I'm new to reloading, and I've got a dilemma.

I inherited a beautiful - but well loved - custom made .257 Roberts Ackley improved on a Mauser action, and with it came 30 reloaded rounds made in the mid 1970s (?) as well as about 150 spitzer type bullets pressed specifically for this rifle. The reloaded rounds are AI made from various brass - some Remington .257 Roberts "UMC", some stamped "L C 53", and others with different markings. Many of them are pretty corroded, but I shot some of the cleaner ones and they survived, though some cracked at the neck - brittle? I have no idea how many times they were previously reloaded.

I thought I'd make myself some new brass so I could get started and bought some Remington Core Lokt .257 Roberts to fire form. About half of them shot - nice and accurate, no signs of trouble at least to my untrained eye. But....the other half, the firing pin dents the primer and they don't fire. This has happened from more than one box, so I don't think it's the ammo. A local says excess headspace.

The dilemma then is how am I going to fire form brass to reload if I can't get them to go bang?! Maybe I'm overlooking something real simple?

I measured the cases (total length including bullet, case length, rim-to-bottle neck length, and weight) and the main difference between factory and the reloaded appears to be that the rim-to-neck length of the loads I inherited is 1.900" - 1.917", whereas the factory ammo is 1.860" - 1.893". The total length is also longer (makes sense) but the total case lengths overlap. My Sierra reloading book indicates those are pretty short for the factory loads, but I don't know what I'm talking about.

Any help would be appreciated.

by local do you mean a "gun guy" or did you have the headspace checked by a gunsmith.
could be the headspace, could be the firing pin spring, could be other things. get the headspace checked, maybe a chamber cast to confirm the cartridge, and go from there.
usually the extractor of a mauser is strong enough to hold a case against a bolt face to fire even if the headspace is off.
other alternatives are pull the bullets and seat them back long to jamb the rifling and hold the cartridge against the bolt face or get 7x57 new brass and neck it down to just chamber and create a false shoulder to fire form.
I don't really recommend the final two without knowing what is the true mechanical condition of the gun but it is an option for you. consider it is your face behind the bolt.

Forming cases for a wildcat requires you to seat the bullets way out to touch the rifling.

That way you are absolutely certain the case is pushed against the bolt face, and a perfect case is formed.

At least that is the way we do it.

quote:

Originally posted by max(hm2):
by local do you mean a "gun guy" or did you have the headspace checked by a gunsmith.
could be the headspace, could be the firing pin spring, could be other things. get the headspace checked, maybe a chamber cast to confirm the cartridge, and go from there.

Thanks. Yes, a gunsmith at a shop here. But he wasn't there when I picked it up, and that's all the notes on the bill said - excess headspace.

now your choice is to get it repaired right or reload around it.
as saeed and I said you can load the bullets long so it is a jamb fit into the rifling. that way the cartridge is pushed against the boltface and when you fire it with a moderate load it will expand the brass to fit the chamber.
option two is to neck down 7x57 mauser brass in small increments until the bolt just closes. this creates a small shoulder in the larger neck of the case which then controls cartridge movement when fired with a moderate load.
the negative side of all this is the use of components and also you will then be relegated to neck sizing or only partial resizing as you will not want to push the shoulder back as with total full length resizing.

Right; it is common on AI cartridges to have excessive headspace with standard ammo because the maker cut it longer than he should have. IE, longer than standard.
So you can easily make brass for it by using the jam the bullet into the rifling with a medium load, technique.
Then after that, don't push the shoulder back. Like said above; only talking about a few thousandths.
It is easy.

these words don't go together .. it's a WILDCAT and AI to boot .. it sure would close on an no-go gauge --

what Saeed said --

That depends on, IF it was a converted standard caliber, or a new chamber job.

1. Talk to the Gunsmith that said "excessive headspace" get him on the phone or in person and get all the particulars of his observation. After hearing his news/ information you have 2 choices unless he says something like lug set back or other hazards.

Choice number 1 is fix it, he will probably set the barrel back a thread and run a reamer in it so that you can fire factory .257 or your own AI reloads.

