Pyrodex loads

Extend your shooting experience while reducing the cost of your ammunition!
Post Reply
User avatar
NavyDoc76-80
500 Shots
500 Shots
Posts: 925
Joined: 05 Jul 2014 21:44
Location: Outer Banks NC
Has thanked: 307 times
Been thanked: 262 times

Re: Pyrodex loads

Post by NavyDoc76-80 »

BCRider wrote:OK, I just went and put proper 3fg black powder into a .357 casing and after tapping it once to settle the powder I kicked out enough off the top to produce the 1/8 inch clearance. The weight of the proper black powder in the casing filled to that level was 23.8gns. So call it 24gns.

I've got a few Lee Dippers so I poured the powder into a 1.6cc and just about filled it. So likely I'm looking at 1.5cc's or a hair

Now given the 1.5'ish CC volume I can't see the extra 28gns of lead taking up a .5cc worth of room. So I'm thinking that you need to run more powder or some sort of filler to be sure you're not leaving an airgap.

And you're 100% right that there is simply no way to overcharge a straight wall casing of ANY handgun round. .45Colt is the largest of the old original calibers and it's sized to take the full case of BP. And let's not forget that .38Spl was originally intended as a black powder round. I don't know if much or any were sold loaded with BP but it was during that cross over time. And for .357 we're only looking at another very few grains of powder courtesy of that extra 0.10 length.

We could even load black or Pyrodex into things like .460S&W Mag or .454 Casull or even the trash bin size .500S&W cases and never even come within 1/3 of the peak pressure such guns are designed to withstand. And in fact they would be "mouse fart" loads from such firearms.

But with anything more than a minimal air gap we start seeing the pressures climb FAST. I would not want to be holding onto the 45-70 rifle that "only" has 35 grains of BP or Pyrodex in the casing and no filler. We're likely talking pipe bomb. And if it didn't split the barrel I'm betting it would be a close thing in some cases. Almost certainly it would be the end of a Springfield Trapdoor given that they aren't tolerant of higher pressures.

Obviously it would be hard to frag a .357 with the smaller charge even if there is an air gap. But good practices start with the small stuff, eh? :D
Eh! BCRider, I would say you have earned your five minutes of fame!
I have edited some out for reason of space, but your third comment that I left for this reply regarding your suspicion is mine own as well. I think the idea of simply measuring the bullet, amount that is inserted, minus 1/8-3/16", pour, pack, insert the bullet is the way to go. Really appreciate your insight on this. It's still a go for tomorrow, if I can, I'd like to make up another 50 rounds with the increased load and make the comparison, we'll see. Thanks again.
Dave M
--//--
Let us tenderly and kindly cherish, therefore, the means of knowledge. Let us dare to read, think, speak and write.
John Adams

20" SS .357
16" SS .44
20" SS .45C
BCRider
Posts: 152
Joined: 10 Jun 2014 00:54
Location: BC Canada
Has thanked: 6 times
Been thanked: 60 times

Re: Pyrodex loads

Post by BCRider »

A .357 or .38Spl casing isn't that big a volume. I'm thinking that the amount of compression suggested by Hodgdon needs to scale to suit the powder volume. So for smaller case volumes such as these two we're likely looking at more like 3/32 to 1/8 at most for compression. On the other hand bigger volume casings like .44Mag or .45Colt and on up will easily accept 1/8 to 3/16 of compression while still being considered as the "light compression" that Hodgdon calls for.
User avatar
NavyDoc76-80
500 Shots
500 Shots
Posts: 925
Joined: 05 Jul 2014 21:44
Location: Outer Banks NC
Has thanked: 307 times
Been thanked: 262 times

Re: Pyrodex loads

Post by NavyDoc76-80 »

Well I feel like I just opened up Christmas presents and had a turkey dinner with all the trimmings.
As hoped I made it to the range to see what the Pyrodex loads would do in 38sp. With the plain jane buckhorn sites I was hitting at 25,50,100 and even 220 yard steel targets. The 220 yard took a few rounds to adjust elevation but once there you could hear that sweet ping! Those were the loads I put the 158gr snakebite Greasewagon big lube flat nose cast lead bullets with a 20/1 alloy from Ozark Plateau bullet company. To say the least, I was impressed. I mentioned about chronographing these rounds, well we ended up having too much fun with all the different rounds I brought for test and my friends arsenal, time just got away from us. But he did leave me the chrony for myself to do at some point. Side bar note: 38sp match rounds cannot and will not cycle in the Rossi.
Last thing, the 1cc by volume charge worked, but still want to see how a 1.3cc volume charge will do and it's measured compression. +guns
Dave M
--//--
Let us tenderly and kindly cherish, therefore, the means of knowledge. Let us dare to read, think, speak and write.
John Adams

20" SS .357
16" SS .44
20" SS .45C
BCRider
Posts: 152
Joined: 10 Jun 2014 00:54
Location: BC Canada
Has thanked: 6 times
Been thanked: 60 times

Re: Pyrodex loads

Post by BCRider »

What are these "match rounds"? You're not trying to use wadcutters sunk down so they barely stick out of the case are you?
User avatar
NavyDoc76-80
500 Shots
500 Shots
Posts: 925
Joined: 05 Jul 2014 21:44
Location: Outer Banks NC
Has thanked: 307 times
Been thanked: 262 times

Re: Pyrodex loads

Post by NavyDoc76-80 »

That's the ones
Dave M
--//--
Let us tenderly and kindly cherish, therefore, the means of knowledge. Let us dare to read, think, speak and write.
John Adams

20" SS .357
16" SS .44
20" SS .45C
User avatar
NavyDoc76-80
500 Shots
500 Shots
Posts: 925
Joined: 05 Jul 2014 21:44
Location: Outer Banks NC
Has thanked: 307 times
Been thanked: 262 times

Re: Pyrodex loads

Post by NavyDoc76-80 »

Well I made it to the range with the Chrony yesterday, statistics can be boring to read I know, but can be interesting as well. The following is the readings from the Pyrodex loads, then standard loads for comparison.

