2 hard bolt lift quick questions:

[bow shot]

so...

IF I have fired a "too hot" load and it causes difficult bolt lift..

AND the fired case from that round still fits my (Wilson) case length gauge..

THEN:

1) What the heck is causing the difficult bolt lift? (this one baffles me??)

2) Are these case no longer safe to load?

2') Why are they unsafe now??

Savage 111 bolt, Laupua Brass, Hornady sizer bumping 0.003" 0.004" back. My cool loads eject fine.

This is a bit of a tag from my "very hot 6.5-284" thread.. I just wanted to get these questions more visible so...

 

[bigedp51]

Bolt lift problems on a Savage are common, go to Savage Shooters and do a search on bolt lift
http://www.savageshooters.com/forumdisplay.php?17-Savage-110-based-Centerfire-Rifles

Read the 5th post down below by the Admin (his is the correct answer)
http://www.savageshooters.com/showthread.php?18136-Help!!-Bolt-Lift-mod-Firing-Spring-trim-Misfires-!!!-Youth-243-Model-11

I have two Savage rifles that work fine, I can't find what I was looking for but one test is inserting a feeler gauge at the rear of the bolt and checking to see if bolt lift improves. It is exactly what the Admin states in his posting and it is strictly a timing issue and various parts not fighting each other.

Sorry I can't get you to the exact posting for the fix.

 

[BoydAllen]

Your gauge does not "know" what the headspace of your chamber is. All that it tells you is whether or not the shoulder to head measurement of brass falls within a given range. Savages' headspace are very close to mimimum, and hot loads can result in brass springing back to a shoulder to head length and body diameter that exceeds that of the chamber in which it was fired. (This is not just the case with Savages.)IMO you would be better off switching to a comparitor such as what Hornady mislabels as a headspace gauge. The other part of the case that can cause bolt lift issues is right in front of the head. FL sizing, using a die that has been properly set, by using before and after sizing measurements should solve your problem. What did your primers and case head look like after firing? Was their an ejector mark? Why are you bumping so far? All that this does is work the brass more than it has to be, and require more trimming.

 

[jr600yd]

I had a simaler problem with a 6BRX I was building. What I found out was this. Was using an old 308 die to size the base of the fired case. Then I would neck size the case and finally bump the shoulder back. Didn't have the 308 die adjusted Dow in the press enough SO the base of the cartridge (web area) was not getting sized. This made for a bolt "click" Once the 308 die was adjusted correctly no m,ore problems.

 

[steve4102]

What does the case head look like? Gotta Picture?

Anything that looks like this?
http://www.google.com/imgres?imgurl=http://www.massreloading.com/images/extruded.jpg&imgrefurl=http://www.massreloading.com/reading_pressure_signs.html&h=600&w=800&sz=278&tbnid=G447pk3y_BuQwM:&tbnh=101&tbnw=135&zoom=1&usg=__aBcqYPpZVcQy2bFDvGPqTbZfPZs=&docid=rjKcd8kArElWDM&sa=X&ei=sAHXUaqyDYLJywGV8oGADQ&ved=0CC8Q9QEwAQ&dur=2744

 

[hepburn45110]

The pictures look my dasher when I try to push 105s and 107 bullets 3000 fps. 2800 fps was the fix.

 

[bow shot]

I'll get pics up as soon as the thunder stops here.. might take till tomorrow...

Well... the look is not as bad as the google shots, but some do have slight "wipes" on the head (where the caliber ID is). Also, rim deformation. Again.. I'l post pics ASAP.

So I hve the answer to this one: Cause: Ok, 'go that from Boyd'.. too hot, and exceeding chamber dimensions.. and my wilson Gauge is not a good indicator since my Savage's chamber may be on the tight side.?

Now, should I consider that brass UNSAFE? If so... why?

 

[bow shot]

BTW Bpyd'... yes I have a Hornady set on the way. I will use that correctly.

I originally judged shoulder bump and set the Hornady sizer by the fear method: 'Shimmed it up with Skip's shims until I had unrestriced bolt closing on freshly sized rounds. I found I had to bump 0.003" (measuring with the wilson gauge) to get rounds to chamber w/o resistance in closing the bolt.

 

[jlow]

Try dropping the fired case into your chamber, if it is really like the case gauge, it will drop in and slide out easily. If not, that is your answer.

 

[bow shot]

Yup, it is difficult to close the bolt on the fired case, though it drops in the case gauge well. I should have mentioned that before.. that's part of what befuddled me so..

Great points folks!!

 

[expiper]

once again this situation shows that you have to make the ctgs. fit the chamber and not various guages and gizmos!!!...Roger

 

[bow shot]

Here's the pics... so what say ye? safe? unsafe? questionable?:

 

[BoydAllen]

Not to belabor the point too much but measuring tools allow you to see what is taking place when you size a case. Evidently a lot of the do it by bolt feel guys have never seen a die that was a little too big for the chamber. In that situation, by the time the feel is right, the shoulder has been bumped more than is desirable. Without some sort of comparitor, one wouldn't know this. Yes, the case has to be made to fit the chamber, but a more precise job can be done with the proper measuring tools. Also, measuring near the head will tell you if that area is being reduced by the FL die. I have seen cases, especially with custom chambers, where it was not. That is one of the reasons that they make small base dies. When all is said and done, yes, you want the bolt close to feel right, but you also need to know what was done to the case to achieve that. I have friends with really nice custom 6BRs that ended up buying two FL dies because they didn't think that I knew what I was talking about, and bought standard S type FL dies, and then sent cases to Harrell's after they discovered that they had a problem. By the time that they got any sizing at the back of their cases, their case shoulders were bumped farther than they wanted.

 

[bow shot]

Understood Boyd'! Not Belaboring at all, I appreciate the intel.

Now, when you mention measuring near the head, you are speaking of the diameter of the case, maybe 1/2" above the rim, correct?

 

[BoydAllen]

If you look at a case that was fired in a generously sized factory chamber, with a load that was warm, you will typically be able to see where the expansion of the back of the case starts, usually about .3 up from the head. Sometimes in a tight chamber this is hard to see, but the location is the same. Below that point, the thickness and reinforcing offered by the solid head, prevent it from expanding to the diameter of the chamber. You can also learn something about how even the thickness of the brass if by noting how even this expansion is. If it appears to be uneven, the side where the the expansion is most noticeable is the thin side. You can use this to sort brass, since cases that show the most even expansion should shoot better, and be straighter after FL sizing, than those that do not.

 

[steve4102]

Here is an interesting article on case head expansion and pressure ring expansion.

http://www.shootingsoftware.com/ftp/dbramwell%20july%2019%2004.pdf

 

[bow shot]

Thanks Steve... very interesting read!!

 

[kelbro]

Here is an interesting article on case head expansion and pressure ring expansion.

http://www.shootingsoftware.com/ftp/dbramwell%20july%2019%2004.pdf

By a person with a vested interest in selling Pressure trace systems...

 

[bow shot]

Ah, I see...

 

[bow shot]

Finally got my comparitor, thanks for the suggestion Boyd', much easier and more repeatable than the method(s) I was using for measuring cases.