Bolt Rotation Question

[Webphut]

I have a Sako 6mm PPC tight neck rifle that I inherited and have been becoming more and more precise with. I am at the point where I am looking at different things about the rifle itself that could be improved. Something that I have no hands on experience with is the force required to open and close the bolt on an actual BR rifle. My rifle is a factory Sako that has been modified for the most capable accuracy it can accomplish, given I full-fill my end of the work. I have read a few forum posts, which directly talk about opening and closing a rifle bolt and not disrupting the bags or the rifle position in the bags. Is it possible, within financial reason, to make my Sako bolt rotation during chambering a round and ejecting an empty case as effortless as it is with a BR rifle? I do not think so without reinventing the reciever, but before I go looking like a idiot at my gunsmiths shop, I would like to explore this a bit more.

 

[tmwinds]

Does your Sako bolt open and close effortless if you cycle it without a cartridge? If it does it could be your brass or the load you are shooting and your sizing and reloading procedure. I do not own a Sako so I don't know what they feel like but I can take the best custom action I own and have to beat the bolt open with a mallet if I screw up when reloading.

 

[Dusty Stevens]

^^^ this. Simple test. Let us know

 

[Webphut]

When loading and unloading rounds/cases it cycles with some needed force. When cycling the bolt with no case, it requires less force, but even without a case, the amount of force needed disrupts the rifle position in the rest. Though there is not much disruption compared to when cycled with loaded ammunition, there is still disruption. From the reading I have done and the persuit for repeatability in bolt cycling with the least amount of rifle disruption, You have given me a new idea the way you replied to my question makes me curious if I can improve my brass during reloading. It’s to late to check now, but I am going to investigate this detail further tomorrow. It is a factory rifle, so I can not expect it to ever act like a BR rifle, but I may be able to lighten the amount of force to chamber and eject my cases with some fine tuning of my brass prep practices. Definitely something to look into. Thank you.

 

[JohnKielly]

As I understand it, there are several mechanical adjustments that have been done (not necessarily all at the same time on one action) to minimize unloading (and recocking) force:

• Reduce firing spring force to the minimum that will reliably ignite the primer consistently.
• Provide more than one cocking cam to balance cocking forces & avoid the firing mechanism binding sideways
• Supply the cocking sear with a roller or rollers.
• Carefully polish & suitably lubricate cocking surfaces

All but the last are beyond your control with the equipment that you have & fiddling with the mating surfaces can be a route to disaster.

Mo better you live with what you have.

 

[Webphut]

I use the LE Wilson FL resizing die when reloading. Does this particular die bump the shoulder back too? I am just wondering if I need to bump shoulder back a few thousandths, now that you all got me thinking.

 

[Webphut]

As I understand it, there are several mechanical adjustments that have been done (not necessarily all at the same time on one action) to minimize unloading (and recocking) force:

• Reduce firing spring force to the minimum that will reliably ignite the primer consistently.
• Provide more than one cocking cam to balance cocking forces & avoid the firing mechanism binding sideways
• Supply the cocking sear with a roller or rollers.
• Carefully polish & suitably lubricate cocking surfaces

All but the last are beyond your control with the equipment that you have & fiddling with the mating surfaces can be a route to disaster.

Mo better you live with what you have.

I think you are right. I am going to be buying a BR 6ppc in next few months but am trying to maximize all details before I do so. I just want to be sure I am growing out of my current rifle before jumping into a BR rifle only to find out I should have stayed with old rifle and honed my habits a bit.

 

[tmwinds]

Webphut, you mentioned a PPC tight neck rifle. What is the neck diameter of the chamber and are you turning the necks of your brass? The neck diameter of a loaded round should be smaller than your chamber neck. I try for about .002 clearance.

 

[Webphut]

I been turning to .258” OD, but it is a little tight so I may turn down to .257”.

My rifle is.262” neck diameter. Now I am still very sloppy in my neck dimensions, meaning my neck dimensions after done turning are plus/minus .0004”. They have gotten better since I started turning necks, but I still have some improvements to make in my habits during case prep.

