Pressure issues reloading for Christensen

[Kelly evans]

I have the christensen ELR 6.5x284, Berger 140 vlds, 55.5 gr. H1000, lapua brass, win primer. Shoots around 2950fps, cuts the same hole.

 

[Lazyace]

I must be one of the lucky ones. I've got a CA Ridgeline in 7mm rem mag, using ADG brass, CCI 250 primers, Reloader 25 shooting 175 ELD-X's at 3050fps. No pressure signs.

Happy yours is working for you. Mine would explode if I got up to 3000 fps.

 

[Bob Wright]

Whats your neck diameter of a fired round? There have been some thick necked batches of Lapua brass that i need to turn.

This^^^^.
Check and see if your fired brass will easily accept a bullet. If it has any drag going into the neck, you have a tight chamber/neck area. Alternately, measure your fired neck o.d. to a loaded round. .004 difference is a good average clearance. Turning necks might be in the equation.
Second, your "trim to" length needs to be consistent and to your loading manual.
Third, a hard carbon deposit may be in the neck area adjacent to the throat, causing your brass to pinch the case mouth, driving pressures up.
It may be something more like a bad chamber job, but these are easy inspections I would start with. Know anyone with a borescope?

 

[Gator 06]

I also hit pressure using 4831 in my prc. But other powders getting more fps without pressure

 

[MTGEEZER]

I also hit pressure using 4831 in my prc. But other powders getting more fps without pressure

LazyAce: I "had" a CA Mesa in 6.5 PRC for a year and a half. Accurate but pressure problems from day one. I did pretty extensive brass prep with ADG brass, tried 6 different bullets, 4 or 5 different powders and primers and could never get to within 2 and a half grains of any listed max load and was 150 to 200 FPS slower than what I bought the PRC for. I took it back to Scheels (love that place) and they hooked me up and sent it back to Christensen explaining that the rifle was pancaking factory loads and that I was uncomfortable with the pressure and Creedless performance. They had it for 1 week and I got it back yesterday. The barrel, action, magazine and stock were literally dripping in oil. It was a disgusting mess! I boxed it back up just as I received it and went right back to Scheels and showed the manager what I got back. BTW, CA did nothing to the rifle and didn't bother to even tell me what they "found". No explanation or comment of any kind except a separate box with their card, a thank you for being a CA customer and a free hat! When I opened the box in front of the manager, he said "what the heck is all that stuff all over your gun and what did they do to correct the problem"? I said it looks like a half quart of oil, they did nothing and said nothing and I am done with this piece of crap. He (Scheels) immediately gave me full credit for the rifle and I left with the new Savage 110 ULTRA in 6.5 PRC (I'm old, small, and like lightweight rifles). End of story: No more Christensen for me! And, yes, it did pancake every primer in several boxes of "Premium Factory Ammo! Sorry for the rant but just my personal experience. GEEZER

 

[john k]

I believe Axl is on the right diagnosis. I have Christensen .280 Ackley and am working thru an issue. Process of elimination has brought me to the neck and throat. Extremely tight tolerances. Some factory rounds do not chamber easy. Am in the process of shooting some factory rounds and reloading them to see if any difference.

 

[Joefrazell]

I've got a Christensen in 6.5x284, 26" bbl. that I started working up hunting loads for. The problem is that I experienced very high pressures approaching max loads. Very tight bolts and extractor marks on cases. Those were still only at 2800-2900 fps. I've tried RL22, RL25 and 4831SC with both Berger 140 and 156 gr. Elite Hunter and Fed 215 primers. I spoke with Berger and they said that Christensen barrels and actions had very tight tolerances and most people had to adjust down to starting loads. The folks at Christensen are no help at all.

I've cut my loads and came up with the best accuracy being 47 gr. of 4831SC but now I'm only pushing 2575 FPS. My COAL is 3.275 which I think is about .035 off the lands. Question is, what can I do to get more velocity while staying away from the pressure issues? This rifle should easily shoot 3000 fps, but i can't get close. I'll be using this for LR elk and mule deer. Out to 800 yards.

How many rounds through the barrel?