Choice number 2 seat your bullets out further until they just engage the rifling, fire. Reload that brass adjusting your loading die so that you only neck size.
Either way problem solved one is a somewhat better fix than the other..

Okay, thanks all for the advice. I've got a couple leads here on what to do next and will follow up at some point.

I had a 257AI built about 30 years ago on an FN action and I found it to be a great rifle/cartridge. The barrel was made/chambered to 257AI rather than reaming out a Roberts so there was no problem with the headspace issue. However, since 7x57 brass was much more common at the time, I'd use it and size the neck down as noted above.

as long as the action is sound I'm sure you will be delighted with the rifle which ever way you solve the headspace issue.

btw, you can take out the expander plug from your dies, and with some imperial sizing wax, resize some 270 or 3006 brass, which will result in a VERY long neck .. trim that till it just BARELY closes in your action, and firmform NO BULLET --- you'll have a slightly bumpy neck, and shouldn't have to worry about headspace -- then set your dies to neck size, minimal shoulder push back...


what i think could be a problem is over sizing the brass -- which means a collision between dies and chamber .. resulting in excessive clearance .. unless the rifle is damaged somehow "excessive headspace" is a misdiagnosis

It is not broken and forming brass is SOP for many if not most, AI rifles. Setting the barrel back means more $ spent and then the stock doesn't fit. Not necessary.
Make correct ammo, hunt, move on.

Another alternative: Expand the necks of your .257 brass with a .264 (or perhaps .277) expander ball. Then run it back into your sizing die with the die backed off of the shellholder and adjusted so that the brass chambers with slight resistance. Load and fire. The brass will now be perfectly fitted to your chamber and unless you insist on loading to rather high pressures it will require nothing other than neck sizing in the future.

TECHNICAL INFORMATION:
https://www.nosler.com/257-roberts-ackley-improved/

While there are several versions of .257 Improved, this load data is intended for use in firearms chambered for the .257 Roberts Ackley Improved (40° shoulder angle). The other prominent version is the .257 RCBS Improved, which features a 28° shoulder. If you are not certain about the chamber design in your rifle, we suggest consulting your gunsmith.

To fire-form brass for the .257 Ackley Improved, we suggest the following procedure:

Start with a standard .257 Roberts cases.

Select a light load of relatively fast powder (IMR4895 is great) from the standard .257 Roberts data.

Seat the bullet well out into the rifling, so that it makes good contact with the lands when the cartridge is chambered. This holds the case head against the bolt face and eliminates case stretching in the web area, a cause of case head separation.

After fire-forming, follow load data for the .257 Roberts Ackley Improved.


NOTE, Just because a rifles bolt closes on a NO-GO gauge doesn't mean the rifle has excessive headspace. The SAAMI cartridge and chamber drawings will list headspace as "MIN" and "MAX" and with most rifles there is .010 between min and max headspace.

A British .303 Enfield rifle at maximum military headspace and a cartridge with a rim thickness of .058 will have .016 head clearance. But when you resize the case with .002 shoulder bump you will have .002 head clearance. And "WHY" proper fire forming is important to prevent the case from stretching in the base.




Pacific Tool and Gauge offers three lengths of headspace gauges per rifle caliber. In order from the shortest to longest, they are: GO, NO-GO, and FIELD:

1. GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gauge, the chamber will accept ammunition that is made to SAAMI’s maximum specifications. The GO gauge is essential for checking a newly-reamed chamber in order to ensure a tight, accurate and safe chamber that will accept SAAMI maximum ammo. Although the GO gauge is necessary for a gunsmith or armorer, it usually has fewer applications for the collector or surplus firearms purchaser.

2. NO-GO: Corresponds to the maximum headspace Forster recommends for gunsmiths chambering new, bolt action rifles. This is NOT a SAAMI-maximum measurement. If a rifle closes on a NO-GO gauge, it may still be within SAAMI specifications or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gauge. The NO-GO gauge is a valuable tool for checking a newly-reamed chamber in order to ensure a tight and accurate chamber.

3. FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gauge, its chamber is dangerously close to, or longer than, SAAMI’s specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gauges are slightly shorter than the SAAMI maximum in order to give a small safety margin.

to build on that -- a 30-06 will totally close on a 308 headspace guage -- so if the dude doesn't have the correct gauge, its wrong

Do what Saeed said.
A down and dirty method is to use your press without a die. Put a store bought cartridge in the shell holder and run it up through the die opening. Grab the bullet with a pair of side cutters and retract the ram enough to slightly lengthen the COL. It should be a snug fit when you chamber it.
Forget all of your measuring thingies.

the mauser claw extractor should have held the round in place enough for the round to go off.


I have a feeling that when the chamber was cut the smith didn't pull the barrel and remove a couple of threads then re-chamber the way it's supposed to be done.

I use the donut on the neck method, since I'm more concerned with centering the case for the initial forming.

On second thought- another possible reason: weak firing pin spring. The problem may result from the strike being not quite strong enough to fire the primers if you got a batch of strong cupped primers. Just a thought.

quote:

Originally posted by Lamar:
the mauser claw extractor should have held the round in place enough for the round to go off.


I have a feeling that when the chamber was cut the smith didn't pull the barrel and remove a couple of threads then re-chamber the way it's supposed to be done.

A) You are supposing that the rifle was originally a .257 then converted.

B) If it did start out as a standard .257 Rbts, unless the barrel had sights, it is not necessary to set the barrel back more than .006-.008". With Sights, the barrel must be set back 1 full turn/thread.

Okay, so I spent some time over the last two weeks learning how to use my press and dis-assembling the unfired but primer dented factory Remington Core-Lokt I had. I also purchased some Hornady +P SST, and then thought twice about firing that in my old rifle of unknown pressure tolerance, so I took those apart too.

I built up a couple of dummy rounds with the bullets seated out past the cannelure, up to nearly 0.25". The Hornady SST bullets can be seated a little further out than the Core-Lokt before they start to require more effort to cam into the chamber [this makes sense to me given the shape of the two bullets]. A relatively easy close on the bolt seems to be about 0.19" ahead of the cannelure, which results in a total cartridge length just a little longer than the reloaded bullets that came with the rifle. Is that (i.e., easy enough to close, without forcing it) what I should look for, or do I want more tension when I close the bolt?

From what I've been able to read, I should then load up a batch with a light load of something like IMR 4895 for fire forming. Nosler manual lists a low .257 Roberts load for a 115 grain bullet as 31gr, Sierra 28.6gr for a 117 grain bullet. I've got CCI 200 large rifle primers and these bullets are both 117gr.

I would suggest you load them pretty warm, maybe a couple grains under "Max". You have more "capacity" than the standard Roberts when you take into consideration (a) bullets seated out further and (b)the bigger chamber of the Improved. The higher pressure will ensure you have well formed shoulders. You can also turn a flat base bullet around and seat it into the lands. You want at least a caliber in that neck for good tension.
A mauser or any make that has a claw extractor has to be turned back one complete round so the groove in the barrel lines up again. The barrel may not have enough "shank" to do that so...most don't bother with them, just ream it out through the action, thus (I don't get to use that word too much! ) the extra headspace. I have pulled the bullets on factory ammo , turned them around and seated into the lands before. So whatever that factory velocity was, that was the charge to use when you handload for it. Good luck, terrific cartridge too! Hats off to ya!

I had a .275 Roberts AI made from my factory Roberts. The gunsmith did not turn it back before reaming the new chamber. Suddenly, all the necks split on the second firing.

If you take virgin brass, neck it up to 6.5mm/.264", and then size back with your AI die just enough so that the cartridge is a slight crush fit. Then load all the prepped cases and fire away. AS DPCD said, only size back 0.002" to 0.003". You will have good brass life. If you anneal between each shot, you should get 20+ reloads. Have fun.

Just seat bullet out and cram/ease it in the chamber and shoot it. Its now fireformed. You can now neck size them and at some point you will need to full length resize them again..send 3 fired cases to the die maker and your gun has custom made dies that will neck size of full length size..