I mention this because I know the pros, Boyer...Ratigan....Bruno, are like dead on what they advertise/discuss in terms of neck diameters. So this is a practice makes perfect as far as I go when it comes to turning necks. I know a couple machinists that are those types of guys who can shave .0002” off here and there and make it look so easy, but unfortunately these talents take me longer to attain.

I think I see where you might be going with this though too. Might need to shave a few tenths off neck diameter to reduce required force to cycle bolt.

 

[Webphut]

It is becoming apparent to me that the 10% in a rifles presision, the case prep, appears to control 90% of the results.

 

[Dusty Stevens]

You need to bump your shoulders back for sure. Your wilson die may not be getting the base as good as it should as well. Every ppc shooter needs a small base die in his box. I recommend a ppc ring die from pbike257 on the forum here. Give that a try- 99% of ppc case problems are the wrong die to size with

 

[xswanted]

Is the bolt know interchangeable like a Tikka?

I don’t remember how Sako has there bolts set up.

If it is, you can order a larger handle, longer with a larger knob for more leverage.

 

[Webphut]

I will check out bumping the shoulder back. I think this might help out in my topic, as I have never specifically bumped any of my case shoulders intentionally. Neither have I ever annealed cases, which is another forum thread I will jump into when That time comes.

I know KE Wilson does one ought dies for customers, so I may call them up first just because I am familiar with the family. If they are unable to help me, I will send your referral a pm.

As for the interchangeability of bolt knobs, no. I can weld a new one on, but I would still disrupt the rifle in the rifle test/bags.

I think my next focus is case prep. I need to really refine my prep habits so I can narrow down the tolerances in my completed reloads, then I will focus on any options to reduce required bolt cycle force.

 

[Webphut]

As I understand it, there are several mechanical adjustments that have been done (not necessarily all at the same time on one action) to minimize unloading (and recocking) force:

• Reduce firing spring force to the minimum that will reliably ignite the primer consistently.
• Provide more than one cocking cam to balance cocking forces & avoid the firing mechanism binding sideways
• Supply the cocking sear with a roller or rollers.
• Carefully polish & suitably lubricate cocking surfaces

All but the last are beyond your control with the equipment that you have & fiddling with the mating surfaces can be a route to disaster.

Mo better you live with what you have.

I think you make some really good points for me to discuss with my gunsmith. I am not familiar with cocking cam, but that more likely due to the fact that I am not familiar with the matrix of the bolt and it’s inter relationships made up of its individual parts. These four items just might put my rifle to that point where the only thing I could do more is to move onto an actual BR rifle and that is where I am trying to be. Thank you. These forums are great!

 

[Dusty Stevens]

Theres not much your gunsmith will be able to do that will not detriment the accuracy in the end. Try putting your thumb on top of the bolt shroud and kinda keep the rifle pushed down as you roll the bolt open with your first finger. Kinda gives you leverage instead of pulling up youre rolling it open

 

[gmorris]

You might try a Redding body sizing die to bump shoulder and not mess necks up. This seems to help with my gun.

 

[JFrank]

I use the LE Wilson FL resizing die when reloading. Does this particular die bump the shoulder back too? I am just wondering if I need to bump shoulder back a few thousandths, now that you all got me thinking.

I'm pretty sure you have things figured out, however Wilson F/L Die will be able to set headspace easily. By way of threads and a feeler gauge under the shell holder. Do you have a case gauge?

 

[JFrank]

Theres not much your gunsmith will be able to do that will not detriment the accuracy in the end. Try putting your thumb on top of the bolt shroud and kinda keep the rifle pushed down as you roll the bolt open with your first finger. Kinda gives you leverage instead of pulling up youre rolling it open

Dusty "
Could a person lap the lugs without removing the barrel?

 

[Dusty Stevens]

Dusty "
Could a person lap the lugs without removing the barrel?

You need to remove the barrel to reset the headspace anyway

 

[Webphut]

Sorry for not posting for a while.

Had a rifle smith look at the rifle. They mentioned that if I want what I am looking for, effortlessly opening/closing bolt, it is time to move onto a used BR rifle. So i have decided to just shoot it and enjoy it for what it is. On another note, I am currently off onto other priorities, so my reloading/shooting needs to wait until I find time for it. Thank you all for the input, appreciated.