20 PPC

[roadkill61]

I have built a 20 ppc for prairie dog shooting. The usual problem is load development in the cooler spring months and then shooting in June and July. Any real life solutions as to powder choices would be appreciated.

 

[steve123]

I have built a 20 ppc for prairie dog shooting. The usual problem is load development in the cooler spring months and then shooting in June and July. Any real life solutions as to powder choices would be appreciated.

Well, 2520 was the worst temp sensitive powder I've ever used! In a 6mmART40 with load workup in summer, 140 fps was lost in the winter, perhaps a 50 degree difference in temps.

No lie, I literally thought my scope was broke before I brought the chrono out!!! Lesson learned here for me, don't chase speed, strive for consistency, even if a 10th moa is the sacrifice.

I changed to H4895 and that powder is the exact opposite. 20 fps in swing. Not that it's the most suitable powder in your 20PPC but it might be an option.

First round hits is what I want....

 

[redrockranger]

Steve,
Odd that you had trouble with Accurate 2520 powder, I have used it in a number of my 20 caliber wildcats as well as the 204 Ruger and never experienced any temp instability.

What does it say on the bottle ? Normally it's on the label.

 

[EXTREME]

Well, 2520 was the worst temp sensitive powder I've ever used! In a 6mmART40 with load workup in summer, 140 fps was lost in the winter, perhaps a 50 degree difference in temps.

No lie, I literally thought my scope was broke before I brought the chrono out!!! Lesson learned here for me, don't chase speed, strive for consistency, even if a 10th moa is the sacrifice.

I changed to H4895 and that powder is the exact opposite. 20 fps in swing. Not that it's the most suitable powder in your 20PPC but it might be an option.

First round hits is what I want....

Good advice Steve. While Ramshot's Compressed load of 29.2 gets 2900+ fps with 39/40 grain bullets at under 58,000PSI (near industry Max.) it can be temperature sensitive. However it should be safe as would running H 4895 to slightly compressed (likely around 28 grains) getting around 2750-2800 fps. I think Varget may be an even better choice Traditionally people have been running fast powders like H 4198, H 322, RL 10 X, X-Terminator and 8208 claiming 4000 fps not realizing that they are running pressures in excess of 63,000 PSI. These low density loads can be very accurate at these high nodes but they can also be very volatile as temperatures rise on hot days under sustained fire. I prefer to run a smaller case designed to run the Hodgdon Extreme powders at 95-100% load density and run 39/40 grain bullets at 3500-3650 with loads that are safe under all conditions.

I found this, on another forum, that discuses this matter of chasing speed, and the results of minor slipups that could spell disaster.

20 PPC powders
I'm working with my second barrel on a Dakota Predator. Originally with the first barrel I started with traditional PPC powders. RL10x, H322, IMR 4198, Benchmark, and XBR. Accuracy was very solid but I felt velocity could be better.

Later I decided that using a powder that works in the same case with bore that has a higher expansion ratio interchangeably with a lower expansion ratio goes against conventional wisdom. So for giggles I tried BLC2. 33grs gets 4008FPS with a 40gr bullet and we are not at max. So I know most guys use 6ppc powders but I'm going to concentrate on powders we normally associate with the 17 Rem.

I'm looking to see if anyone has data for 40gr Bullets using RL15, AA2520, 748, IMR4320, Varget and the kind.

Another guy asking for loads:
Could you possibly pm me with some of your previous load data for your 20ppc? I am going to build one and there does not seem to be a lot of good hard data that's been tried out there. I also have not seen too many groups posted for the 20ppc and that has me worried that it "may not" be as inherently accurate as one might think. Anyway, I would appreciate some of your previous ventures with the powders you have mentioned...RL10x, 8208, benchmark and 4198...if you would please. Thanks
Reply:
Ya guys, I can send you some of my loads. Thing is they will be loads I'm thinking of abandoning. I just was looking in my 20ppc load journal. One day 29 gr xterm w/ 40gr vmax I'm shooting good groups with this then later it's terrible. I realize I could have been the problem causing accurate groups also. Velocity 4020fps.

Something I did not mention earlier about being on my second barrel. I blew the gun up with a load of surplus 8208. I'm convinced the so called traditional powders for this wildcat are too fast and not because I had an accident. The appropriate powder can be a full density load and maybe slightly crater a primer not totally blow a gun to hell.

I'm mean think about it. This is a magnum 20 cal like the 17 rem or 22 swift is in their calibers. A guy with a swift wouldn't use the same powders as the guy with a 222 so why do 20 PPC guys seem to use 20 Vartag powders? I don't know why. I'm going to work with powders used in the 17 rem and swift, ie rl15&4320 up to the h380&h414 class. I found data for aa2520 last nite. Good cause I have a 8 pounder of it growing mold. I'll get back to you guys

My Response:
I really don't think that it was an accident that you blew up your 20 PPC. It was because you really had no concept about what you were doing and the pressures others are actually running with powders used in the 6mmPPC. Powders like LT-32, H 322 and IMR 8208 XBR are used with 66 grain bullets because they give optimal case fill and get 3100-3200 fps at under 59,000 PSI.

You are on the right track now that you realize that the 20 PPC is an entirely different cartridge and needs much slower powders to run the 40 grain V-Max. I think that you are also suspecting that less dense powders fill the case and burn much faster than denser ball powders, of similar burn rates on the charts, that do not fill the case. Ramshot X-Term and IMR 8208 XBR are good examples of that and running 4000+ with these powders is likely generating pressures well in excess of 65,000 PSI. I say this because RS Tac, which is a ball powder very similar to H 335, and a bit denser and slower burning than X-Term generates 62,900 PSI pushing a 40 V-Max to 3883 fps.

