I went to the range this weekend and had two new rifles to get going. I was putting one through the Final Finish process (50) rounds in ten shot strings, then cleaning before next ten-- really only three or four shots and then allowing barrel to cool-- and I had about four rounds have sticky bolt, one really firm to lift. Definately not acceptable in a hunting situation! The brass was second time reloaded WW nickel-plated in 300 WSM. The load was about five grains below minimum for the bullet weight, 60 instead of 65.5 grains of 4831sc. The sticky rounds were not in succession or even the same level of bullet within the final finish abrasive classes, (maybe 2 were) I didn't have this issue with the .270 WSM I was shooting for the first time--Same type brass etc. Is there anything to 'polishing the chamber' -How do you do that? I had a friend with the same 300 WSM and he had hard bolt lift with factory ammo and sent his rifle back to SAKO, (last year -- pre Beretta?) and when he got it back it functioned flawlessly, the work ticket on his rifle said check and polish chamber. The rifle is a Sako 75 Finnlight in the V Action, I have a new one in the SM action and haven't had the problem--yet??? Would appreciate your thoughts and advice.

Nickel-Plated brass is a major pain in the a*s. I bought new RP Nickel-Plated brass for my 300WM Remington 700 BDL. The Nickel crap won't chamber with out a lot of force even after full length resizing. Regular brass is no problem. I suggest that you try reloading and shooting some non nickel brass first. If the problem persists try some factory loads you might be loading them to hot. Just because the load is in the reloading manual doesn�t mean that it is not to hot for your rifle.

Thanks Swede, I'm still trying to figure out how to 'polish the chamber', I haven't had the issue with the factory non-nickel stuff so maybe that np brass is a culprit indeed. I would still like to be able to shoot it though as I really like the Winchester ammo with the lubalox coated accubond and ballistic tip bullets.
Regards--Don.

I would take it to a gunsmith to have it polished.
It is taking a fired casing, drilling and tapping it through the primer pocket in like a 1/4-20 thread, applying an oil to the casing and then applying a fine abrasive to the casing. I use a 600 grit. Then you chuck the rod, onto which the case is threaded, into a hand drill and place it in the chamber and spin it at high speed.
The way to tell if your chamber needs polishing is if your fired cases have a texture on them.
If so, it should take just a nice polishing to get whatever roughness there is out of the chamber.
But I reiterate, please send this to a smith who knows whats up because your do not want to remove too much metal.

-Spencer

I'll repost what I said over on the gunsmithing board where you also posted this:

Kinda hate to bring this up as it always causes some controversy on loading boards, but the "detonation" or "secondary explosion effect" has been reported with reduced loads of 4831 in large-for-bore cartridges like the .25-06. It's not what I'd choose for reduced loads, and going below the minmum load in the manual you're on your own.

Thanks Ricochet, I hadn't read about the issues with being 5 or so grains under the minimum. I was trying to follow the final finish advice about minimum loads and I didn't realize this was to far under for good results.
Regards-Don.

Thanks ShopCart, I think I could handle what you outlined, but I'll find a smith in my area and let him advise me/polish my chamber. I don't detect any noticeable texture on my cases but the stiff bolt lift was there for sure. Appreciate the info--Don.

You are advised to be extremely careful if you try to use slow powders IN LOADS THAT ARE SIGNIFICANTLY BELOW MINIMUM!! This is particularly true in large-capacity, small bore diameter cartridges.

Thank you, Eldeguello. Certainly have learned on this one. Do you have any thoughts on how one would load for 'minimum speeds' while using something like the final finish system--firelapping-- is that worrying about something not worth worrying about, my gut tells me it is..... Thanks again for the advice,
Regards-Don.

The probem you described seems to me to be a pressure problem. Polishing the chamber is not likely to change that. I would check several things to determine that they are ok and not creating the problem. First, be sure your case necks are not too long. Second, check to be sure that a new bullet will easily slip into a fired case. In other words, be sure there is room for the case neck to expand and free the bullet to travel down the barrel. Third, be sure the barrel itselfe is clean on the inside; that is, nothing acting as an obstruction. Fourth, be sure the chamber is not oily causing undue rearward stress on the locking lugs. Fifth, be sure you have the correct primers in the load. If all of these things are ok, I would be suspicious of your using too little of too slow a powder. Change to a different relatively slow powder but do not go lighter than the minimum loads in the manuals. If these shoot ok , go back and try your original powder with no less than minimum loads of the manuals.