Did I bump back too much?

[Brown274]

Just starting out reloading.
Loaded my first last week from fired Hornady whitetail ammo. The fired cases were 1.621 on the Hornady headspace gauge and +.005 on the whidden case gauge. First time I FL resized them I bumped them to 1.619 and +.003

I just finished shooting them and resized them again but now it seems like I must not have locked the ring down enough and they are reading 1.615 and -.002

Did I bump these back too much? Is -.001 to -.003 on the whidden case gauge too much? Thanks

Gun is a factory Savage 7mm-08 bolt action.

 

[zipollini]

Using the Whidden case gauge I usually bump my Norma 6XC shoulder back .003-.004" when using my Redding Type "S" full length bushing die. It is shot in my Tubb 2000 bolt gun.

 

[BW64]

I would be very careful with that brass. I did the same thing & had brass separation on the next firing. The brass stretches too much when you bump back too far & it weakens. I go at least 4 or 5 firings before full length sizing again. I just neck size. Just my experience.

BW

 

[potatoe]

.001-.003 isn't horrible, .001-.002 is great as long as the die fits your chamber. Did you re seat the fired primer before measuring bump? Also just bump slowly letting a stripped bolt with a light crush fit tell me if I FL sized enough and measure the fired case (re seated fired primer) vs. the bump of the very slight crush fitting resized case. If I have to bump more than .003 (on relativley new brass - less than 4x fired and the loads aren't hot) to get a slight crush fit then I get a new die that fits the chamber. The stipped bolt tells you when your chamber likes the sized brass, the shoulder bump is a secondary measurement that tells you if the die fits your gun

 

[fguffey]

I would be very careful with that brass. I did the same thing & had brass separation on the next firing. The brass stretches too much when you bump back too far & it weakens. I go at least 4 or 5 firings before full length sizing again. I just neck size. Just my experience.

Many reloaders assume all of the problems are created when sizing. No one considers case head separation could start with the first firing. I have one rifle that would have .016" clearance if I fired minimum length/full length sized cases in it. It is assumed by reloaders if I fired a factory/minimum length case in the chamber with .016" clearance I would have case head separation because they all know a case will not stretch .016".

And then after the thread turns into 6 page of responses reloaders are still convinced my case stretches and they all blame the firing pin.

They blame the firing pin because the firing pin drives the case shoulder to the chamber shoulder etc..


F. Guffey

 

[BW64]

Many reloaders assume all of the problems are created when sizing. No one considers case head separation could start with the first firing. I have one rifle that would have .016" clearance if I fired minimum length/full length sized cases in it. It is assumed by reloaders if I fired a factory/minimum length case in the chamber with .016" clearance I would have case head separation because they all know a case will not stretch .016".

And then after the thread turns into 6 page of responses reloaders are still convinced my case stretches and they all blame the firing pin.

They blame the firing pin because the firing pin drives the case shoulder to the chamber shoulder etc..


F. Guffey

So no one post their experience?? Sorry but I don't get your response.

BW

 

[r bose]

Many reloaders assume all of the problems are created when sizing. No one considers case head separation could start with the first firing. I have one rifle that would have .016" clearance if I fired minimum length/full length sized cases in it. It is assumed by reloaders if I fired a factory/minimum length case in the chamber with .016" clearance I would have case head separation because they all know a case will not stretch .016".

And then after the thread turns into 6 page of responses reloaders are still convinced my case stretches and they all blame the firing pin.

They blame the firing pin because the firing pin drives the case shoulder to the chamber shoulder etc..


F. Guffey

I have the exact same situation with a 308 bolt rifle. From minimum length it stretches 17 thou when fired. This is a custom bolt action, hart barrel, that shoots very well but I have no idea why the previous owner wanted the chamber set this way. I bought the rifle used and yes it eats brass. Perhaps he planned on shooting some NATO spec 7.62x51 ?

 

[fguffey]

If the case increases .017” from the shoulder to the case head when fired I suggest you learn to form case. I form 308 W cases from 30/06 cases. With the additional length of the 30/06 case there is absolutely no way I can miss when offsetting the length of the chamber with the length of the case.

Same for 30/06 chambers; I use the 280 remington case when forming 30/06 cases for my long chamber. I adjust the sizing die off the shell holder .014” and then size the case. I check for fit and measure the length of the case from the shoulder to the case head when finished.


