Heavy Bolt Lift

[25WSM]

I had a lady swing by my shop after getting a scope mounted at a local gunshop. She asked why the bolt stuck out from the stock more now. Yup the front mount screw was way to long and the bolt lug was hitting it not letting the bolt close. Yes there are people out there that shouldn't be doing any gun work. How do you not notice the bolt not closing all the way. So yes screws can cause issues on actions but I don't think it's causing this issue.
Shep

 

[HappyWarrior]

More reasons to build on seasoned M70s and 722s.

 

[6.5x300 WBY]

Very very interesting thread. Also the knowledge on this site is nothing less than phenomenal.

 

[Stgraves260]

Hey Everyone, been a while. I decided to pull the 300 Norma out of the safe a few days ago and forgot why I put it up for so long to begin with, but I remembered as soon as I shot the first round. The BOLT LIFT IS LIKE MOVING A MOUNTAIN.

Strangely, it is built on a BAT action and it's as sturdy as they come. I posted a thread on here a few years ago about the bolt lift and at the time no one was able to help me. I decided to revisit the forum to see if anyone had any ideas or have encountered this problem. The bolt is much heavier than any of my other factory bolt guns and after I pull the trigger (even on an empty chamber) the bolt lift becomes EVEN heavier. It's so frustrating trying to "feel" pressure signs before viewing brass as the bolt lift is always heavy. I've lubed this thing to death, I've changed out triggers, I've tried factory ammo. I've even sent the **** thing back to BAT and in about 2 weeks I received my action back with a note that assured me everything was working flawlessly.

They obviously know more about the products than I do, but I just can't understand how they could not feel such a heavy bolt lift as compared to the other rem 700's, savages, tigers, etc that I have. I just wonder if it's not the firing pin spring. And if it is, I'm afraid to alter it in fear of inducing ignition problems.

Any suggestions guys?

It's prob been to long now. But it would have been a good idea to take the gun back to the smith You had the work done after you shot it. I would say try factory ammo and see if it still sticks, but you said it's even harder to lift even when the chamber is empty. Best advice, find a good gunsmith with a good background. A gunsmith that not only works on guns but is a avid shooter. Just my opinion how can a gunsmith that doesn't shoot tell me how a gun is supposed to act, function, handle, shoot whatever you want to call it.

 

[Mikecr]

I wouldn't let a gunsmith anywhere near one of my BAT actions.
A gun builder, familiar with BR actions and known for building great guns, that's what you need.
Alex Wheeler would determine the cause real quick I'm sure.

For those of you not familiar with BAT actions, let me just suggest that they're not prone to issues gunsmiths repair.
They're so tight in tolerances that if ever working at all -they're perfect. With this, I seriously doubt you have an action problem.

You have options with various triggers, trigger hangers, springs and pin weights. You can have a roller installed on your cocking piece even if a 2-lug action to reduce lift effort. Perhaps you could install a lighter spring & heavier pin.

 

[LVJ76]

If the scope mount screws are too long, and scraping against the bolt, you would have marks on the bolt where they rub. You might check that (easy enough to do without disassembling anything -- just open the bolt) so you can check that off the list.

I'm with those who are saying it has to do with faulty timing or a trigger issue, but the factory would have found those when you sent it back.

Please let us know what it was when you find out.

I though this also but then they would also scratch when closing the bolt and should be tight then as well.

 

[Cammo]

Could it be head space is to short? Have you looked at this possibility? Might just be a problem with your barrel.

 

[Maol]

Could it be head space is to short? Have you looked at this possibility? Might just be a problem with your barrel.

Is the OP using a case when performing all tests? Maybe I missed it, but thought that the issue was there at all times, except with the firing pin and spring not installed. That point and the bolt finishing the bolt closing unassisted (completely on it's own) indicates to me it is a bolt thing and not a barrel thing.

Funny, really thought long and hard about a BAT instead of a Savage because their bolts are maybe the heaviest, but they do have the fastest firing pin in the world. So for me to be almost happy Savages need a lift kit, longer bolt handle, and timing.

Following this one with interest!

 

[jdyoung]

I wouldn't let a gunsmith anywhere near one of my BAT actions.
A gun builder, familiar with BR actions and known for building great guns, that's what you need.
Alex Wheeler would determine the cause real quick I'm sure.
For those of you not familiar with BAT actions, let me just suggest that they're not prone to issues gunsmiths repair.
They're so tight in tolerances that if ever working at all -they're perfect. With this, I seriously doubt you have an action problem.

You have options with various triggers, trigger hangers, springs and pin weights. You can have a roller installed on your cocking piece even if a 2-lug action to reduce lift effort. Perhaps you could install a lighter spring & heavier pin.

What if the mating position of the trigger sear and cocking piece sear is not far enough rearward. Given the tighter tolerances, would that put pressure on the bolt cocking cam surfaces by the cocking piece nose, causing the bolt to react as the OP described in #5 when rotating the bolt handle downward to firing position ?

 

[Mikecr]

jdyoung, yes it would, and that's not an action problem. It's a trigger installation problem.
Found a video of Bruce Thom in action:

 

[Alex Wheeler]

The trigger has nothing to do with the bolt lift of the action. A Bat Hr has about a 26-28lb spring in it, vs your typical 20-22lb spring in most other actions. These are measured numbers not advertised numbers. You should expect it to open a bit stiffer. Without feeling it I cant tell you if its abnormal or not. Depending on the vintage and shroud design it may or may not be able to be improved, assuming there are not real problems. Bat has very good geometry in the cocking cam and shroud design, its very hard to improve the opening force on these actions from my testing, they are very good. You can reduce the spring pressure some, I wouldnt go lower than 24lb. If this is to be used in cold weather.

 

[6.5x300 WBY]

The trigger has nothing to do with the bolt lift of the action. A Bat Hr has about a 28lb spring in it, vs your typical 20-22lb spring in most other actions. These are measured numbers not advertised numbers. You should expect it to open a bit stiffer. Without feeling it I cant tell you if its abnormal or not. Depending on the vintage and shroud design it may or may not be able to be improved, assuming there are not real problems. Bat has about the best geometry in the cocking cam and shroud design, its very hard to improve the opening force on these actions from my testing, they are very good. You can reduce the spring pressure some, I wouldnt go lower than 24lb. If this is to be used in cold weather.

Send it to this guy^^^^^^and be done with it.

 

[arch408]

I know absolutely nothing about your action, but by reading your post, I think that it has less than a 90 degree bolt lift. If that is true, than a heavier bolt lift is the nature of the beast because of less mechanical advantage because of a sharper cam angle than a 90 degree bolt lift. If it is a 90 degree bolt, than I would suspect that the firing pin spring is too heavy or the bolt is hanging up some where. Have you compared to an identical action? If the bolt is "normal"with the firing pin cocked, than I would try a lighter firing pin spring. That is the only other restriction during the bolt lift if the recoil lugs aren't binding with the action or the firing pin cam isn't binding with the bolt. Good luck!

 

[HRM Johnny]

ishootkittens - I Love your screen name. When you get the problem solved, please let us know what it was, and how you found out and solved the problem. Often times I see interesting threads like this but then we never find out what the problem was or how it was solved. Please let us know!
Johnny