Striping a tikka bolt for brass sizing

[coast range]

So I have pulled the firing pin from my tikkas before and it’s pretty simple. But I am wanting to check brass sizing by checking the bolt drop. I have 100 adg bras 1x fired that I don’t want to over work.
So is it possible to easily strip these bolts down further to do this technique?

 

[Axlrod]

Yes. You just need to remove the ejector plunger, with a small punch. I leave mine out during all load development. I put it and the spring in a zip lock bag, mark it, and hang it on my loading bench.
While the bolt is stripped you can also check to see exactly where your bullets touch the lands, by progressively seating deeper, until the bolt falls shut.

 

[Castle Rock]

Easy enough but that ******* pin can launch a long way, don’t ask me how I know

 

[TaperPin]

I enjoy all the fancy videos, I really do, even the dude that pulled his barrel to measure shoulder pushback directly with a case in the chamber.

As a practical matter the same can be done with a fully assembled bolt. A bolt handle is a handy spot to pull on with a spring scale. Measure resistance to move bolt on a new or under size case, and that is essentially the resistance of dragging the ejector across a case head. Adjust down to that number when adjusting full length dies and you will be very close to the stripped bolt method.

Definitely strip the bolt at least once to remind yourself what a pain it is.

 

[General RE LEE]

Maybe I’m doing it wrong but I simply load up some new brass, fire it, measure a case and then run it through a FL die bumping it back two thousandths from the fired case measurement.

 

[Axlrod]

Maybe I’m doing it wrong but I simply load up some new brass, fire it, measure a case and then run it through a FL die bumping it back two thousandths from the fired case measurement.

If that works, then keep on doing it. But bumping back .002" without knowing how your case fits the chamber is arbitrary. Why not bump back .001" or .003"?
Your own chamber is the best measuring tool you have, why not use it?
I have found on many rifles, that the case doesn't need to be bumped back at all for 2-4 firings. And in one gun, new brass needed bumping back before ever being fired.

The stripped bolt measuring procedure is the most accurate and repeatable way to set up your sizing die. I don't "measure" the bump back, just adjust the die till the bolt drops shut. The brass fits in the chamber, and has been sized the absolute minimum amount.

 

[General RE LEE]

If that works, then keep on doing it. But bumping back .002" without knowing how your case fits the chamber is arbitrary. Why not bump back .001" or .003"?
Your own chamber is the best measuring tool you have, why not use it?
I have found on many rifles, that the case doesn't need to be bumped back at all for 2-4 firings. And in one gun, new brass needed bumping back before ever being fired.

The stripped bolt measuring procedure is the most accurate and repeatable way to set up your sizing die. I don't "measure" the bump back, just adjust the die till the bolt drops shut. The brass fits in the chamber, and has been sized the absolute minimum amount.

I thought a fired case conforms to chamber or at least close.

 

[Axlrod]

I thought a fired case conforms to chamber or at least close.

It takes a few firings, I'm sure the number is dependent on the chamber, brass composition, how hot the load is, how much spring back, etc. But every one I have done, the brass doesn't fully form on the first firing.

 

[General RE LEE]

It takes a few firings, I'm sure the number is dependent on the chamber, brass composition, how hot the load is, how much spring back, etc. But every one I have done, the brass doesn't fully form on the first firing.

Cool. I’ve been pleased with results how I’m doing it, but I’m sure it’s not the best way.

 

[Castle Rock]

If that works, then keep on doing it. But bumping back .002" without knowing how your case fits the chamber is arbitrary. Why not bump back .001" or .003"?
Your own chamber is the best measuring tool you have, why not use it?
I have found on many rifles, that the case doesn't need to be bumped back at all for 2-4 firings. And in one gun, new brass needed bumping back before ever being fired.

The stripped bolt measuring procedure is the most accurate and repeatable way to set up your sizing die. I don't "measure" the bump back, just adjust the die till the bolt drops shut. The brass fits in the chamber, and has been sized the absolute minimum amount.

Correct

 

[Shortschaf]

Maybe I’m doing it wrong but I simply load up some new brass, fire it, measure a case and then run it through a FL die bumping it back two thousandths from the fired case measurement.

I and most reloaders I know have run into issues trying to do this at one point or another. It works until it doesnt

I bump, chamber, screw down, bump, repeat until it chambers now

No calipers gets used

 

[General RE LEE]

I enjoy all the fancy videos, I really do, even the dude that pulled his barrel to measure shoulder pushback directly with a case in the chamber.

As a practical matter the same can be done with a fully assembled bolt. A bolt handle is a handy spot to pull on with a spring scale. Measure resistance to move bolt on a new or under size case, and that is essentially the resistance of dragging the ejector across a case head. Adjust down to that number when adjusting full length dies and you will be very close to the stripped bolt method.

Definitely strip the bolt at least once to remind yourself what a pain it is.

You need to make another fancy video to show us how you do this method lol

 

[pods8 (Rugged Stitching)]

Easy enough but that ******* pin can launch a long way, don’t ask me how I know

Then you get to explain why you're crawling around the floor with a flashlight and cheaters on.