 

[SilverbulletMAG]

I have the same issue with a 6.5 PRC Ridgeline. Of note, it does this with factory 143 ELDX loads as well. I've been chasing my tail on this one for several months. Neck turned the brass, tried a few different brands of brass, and have ruled out neck thickness as the issue with mine. Sized the brass down as much as possible with with dies and with the firing pin removed, it's still not smooth when chambering a resized bare case trimmed to SAAMI. For reference, a fired case measures 1.646" via the E420 comparator. The die bottoms out at a max resizing (annealing after every reload) of 1.633", and at that length it still clicks on the bolt lift and takes decent force to chamber an unloaded round.

The rifle is extremely accurate with Berger 156's (consistent 1/4" groups) but the extremely difficult bolt lift at velocities that are way below max is getting on my last nerve. Finally reached out to them for warranty work and/or to see what they have to say. Not real keen on sending them my rifle for who knows how many months and not know what condition it will come back in or how it will shoot after...

 

[Lazyace]

How many rounds through the barrel?

Just breaking in. 200 or ao

 

[Rexby4]

I have the same issue with a 6.5 PRC Ridgeline. Of note, it does this with factory 143 ELDX loads as well. I've been chasing my tail on this one for several months. Neck turned the brass, tried a few different brands of brass, and have ruled out neck thickness as the issue with mine. Sized the brass down as much as possible with with dies and with the firing pin removed, it's still not smooth when chambering a resized bare case trimmed to SAAMI. For reference, a fired case measures 1.646" via the E420 comparator. The die bottoms out at a max resizing (annealing after every reload) of 1.633", and at that length it still clicks on the bolt lift and takes decent force to chamber an unloaded round.

The rifle is extremely accurate with Berger 156's (consistent 1/4" groups) but the extremely difficult bolt lift at velocities that are way below max is getting on my last nerve. Finally reached out to them for warranty work and/or to see what they have to say. Not real keen on sending them my rifle for who knows how many months and not know what condition it will come back in or how it will shoot after...

I have similar pressure issues with my CA Mesa in 6.5 PRC. It sounds like your chamber is too tight. You may need to get it re-reamed.
SAMMI SPEC for head space is 1.6517 -.007 = min 1.6447
Your fired cases are only .002 off the min. New unfired Hornady brass is 1.6420, New unfired ADG brass is 1.6430. And I measured unfired Hornady Precision Hunter 143 eld-x and got 1.6440.
My average fired round measures 1.650, I've seen 1.6515
The two thing that have helped me is, I full length my cases to 1.6435 (I've stopped trying to just bump the shoulders back) and I trim my cases to a max of 2.02
I also like using H-1000, but have see impressive accuracy with VV N565

 

[john k]

How many rounds through the barrel?

Less than 100

 

[john k]

Sorry, less than 50

 

[Joefrazell]

Sorry, less than 50

Barrel may speed up a bit in the next 50

 

[SilverbulletMAG]

I have the same issue with a 6.5 PRC Ridgeline. Of note, it does this with factory 143 ELDX loads as well. I've been chasing my tail on this one for several months. Neck turned the brass, tried a few different brands of brass, and have ruled out neck thickness as the issue with mine. Sized the brass down as much as possible with with dies and with the firing pin removed, it's still not smooth when chambering a resized bare case trimmed to SAAMI. For reference, a fired case measures 1.646" via the E420 comparator. The die bottoms out at a max resizing (annealing after every reload) of 1.633", and at that length it still clicks on the bolt lift and takes decent force to chamber an unloaded round.

The rifle is extremely accurate with Berger 156's (consistent 1/4" groups) but the extremely difficult bolt lift at velocities that are way below max is getting on my last nerve. Finally reached out to them for warranty work and/or to see what they have to say. Not real keen on sending them my rifle for who knows how many months and not know what condition it will come back in or how it will shoot after...

Update: Sent my rifle back to CA today to see what they will do. It is nice they cover shipping to/from. They said if the chamber is only "slightly tight", they will polish it out and call it a day. If it is "significantly off", most likely they will replace the whole barrel and action. Hoping this isn't a several month process or get the rifle back in worse condition than it went in...