PS90 sbr upper/lower separating when firing subs

Discuss rifles chambered for the 5.7x28mm; P90, PS90, and AR57.
Post Reply
shopsmart
Silver Member
Posts: 98
Joined: 23 Jan 2011, 10:39

PS90 sbr upper/lower separating when firing subs

Post by shopsmart » 03 Jul 2021, 06:53

Have a decade under my belt but a new situation. About 10% of the time firing my newer reload subs, my PS90 separates itself. Doesn't go all the way off, but the dis-assembly button has well cleared the recess. Magazine still fully latched on. Normally in my experience the magazine pops up, even with the elite ammo latch sping. Starting to wonder if my receiver might be getting fubared OR screws need to be tightened.

EDIT: Just remember the two didn't completely separate because a wire connecting the laser pointer was velcroed between the two items. THat wire has since broken.
EDIT 2: Just found Jay's vid on the PS-90 stock primary failure point. Took a look and sure enough some material starting to wear out. 40 gr rounds are find but the 55 gr pop it out. So looks like supers for me for awhile AND in the market for a new stock.

PS90
sbr-ed
suppressor equipped
been fired ALOT
Elite Ammo magazine latch spring
55 gr over 2.5 gr Trail Boss

Buffman
Silver Member
Posts: 2937
Joined: 12 Jan 2009, 22:48
Location: SW Michigan
Contact:

Re: PS90 sbr upper/lower separating when firing subs

Post by Buffman » 06 Jul 2021, 20:35

What velocity are you getting out of those subs with 2.5gr of TB?

Buffman
Silver Member
Posts: 2937
Joined: 12 Jan 2009, 22:48
Location: SW Michigan
Contact:

Re: PS90 sbr upper/lower separating when firing subs

Post by Buffman » 06 Jul 2021, 20:35

What velocity are you getting out of those subs with 2.5gr of TB?

shopsmart
Silver Member
Posts: 98
Joined: 23 Jan 2011, 10:39

Re: PS90 sbr upper/lower separating when firing subs

Post by shopsmart » 07 Jul 2021, 05:47

Doing about 1000 fps. Formula is from here and works well. Have discussed with you before. I think on FB.

User avatar
panzermk2
Forum Supporter
Posts: 11911
Joined: 19 Aug 2008, 15:51
Location: Around here it's more like what can we shoot through next.
Contact:

Re: PS90 sbr upper/lower separating when firing subs

Post by panzermk2 » 08 Jul 2021, 10:09

Well here is the issue, after it happens the first time it will keep happening even with good loads.

Link to a video showing what has gone bad on your stock. https://youtu.be/k25SAf9D65U
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: 11911
Joined: 19 Aug 2008, 15:51
Location: Around here it's more like what can we shoot through next.
Contact:

Re: PS90 sbr upper/lower separating when firing subs

Post by panzermk2 » 08 Jul 2021, 10:11

And this is the whole playlist,

PS90 and P90 Service and Inspection Series Elite Ammunition, https://youtube.com/playlist?list=PLu1o ... RIQ_WNBcRw
Jay Wolf
Pr. Elite Ammunition

"Engineers, the oompa-loompas of science!"

Be'ein Tachbulot Yipol Am Veteshua Berov Yoetz
Image

Buffman
Silver Member
Posts: 2937
Joined: 12 Jan 2009, 22:48
Location: SW Michigan
Contact:

Re: PS90 sbr upper/lower separating when firing subs

Post by Buffman » 08 Jul 2021, 20:03

shopsmart wrote:
07 Jul 2021, 05:47
Doing about 1000 fps. Formula is from here and works well. Have discussed with you before. I think on FB.
That's right. I was running about 3gr and only going 750-800, but I think TB is not temperature stable so the 30F temps may have been impacting it a bit.

Post Reply

Who is online

Users browsing this forum: No registered users and 5 guests