A friend of mine had a problem on the shooting range with his reloads - 2 out of 10 reloads did not go off and were lightly struck. I measure it on the shoulders and found the failed cases was sized 0.004" under the chamber measurement for his rifle (fired case). His rifle is a Sako 222Rem. Is it possible that he had his sizer die setup too deep and thereby pushing back the shoulders too far?

YES. Why doesn't he set his size die to zero setback. No misfires and his cases will last a lot longer.

There is something else wrong.
I would recommend checking the trigger carefully. Sakos have a funky trigger assy.
The sear is a plunger that slides vertically in the trigger housing. The fit of the sear is close and can get gummed up if he has been using a poor quality bore cleaner a long time.

Note******
.004 is less than the difference between a max chamber and a minimum cartridge for all cartridges that I have ever checked.
Checked means comparing the head to datum minimum dimension on a SAAMI or CIP cartridge drawing to the same maximum dimension on the chamber drawing. What I am saying is all firearms I know of will tolerate much more than .004 clearance and will still fire.

quote:

Originally posted by Reloader270:
A friend of mine had a problem on the shooting range with his reloads - 2 out of 10 reloads did not go off and were lightly struck. I measure it on the shoulders and found the failed cases was sized 0.004" under the chamber measurement for his rifle (fired case). His rifle is a Sako 222Rem. Is it possible that he had his sizer die setup too deep and thereby pushing back the shoulders too far?

I set all mine back .004 to .005

Sako's are famouse for light strikes

Yep. Often if you have a CRF the extractor will hold the case even with way to much headspace. Push feed not so much.

Reloading 101.
First lesson: Set your sizer to your chamber.

Your first day's homework is to set your sizer long and gradually screw it down until the bolt will just close with a bit of resistance.
Class dismissed.

Factory ammo can often be sloppy fitting but still fire off fine, Check his primer seating, not seating fully home in the pocket can cause misfires even when head-space is perfect.

Clean firing pin channel. The velocity of the firing pin may be slowed by old oil/dirt.

Get one of these and you should have no more problems. https://www.youtube.com/watch?v=P-UrMTyJ1_E

I wish I had got this 20 years ago!

I have never set my shoulder too far back. I always had the opposite problem of not setting the die down far enough for fear of affecting head space. As a result, I was pushing the shoulder forward and having tight chambering & in rare cases the round refused to chamber.

Since I got this tool I am sweet.

I also have the bushes for the cartridge measurement / bullet seating depth. That measures the ammo on the ogive of the bullet. In the past I used the "bullet in the chamber with case & cleaning rod marked" method. The lead tips of a box of bullets are not uniform & this gives variable reading for OAL / seating depth.

YES; if you set your shoulder back, you are just increasing headspace; you should make your brass so the bolt closes with a slight feel to it. Having said that, yes, there is more allowance between ammo and chambers than you think; it works but will stretch your brass too. As said, it is reloading 101. BUT, .004 is not enough to make it misfire, so you have another problem. I suspect it is more like .040.

If you are setting back the shoulder enough to cause a misfire then a misfire is the least of your worries. But your dies should be manufactured to not allow that kind of headspace. I agree with others that there is some other kind of issue. First thing I would do in this case is make sure the firing pin assembly is clean and lightly oiled.

Yes, brass, die and chamber combinations can indeed produce a situation of excessive headspace, which is not really dangerous, despite what you think. Modern brass is very ductile and even if it separates, nothing bad will happen. SAAMI specs allow for some very large swings in tolerances.

quote:

I measure it on the shoulders and found the failed cases was sized 0.004" under the chamber measurement for his rifle (fired case).

The die and shell holder combination should not be able to size the case shorter than minimum length/full length sized from the datum/shoulder to the head of the case.

Once the die hits the shell holder that is it, there is no way a reloader can crush the die and or shell holder. A reloader can increase the presses ability to overcome the cases ability to resist sizing.

F. Guffey

quote:

Originally posted by Wstrnhuntr:
If you are setting back the shoulder enough to cause a misfire then a misfire is the least of your worries. But your dies should be manufactured to not allow that kind of headspace. I agree with others that there is some other kind of issue. First thing I would do in this case is make sure the firing pin assembly is clean and lightly oiled.

