that the larger charge of slightly slower burning powder was going to produce a heavier recoil even at a lower peak pressure. Unfortunately, this summer was dedicated to a number of trips to Europe so I didn't get to do my chrono testing until recently.
When I set up my rig and ran the first string of 10 rounds from my 24" rifle recently, the results were surprising, bordering on astounding! I thought that my chrono was off because I couldn't believe the results so I replaced the battery and shot a few rds from my Mini-14 that I'd previously chrono'd to compare the results. When I realized that there was nothing wrong with the chrono as my Mini's loads clocked what I expected, I decided to run another string with my Rossi.
That next string of 10rds from my rifle produced virtually the same data as the first. The high 10rd average was an astounding 2,011fps and the low one was 1,999fps averaging 2,005fps!!! The SD was a bit higher than I'd like at 18 but I can live with it as I've shot this load at my favorite target, bowling pins at 200yds from the bench, and the accuracy is good. So, next I chrono'd my 20" carbine which has run 1,789fps with the H110 loads for years. After 2 strings of 10rds I got an average of 1,952fps with an SD of 19 which I consider very consistent with my previous results with H110; slightly slower velocities but equally good SDs and accuracy.
The best part of this whole thing is that even in the heat of summer, my Starline brass shows none of the abuse that was common with H110. My primers show only the least amount of flattening, most still with rounded corners showing no high pressures compared to the absolutely flat primers with H110, and the base diameter measurements are way down showing significantly less pressure stress on it. It's clear that this batch will last much longer than what I've become use to with my H110 loads.
In summary, I'm pleased as punch with the results and may develop a lower charge weight load at another accuracy node with my 158grn plated bullets so that I'll have some great plinking ammo. In addition, I'm thinking of looking at a 180 or 200grn load for medium game or maybe even a go at 400yd steel!!!
Lil'Gun and 357mag in a Rossi '92 style levergun. All I can say is WOW!!
I use my rifle with it's tang and globe sights to shoot at steel plates some 300yds down range. Surprisingly accurate and lots of fun. Anyway, about 1.5 years ago I decided I'd try a change of powder as my H110 charges in 357mag have a rep of being hard on brass and mine certainly proved it to be true. Hodgdon's Lil'Gun claimed significantly lower peak pressures with almost as high velocities in pistol length arms, with significantly less abuse of the brass, so I thought I give some a try. As the velocities in pistols were listed as slightly slower, I decided to load up some full charge weight loads (18.0grns Lil'Gun under my 158grn Zero Bullets) and see how they worked.
When I took them to the range early last May and gave them a go I noted that the recoil was stronger than with H110, but more of a stout push vs the sharper kick with the H110. That surprised me a bit until I thought about it some and realized that the larger charge of slightly slower burning powder was going to produce a heavier recoil even at a lower peak pressure. Unfortunately, this summer was dedicated to a number of trips to Europe so I didn't get to do my chrono testing until recently.
When I set up my rig and ran the first string of 10 rounds from my 24" rifle recently, the results were surprising, bordering on astounding! I thought that my chrono was off because I couldn't believe the results so I replaced the battery and shot a few rds from my Mini-14 that I'd previously chrono'd to compare the results. When I realized that there was nothing wrong with the chrono as my Mini's loads clocked what I expected, I decided to run another string with my Rossi.
That next string of 10rds from my rifle produced virtually the same data as the first. The high 10rd average was an astounding 2,011fps and the low one was 1,999fps averaging 2,005fps!!! The SD was a bit higher than I'd like at 18 but I can live with it as I've shot this load at my favorite target, bowling pins at 200yds from the bench, and the accuracy is good. So, next I chrono'd my 20" carbine which has run 1,789fps with the H110 loads for years. After 2 strings of 10rds I got an average of 1,952fps with an SD of 19 which I consider very consistent with my previous results with H110; slightly slower velocities but equally good SDs and accuracy.
The best part of this whole thing is that even in the heat of summer, my Starline brass shows none of the abuse that was common with H110. My primers show only the least amount of flattening, most still with rounded corners showing no high pressures compared to the absolutely flat primers with H110, and the base diameter measurements are way down showing significantly less pressure stress on it. It's clear that this batch will last much longer than what I've become use to with my H110 loads.
In summary, I'm pleased as punch with the results and may develop a lower charge weight load at another accuracy node with my 158grn plated bullets so that I'll have some great plinking ammo. In addition, I'm thinking of looking at a 180 or 200grn load for medium game or maybe even a go at 400yd steel!!!
Lil'Gun and 357mag in a Rossi '92 style levergun. All I can say is WOW!!