When using 30/06 cases for 308 W the neck must be turned and or reamed; if the chamber is military there is a good chance the 30/06 case will tighten the case neck by .006”+/- a few.

Number one: if the case increases in length .017" from the shoulder of the case to the case head you should not insist on returning the case to minimum length. I would suggest you start by adjusting the die off the shell holder .012" before sizing. There is an advantage to the long chamber, one there is slightly more room for powder and if you do not use the adding powder the extra room will lower the pressure.

F. Guffey

 

[fguffey]

Sorry but I don't get your response.

And that is OK; I place no demand or responsibility on your part to even try. A good start would began with explaining how you bump the shoulder back; I said I can not do that because the shoulder on my cases do not move. I said moving/bumping the shoulder upsets the case body. I said I use a die with case body support to prevent the case from increasing in diameter.

And I said bumping sounds like a small accident or something that happens that was not intended. When I size a case I am very deliberate.

F. Guffey

 

[BoydAllen]

Ignoring the confusion that may have accompanied some previous posts...to answer the question, I would be concerned, and keep an eye on the brass. You can make a tool from a straightened paper clip to check cases for a groove on the inside, just above the head. A short 90 degree bend on one end should allow you to feel this, and you should also look for a bright line on the outside. I always check the first fired case before and after sizing to see if the die setting is correct, and I usually back off and reset the die each time, because brass that has been work hardened requires a different setting than newer brass. One more suggestion, because brass does not get tight at the shoulder on its first firing, I find that setting up a FL or body die to replicate the head to shoulder dimension of a once fired case often works very well. What I prefer is to neck size and fire a single case several times until it becomes tight and then set my die to bump from that dimension. Light loads can actually cause rimless cases with shallow shoulder angles to shorten from head to shoulder, so if you are trying for a tight case, use safe but stout loads.

 

[wapiti25]

rbose, why not set the barrel back a few thousand's to make things the way you want them.

 

[dcali]

You're fine. .006 is not the end of the world. You want closer to .002, but this is not a big deal. Just adjust them right next time.

 

[Patch700]

Just starting out reloading.
First time I FL resized them I bumped them to 1.619 and +.003

I just finished shooting them and resized them again but now it seems like I must not have locked the ring down enough and they are reading 1.615 and -.002

Did I bump these back too much? .

Your lock ring may not have moved at all.... What you have just experienced is that brass has properties that change with use , having said that it means the die adjustment may need to be fine tuned on an individual basis case by case..

For a person who is reloading and not measuring clearance to .002" they may very well be happy with setting a die one time and if it chambers then they assume all is well... If you are sizing cases and trying to keep tolerances to within .001" then you will quickly see (as you have in this case) that a die adjustment may be needed for each and every case.

You don't have to over think this as you have already proven it if indeed your lock ring has not moved but the base to shoulder numbers have changed.

Good luck and remember , it's the internet...

 

[r bose]

rbose, why not set the barrel back a few thousand's to make things the way you want them.

I have a new barrel on hand. Waiting for this one to die. I don't have an accurate round count but it's not gonna last much longer. For now I work with just enough cases at one time for a match. I fire new cases first, then and only bump back the shoulder just enough so they chamber again.....about .002" using hornady bump gauges. Getting about 6-7 firings out of a case. I Use a flashlight to inspect inside of the brass for a visible crack. Much easier to see rather than feel with a paper clip. But, like someone said above, the first firing from new brass does the most damage. I'm using some LC match and Win brass I've had laying around for years.

 

[r bose]

If the case increases .017” from the shoulder to the case head when fired I suggest you learn to form case. I form 308 W cases from 30/06 cases. With the additional length of the 30/06 case there is absolutely no way I can miss when offsetting the length of the chamber with the length of the case.

Same for 30/06 chambers; I use the 280 remington case when forming 30/06 cases for my long chamber. I adjust the sizing die off the shell holder .014” and then size the case. I check for fit and measure the length of the case from the shoulder to the case head when finished.


When using 30/06 cases for 308 W the neck must be turned and or reamed; if the chamber is military there is a good chance the 30/06 case will tighten the case neck by .006”+/- a few.

