Pressure signs

Reloading info for the 5.7x28mm

Moderator: Grantness

Post Reply
ryan77724
Junior Member
Posts: 12
Joined: 27 Mar 2019, 17:56

Pressure signs

Post by ryan77724 » 02 Jun 2020, 08:41

i'm having problems loading for my 5.7, i got my load data for true blue from loaddata.com for a 35gr bullet, and every single powder load is cratering the primers, and starting to flatten them a little. i'm not crimping yet, and i'm using 36gr varmint grenades set to an oal of 1.594", using cci small rifle primers. any suggestions would be greatly appreciated.

ryan77724
Junior Member
Posts: 12
Joined: 27 Mar 2019, 17:56

Re: Pressure signs

Post by ryan77724 » 02 Jun 2020, 08:43

my powder charges start at 5.7 and go to 6.2gr increasing by .1gr for each different group

Buffman
Silver Member
Posts: 2990
Joined: 12 Jan 2009, 22:48
Location: SW Michigan
Contact:

Re: Pressure signs

Post by Buffman » 02 Jun 2020, 19:42

post a picture of them. What velocity are you getting?

ryan77724
Junior Member
Posts: 12
Joined: 27 Mar 2019, 17:56

Re: Pressure signs

Post by ryan77724 » 04 Jun 2020, 07:33

i don't have any pictures right now, i'll post some in a couple weeks when i'm home. and i wasn't using my chrony when i shot the test loads, i'll try to get data next time i'm home

User avatar
panzermk2
Forum Supporter
Posts: 12380
Joined: 19 Aug 2008, 15:51
Location: Pr. CEO Elite Ammunition
Contact:

Re: Pressure signs

Post by panzermk2 » 19 Jun 2020, 09:55

For starters primer pressure signs mean absolutely NOTHING with the 5.7x28mm. They mean that also for standard caliber often also but the myths are strong.

The 5.7 is a high pressure delayed blowback round. They beat the hell out of the primers. This is why you have to use
small rifle primers for your loads.
Jay Wolf
Pr. Elite Ammunition

"Engineers, the oompa-loompas of science!"

Be'ein Tachbulot Yipol Am Veteshua Berov Yoetz
Image

ryan77724
Junior Member
Posts: 12
Joined: 27 Mar 2019, 17:56

Re: Pressure signs

Post by ryan77724 » 18 Aug 2020, 12:53

<a href="https://ibb.co/XXn2f5k"><img src="https://i.ibb.co/JnYBWpF/DCEE8-D09-93-F ... E7-AD2.jpg" alt="DCEE8-D09-93-F6-4-B4-F-AFD2-EA12-CE5-E7-AD2" border="0"></a>



See if I uploaded this pic correctly

ryan77724
Junior Member
Posts: 12
Joined: 27 Mar 2019, 17:56

Re: Pressure signs

Post by ryan77724 » 18 Aug 2020, 12:55

Click the second https link and it’ll work, but that’s the pics of the cratered primers I’m getting. Is this anything to worry about?

User avatar
panzermk2
Forum Supporter
Posts: 12380
Joined: 19 Aug 2008, 15:51
Location: Pr. CEO Elite Ammunition
Contact:

Re: Pressure signs

Post by panzermk2 » 19 Aug 2020, 09:40

Pretty normal, the 5.7 is hell on primers. You can't use ordinary signs. You much better off looking inside the case.

You can see these gold rings once you know wht you are looking for.

These cases have been cut to make it easier to show what to look for.

Image

Image

Image

Image
Jay Wolf
Pr. Elite Ammunition

"Engineers, the oompa-loompas of science!"

Be'ein Tachbulot Yipol Am Veteshua Berov Yoetz
Image

ryan77724
Junior Member
Posts: 12
Joined: 27 Mar 2019, 17:56

Re: Pressure signs

Post by ryan77724 » 20 Aug 2020, 11:17

So would you say those loads I loaded are safe to shoot then?

User avatar
panzermk2
Forum Supporter
Posts: 12380
Joined: 19 Aug 2008, 15:51
Location: Pr. CEO Elite Ammunition
Contact:

Re: Pressure signs

Post by panzermk2 » 21 Aug 2020, 08:08

Your at the limit of your primers.

What powders are you using? You listed the primers, small rifle which are correct. BUT what exact powders and charges are you using?
You do know if you browes this section there is verified good and also safe loading data correct?
Jay Wolf
Pr. Elite Ammunition

"Engineers, the oompa-loompas of science!"

Be'ein Tachbulot Yipol Am Veteshua Berov Yoetz
Image

User avatar
panzermk2
Forum Supporter
Posts: 12380
Joined: 19 Aug 2008, 15:51
Location: Pr. CEO Elite Ammunition
Contact:

Re: Pressure signs

Post by panzermk2 » 21 Aug 2020, 08:09

Also cut a case open and inspect it.
Jay Wolf
Pr. Elite Ammunition

"Engineers, the oompa-loompas of science!"

Be'ein Tachbulot Yipol Am Veteshua Berov Yoetz
Image

ryan77724
Junior Member
Posts: 12
Joined: 27 Mar 2019, 17:56

Re: Pressure signs

Post by ryan77724 » 24 Aug 2020, 14:15

panzermk2 wrote:
21 Aug 2020, 08:08
Your at the limit of your primers.

What powders are you using? You listed the primers, small rifle which are correct. BUT what exact powders and charges are you using?
You do know if you browes this section there is verified good and also safe loading data correct?
I’m using true blue. I’m not home right now but if I remember correctly I’m using 5.9gr

User avatar
panzermk2
Forum Supporter
Posts: 12380
Joined: 19 Aug 2008, 15:51
Location: Pr. CEO Elite Ammunition
Contact:

Re: Pressure signs

Post by panzermk2 » 26 Aug 2020, 13:13

That can be at the max limit for 1x brass.
Jay Wolf
Pr. Elite Ammunition

"Engineers, the oompa-loompas of science!"

Be'ein Tachbulot Yipol Am Veteshua Berov Yoetz
Image

User avatar
panzermk2
Forum Supporter
Posts: 12380
Joined: 19 Aug 2008, 15:51
Location: Pr. CEO Elite Ammunition
Contact:

Re: Pressure signs

Post by panzermk2 » 26 Aug 2020, 13:13

That can be at the max limit for 1x brass.
Jay Wolf
Pr. Elite Ammunition

"Engineers, the oompa-loompas of science!"

Be'ein Tachbulot Yipol Am Veteshua Berov Yoetz
Image

748
Junior Member
Posts: 17
Joined: 25 Dec 2014, 09:37
custom title: new old member
Location: NM

Re: Pressure signs

Post by 748 » 23 Sep 2020, 22:17

I have some loads that make the brass 1x use. It blows the primers out of their pockets. I don't load like that any more.
Shooting with the gemtech SFN seems to stretch the brass more then shooting without.

User avatar
panzermk2
Forum Supporter
Posts: 12380
Joined: 19 Aug 2008, 15:51
Location: Pr. CEO Elite Ammunition
Contact:

Re: Pressure signs

Post by panzermk2 » 29 Sep 2020, 10:05

5.7 Beats up the primer and primer pocket.
Jay Wolf
Pr. Elite Ammunition

"Engineers, the oompa-loompas of science!"

Be'ein Tachbulot Yipol Am Veteshua Berov Yoetz
Image

Post Reply

Who is online

Users browsing this forum: No registered users and 11 guests