.357 velocity with VV powders from Python, GP100, Henry

[Joe Texas]

I did some chronograph work yesterday with my most accurate .357 magnum loads. I thought the findings might be interesting to some of you.

Guns:
Average velocity for 5 shots in this order: Ruger GP100 4.2”, new production Colt Python 4”, Henry Big Boy Steel 20”

125 grain XTP
Starline brass
CCI-500 primers
1.565” COAL

17.2 VV N110 - 1347, 1430, 2010
13.7 VV N105 - 1429, 1461, 1956
7.0 VV N320 - 1190, 1218, 1346

158 grain XTP
Starline brass
CCI-500 primers (CCI-550 w/ W-296)
1.565” COAL

16.7 W-296 - 1206, 1305, 1764
14.1 VV N110 - 1130, 1213, 1610
12.0 VV N105 - 1294, 1331, 1667

Learnings:
• Surprisingly, the N105 loads are faster from the revolvers than the N110 or W-296 loads.
• The Python gave better velocity than the GP100 with every load tested. The Colt does have less cylinder gap and less cavernous cylinder chambers. The Python barrel also has a 1:14 twist rather than the 1:16 on the Ruger.
• The N320 load was soft and pleasant to shoot.
• I was almost ready to give up on N105 based on lack of accuracy in .45 Colt tests. I’m glad I didn’t. I use it for top velocity .45 ACP and now, excellent 357 magnum revolver SD type loads. The recoil isn’t crazy and it is only slightly less accurate than N110.
• The VV powders burn extremely clean.
• The 158 grain W-296 load continues to be the gold standard from my rifle. It groups really well and has a low standard deviation. With Sierra’s 158 grain jsp I can get 1800 fps with that same charge. I’ve exceeded 2200 using Sierra’s 125 grain jsp over 21 grains of W-296. I wish those were easier to find.

Anyway, I hope this is helpful to anyone considering using VV powders in .357. N105 seems to perform well in 4” barrels. Looking at older chrono data, it seems that N105 gives better velocity with less powder than AA#9, 2400, and N110.

 

[AJC1]

I did some chronograph work yesterday with my most accurate .357 magnum loads. I thought the findings might be interesting to some of you.

Guns:
Average velocity for 5 shots in this order: GP100 4.2”, Python 4”, Henry 20”

125 grain XTP
Starline brass
CCI-500 primers
1.565” COAL

17.2 VV N110 - 1347, 1430, 2010
13.7 VV N105 - 1429, 1461, 1956
7.0 VV N320 - 1190, 1218, 1346

158 grain XTP
Starline brass
CCI-500 primers (CCI-550 w/ W-296)
1.565” COAL

16.7 W-296 - 1206, 1305, 1764
14.1 VV N110 - 1130, 1213, 1610
12.0 VV N105 - 1294, 1331, 1667

Learnings:
• Surprisingly, the N105 loads are faster from the revolvers than the N110 or W-296 loads.
• The Python gave better velocity than the GP100 with every load tested. The Colt does have less cylinder gap and less cavernous cylinder chambers. The Python barrel also has a 1:14 twist rather than the 1:16 on the Ruger.
• The N320 load was soft and pleasant to shoot.
• I was almost ready to give up on N105 based on lack of accuracy in .45 Colt tests. I’m glad I didn’t. I use it for top velocity .45 ACP and now, excellent 357 magnum revolver SD type loads. The recoil isn’t crazy and it is only slightly less accurate than N110.
• The VV powders burn extremely clean.
• The 158 grain W-296 load continues to be the gold standard from my rifle. It groups really well and has a low standard deviation. With Sierra’s jsp I can get 1800 fps with that same charge.

Anyway, I hope this is helpful to anyone considering using VV powders in .357. N105 seems to perform well in 4” barrels. Looking at older chrono data, it seems that N105 gives better velocity with less powder than AA#9, 2400, and N110.

Nice update. I have been curious about n110 and the two 3n37/38 powders. Do you have any thoughts on the 320 series. I was intrigued by them being some of the last single base pistol powders available. The only other I know of is universal which I recently picked up.

 

[Joe Texas]

Nice update. I have been curious about n110 and the two 3n37/38 powders. Do you have any thoughts on the 320 series. I was intrigued by them being some of the last single base pistol powders available. The only other I know of is universal which I recently picked up.

I’ve switched most of my target loads over to N320. I sold most of my Titegroup, CFE Pistol, W-231, and AA#9.( I’m using N340 in one slightly over standard pressure .45 Colt load. ) That reduces my pistol powders to N320, N340, N105, and W-296.

N320 has proven excellent in .38 special, 9mm, .357, .45 acp, and .45 Colt. If you’ll PM me your email address, I’ll send you a spreadsheet that includes all of my developed loads. You’ll be able to compare where I landed vs. where I was w/‘merican powders. * I can process brass from N320 loads and my hands are clean afterwards.

I’ve worked with 3N37 and 3N38 quite a bit also. I found a couple of great Tier 2 .45 Colt loads and a top velocity 9mm SD load with 3N38. 3N37 was a little disappointing. It has very little flash though compared to the 3N38 fireball.

 

[Joe Texas]