KEY HOLE PROBLEM

[David Emerson]

I put together a 25PRC and bought a 7 twist barrel from blackjack but they say 3300 is it and they will come apart. And the 131 blackjack is made by sierra. So I ordered a 7 1/2 from K&P. The hammers will take it fine but I know from experience the Hornady,s jackets are really thin.

 

[DJ Fergus]

The jackets on the eldm bullets are thin for the ones I've owned. Berger made the jackets thicker on their target bullets than from the original design. With a thin enough jacket, if there's something not just quite right...its a possibility to sling the jacket off. I've sought out thin jacketed bullets to shoot for years just because they always seemed to shoot more accurately and consistent for me but if I were slinging jackets off, then I would certainly try a thicker jacketed bullet. Ultimately whether the bullet or barrel is blamed, it's either go to a different bullet or different barrel to remedy the situation. It's cheaper to try another bullet.

 

[foul bore]

Is the top right hole under 5L what you are talking about key holing?

yes

 

[foul bore]

What's your velocity?

2905 fps

 

[foul bore]

Have you checked your twist rate I have seen factory rifles way off their stated twist rate

No, but I will

seen this happen at creedmore velocities in a 1-8 but yet survive my 6.5-300 win mag at 3300 fps in an 1-8
my 6.5 prc 1-7.5 had all kinds of problems after 30 rounds with the 147s and h1000 had to clean the carbon ring then go another 30 or so rounds and repeat changed to faster powder and no carbon ring and problem stopped with the 147s

Sounds very familier , what powder did you go with? {PRC}

 

[can1010]

RL-16 with 130-140 class
RL-23 with 143-153 class
right now working with the Barnes 145 matchburner RL-16 wlr primers and gunwerks brass at 3045 fps but not as good as RL-16 and 140s either the barnes mb or the Hornady hpbt match
my gun just didn't like h-1000 or RL-26 doth were causing carbon rings and dirty

 

[DJ Fergus]

RL-16 with 130-140 class
RL-23 with 143-153 class
right now working with the Barnes 145 matchburner RL-16 wlr primers and gunwerks brass at 3045 fps but not as good as RL-16 and 140s either the barnes mb or the Hornady hpbt match
my gun just didn't like h-1000 or RL-26 doth were causing carbon rings and dirty

What length barrel are you running in your 6.5 PRC. Just curious.

 

[MagnumManiac]

Looks like jacket failure to me. Bullets go in sideways and look like bullet profiles, not a 'V' shaped like that.
I had bullets blow up about 15-20yrds out from the muzzle with a 300WM shooting 125gr TNT bullets. It would leave strange shaped holes in the target, if it hit it all.

Cheers.

 

[Joefrazell]

How many rounds do you have down the barrel?

 

[DJ Fergus]

You can try berger 156 and your problem will likely go away. It should go away with a 143 eldx also.

 

[foul bore]

How many rounds do you have down the barrel?

about 350

 

[Roninco]

I had a similar issue with these bullets. Factory ammo was also showing higher than normal pressures. Borescope found a carbon ring at the lands. After aggressively cleaning the barrel to remove the carbon ring the pressure and velocities returned to normal and bullet issues stopped.

 

[L.Sherm]

First thing i would do is verify the twist like stated above with the cleaning rod method, ya gotta start doing the process of elimination.

 

[foul bore]

You can try berger 156 and your problem will likely go away. It should go away with a 143 eldx also.

Do you think the 144 gr Berger would be a good choice?