Cases snug after FL resizing

[roklock]

OK, been reloading for years but all volume and no "precision". So trying to work up some loads for a 300 wsm, I'm using a redding FL die and set it up to bump the shoulders back .003. I am using once fired norma cases. I did 10 shells and I had three where when closing the bolt (downward) it took a much more noticeable effort to do it. Where do I start looking for the cause? The die is stock, only thing I did was take apart and clean it. Is there something I should be checking with my brass?

Thanks,

Steve

 

[witchhunter]

Use a sharpie and mark the tight case, chamber and look for rub marks. Chances are it is too long, needs trim? or not enough shoulder bump? or case expanded at the base, near the rim. Post results and we can help decipher.....

 

[AZ.noob]

Sounds to me like the three 'problem' cases didn't hold -.003 for whatever reason. With such a specific number (three thou) I assume you're using comparator? I'd re-zero the measuring instrument on a known fired case, and re-measure all of your sized brass. Sounds like your sizing die may need a tad of adjustment

Something I've found useful: if using a comparator, and zeroing it against a fired case, use a universal decapper (NOT a sizing die) to punch out the spent primer out of your fired case before using that case as a measuring stick. A spent primer can have a bit of bow, or crater, enough to effect the measurement a few thousandths. Since we are in fact splitting hairs a few thou can make the difference between GO and NO GO

 

[dimar1492]

Sounds like you are getting an inconsistent bump on your shoulders. Measure the three that were too tight. If the measurement is the same as the other shoulders then there may be another issue. But I would start with that.

 

[dimar1492]

Didn't mean to repost the obvious, looks like we were all typing at the same time.

 

[AZ.noob]

I know, right? LOL

 

[roklock]

Sounds to me like the three 'problem' cases didn't hold -.003 for whatever reason. With such a specific number (three thou) I assume you're using comparator?

Yes, that is correct, and the reason .003 was chosen was it was where I first could "close my bolt" with very little resistance.

Something I've found useful: if using a comparator, and zeroing it against a fired case, use a universal decapper (NOT a sizing die) to punch out the spent primer out of your fired case before using that case as a measuring stick. A spent primer can have a bit of bow, or crater, enough to effect the measurement a few thousandths. Since we are in fact splitting hairs a few thou can make the difference between GO and NO GO

I will do this tomorrow and recheck measurements...

Use a sharpie and mark the tight case, chamber and look for rub marks. Chances are it is too long, needs trim? or not enough shoulder bump? or case expanded at the base, near the rim. Post results and we can help decipher.....

I will double check case lengths as well tomorow.

Thanks to all that replied.

Steve

 

[Big Z]

So long as the length is safe, tight is right.

 

[ZiaHunter]

Make sure you are lubing the cases properly especially near the base of the case. If you not sufficiently lubed the case will drag in the die which will can slightly stretch the case on the downstroke. After cleaning my dies I generally swab a small amount of lubricant inside the die prior to running cases through it. Newly cleaned dies have a tendency to be sticky until a number of lubed cases are run through it.

 

[former naval person]

Also, the expander ball can stretch the neck a bit at the neck-shoulder junction. If the neck is tight and dirty, that may be enough to cause an interference fit at the junction.

 

[roklock]

Make sure you are lubing the cases properly especially near the base of the case. If you not sufficiently lubed the case will drag in the die which will can slightly stretch the case on the downstroke. After cleaning my dies I generally swab a small amount of lubricant inside the die prior to running cases through it. Newly cleaned dies have a tendency to be sticky until a number of lubed cases are run through it.

How do you know? I put my shells in a case tray and sprayed with one shot. Can is angled slightly to make sure some gets in the neck

Also, the expander ball can stretch the neck a bit at the neck-shoulder junction. If the neck is tight and dirty, that may be enough to cause an interference fit at the junction.

hmmm, do undersize this slightly by sanding and polishing? Not sure what cases were what when I did my ten but some definitely pulled out of the die harder. This could also be atributed to Ziahunter's comment to, correct?

 

[roklock]

Use a sharpie and mark the tight case, chamber and look for rub marks. Chances are it is too long, needs trim? or not enough shoulder bump? or case expanded at the base, near the rim. Post results and we can help decipher.....

OK, I measured my case lengths and all were 2.091-2.092, nothing raises a flag there. I also measured the bases and they were al the same. When I did chamber the "markered" round the only placed there are rub marks are on one side. On the shoulder right before it joins the case body. So that means should bump, right? Or possibly one of the issues on above post?

 

[roklock]

Something I've found useful: if using a comparator, and zeroing it against a fired case, use a universal decapper (NOT a sizing die) to punch out the spent primer out of your fired case before using that case as a measuring stick. A spent primer can have a bit of bow, or crater, enough to effect the measurement a few thousandths. Since we are in fact splitting hairs a few thou can make the difference between GO and NO GO

Thanks and good point, I did this today and remeasured. All fell in the .003-.0035, of course my caliper has a +/- .001 degree of accuracy.

 

[Killshot44]

When I did chamber the "markered" round the only placed there are rub marks are on one side. On the shoulder right before it joins the case body. So that means should bump, right? QUOTE]

If the rub mark is on the shoulder then I'd suspect this to be the problem, not enough set-back.

At times our measuring mothods fail us but the chamber has the final say.

 

[roklock]

When I did chamber the "markered" round the only placed there are rub marks are on one side. On the shoulder right before it joins the case body. So that means should bump, right? QUOTE]

If the rub mark is on the shoulder then I'd suspect this to be the problem, not enough set-back.

Yeah, I am assuming that as well, but why if the other 7 cases have enough set back? I am going to tear the die apart and clean it again. Then apply a small amount of lube to the die and try again. Will have to wait till next weekend as I am getting ready to leave for the week.

 

[KYpatriot]

I hate to be too obvious here but these once fired cases were fired in the same rifle you are testing them with right??

Assuming so, then the different "feel" you are getting in the die is a clue to me. Try some imperial size wax. I believe it is far more consistent than one shot. The .003 set back should be plenty, I only use .001 to .002 for bolt rifles and don't see this problem.

Also, dies can and do loosen due to the vibration and forces on the press. Make sure your adjustments aren't walking on you.

 

[witchhunter]

Size the tight ones again, you might not have reached full extension. Size slowly, not in a hurry. Sounds like you found it though.

 

[KYpatriot]

Size the tight ones again, you might not have reached full extension. Size slowly, not in a hurry. Sounds like you found it though.

Good point I pause for a sec when it bottoms out to prevent that...after all we are talking thousandths of an inch here.

 

[roklock]

I hate to be too obvious here but these once fired cases were fired in the same rifle you are testing them with right??

QUOTE]

Yes, that is correct.