resizing question - hard bolt close and open

[bsumoba]

Do you resize enough for the bolt to close freely with no resistance due to the round or do you have a little resistance on the bolt close?

reason I ask is I went to a match with loaded rounds that were on the tight side for the bolt close. after firing, the bolt open was tougher than normal also. could initial tight fitting brass result in a harder bolt open after firing?

The loads for the 284 Shehane with 56.8gr H4831SC, are not crazy by any means and I have been shooting this load for a while. I did see velocities decrease a bit, but not sure if that means anything. I have 1300 rounds down the barrel and could be reaching the end of its life for f-class standards and velocities could be decreasing because of the high round count and crazy long strings of 17-26 rounds.

I checked my headspace with a go gauge and everything is good. checked with the same go gauge with about 0.004" of tape on the bottom of it and does not close, so it looks like the headspacing is okay.

I checked the headspace on some virgin 6.5x284 necked up to 7mm. If I put this brass into the chamber, there is no bolt close resistance. it sounds like I need to resize my brass a little more. I can incrementally screw the die down until the bolt will just close freely. would this be the best way to do it? I do not have a repeatable way to measure headspace as I do not have the right size collar that will go on the shoulder of the brass.

 

[Road_Clam]

Sounds like you need to bump the shoulder back a few more thousandths. When I use my fire formed .300 win mag or my .308 I set the shoulder back about .003" to ensure a nice fit and an easy bolt extraction. I have a Larry Willis headspace gauge so it's easy for me to set my shoulders on my rounds. Even using the gauge I get a "tight" round once in a while.

 

[Preacher]

If they go in tight-- they will also come out tight....
You need to bump the shoulder back a bit.
I like a empty bolt to close most of the way down on a sized chambered round....

 

[jr600yd]

+1 for Larry Willis and Innovative Technology. You can check it out at www.larrywillis.com if you shoot more than 1 caliber this is the cats meow. 1 tool for almost all calipers except magnums.

 

[butchlambert]

I wouldn't bump anything until you are sure that is the problem. Do you have a gizzy to check your headspace on your fired brass. Are you sure the problem is not brass that is oversize at the base?

 

[bsumoba]

I improvised just now and used a 10mm pistol brass as a collar that goes down the shoulder about 80% from the shoulder/body junction. I checked the headspace of virgin 6.5x284 that was necked up to 7mm brass and set that to zero (I checked multiple pieces and they were nearly the same). Then, I checked a few fired pieces of brass (these pieces of brass, upon inserting into the chamber is still a little stiff to close the bolt) and it was about 0.060" bigger. Web area difference was only 0.0005-0.001", but was still undersized from my reamer spec at the web.

I then proceeded to take a fired piece of brass and I started to do very small incrementally adjustments down on the die until I was just getting an easy bolt close that was similar to the virgin necked up brass. I then measured this piece of resized brass and it came out to within 0.0005" of the virgin brass with the 10mm pistol collar. Yea, I know it is crude, but it was close enough for me to see that I needed to bump the shoulders back more.

Anything look odd in my method?

 

[Scott Harris]

Do you resize enough for the bolt to close freely with no resistance due to the round or do you have a little resistance on the bolt close?

reason I ask is I went to a match with loaded rounds that were on the tight side for the bolt close. after firing, the bolt open was tougher than normal also. could initial tight fitting brass result in a harder bolt open after firing?
...

If you chamber tight-to-fit cartridges and fire full-pressure loads, then don't be surprised if they are even more difficult coming out than going in. Full-length size your cases such that they go in easily and they will also come out easily. Now, that you have let your cases grow and become a problem, you may need to run them through a F/L small base die to get them back to normal.

Regards,
Scott

 

[BoydAllen]

Short answer, you are doing it wrong. A new case has no place in determining bump. You should measure a fired case that (that has had its primer removed or re-seated below flush) using a gauge, or you pistol case in a pinch, and then set your die to bump cases' shoulders back .001 to .002. It is very common to read about setting FL dies by feel. This should not be done with that as the only reference, because it presumes that the die is small enough for the chamber that it is paired with. If the proper amount of measured bump does not give you the bolt feel that you want, adjustment will not solve your problem. You need a different die. Normally I fire a single case several times without bumping its shoulder, with stout loads, to use as a reference for determining the proper die setting. If you only have once fired brass to work with, it will not be at its maximum shoulder to head dimension. Setting the die so that the shoulder to head dimension is the same as a once fired case will still leave you clearance.

