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.222 ND
06-06-2011, 06:38 PM
I have recently aquired a sako rifle in .22 ppc USA. I had a chance to fire a few rounds (reloaded norma cases) that I recieved with the rifle and they seemed to have powder blowing by the case walls and there was a quite noticeable amount of powder residue around the rim of the case. I have been trying to research the difference between the sako ppc and the norma ppc but have not found much. I would really apreciate it if anybody would share any expierence they have had with a sako ppc usa and older norma brass.

Larry Elliott
06-06-2011, 10:20 PM
What did the primers look like, and how was extraction and bolt lift. It sounds like low pressure to me, not enough pressure to expand the cases on firing to fit the chamber. The necks should expand rapidly and obturate the powder gasses from blowing back into the chamber. If the pressure is too low that's what happens. The only "normal" pressure loads that I've ever seen do this were some .300 Savage loads with RL-12 which went from powder residues clear back to the extractor groove to max in about 1 or 1.5 gr increase in charge.

From experience with Norma and Sako brass the Norma is much more uniform and generally higher quality. Don't know who made the old Sako brass, but it wasn't any better than run of the mill domestic stuff although way more expensive.

.222 ND
06-06-2011, 10:53 PM
The primers looked fine and bolt lift was normal. I will have more time to shoot it this weekend. My main question is there any dimensional differences between sako and norma brass. I don't have the ability to check this I am building a house. My stuff is all packed away right now.

DaveT
06-06-2011, 11:38 PM
.222ND
No one can help you with this problem unless they own one of the Sako PPC USA rifles. I have the same rifle in 6PPC USA and have had the exact same problem with gases blowing back on the shoulder and even down onto the body of the cases. If you check I have a thread on this very same problem, in a couple forums actually. I tried everything imaginable to fix this blow back problem. I asume you will be reloading for this gun? First thing you want to do is take the Norma brass that is blowing back and toss it in the garbage. You'll need some brand spanking new brass, preferably the Sako 22 PPC USA brass that was made just for these guns, if you can find any, which you may not find any, maybe someone reading this can help you. I recently bought some of the Norma 6mm PPC headstamped brass and found that after the first firing I had no blow back problem. When I bought my Sako 6PPC USA rifle, I bought enough brass to hold me for a while, and recently I prepped out 60 cases of this new brass and after first firing had no blow back. I had this same brass that had been fired many times and I guess became work hardened and I got blow back and tossed them in garbage. I also tried the Lapua 220 Russian head stamped brass brand new and with this brass I got blow back, not sure why. I normally shoot brass many many times and never had this problem, only with this Sako rifle. So get some new brass and let us know how it works. If you need help with loads and anything else just yell. Just one other thing, these Sako PPC's are really great guns and they are the most accurate out of the box gun ever made, I know mine is. I hear the cow bells.
Dave T

alinwa
06-07-2011, 12:36 AM
MORE COWBELLS!!!

You need some new brass and some stouter loads. If you're getting blowback you aren't making enough pressure for proper seal. The primary function of the brassd cartridge case IS NOT that of being a handy way to carry powder and ball......... it's to act as a gasket against the tremendous pressures generated by smokeless powder.

Y'er gasket's leaking


al

flatlander
06-11-2011, 09:22 AM
Wonder if annealing the necks of the Norma stuff would help? Seems a shame to toss high-dollar brass, especially when it's so hard to find.

DaveT
06-11-2011, 12:34 PM
Wonder if annealing the necks of the Norma stuff would help? Seems a shame to toss high-dollar brass, especially when it's so hard to find.

Flatlander makes a good point with the annealing idea, I didn't mention it because I've never annealed cases before and I just felt safer just tossing them, which also speaks to flatlander's point about expense. I may try annealing if these new cases seem to blow back after only a few firings.
Dave T

skeetlee
06-11-2011, 02:16 PM
I was under the impression that the USA chambers were much bigger than the ppc chambers commonly used with Lapua or norma brass. I did a little research on this subject pertaining to a 22ppc .100 short. I think i will order a 22ppc usa reamer and stop it .100 short for my next barreling job. Since the reamer on the usa chamber is bigger i can stop it short and still not have any trouble finding a good fit on a FL harrels size die. At least this is my plan. Also by using a full size 22ppc reamer i can play with different lenghts. I can do a .070 short or i can do a .125 short. I need to get a reamer ordered as it may be a while getting it. Lee

DaveT
06-11-2011, 04:29 PM
I was under the impression that the USA chambers were much bigger than the ppc chambers commonly used with Lapua or norma brass. I did a little research on this subject pertaining to a 22ppc .100 short. I think i will order a 22ppc usa reamer and stop it .100 short for my next barreling job. Since the reamer on the usa chamber is bigger i can stop it short and still not have any trouble finding a good fit on a FL harrels size die. At least this is my plan. Also by using a full size 22ppc reamer i can play with different lenghts. I can do a .070 short or i can do a .125 short. I need to get a reamer ordered as it may be a while getting it. Lee
skeetlee,
You are exactly correct, the Sako PPC USA chambers are larger then the bench rest chambers. When I got my Sako 6PPC USA Varminter, my cases wouldn't fit into my Wilson hand dies that I used for my bench rest competition gun at that time. I had to order what Wilson calls oversize 6MM PPC dies. But one question skeetlee, it shouldn't matter if the 220 Russian or the Norma brass is made smaller then the Sako factory chamber after fire forming, correct? Oh and do you have an old Sako PPC USA gun?
Dave T