AA 2520 is compressed at 29.2 grains and gets 3925 fps at 57,925 PSI. You may be able to run 29.7 grains and safely get4000 fps at about 59,000 PSI if you have enough barrel.
See Western Powders load data. http://www.ramshot.com/wp-content/up...2016_Web-1.pdf

A sensible load with VV-133 that has a burning rate similar to the BLC(2) that the fellow claimed 4008 with 33 grains showing no pressure:
20ppc
I built a 20PPC in 2004 on a SAKO AI 6PPC single shot
PacNor 24" bbl
My pet load is 40gr. Berger w/26.0 N133 @ 3721fps

I really hope that the OP takes heed and finds a "Good Safe Load" with H 4895 or Varget.

 

[GAnderson]

roadkill61, Western Powders load data gives 20PPC loads in both 59K PSI and 63K PSI categories and lists A2520 as a powder of choice for the 20PPC. I would say that their extensive testing would eliminate any issues with over pressure problems in both of those PSI categories and certainly one would think their data would be on the conservative side. Also it would stand to reason that the data is not extrapolated data but actual test data.
As has always been said...when all else fails...READ THE MANUAL. Western Powders manual has a few good wildcat cartridges listed for load data. Here is the link:

http://www.accuratepowder.com/wp-content/uploads/2010/09/WesternLoadGuide1-2016_Web-1.pdf

 

[Bill K]

Well Roadkill61, if you would go back too some of the old articles or even google up the PPC line that Lou Palmisano and Ferris Pindel came out with back in 1975 you will see what they did and why that first 22PPC round lead to the 6mmPPC and others, that others worked up.
It was one of the most accurate rounds out to 300 yards and held/holds many bench rest records, to this date.
You can see what they used and work around that, you will have no issues with pressure or accuracy, if you do so. There is a very good reason that the round they came up with , so long ago, is and has done so well.
Enjoy it, follow their example and do not get overlee wrapped up in issues that are not there, with proper and safe reloading procedures. Just some thoughts. Bill K

 

[ballpowder]

EXTREME

That is my series of posts on the expansion ratio of the 20 PPC. Yes, the gun blew up due to an accident. Sloppy yes but it was because I miss wrote the load in my journal and I was loading at the range the day it happened and it had been a while since I last shot the load and didn’t quite remember how far up the case the powder should have been. If anyone wants to discuss the 20 PPC with me not through the other guy I will be glad to

 

[ballpowder]

BLC-2 is slower than H4895 and way slower N133. Varget depending on the cartridge is similar to BLC-2 in burn speed. In a 6PPC the lot of surplus 8208 is very close to N133 and that was the point I was trying to make. These powders have to be too fast for this cartridge.

Since I posted all that was shared above by EXTREME I have spoke with Todd Kindler about this very topic and he insists I am wrong on this. He says he prefers Benchmark speed powders. Having read just about every article in his magazine series I chalked it up to his barely trying those slower powders but several months later, severely confused on which way I wanted to continue experimentation, I stumbled onto an article Written by Todd where he uses slower (meaning 4895 and slower) powders in the 20 PPC. So he has travelled down that road afterall and his opinion was duly noted.

In my enviornment, S.E. Alaska where the weather is very temperate: 80-100% humidity 30-65 F temps and 190" of rain a year I believe that slower extruded powders with a Rem 7 1/2 primer is where its at. Generally I go no slower than XBR8208 with 40 gr bullets.

Tim

 

[EXTREME]

BLC-2 is slower than H4895 and way slower N133. Varget depending on the cartridge is similar to BLC-2 in burn speed. In a 6PPC the lot of surplus 8208 is very close to N133 and that was the point I was trying to make. These powders have to be too fast for this cartridge.

Since I posted all that was shared above by EXTREME I have spoke with Todd Kindler about this very topic and he insists I am wrong on this. He says he prefers Benchmark speed powders. Having read just about every article in his magazine series I chalked it up to his barely trying those slower powders but several months later, severely confused on which way I wanted to continue experimentation, I stumbled onto an article Written by Todd where he uses slower (meaning 4895 and slower) powders in the 20 PPC. So he has travelled down that road afterall and his opinion was duly noted.

In my enviornment, S.E. Alaska where the weather is very temperate: 80-100% humidity 30-65 F temps and 190" of rain a year I believe that slower extruded powders with a Rem 7 1/2 primer is where its at. Generally I go no slower than XBR8208 with 40 gr bullets.

Tim

Hi Tim,
As I said I think that you re on the right track as pushing Extremely High pressures to claim 4000 fps with the 40 V-Max is not the way to go. The PPC case is industry rated at about 58,000 PSI and a compressed load of 29.2 grains of AA 2520 generates 3925 generates near that. A 63,000 PSI load is not shown as it would be compressed and likely quite volatile with temperature extremes.

Varget has a burn rate similar to AA2520 but would have a faster Relative Burn Rate as it would be more compressed. According to the Ramshot Burn Rate Chart BLC(2) has a faster burn rate, like N-133, but would have a Relative Burn Rate similar to Varget as it would not be as compressed. Pressures will be safe with a slightly compressed load of Varget at about 3800 fps but a Compressed Load of BLC(2) could be another story at over 4000 fps.

If the Surplus IMR 8208 you used was not IMR 8208 XBR then it would be the same the Accurate L-T32 which is much faster burning and Denser as well. I believe that these powders should be left to the 6PPC. I don't agree with the 63,000 PSI loads in any 20 caliber based on cases rated at less than 58,000 PSI and that puts one in the 3650-3800 fps range with 39/40 grain bullets.