One thing about things getting tighter... if you know someone with a good bore scope, check the throat of your chamber for what we refer to as hard carbon, stuff that will not show up on a patch, and which requires the careful use of something like IOSSO to remove.

 

[Buzzardab]

I had this same problem and it turned out to be that the case was not sized all the way down to the base

 

[bsumoba]

Does it make sense, assuming my brass are a little "big" considering that it take some effort to close and the open the bolt after firing, to resize such that the brass closes easily, then fire and measure the headspace again and that will give me a better idea of what to set my die to?

 

[BoydAllen]

Just measure a tight case, that has had its primer removed or re-seated below flush, and set your die to produce a shoulder to head dimension that is .001 to a maximum of .002 less. To do a good job of this you need a proper measuring tool. If you bump the shoulder as I have suggested, and your bolt feel is not what you want, you need another die for that chamber. No amount of adjustment will solve your problem. IMO the only time that you should use feel is after you have the bump right, to see if your die is suitable for your chamber...not to set bump in the first place. I don't know how to explain it more clearly than that.

 

[hogan]

You are shooting a .284 Shehane and asking rudimentary, basic handloading questions?

I am just continually amazed here by lack of interest, or maybe disregard for learning sound handloading principles before heading out with a Precision Wildcat rifle... Seems like the mentality is all about "the build" but not learning how to craft ammunition which will make it perform.

Need a mallet to lift bolt and maybe a few poundings to get that extraction? Might be a sign for concern. At least to the clueless.
Yeah, tight bolt closure to seat your case WILL result in heavy lifting and difficult extraction. If don't need to beat on the bolt, you might try sizing or trimming .0005" from current brass dimension.

Truly, you will be well served to acquire a Wilson Case Gauge and measure before/after firing brass dimensions. Be sure about your neck length for sure, because neck jammed into lands will jump pressures greatly!

If your neck length is fine, why not adjust your sizer about .00025" and get an easier bolt close?

Hoping you are savvy enough to have a pristinely clean chamber and to have checked boltface for brass residue or debris that could push case out .001 or more... Not seeing any signs of High Pressure on primers or case head are you?

 

[savagedasher]

Take a brass that you have sized. With a marker color the whole case including the bolt head close it in the gun and you should see where the inference is. Without knowing where the tight spot is we all a guessing.
Larry

 

[MagnumManiac]

All info given is correct, but I will add this as no one else has addressed this issue.
A FL die not only bumps shoulders, it also squeezes the case body well before the shoulder gets touched, this elongates the case head to shoulder measurement.
Also, if you size a case and there is a gap between the shell holder and the die bottom, then there is room for more sizing and FL sizing is NOT taking place back to SAAMI minimum. Not all rifle chambers require this, BTW.
To get known amounts of sizing, you can measure the gap and reduce it by using feeler guages to measure how much you're adjusting the shoulder. I also use indexing marks on the lock rings, each graduation represents 1/12 turns. 1 turn of a 7/8"-14 thread is .0714", 1/12 of this is .006", so this gives very fine die adjustment.
I recommend using the closest collar in the Hornady Headspace Guage, it may not match the exact datum, but it WILL be a set standard to work off for all future sizing.
To set your cases with free bolt fall requires removing the firing pin assembly, using 1/12 increments helps greatly doing this method.
Hope this helps.

Cheers.

 

[BoydAllen]

Just remember that if your chamber is too small for your FL die setting the die by feel may ly result in your shoulder being bumped back too far, and if you leave it at that setting, will lead to an incipient separation, and if you ignore that, separations, just above the head. If you simply use your Hornady gauge and make small adjustments, checking after each, you can probably get to your desired bump without overshooting the mark. If you are using a bushing die, which is highly likely, since I do not know of anyone that makes a one piece FL die for your caliber. you can remove the bushing from the die while you are setting it, so as not to over work the neck of the case. Once you have the right setting, you can replace the bushing, and size the case one more time to size the neck. If you cannot find a die setting that bumps the shoulder of a tight case, you may be in one of those rare situations where tolerance stack combined with work hardening makes is necessary to modify your shell holder so that you can push your cases a few thousands into your die.