In 60+ years of hunting big game, I have NEVER oiled either firing pin/striker or spring. As a resultI never ever had sluggish oil freeze up my firing mechanism even at -30° below zero .

And never had any rust in there either. If I get my gun wet either from condensation or a dip in the creek or rain, I am careful to clean the firing mechanism that evening when I first get back to camp, and leave it bone dry.

Due to manufacturing tolerances in dies and chambers, it can be easy to make brass shorter than minimum headspace. Do not assume anything. There is, indeed, a way a reloader can do it; it is built into the specs and tolerances.

quote:

Do not assume anything.

The instructions do not start with "Due to manufacturing tolerances in dies and chambers", instructions start with raise the ram and then screw the die down to the shell holder. Then eventually the reloader discovers an addition 1/4 turn beyond contact is necessary to increases the presses ability to overcome the cases ability to resist sizing.

Increase or decrease head space? It is not possible to increase or decrease head space with a die, press and shell holder. SAAMI does not list case head space, the case does not have head space, the case has a length from the datum to the head of the case. To some reloaders everything is a head space gage and everything has a head space. To change head space the length of the chamber from the shoulder/datum to the bolt face must be changed.

If my dies do not size a case to minimum length I want my money back, unless I purchased them used from a misguided reloader that ground the bottom of the die or top of the shell holder.

F. Guffey

Any barrel maker will tell you that many factory chambers are too long.
If you full length resize a case for such a chamber you simply recreate the headspace problem.
Try neck sizing only and see if this helps.

If you think that all your dies produce the same length brass from shoulder to base and that that dimension is minimum SAAMI length (true, it is not headspace), then you are not facing reality.

quote:

Try neck sizing only and see if this helps.

Or purchases a press, dies and shell holders then learn to use them. It is possible to determine the length of the chamber before a reloader starts reloading. All of my dies and presses have threads, threads make it possible for me to size cases to off set the length of the chamber, to do that I have to know the length of the chamber.

reloaders today set the shoulder back .002", I ask: "How do you do that?" Seems a reloader that can set the shoulder back .002" can avoid setting the shoulder back or set the shoulder back a pre-determined amount. I have one chamber with the shoulder forward of SAAMI specks by .016", no problem, I adjust the die off the shell holder .014". The .014" is field reject length, after sizing I chamber a case that is shorter than the chamber from the shoulder to the bolt face by .002".

I assume nothing.

F. Guffey

I am of the opinion that the answer is yes.

I was looking at M1 carbine firing pin protrusion specs, and the Carbine firing pin should protrude from 0.048” to 0.064”. Eley says that rimfire ammo needs a firing indentation of 0.015”, don’t know why centerfire should be less. Push the shoulder too far back, ream the primer pocket too deep, and have a minimum protrusion firing pin, I don’t see why tolerance stackup results in a misfire.

I have a this 35 Whelen.

The only 35 Whelen I own. I had misfires and hangfires with the thing. This occurred in cold weather and I think that was an aggravating factor. I tried AA2520 and that powder gave me hangfires and weird, long combustion, in cold weather. I don’t have a nice technical term, but some rounds, it felt as though I was igniting rockets in the barrel. The Whelen has a very shallow shoulder, and I think that “cushions” the firing pin blow. I used the most sensitive primers on the market, Federal, I made sure that I had zero cartridge headspace, set the sizing die so that there is no back and forth on the bolt when the bolt is closed with an empty case in the chamber. It was easy to take the firing pin mechanism out of this 03 action to set the shoulder set back, later commercial actions, there was no consideration for the shooter to remove the firing pin; some designs require special tools, and is usually difficult regardless of the action. I installed an extra power Wolff mainspring, cleaned everything up, and ignition was much more positive.

If you are shooting a more or less normal sized chamber you would be better off with bushing dies and a small base die instead of a full re-sizing die.That would make things simpler and be easier on the cases.

Thank you for all your advise. It all makes sence. I would go through the checklist.