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Discussion Starter #1
Got a Savage 12FV in 6.5CM last fall and been having a problem with it destroying cases as I work up loads. About the time I start getting near the middle of published data it starts stretching primer pockets. Today I was finally able to set up the crony as the snow drift is gone in front of my shooting bench and I found out I was pushing my bullet about 150+ fps faster then what it should be. What the heck is going on? Max load for 130gn ELD is 44.8 gns of Hybrid for around 2800 FPS and I'm getting 2850-2900 with 41 grns of powder and .020" off the lands.
 

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Wonder if its a case problem?
Think I would try some different type of powder to see if its repeating the same results.
 

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The Hog Whisperer (Administrator)
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Well, the load is clearly too much for the brass you have. I'd wager that your brass has much less capacity than what the loads were developed with. Does your load data show the capacity of the brass? 0.20" is pretty close to the lands. Shouldn't be a problem... but....
 

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The Shadow
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I agree with MikeG, different cases and obviously different lot of powder.
 

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Upon inspection of the full side of the glass: You get published velocity with 4 grains less powder, so more loads per pound! ;)

This is why you always start low and work your way up. Is there a good accuracy node a couple of grains below the point where primer pockets loosen up?

I had a 7RM chamber that was cut with a really short throat and ran into the same problems with anything heavier than 150 grain bullets. Even those had to be seated pretty deep, almost to the ogive.
 
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I guess I would tend to agree with broom_jm. Back the powder charge down to what appears to be safe pressure levels and the velocity and accuracy that you want and go forward. Since you already have the brass, powder and bullets, I don't really see any reason to start over.
 

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Discussion Starter #8
I was thinking it was a case problem myself but I would think it would of showed up in the other 6.5 CMs I and my buddys have been loading for. My future SIL has the same rifle as I, my buddy has an X-Bolt and I also been loading for a LR 6.5. My gun is the only one that has this issue. Have tried Rem cases and they stretch worse sooner. Hornady cases are a bit stronger. Powder doesn,t seem to make a diff either.Tried H4350, Superform and Hybrid. Moving back of lands makes no diff either. I,m kinda leaning toward a chamber issue now. Accuracy is great just before the cases start stretching so deff a good node there which I have seen before when nearing max charges in other guns. Really happy I ran the loads through the crony before I toasted any more cases though.
 

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Hm. Didn't know you had tested the same load in multiple rifles an the other rifles are showing no issue. Have you measured the fired brass from the other rifles to compare to yours to see if there is a difference in dimensions. A quick thought might be something going on in the neck area of the chamber.
 

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Maybe you should make some chamber castings. Compare dimensions of problem rifle against a rifle with no problems. Savage might make it right if the chamber was cut too short or small. Worth a try.
 

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Loading in other rifle's doesn't mean a whole lot! Chamber's may vary! Barrel dia my vary, throat may vary. if your getting pressure sign's back off. If you think something is wrong, have a gunsmith check it. Just a though, how long is your brass?
 

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Discussion Starter #12
Downloaded the saami spec sheet with max cartridge and min chamber specs. My fired brass is really close to min chamber spec with the other fired guns brass being closer to to the max cartridge specs. Looks like a tight chamber to me. Seems to me I ran into this prob before with another savage rifle but my memory isn't what it used to be anymore.
 

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The Shadow
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Powder doesn,t seem to make a diff either.Tried H4350, Superform and Hybrid. Moving back of lands makes no diff either. I,m kinda leaning toward a chamber issue now. .
IF all powders act this way, then it would likely be a chamber issue. Be cautious with Superformance though. Due to it's extremely progressive burning curve in the Creed; Velocity won't track linearly like standard powders. Similarly, when pressure testing it early on, my specific lot, per velocity(no listed pressures) my lot was VERY different than the stuff tested in Hornady's first iteration.

Seems to me I ran into this prob before with another savage rifle but my memory isn't what it used to be anymore.
Savage has had several chamber issues in Creedmoor rifles in the past some number of years. Jack has a neat sulphur casting recipie floating around on the board.

Cheers
 

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The Hog Whisperer (Administrator)
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What kind of velocities do you get with factory ammo?
 

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Discussion Starter #15
I know we ran some factory stuff through the crony last fall but I dont remember what we were getting for FPS. I do recall I was running an easy 30FPS faster then the other 12fv. I still have some 140 factory match rounds so I'll clock some this weekend and see.
 

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Discussion Starter #16
Weekend came early for me. Fired three shots of Hornady 140 gn match through the crony this morning. Hornady says 2710FPS I got 2791, 2789 and2784 FPS in that order. Nice 1/2 group @ a hunderd, nice flat primers and no stiff bolt to open.
 

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The Hog Whisperer (Administrator)
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If the factory loads are estimated for the same barrel length, then you are on the high side. Plus factory claimed velocities tend to be a bit exaggerated, in my experience. So I'd say it is likely that your gun has a tighter chamber and/or shorter throat, than the usual.
 

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The Troll Whisperer (Moderator)
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Sounds like Savage got the goodie use out of the reamer.
 

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Most likely a throat or barrel problem. Your speeds tell you the pressure is real. The fact that your loads only cause a problem in _your_ gun, not the others you listed (if I understand you correctly), tells you it’s not the brass or the powder. The fact that you’re well over book speeds tells you, presuming you’re using a manual that performs testing on universal receivers and pressure barrels, it’s not just a SAAMI-minimum chamber you got ‘lucky’ to get. It’s your gun that’s the problem. It wasn’t made correctly and is causing over-pressure conditions.

You can keep this in mind and reduce your loads accordingly if you like, since it seems to shoot quite precisely for you. Or you can send it back (if it’s new) and ask Savage to fix it.

This situation is why, when working up handloads, you STOP adding powder when you reach the FIRST of:

1) Max book charge, or
2) Max book speed.
 

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Discussion Starter #20
Right on MZ5. Glad I have a crony. A lot of reloaders dont. The gun was new last fall but I'll play around with a bit more as it is quite accurate. Gonna have another savage 12fv here in a week a so to sight in and will definitely be shooting it over the crony too.
 
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