Number one: if the case increases in length .017" from the shoulder of the case to the case head you should not insist on returning the case to minimum length. I would suggest you start by adjusting the die off the shell holder .012" before sizing. There is an advantage to the long chamber, one there is slightly more room for powder and if you do not use the adding powder the extra room will lower the pressure.

F. Guffey

Yes sir, I understand what you're proposing by forming brass. But, this barrel is wearing thin and will be replaced soon. For now, after the initial firing of new brass, I only bump the shoulder back .002 watching for a visible crack in the interior of the brass with a flashlight then it's recycled.

 

[Jeff A]

I was going to start a new thread but this is too close, so here goes. Just setting up a new die for my 6.5x47L. Using a Redding Competition Shell Holder set, I can set the shoulder back .001" on once fired cases. There is no drag on the bolt handle. So, any problems with a .001" set back? My next option would be .003".

 

[dcali]

I was going to start a new thread but this is too close, so here goes. Just setting up a new die for my 6.5x47L. Using a Redding Competition Shell Holder set, I can set the shoulder back .001" on once fired cases. There is no drag on the bolt handle. So, any problems with a .001" set back? My next option would be .003".

People largely get away with neck sizing (until they don't), so .001 is fine if it's consistent. I like .002 just to be sure. If you start to feel tight cases after firing, it's not enough. Mileage may vary.

 

[Nude nut]

Just starting out reloading.
Loaded my first last week from fired Hornady whitetail ammo. The fired cases were 1.621 on the Hornady headspace gauge and +.005 on the whidden case gauge. First time I FL resized them I bumped them to 1.619 and +.003

I just finished shooting them and resized them again but now it seems like I must not have locked the ring down enough and they are reading 1.615 and -.002

Did I bump these back too much? Is -.001 to -.003 on the whidden case gauge too much? Thanks

Gun is a factory Savage 7mm-08 bolt action.

With brass that has been bumped back to much load them with a mild load and jam the bullet well into the lands it will hold the case head hard against the bolt face and minimise caes stretch. I had some 308 brass that I bumped the shoulders back way to far Was told to do what I have just mentioned those cases have 15 firings on them now.

Cheers Trev.

 

[BoydAllen]

Guys....The first firing of new brass will generally not make it tight at the shoulder. That usually happens on the second or third firing, depending on how hot your loads are. The reason that I bring this up is I am reading all of these posts by fellows who are setting up FL or body dies to bump once fired brass by some amount. Unless you have an unusual die or chamber, the die will reduce the diameter of the whole body of the case, and if you still have room at the shoulder your bolt should close fine if you set the die to produce the SAME shoulder to head measurement as once fired brass. Just remember to remove or re-seat the primer before measuring your fired cases. To get some idea of what is taking place, before depriming a fired case put it in the jaws of a caliper (dial or digital) so that one of the jaws goes across the center of the primer, and hold the calipers up so that you are looking at the side of the jaw that crosses the primer with a light source directly behind it. What you are very likely to see is a very thin space on either side of the primer, indicating that it is protruding very slightly above the case head. This is an indication that you have some shoulder to head clearance on that fired case. The less that you work your shoulder to head dimension, the better it will be for the life of your brass. The one limit to how little you can bump your shoulders is the uniformity of your cases annealing. New brass is not perfect in this respect. We ran into the problem of inconsistent shoulder brass when carefully loading for a couple of my friend's custom hunting rifles, one a .338 Lapua, the other a 7mmWSM. I had set up the FL dies so that the case that I used was bumped .001 and some of the harder cases (all fired the same) were not bumped with the same setting due to differences in spring back. He bought an annealing machine that we carefully set up to do just enough to fix the shoulder problem, but not so much as to make the necks too soft for magazine use. It worked. Shoulder bump became +- .0005 and we still had good bullet seating force. IMO the amount that you work the shoulders of your cases is a major factor in case life.

As a final point, cases may not show cracks on the inside before they crack through or separate, that is why I suggested using the paper clip trick to FEEL for a thinning near the heads of cases. That is standard advice that has been around for years, and works, along with looking for a bright ring around the case, a little above the extractor groove. http://bulletin.accurateshooter.com/2013/01/case-head-separation-causes-and-how-to-spot-problems/

https://www.google.com/search?q=Inc...hUT12MKHUUJBXAQ_AUIBigB#imgrc=xPZ9CDYajMYCIM:

 

[22BRGUY]

+many on what Boyd says. He definitely has it right.