 

[johnfred1965]

You say this load has worked for you before and now you are having problems. What if anything did you change when you reloaded the rounds this time? I read on another thread here, someone bought a new press and did not adjust his dies to the new press, and all his loads were too long.

Don't be discouraged by those that say you are doing it wrong or you nedd to do this or that. I've used the inverted 9mm case method to diagnose a min spec chamber and shoulder bumping. I will agree with those who say don't use virgin brass as a baseline, I have heard that brass is often manufactured to minimum or lower specs, not the best for accuracy for the load up and shoot fans. once the case is fireformed, either once or twice, you get a much better idea of your rifle's chamber and how you need to bump the shoulder. If you have only neck sized this brass for many firings, it will continue to grow until it is a tight fit, but from your responses, I don't think that is your problem. Don't know about carbon rings, I'm not that advanced this sport to tell without looking.

I think others have mentioned neck lengnth and the possibility you are crimping the case mouth when you load a round. hope this helps, even though I know I am forgetting many solutions from my absentmindedness. good luck

 

[BoydAllen]

One other thing that comes to mind. Some shooters seem to thing that a FL die setting is something that once arrived at, does not need to be changed. This is not the case. Brass becomes work hardened as it is fired and FL sized repeatedly. This increases spring back. A setting that bumped shoulders of relatively new cases at some point will fail to bump shoulders at all. Similarly, a die that minimally sizes the body diameters of a case, on cases that do not have many firings, may not create enough clearance after cases are fired a number of times. We run into these issues in short range benchrest, particularly because we buy our dies to fit our chambers so closely. Some shooters, whose initial dies fit their chambers very closely, have to have a second slightly smaller die to use when brass becomes more work hardened, and even if that is not the issue, it is very common to have to make slight die adjustments as brass hardens. Being able to to this with precision and not overshoot the mark takes experience, and that is one of the reasons that PMA tool came out with their Micro Die Adjuster. If you look on You tube you can find a couple of videos about that product. I am not saying that you have to have one, but you may find it an interesting piece of equipment. Those of us who have competed in benchrest have had to learn how to do minor die adjustments, this just makes it much more precise and quick. Everyone needs some sort of gauge to be able to precisely set their FL dies. I like the one that Hornady calls their headspace gauge. It is not a real headspace gauge, but rather a comparitor used for setting dies. Once you have a tool use for this job, if you use it to check a fired case (with primer removed or re-seated) and compare it to a new one, you will see that new cases are well below minimum chamber headspace, usually .005 to .006. If you do this check on a belted case you will see a difference in the neighborhood of .020" which is why it is important to set your dies for those cases the same way that you do for rimless cases. so that they will not prematurely fail from having their shoulders pushed back way too far when they are sized.

 

[260Ravage]

As to setting or readjusting my fl die: for many years I struggled to get the minute settings on my die to get proper headspace. Due to the couse threads on the die it was almost impossible for me to the desired affect. Then I stumbled across "die shims" with the shims I could simply adjust my die as little as .001. I use them religiously. Mine are termed "skips die shims" . They are quite inexpensive. Think I bought from Midway. I am usually way behind on stuff...you may already own a set. FWIW.

 

[savagedasher]

Head space is hard to get the same unless the brass has the same hardness. I sized 80 last night 50 were annealed and 30had ben shot one time . Had to change the die setting for the 30 Larry

 

[noload]

Boyd has explained about all you need to know about the dies and the results you can expect to get with them. I have a lot of experience with Shehane brass and the problems that may occur. If you get the shoulder bumped correctly and your brass chambers smoothly, and then has a hard lift after firing, then its probably because the base of the brass is a little big for your tight chamber. Then like Boyd said you'll need a slightly small die to bump the base diameter. Measure the base diameter of a fired case,(just above the web) after sizing it I think it should be at least .001" smaller.

I will add that this may be your problem as long as you have checked you chamber neck area for carbon build up, neck clearance and neck length. If no problems there ....then A hard bolt close can can only be caused by the shoulder bump or the base diameter too big.