Another sticky bolt question

[cornchuck]

My 308, as of yesterday, has 200 rounds through. I was testing some loads yesterday and was having some sticky bolt situations. Even seeing ejector marks on case haed. The powder was IMR4064 with 210m primers in Rem. cases. One batch was loaded with 178 gr. A-Max loaded from 39.5 grs. of powder to 41.3 grs. 41.3 grs. is max according to Hornady's book. Bullets were set 2.200 OAL by the ogive.

Second batch had the same loads as above but had 175 gr. SMK. Didn't have as much of a sticky bolt as with the A-Max's. These bullets were set 2.227 inches by the ogive.

Even the factory rounds I was using for fouling shots were some what sticky.

When I tried Varget (41.4gr.- 43.2 gr.) and Reloader 15 ( 39.6 -41.4 grs.) last fall, I didn't noticed the sticky bolt. That time I was loading for the 178 A-Max with the same measurement as above.

I am going to try Varget with the 175 SMK when I get a chance.

The gun is a Rem 700P with a 26 inch tube.

What is going on? Should I be concerned?

Jason

 

[cholla chomper]

Does it somewhat get sticky after the gun heats up or anytime? retorque the action mounting screws to spec and see if this helps any.

 

[Broz]

I take it by the term "Sticky bolt" you are refering to a firm or hard bolt lift after firing the shot. correct?

If so, and this is also accompanied by ejector marks on the head of the case you are over pressure and need to back off 3 to 5 grains and creep back up.

Also note that sometimes these loads that are borderline over pressure are increased pressure wise by a hot chamber that comes from a range session or multipul shot groups.

And yes I have seen factory loads be on the hot side, but those might be ok in a cool chamber. All rifles are different, some just take a lower charge but that does not mean velocity will be down. Pressure is pressure no matted what the charge number is.

You asked if you should be concerned. I say yes, any over prssure loads can be dangerous and for sure are not doing your rifle and brass any good.

Jeff

 

[Bughole]

There is a multitude of things that could be going on. Just some of the things to consider< Did you change powder lots, and or bullet lots. I've had bullets from different lots of the same company, and make, mike out 3 to 4 ten thousands different affecting pressure. Are you using the same brass etc., Are your case length dimensions correct(this is huge and if your cases are stretched overlength you can really screw up an action or your life) Some people are too lazy to check this and simply keep loading and shooting. Is your neck diameter correct for your rifle or have they thickened, needing about 3 to 4 thousandths for proper clearance in a hunting rifle. What were the weather and temp conditions at the different firing times, Is your barrel clean? A dirty barrel can have a significant impact on pressure and velocity, I don't mean do you think that it's clean I mean is it really clean. Just some things to consider, and yes any kind of bolt lift problem is of concern, It is one of the tell tale signs of too much pressure. Figure it out or get someone to with the knowledge to help you. Good Lucklightbulb

 

[338winmag]

This is just a thought. Jacket hardness can atribute to pressure issues with a sticky bolt result sometimes as well. I had a 7mm Rem Mag last year that had pressure issues using Sierra Gameking bullets. I tried everything under the sun to correct. Even with some serious reduced minimum loads and standard C.O.L.. Finally talked with someone that had the same type of issue with SGK bullets for one of his rifles. I switched to Hornady and no longer had the problem or sticky bolt. Tried again SGKs and sticky bolt. Tested with Hornday interlcocks and problem gone.

Just a thought
338winmag

 

[cornchuck]

Thank you for the replies. The A-Max's and the SMK's are the first reloads that I put through the gun. Other than the factory loads I got to break in the barrel. So the bullets are from the same box. And I haven't bought new powder to where I need to switch container.

I was shooting in 42 degree weather but in a shooting house where it was 50-55 degrees.

I was talking with someone yesterday about my situation and he asked about the bolt lift. I did tell him even with a empty chamber the bolt is still alittle tight. Alittle tighter than my other 700's. He said that the bolt lugs might need to be squared to the receiver. I was going to have a accuracy job done to it anyway.

Jason

 

[Broz]

I did tell him even with a empty chamber the bolt is still alittle tight. Alittle tighter than my other 700's. He said that the bolt lugs might need to be squared to the receiver. I was going to have a accuracy job done to it anyway.

Jason

The first thing I asked you was in referance to what you mean by "sticky bolt" and when it occurs, There is a diference in diagnosing a hard to close bolt and a hard to open bolt after firing. Many here could help you, but first you need to discribe in detail what you mean by "sticky bolt" and when it is happening??