204 not showing good pressure sign.

[eselkopf1]

Hello everyone.

I am a relatively new reloader. I have done alot or .40 s&w loads for power factor and competition. I have done several 7mm rem mag loads for various game, targets, and distances, and I have done some 5.56 chasing tiny groups and range.

I own a magneto speed and have learned to read pressure sign and doing Satterlee load tests follows by optimum charge weight tests, followed by 300 yard groups, followed by collecting dope out to 700 on steel. I put the data into excell and make nice graphs and all that its so much fun.

So I have been running my process on my Savage model 12 BTCSS. A lovely rifle. My 12 shot saterlee load test at .2 grain climbing increments made a 1 7/8 group at 100. I might have done better but I wasn't even really trying to group, I was logging velocity data and checking pressure sign.

Now I do typically load over book pressure by a couple increments never more than just a few percent over. But with good velocity data and close inspection of brass I have never had a problem. I like to see what the graphs produce just a few steps past max. I also go a bit under minimum for the additional data points. I have found nodes and best groups at max pressure and at min pressure in other rifle/bullet combinations. But to know that you need just 1 or 2 more data points. I know I'll probably get the "stick to published loads" talk, but it depends on who is publishing or even what year they published.

I won't list my powder charges, but its 8202 xbr with 39 grain blitzkings, and 35 grain bergers for test bullets. I have pushed a bit past published data in both directions. Hornady brass, and CCI small rifle primers.

I have found great groups, and the rest of the process is coming along smoothly. I am up to collecting dope out to 700 in the load development now. These loads are for rabbit and coyote, but never actually out that far in hunting.

K there is the back story, here is the question.

Has anyone else noticed that the 204 does not show good pressure sign? My brass shows absolutely no pressure sign, the primers get a little flat, but no more than normal. Velocity climbs nicely, the graphs look great, good nodes and antinodes. Then suddenly I get a pierced primer. At which point I obviously stop. Even the pierced primer is not flattened to the point of raising the alarm.

Im curious if its just Hornady brass or my rifle. Normally I start seeing sign and the sign follows an observable progression. The CCI primers which I also use in ARs are also not flattening in the normal manner. The brass shows absolutely nothing, no smear, no hard bolt lift, no shiny spots. Nothing

Anybody else experiencing this?

[Bill K]

Anytime you start having primers flatten and the a pierced primer, tread with caution and back off. You are starting to get into too much pressure and that is at the temp you are working in then. When the temp starts going up, your more that likely will really start showing pressure signs and they could come very fast and when you don't expect it. Safe and sane along with a good accurate load will trump working at max area and trying for the fastest FPS.. Bill K

[Rick in Oregon]

You may want to consider using Rem 7-1/2 primers with their thicker cup. I also use the Fed 205M in my four 204's, but find the Remmy primer gives the best overall performance. You don't say what primers you've been using, so can't comment further.

To date in all four of my 204 rifles, I have never pierced a primer and none of my bolts have been bushed either.

The 204 is a zippy cartridge that operates at high pressure. With the speed attainable with moderate 'book loads', most here do not see the need for even more speed, favoring accuracy much more. I've been shooting the cartridge since 2006 using book loads, and thousands of ground squirrels, rock chucks and other vermin will attest to the effectiveness of the cartridge without hot-rodding it further.

Back off your loads a mite and just enjoy the 204 for what it is......FUN!

[eselkopf1]

Yeah. It is tough in the early stages comparing different loads from different publishers. Some will have a lower min or a higher max. Some publishers will have different data in different editions. All rifles are different.

I live out west in the Rockies so I deal with big temperature swings so I like to push it just a tiny bit. I have to know where the pressure limits are. My testing is done in Wyoming, I hunt elk late season at 10k feet in 0-degree weather, I also like Montana where it gets even colder. Then I also hunt in New Mexico where it might be 100+ degrees. That is another reason to push and look for sign in my personal opinion. My testing might be at 40 degrees, but I wanna know how close I am to getting sign because I may be in 100 degrees in 4 months. Its a mix of paranoia and just me nerding out with data collection.

Im a geologist so I get around.

[eselkopf1]

My finalized loads are rarely outside published data. I do go with whatever makes the smallest group. I am sitting at 5/8 inch with the 35 berger right now, and 3/4 with the blitzkings. I havent done COAL testing, that will be next season maybe. I use the same process for all my rifles.

[jo191145]

Which CCI primer are you using?
I’ve been out of shooting for quite a few years now. Memory isn’t the best. I think it was the CCI 400’s that we’re the thinnest primer out there. Not recommended in the 204.

[skipper]

I live in Cypress, TX where there are relatively minimal temperature swings. I built a custom 204 years ago, one where I could easily reach the lands and grooves. I did the load testing with a chronograph and found that 4300 FPS was a really sweet node for that rifle. While I was working up I compared the powder increase with the velocity increase. This led me to believe that when the powder increase did not result in a comparable velocity increase THAT was a sign that pressure was an issue. If you record the load and the velocity from your load development you will notice a pattern of increased velocity with additional powder. When that ratio/percentage starts to decline, additional powder is not going to accomplish much except MORE/DANGEROUS pressure.

Every rifle is different SO load development is critical to each and every rifle. If I moved somewhere that had large temperature swings I would load test in the extremes just for safety's sake. My body parts are critical to my health.

Plus 1 on the primers with thicker cups.