Hitting pressure early in 6.5 PRC

skookum

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I have a newly barreled 6.5 PRC that I am hitting pressure with a modest load of H1000 and 143gr ELDs. Book max said 59.0 gr and in my experience with every other gun I have ever shot the book max is still under what the gun will actually do. I started hitting pressure at a modest 56.5gr of H1000, Nosler Brass, and a FED 215. By 57.5gr I gave up when I started getting a heavy bolt lift. Any ideas on why? I know every gun is a little different but this seems extreme. Could the chamber be a little too tight?
 

cowboy

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Did this happen with reloads, and if so, how many times has the brass been reloaded? If these are reloads with brass with multiple firings you have just experienced a very common 6.5 PRC problem.
 

skookum

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Virgin Nosler brass. Used a magneto, all velocities were in normal range, all above 2900 none broke the 3000 mark. I did find an OK load with an ES of 23
 

Subzero

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Barrel length? Powder?
Could be a slightly tight chamber, but if you can easily chamber virgin brass then I wouldn't say it's "too" tight.
 

skookum

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Jump is .050" that i settled on. And now that I think about it some of the Hornady factory ammo was a bit tight like a handload that didn't have enough shoulder bump.
 

Pdyson

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I’ve experienced the same early pressure signs at modest velocity. Stiff bolt lift, ejector marks in my 28 Nosler. I went home and pulled between 15 and 30 bullets. Then loaded a new series with a different powder only to have the same issues. I did this 3 times and finally realized it was the Nosler brand brass.
Switched to Peterson brass and never had another problem.
 

Liddy

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Switch primers to 210’s, see if that helps. I am running 58.5 grains of H1000 pushing 143 ELDX at 3,050 with Fed 210’s in two 6.5 PRC’s, one in a Bartlein #3 fluted 24” and one in a Proof CF Sendero 24” both 1-8tw barrels. They both stay within 10fps of each other.

Liddy
 

MTGEEZER

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I have a newly barreled 6.5 PRC that I am hitting pressure with a modest load of H1000 and 143gr ELDs. Book max said 59.0 gr and in my experience with every other gun I have ever shot the book max is still under what the gun will actually do. I started hitting pressure at a modest 56.5gr of H1000, Nosler Brass, and a FED 215. By 57.5gr I gave up when I started getting a heavy bolt lift. Any ideas on why? I know every gun is a little different but this seems extreme. Could the chamber be a little too tight?
I've been trying to figure out the 6.5 PRC for a couple of years. The "pressure problem" was, in my opinion, best explained by the Alex Wheeler posts that, IIRC, explained that SAAMI chambers were (are) cut a tad too tight. When I started my load workup, I could never get close to any max load. At that time, data was hard to find and even now that data is readily available, and I'm on to another brand of rifle ( all medium priced factory ), I still have to load towards the lower end of the charges for all powder/primer recommendations. Is your barrel cut to SAAMI specs? PS: I use ADG brass and have also used Hornady
 

skookum

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This is with Hornady brass

I have a friend that is in the same wheelhouse with 59gr
I've been trying to figure out the 6.5 PRC for a couple of years. The "pressure problem" was, in my opinion, best explained by the Alex Wheeler posts that, IIRC, explained that SAAMI chambers were (are) cut a tad too tight. When I started my load workup, I could never get close to any max load. At that time, data was hard to find and even now that data is readily available, and I'm on to another brand of rifle ( all medium priced factory ), I still have to load towards the lower end of the charges for all powder/primer recommendations. Is your barrel cut to SAAMI specs? PS: I use ADG brass and have also used Hornady

Not sure what the chamber is, I am assuming it is supposed to be SAAMI but I think it may be a tad too tight.
 

MTGEEZER

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I have a friend that is in the same wheelhouse with 59gr


Not sure what the chamber is, I am assuming it is supposed to be SAAMI but I think it may be a tad too tight.
Again, if I remember correctly, Mr. Wheeler was addressing the problems with pressure and "clickers" in SAAMI cut 6.5 PRC chambers. Maybe it would be best to just refer you to his posts as I do not want to give bad advice or misquote a really well known Gunsmith. After 5 loads on the good ADG brass, I can no longer size the last .2-.3 inch (base) enough to prevent clickers. This is with a charge (for MY gun) of 54 gr. RL 23, CCI BR2 primer pushing a 124 gr. Hammer Hunter to a modest 3230 FPS. (Still makes critters alot easier to get into the freezer!) Good luck with your new barrel!
 
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