 

[TaperPin]

You need to make another fancy video to show us how you do this method lol

I wish there were enough smarts up top to make fancy videos. Honestly, it’s rather boring and the title would be the entire content of the video, “Turn sizing die until brass chambers easily.” The end.

Dies have 14 threads per inch, which is .071” for every revolution. The lock ring on Redding dies has about 71 grooves, so it’s a rough gauge of how far to turn to get .001”.



I unscrew the sizing die 1/2 turn (.035”ish) from bottoming out, reload 5 cases until all of them make the bolt drag a little, then simply turn the die down half the distance (.017”ish) and chamber it to check if drag has gone away. If not, turn half that distance (.009”) and check. Say it takes one more step and that last .005” clears up all the drag and the first case now has a shoulder pushed back too much. Then I’d back the die out .002” and see if the drag comes back with case number two. If not that case has the shoulder pushed back too far, so the die would get backed up another .002” and case number three is used. Say at this point the drag has come back, so tighten it .001”. Check it with case #4 and #5, and there will be variation between cases so some may drag a little more than others, so just keep screwing it down .001” at a time until all the cases chamber easily. This is maybe 10 minutes if you aren’t over thinking it too much. Most folks can feel the bolt pressure enough to not need the spring scale.

I still think if the goal is to chamber easily, then the perfect gauge is an actual case in the chamber.

 

[seand]

Cool. I’ve been pleased with results how I’m doing it, but I’m sure it’s not the best way.

Easy to check - scotch tape is ~0.002 thick. Does the bolt close with 2 layers of tape on the case head - if it does you are at or exceeding 0.004 less than chamber

 

[EastHumboldt]

I keep reading about pulling the firing pin to do this so it eliminates whatever spring tension you’d get off the uncocked firing pin, and the cocking ramp. So you get a better feel for bolt closing pressure. But I must be missing an important detail here. When you pull the firing pin out of a T3 the bolt handle pretty much falls off, because the firing pin spring is what holds the bolt handle in place. So how do you work the bolt with no bolt handle?

Edit: I’m convinced I can feel and compare the closing pressure on a cartridge pretty well with no scale or pulling the bolt apart.

 

[wyosam]

I keep reading about pulling the firing pin to do this so it eliminates whatever spring tension you’d get off the uncocked firing pin, and the cocking ramp. So you get a better feel for bolt closing pressure. But I must be missing an important detail here. When you pull the firing pin out of a T3 the bolt handle pretty much falls off, because the firing pin spring is what holds the bolt handle in place. So how do you work the bolt with no bolt handle?

Edit: I’m convinced I can feel and compare the closing pressure on a cartridge pretty well with no scale or pulling the bolt apart.

I go by fully assembled feel as well. Close enough for the women I hang out with.


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[Castle Rock]

I keep reading about pulling the firing pin to do this so it eliminates whatever spring tension you’d get off the uncocked firing pin, and the cocking ramp. So you get a better feel for bolt closing pressure. But I must be missing an important detail here. When you pull the firing pin out of a T3 the bolt handle pretty much falls off, because the firing pin spring is what holds the bolt handle in place. So how do you work the bolt with no bolt handle?

Edit: I’m convinced I can feel and compare the closing pressure on a cartridge pretty well with no scale or pulling the bolt apart.

I’m sorry to say but you’re pretty misguided on this topic, there is no way that you can get a proper feel for the bolt closing if you haven’t taken out the ejector and the firing pin.

As for measuring bolt closing pressure while it still has all its fixtures in, that is totally nonsensical, I’m surprised no one has called that crap out yet.

 

[Axlrod]

I keep reading about pulling the firing pin to do this so it eliminates whatever spring tension you’d get off the uncocked firing pin, and the cocking ramp. So you get a better feel for bolt closing pressure. But I must be missing an important detail here. When you pull the firing pin out of a T3 the bolt handle pretty much falls off, because the firing pin spring is what holds the bolt handle in place. So how do you work the bolt with no bolt handle?

Edit: I’m convinced I can feel and compare the closing pressure on a cartridge pretty well with no scale or pulling the bolt apart.

You just slide the bolt handle back into the bolt body- there really is no issue at all.
I have done this side by side with and without the fire control, there is no way you can feel when your brass is sized properly with the firing pin/ejector installed.

The bolt nearly falls shut when stripped. It takes maybe 2-3 minutes to remove the firing pin and ejector, it is ridiculously easy. But if it is too complicated, lots of people have acceptable results just screwing the die down until the press cams over.

 

[Lawnboi]

I get fine results just with a comparator too. It’s not hard to figure out what’s tight in your chamber with a few pieces of brass and a couple firings. Measure your virgin, compare it to once fired, compare that to twice fired and you probably have a decent idea of where your headspace should be. But just as if I removed an ejector, I test a hand full before a mass loading.

I dont have much interest in taking my ejector out every barrel.