6.5 PRC over pressure issue

[806guns]

May have a issue here.
Using Peterson brass 50gr of h1000 got me 2890 fps with hard bolt lift. 156gr Bergers

Running 20 thou jump

Remage barrel set using go gauge and no go gauge. Not my first remage barrel setup.

What measurements can I do to see where my problem is. When chambering a new round it's smooth as butter.
Brass or chamber issue?

Using the hornady comparator tool. Headspace grows .004-.005 on this piece of brass vs new brass.

Bought some factory 147gr eldm shows 3017 fps and had slight bolt lift.
Berger 156gr set at .050 off lands and new peterson brass trimmed to 2.015" loaded with bergers starting load of 54.5 H1000 with wolf magnum primers showing 2978!!! This is suppose to be around 2644 fps according to berger load data.

 

[Straightshooter1]

May have a issue here.
Using Peterson brass 50gr of h1000 got me 2890 fps with hard bolt lift. 156gr Bergers

Running 20 thou jump

Remage barrel set using go gauge and no go gauge. Not my first remage barrel setup.

What measurements can I do to see where my problem is. When chambering a new round it's smooth as butter.
Brass or chamber issue?

Using the hornady comparator tool. Headspace grows .004-.005 on this piece of brass vs new brass.

Bought some factory 147gr eldm shows 3017 fps and had slight bolt lift.
Berger 156gr set at .050 off lands and new peterson brass trimmed to 2.015" loaded with bergers starting load of 54.5 H1000 with wolf magnum primers showing 2978!!! This is suppose to be around 2644 fps according to berger load data.
View attachment 1584411View attachment 1584412View attachment 1584413

Since chamber's freebore can vary a lot from barrel to the next, stating .050" off the lands doesn't really tell anyone the actual seating depth your using. Tell us what your COAL is and that'll give us a better idea.

 

[105Coues]

Great pics. What borescope are you using? Can't help ya but good luck!

 

[Bill K]

My understanding with Lapua and Peterson brass, they are thicker in body and hold less volumm, so maybe that load is producing higher pressures than you other brass is and causing the hard bolt lift. Just a thought.

 

[806guns]

@Alex Wheeler
I

Great pics. What borescope are you using? Can't help ya but good luck!

Teslong ntg 100 $55 on amazon

 

[280ai]

Back off to the absolute minimum load and start there. Had that problem with a 280 ackley and nosler brass it's also heavier brass

 

[280ai]

also try H4831sc

 

[Kracken McGraw]

Carbon and copper build up causing the excessive pressure?

 

[jelenko]

Where are those pics in the barrel? It looks like they are both at the beginning of the freebore - but since they look different, I assume they are from different places.

 

[boltfluter]

Hornady brass is soft. Can't tell what pics 2 and 3 are? What kind of chronograph are you running?

 

[Kracken McGraw]

P

Hornady brass is soft. Can't tell what pics 2 and 3 are? What kind of chronograph are you running?

Pic #2 brass in chamber showing end of bass neck and throat of barrel.

 

[STOMP442]

Hornaday brass is junk. The 6.5PRC and the 6.5-284 are very similar. Most of the time I can find a load between the 55 and 56gr mark that will shoot in that 2950 range with a 140 with either cartridge. Since you are running the 156 I would say that yes you are probably on the hot side. back it down.

 

[806guns]

Hornady brass is soft. Can't tell what pics 2 and 3 are? What kind of chronograph are you running?

New garmin chrono

 

[trichards0215]

I run the same bullet in 6.5PRC with 57gr of H1000 at .03 off the lands and it shoots great, one hole at 100 yards. I tried bumping it to 57.2gr and started getting signs of pressure like a sticky bolt and flattened primers. I used new Hornaday brass that I sized before loading.

 

[806guns]

Scrubbed the barrel down last night. Bolt lift was almost non existent. But still seeing this on brass

 

[Stumpy1]

Is it possible that the walls of the chamber are either a little too slick, or a bit oily?
I think that might cause a bit of excess bolt thrust that would show up like what you are seeing.

Perhaps something to think about/investigate.

Frank

 

[Idaho-Lefty]

My grandson is using,. StaBall HD powder, ADG Brass, F-210 M's and Berger 140 Gr., Elite Hunters at, 3,085 FPS and getting, Sub 1/2 MOA from, his New Savage Lite Hunter Rifle with, the Factory, Proof Barrel.
140's at 3,100 FPS ,. ARE, a Proven, Elk Killer ( Speed Kills, with,.. BERGERS !! ).
ADG, is some, GREAT Brass and the StaBall HD powder, seems to Be, "Fairy Dust" in BOTH, the 7 and 6.5,.. PRC's.
My son and Grandson are Both using, StaBall HD with Awesome Accuracy and, NORMAL,.. Pressures !
Both are using,. ADG Brass, also !

 

[Gabe22BR]

I’m shoot Hornady brass- 144 hybrid jump 20, 57.7-58gr Retumbo powder- on my 7th reload- got brass used from a friend….
My velocity is at 2997fps-3015fps… no swipe, or intentions on case head..

Rifle- maxi tracker
28” kreiger
Bat SV action