6 br heavy bolt lift ?

[BJ44BJ]

I have a 6 br that has heavy bolt lift even with what seems to be a light load. It is a Krieger 12 twist with .237 bore. Chambered with a PTG reamer. My load is 30.0gr IMR 8208 xbr 80 gr berger .015 in the lands. It shoots real well but bolt lift seems to be excessive. I sent fired brass to Harrells and had them send me another die b2.5. I use a .265 neck bushing. This is a .272 no turn neck chamber. I have another 12 twist Krieger that I chambered less than 2 months later with the same reamer and have shot much hotter loads all with very easy bolt lift. Both actions are BAT SV actions. Originally the chamber was very lightly polished with 320 and one local gunsmith opinion was that was too rough. I set the barrel back in the lathe and polished up to 600. Same problem. Any help or suggestions would be appreciated.

 

[fdshuster]

Question? Is the heavy bolt lift with the first couple of rounds fired only, or does the problem continue with multiple shots fired?

 

[BJ44BJ]

It seems to lessen slightly after a few rounds are fired.

 

[fdshuster]

BJ44BJ: O.K., that's what I was getting at, without saying it.

I had the same problem, first 3 or 4 rounds were a hard bolt lift, then all normal. Simple fix for me: make extra sure your chamber is perfectly dry before firing. Ran it by my gunsmith & it's his opinion that the 6BR case design, short & fat, is more difficult to get dry with patches when cleaning. Some solvent is always left in the chamber.

When done cleaning, I go into the chamber with an oversize patch, one that is way too big to fit in the bore, but all I'm doing is drying out the chamber.

I also see a lot of wet chambers when I go into other peoples rifle barrels with my Hawkeye borescope. I emphasize to them that the chamber must be dry before I slide the scope tube into the barrel. Many I find are wet, very wet, and the owners are surprised, saying that they thought the chamber was dry.

Before firing I sometimes run an oversize patch with a small amount of brake cleaner into the chamber & have never had the problem after doing that. It will remove any & all solvent that may have been in there.

 

[BJ44BJ]

Thanks. You just solved my problem. I have been using a light lubricant to wipe down my cases as it cleans the carbon off the necks very easily. After cleaning I did just as you said and used an oversized patch with brakecleen on the chamber and then another to make sure it was very dry. I also wiped my cases with a rag and brake cleen and now very easy bolt lift. Thanks

 

[fdshuster]

My suggestion was just a stab in the dark, one of several likely causes. Glad it worked.

 

[Shynloco]

Thanks. You just solved my problem. I have been using a light lubricant to wipe down my cases as it cleans the carbon off the necks very easily. After cleaning I did just as you said and used an oversized patch with brakecleen on the chamber and then another to make sure it was very dry. I also wiped my cases with a rag and brake cleen and now very easy bolt lift. Thanks

BJ,
Let me run this by you and I'm not pushing a product here. But a few years ago, a Benchrest buddy turned me on to a product named, "Prolix." This lubricant/cleaner is made specifically for firearms and they have their own website if you want to investigate further. I usually use this stuff after all all the other regular products I use to clean my rifles after shooting. That includes runing a wet patch of the stuff down my barrel, followed by a dry patch. The stuff is bio-degradable and evaporates so as not to leave any dampness or oily films that contribuite to what you describe. They sell the stuff in various bottle sizes so you might consider buying a small bottle and see how it works for you. I've found it works great on all portions of my rifle, whether the receiver, barrel or stock. Info only.

Alex

 

[rogn]

One of the things Ive found handy for chamber hygiene is a clarinet mop/brush? Got my from music store,(where they sell instruments), wash when dirty. Can use two, one to clean with solvent the second to swab.