To save typing, those rounds that used the bullet 158gr Snakebite Greaswagon Big lube, flat nose lead bullet will be referred to as "GW".

38sp, 158gr GW
1cc Pyrodex
CCI 500 standard primer

1. 1007
2. 1005
3. 987.6
4. 972.3
5. 1001
avg f/ps 994.58 E= 347 ft.-lbs.

2nd set of 5

1. 992.01
2. 1025
3. 1003
4. 995.9
5. 1033
avg f/ps 1009.78. E = 357 ft.-lbs.

For comparison,
38sp 158gr GW
6.7gr AA#7
CCI 550 Mag primer
1. 1101
2. 1065
3. 1060
4. 1065
5. 1122
avg f/ps 1083 E= 411.45 ft.-lbs

.357 158 gr GW
10.4gr AA#7
CCI 550 Mag primer
1. 1541
2. 1574
3. 1575
4. 1605
5. 1550
avg f/ps 1569 E= 863.6 ft.-lbs

Last,
.357 125gr Berry's plated flat point
11.6gr AA#7
CCI 550 mag primer
1. 1580
2. 1689
3. 1695
4. 1712
5. 1701
avg f/ps 1675.4 E= 779 ft.-lbs

I wanted to know the muzzle energy, so there is an energy calculation we can apply to all our loads by simply knowing the weight of our bullet (W), and our muzzle velocity (V) in feet per second. E= energy in ft. - lbs.
The formula is: E= W x Vsq / 450,400, I added the results to each test above. To further simplify the formula: E=WxVxV divided by 450,400. For the 125gr bullet it would look like this:
E= 125x1675.4x1675.4/450400= 779 ft.-lbs
Dave M
--//--
Let us tenderly and kindly cherish, therefore, the means of knowledge. Let us dare to read, think, speak and write.
John Adams

20" SS .357
16" SS .44
20" SS .45C
aragornelessar86
Posts: 58
Joined: 09 Jul 2013 14:47
Location: N. San Diego County
Has thanked: 2 times
Been thanked: 15 times

Re: Pyrodex loads

Post by aragornelessar86 »

Outdated info. Follow the MFG's instructions, but do be cognizant that not all BP substitutes are equal in power to BP. For instance, Triple Seven is formulated to be more powerful than BP by volume, and charges must be adjusted accordingly.

Quick note about BP substitutes from a long time BP shooter:

Real BP is the ONLY powder that should be measured by volume. All substitutes should be measured by weight, and the correct BP charge may not be the correct charge for a substitute. Please, please check the MFG's conversion tables, and always measure as you would with smokeless powder.
Last edited by aragornelessar86 on 02 Sep 2014 15:27, edited 2 times in total.
User avatar
NavyDoc76-80
500 Shots
500 Shots
Posts: 925
Joined: 05 Jul 2014 21:44
Location: Outer Banks NC
Has thanked: 307 times
Been thanked: 262 times

Re: Pyrodex loads

Post by NavyDoc76-80 »

NavyDoc76-80 wrote:https://www.hodgdon.com/loading.html

Food for thought, .
aragor, please see what Hodgons has to say about that and let me know what you think.
Dave M
--//--
Let us tenderly and kindly cherish, therefore, the means of knowledge. Let us dare to read, think, speak and write.
John Adams

20" SS .357
16" SS .44
20" SS .45C
Ohio3Wheels
1000 Shots
1000 Shots
Posts: 1599
Joined: 31 Jul 2014 15:18
Location: Dayton Oh
Has thanked: 227 times
Been thanked: 328 times

Re: Pyrodex loads

Post by Ohio3Wheels »

Doc, I noticed that you used standard primers with the pyrodex. Have you thought about using magnum primers?
Curt... makin' smoke and raising my carbon foot print one cartridge at a time Image
User avatar
NavyDoc76-80
500 Shots
500 Shots
Posts: 925
Joined: 05 Jul 2014 21:44
Location: Outer Banks NC
Has thanked: 307 times
Been thanked: 262 times

Re: Pyrodex loads

Post by NavyDoc76-80 »

Curt,
My initial chrony measurements are certainly lacking the possibilities. I would even go as far to say that my comparisons were hardly that given only one set was Pyrodex and the others were not. And that I had know .357's in Pyrodex also left a lot of questions. So, I have just loaded up 10 & 10 of .357, 10 with standard primer, and 10 with magnum primer. For those that prefer the charge by weight, I used 15.8gr. That weight so happened to measure in volume at 1.3cc with a light 1/8< inch compression under the 158 gr bullet I have been using. I want to go back to my original recipe using 1cc in the .38special cartridge that I used, while successful, I want to get down to the nitty gritty through measurement just what a perfect load should be. Whether I change it or not, I will load 10 with a magnum primer for comparison from before. My friend aloud me to hold on to his chrony so I just need to get down the road and do another test.
Dave M
--//--
Let us tenderly and kindly cherish, therefore, the means of knowledge. Let us dare to read, think, speak and write.
John Adams

20" SS .357
16" SS .44
20" SS .45C
Post Reply