Heavy Bolt lift - first 2 or 3 shots?

[roklock]

Breaking in a new barrel and "fire forming" brass today. It was strange that I was getting heavy bolt lift on my first 2 or 3 shots after cleaning. Then any rounds after that bolt lift was smooth as butter. Last string was first three shots were heavy bolt lift and then the next 7 were "butter"

Any thoughts that would cause such a consistent heavy bolt lift, then adjust to what I would call normal?

Some details on the load...

Brand new Alpha 6 BRA brass - necks turned
205M primers
H4895 - 29.5 grains
Bart 105 hammers (culls), loaded .009 in from touch
200 datum ranges (after fired) from .4688-.46905 (no correlation the heavy bolt lift and larger datum numbers)

Thanks,

Steve

 

[bugman]

make sure the chamber is free of cleaning solution. Anything like that in the chamber will overpressure the first few rounds. The heat generated from the first few rounds, evaporates the cause of the pressure, and bolt lift returns to normal.

 

[roklock]

make sure the chamber is free of cleaning solution. Anything like that in the chamber will over pressure the first few rounds.

I do use a chamber mop after I pull out the bore guide, will be double check next time out to confirm. Strange that I haven't experienced this before.

 

[acloco]

Do you clean and lube the bolt lugs/action after cleaning?

 

[bugman]

I do use a chamber mop after I pull out the bore guide, will be double check next time out to confirm. Strange that I haven't experienced this before.

unchlorinated brake cleaner is your friend.
Wrap a clean patch around that dirty mop, and get it damp with brake cleaner. Use a new patch every time.
The Alpha can be quirkier than lapua when it comes to just a little surface gunk causing overpressure. Try wiping off loaded cases with the brake cleaner, and it easily removes any overlooked imperial, oil, etc.
Try brake cleaner on the cases and the chamber, and find out for yourself.

 

[boltfluter]

unchlorinated brake cleaner is your friend.
Wrap a clean patch around that dirty mop, and get it damp with brake cleaner. Use a new patch every time.
The Alpha can be quirkier than lapua when it comes to just a little surface gunk causing overpressure. Try wiping off loaded cases with the brake cleaner, and it easily removes any overlooked imperial, oil, etc.
Try brake cleaner on the cases and the chamber, and find out for yourself.

Excellent advice from bug man. Exactly what I was going to say.

Paul

 

[roklock]

unchlorinated brake cleaner is your friend.
Wrap a clean patch around that dirty mop, and get it damp with brake cleaner. Use a new patch every time.
The Alpha can be quirkier than lapua when it comes to just a little surface gunk causing overpressure. Try wiping off loaded cases with the brake cleaner, and it easily removes any overlooked imperial, oil, etc.
Try brake cleaner on the cases and the chamber, and find out for yourself.

Thanks, I'll give that a try. Thinking harder on it this morning I probably should have changed mops too since I was cleaning more often than normal and I bet it wasn't drying out the chamber as it normally would.

Do you clean and lube the bolt lugs/action after cleaning?

Yes, always.

 

[Sumtoc]

Breaking in a new barrel and "fire forming" brass today. It was strange that I was getting heavy bolt lift on my first 2 or 3 shots after cleaning. Then any rounds after that bolt lift was smooth as butter. Last string was first three shots were heavy bolt lift and then the next 7 were "butter"

Any thoughts that would cause such a consistent heavy bolt lift, then adjust to what I would call normal?

Some details on the load...

Brand new Alpha 6 BRA brass - necks turned
205M primers
H4895 - 29.5 grains
Bart 105 hammers (culls), loaded .009 in from touch
200 datum ranges (after fired) from .4688-.46905 (no correlation the heavy bolt lift and larger datum numbers)

Thanks,

Steve

I am having the exact issue with the same brass and cartridge. I use Hornady One Shot to lube cases for resizing then tumble clean in crushed corn cob. I also run 2-3 dry patches through the chamber without a bore guide as my last cleaning step. Never had this happen with any other cartridge in 30+ years of reloading.

I'll be trying the brake cleaner trick next, but how to tell if it is "unchlorinated"?

Thanks

 

[JMayo]

Put a patch over a 50 cal bore mop. No takes up the room while patch collects the wetness/crud.
Boretec products are real sticky if ANY are left.

I rarely use the rectangle or round long thingy to get around lugs when actively shooting at a match. Just mop with patch on the mop..

 

[Coyotefurharvester]

Will say on the container.

 

[Mike Casselton]

I am having the exact issue with the same brass and cartridge. I use Hornady One Shot to lube cases for resizing then tumble clean in crushed corn cob. I also run 2-3 dry patches through the chamber without a bore guide as my last cleaning step. Never had this happen with any other cartridge in 30+ years of reloading.

I'll be trying the brake cleaner trick next, but how to tell if it is "unchlorinated"?

Thanks

CRC makes it and it says so right on the label

 

[dkhunt14]

Thanks, I'll give that a try. Thinking harder on it this morning I probably should have changed mops too since I was cleaning more often than normal and I bet it wasn't drying out the chamber as it normally would.



Yes, always.

Most cleaning fluids have oil in them. That's why you need to make sure you really dry that chamber. Brake Clean or alcohol can help get it clean. Matt

 

[bugman]

Thanks, I'll give that a try. Thinking harder on it this morning I probably should have changed mops too since I was cleaning more often than normal and I bet it wasn't drying out the chamber as it normally would

you are welcome. I don't forget the favor when you sold me those primers.
I hope this helps, but there could be other reasons for your problem....... Start with a cleaner chamber and cases, and if you get no joy, PM me .

 

[AlNyhus]

When f-forming, I routinely lightly oil the cases. At times...depending on the chambers finish...the bolt can be a bit harder to open due to the oil taking up some space and in effect making the brass 'bigger'.

For what it's worth.... -Al

 

[K22]

May not be relevant here but I'll pass it along.

Had a friend with a similar problem but with a different cartridge. What we determined was that the preservative lube (gun oil) in the clean barrel was draining down into the chamber creating the problem. Like most of us, he stored his rifles in a safe, muzzle up which creates a gravity drain. Also, he was using far too much lube.

Once he started cleaning the chamber with a solvent (used mineral spirits) before shooting a clean barrel rifle the problem disappeared. Also, he began using only a thin coating of oil as preservative on a clean barrel going into storage.

I've always cleaned the chamber during routine cleaning and before going to the range or a hunt if the rifle had been previously cleaned a lubed for storage. I've used mineral spirits which seem to work quite well. Also, be careful of too much lube on bolt lugs.

 

[Skeptic123]

I had this exact same issue. I found that when I took my rifle from a cool house out into a humid environment the chamber would sweat. If I swabbed the chamber with alcohol before shooting it would take care of the hard bolt lift issue.