6.5 PRC over pressure signs

[Ga6570]

definitely seeing some ejector marks on the bases.

i'm running IMR 4831 with 52.6 gr in Hornady cases and 143 ELD-X and getting 3015 FPS out of a 26" barrel. no pressure signs.

i havent tried using the RL-26 or H1000 in this gun yet... was trying to use up the 4831 i had... been pretty consistent so far.

 

[257 STW]

I see ejector marks and swipe. Is that the first firing on new brass?

 

[257 STW]

If brand new brass, is it possible the shoulders are pushed far enough back that the headspace is that excessive? I have always fireformed with a middle of the road charge weight, then measured my cases with a comparator, and then bumped shoulders .002. Someone correct me if I`m thinking wrong here.

 

[kiwikid]

Measured the new Hornady rounds at the neck with 143 ELD-X and diameter is 0.292" the Norma is slightly larger by only 0.001" this is the brass OD. The projectile (130gr) is perfect at 0.264" the specifications for this neck diameter are 0.297"
Powder to hand is H1000, H4831SC, N565 and AR2217 that suits this cartridge. I lightly oil the bore after cleaning using a bit on a small patch, in theory this could run down the barrel into the chamber while being stored?
Fired cases measure 0.523" at the projectile end and before firing are 0.513" Norma & 0.515" OD with Hornady (specification = 0.5166") so a ten thou increase while the bases go up by only four thou post firing.
View attachment 327049

Will a new projectile slide into the mouth of a fired case and what is the neck OD of your fired Norma cases please?
Although I don't have a 6.5 PRC I do have a 6.5-284 and your loaded OD figures sound right to me. My fired Lapua 6.5-284 necks measured .297".
Where in NZ are you based?

 

[Iron Worker]

I run Ramshot Magnum in my 6.5 PRC with a Berger 156 EOL at 3003 AVG. I have heard H1000 will sometimes pressures out sooner than expected as well, but that is second hand info as I have never tried H1000 in my PRC so don`t quote me. Is there a reason you want to run the lighter 130s? Either way you have a pressure issue, and you are aware of it so lets get some others to jump in and see if we can help you figure it out. Couldn`t really find any load data on the HDY 130 ELDM, But Nosler says 60.0 MAX H1000 with their 130s FYI. I also know that VV N565 works well with the heavies in 6.5 PRC. You may have to try some different powders if your set on 130 class bullets. And as I said before your case volume could be very different between Hdy and Norma brass.

What is your load with ramshot magnum, brass maker?

 

[BrentM]

I'm with others on loading to the lands. I'd jump those .070-.120. Your barrel will speed up as well but the pressure issue is route of discovery like all the others have mentioned.

 

[257 STW]

What is your load with ramshot magnum, brass maker?

60.1 @68 deg. 3300 ASL. CCI 250 with Hornady brass. (3 firings) PPs still tight. Berger 156 EOL -30 OL. Shoots .5 or better.
AS ALWAYS START LOWER AND WORK UP SAFELY

 

[Hotrod617]

I run Ramshot Magnum in my 6.5 PRC with a Berger 156 EOL at 3003 AVG. I have heard H1000 will sometimes pressures out sooner than expected as well, but that is second hand info as I have never tried H1000 in my PRC so don`t quote me. Is there a reason you want to run the lighter 130s? Either way you have a pressure issue, and you are aware of it so lets get some others to jump in and see if we can help you figure it out. Couldn`t really find any load data on the HDY 130 ELDM, But Nosler says 60.0 MAX H1000 with their 130s FYI. I also know that VV N565 works well with the heavies in 6.5 PRC. You may have to try some different powders if your set on 130 class bullets. And as I said before your case volume could be very different between Hdy and Norma brass.

I am working up a load for my 6.5 PRC as well. On your Berger load, what is your powder load with the Magnum?

 

[Rocketeer77]

Will a new projectile slide into the mouth of a fired case and what is the neck OD of your fired Norma cases please?
Although I don't have a 6.5 PRC I do have a 6.5-284 and your loaded OD figures sound right to me. My fired Lapua 6.5-284 necks measured .297".
Where in NZ are you based?

Blenheim and need some fired cases again, resized them too quickly!

 

[PatriotHenry]

Have a budget build with a Howa action & barrel, laminated glass bedded stock along with a decent Bushnell scope. With 130gr ELD-M projectiles and 57gr of H1000 powder new Norma brass it groups very well at around 0.5 MOA and that's after only thirty off rounds from new, average velocity seen is 2,900 FPS with only 16 FPS velocity spread. But seeing quite heavy bolt lift, rear of cases marked and flattened primers (not too bad). I have some unused Hornady factory rounds 143gr ELD-X. So it looks like excess pressure signs along with slower velocities than I expected.

Would like to hear your thoughts on possible issues, again it's only had thirty rounds through a new OEM barrel

I would suggest a faster powder than H1000 for the 130 class projos. Do you have any H4831SC, or RL 17,19,22 or 23? or similar burn rate powders to try?

My 2 cents

 

[Rocketeer77]

I see ejector marks and swipe. Is that the first firing on new brass

Yes, but second firing they were full length resized with Redding die set

 

[BrentM]

Yes, but second firing they were full length resized with Redding die set

Better check on your measurements. Make sure shoulder bump is adequate .002-003, base is properly sized .5285-.530, and neck tension is correct .002-.004.

 

[PatriotHenry]

Measured the new Hornady rounds at the neck with 143 ELD-X and diameter is 0.292" the Norma is slightly larger by only 0.001" this is the brass OD. The projectile (130gr) is perfect at 0.264" the specifications for this neck diameter are 0.297"
Powder to hand is H1000, H4831SC, N565 and AR2217 that suits this cartridge. I lightly oil the bore after cleaning using a bit on a small patch, in theory this could run down the barrel into the chamber while being stored?
Fired cases measure 0.523" at the projectile end and before firing are 0.513" Norma & 0.515" OD with Hornady (specification = 0.5166") so a ten thou increase while the bases go up by only four thou post firing.
View attachment 327049

Are you seeing pressure on all the cases or just the first after your cleaning process? You should not have any oil in your bore this will cause over pressure on your first shot. Only do the light oil in bore for extended storage.

 

[Rocketeer77]

I would suggest a faster powder than H1000 for the 130 class projos. Do you have any H4831SC, or RL 17,19,22 or 23? or similar burn rate powders to try?

My 2 cents

Have some H4831SC and not much RL19 left, powder and Unicorns have a lot in common