Headspacing question

[DeanWinchester]

I picked up a nice little Swede in 6.5 today. It was missing the bolt body (I have the firing pin and cocking peice assembly. It's also missing the ejector/bolt stop, so if any of you guys got extras, let me know PLEASE.

Anyway, the chances of finding a bolt that headspaces perfectly are slim. I'm not interested in barrel removal or putting a reamer to it. If I were to find a bolt that closes on a full length sized case without too much slop, couldn't I fire some light cast loads to fireform to the chamber and use my collet neck sizer only from now on?
I've always wondered why excessive headspace is dangerous but we load fireforming loads all the time.

Am I asking for trouble here? Obviously if the shoulder has to scoot forward a bunch, that could be bad but it oughta be relatively close. I neck size only on all my bolt guns and have dedicated lots of brass for that rifle ONLY.

Thanks!

[JHeath]

I'm no gunsmith but think the problem is that excessive headspace leaves too much unsupported case length between the bolt face and breech face. The brass won't handle the pressure. It needs a bolt long enough to push it inside the chamber walls.

[Green Lizzard]

i take out firing pin and extractor use a fac round and plasti-gauge

[DeanWinchester]

i take out firing pin and extractor use a fac round and plasti-gauge

Yep, that's the plan if I can ever find a bolt. The chances of it being too tight are slim. If its a few thousandths too much it should be fine once the shoulder moves forward, as long as there's not so much that the case is exposed like Jheath was saying.......I think...lol

[fouronesix]

Yes, long or short, if you handle the brass correctly it can be made to work within reason... as long as there isn't a bunch of unsupported case sticking out of the chamber--- as was posted.

If less than zero headspace, you can simply grind a little off the bottom of sizer die to clear the shell holder, adjust the sizer depth to set shoulder back a little to fit the chamber- a little crush fit on the shoulder datum ring is fine. Then you're good to go.

If a little excess headspace, then fire form with a hard cast bullet seated out to jam hard into the lands. A firm crimp helps keep the bullet in place. Need 30-35kpsi to fully fire form the shoulder. The idea is to make the case shoulder fire form to the chamber shoulder and not stretch the case just forward of the web. By jamming the cast bullet into the lands it keeps the case head firmly in contact with the bolt face during the firing cycle.

In either instance, once fire formed, adjust the sizer die to just BARELY touch the shoulder when sizing- maintaining near zero headspace to the rifle's chamber from then on.

Be sure to trim brass to fit the chamber length in the rifle.

[DeanWinchester]

Thanks! Thts what I was thinking. I don't even have to worry about setting the die to touch the shoulder if I use a collet neck die.

...now to track down the parts I need.

[fouronesix]

The Lee collet neck die is an excellent system for accuracy related loading. But, sooner or later you may need to re-set the shoulder and/or re-size the case body if chambering becomes too difficult after a few reloadings. In which case you'll need a regular sizer die. Also, if you get a bolt/rifle combo where the headspace is quite a bit less than zero (short) then you'll need a regular sizer to set the shoulder back some to start with.

[Multigunner]

I try to always recock and dry fire with the fired case still in the chamber, or dry fire each fired case later at home. The impact of firing pin on an expended primer wil micro size the case so it will chamber easily when neck sized and reloaded.
It also allows plenty of dryfire practice to improve hold, sight picture, and trigger squeeze.

[historicfirearms]

I try to always recock and dry fire with the fired case still in the chamber, or dry fire each fired case later at home. The impact of firing pin on an expended primer wil micro size the case so it will chamber easily when neck sized and reloaded.
It also allows plenty of dryfire practice to improve hold, sight picture, and trigger squeeze.


Great tip, thanks!

[KCSO]

Don't be so hasty, you would be surpries how easy it is to find a bolt to headspace correctly. These guns were made when craftsmanship was an everyday item. I have had as many as 9 of these in the shop and just for a hot chanded the bolts around and I think of 9 guns 6 were on with most of the bolts and the others were too tight. try the bolt body first.

[swheeler]

KCSO gives good advice. If I have to fireform to a long chamber I will create a false shoulder, run your brass over a 7mm expander, then size back in 6.5 dies until you get just a slight resistance on closing. Whenever i tried using a bullet seated into the lands I got brass that stretched in the web, the bullet leaves before brass is formed. Use a false shoulder and that won't happen.

[Reg]

First off you are making the assumption that a replacement bolt will not headspace to some degree. Not always so.
Get your replacement bolt and then try to run down a field gage, they are out there. Check . There are a couple of places out there that rent reamers and they generally have headspace gages as well. A couple of bux to rent a gage might be the cheapest
investment you could make.
Generally most guns are held to w/n .004 to .005 or so on headspace between go and no-go and this is the ideal but another gage that is used a lot in military rifles ( and sporting ) is the field gage and it can run out to as high as plus .012. Not the ideal for sure but acceptable. If your rifle will come within the field gage then you can play various games like suggested to get longer brass life.
A couple other things going for you is the fact the Sweeds were generally quite well made to good tolerances and overall well taken care of . Other than handling most saw very light use and this equals little wear.
Add all this up and you might be surprised how well that replacement bolt might work.

[DeanWinchester]

Reg, that's what I'm hoping.

[MtGun44]

Millions of Mausers out there with mismatched bolts and OK headspace. Odds are
fairly good on another bolt headspacing pretty well.
Good handloading techinque can make up for sloppy headspace, up to a point.

I hope you fine a bolt and get thaqt old girl back in working condition.

Bill

[Dutchman]

I have to wonder what happened to the original matching bolt... Some rifles imported less bolts were "condemned" and awaiting either scrapping or rebarreling. I have one m/96 that has barely any discernable rifling remaining yet the rifle is in very nice original condition. Such rifles came out of shooting clubs rather than military stores where maintenance protocol was followed.

I own one of the relatively few sets of Swedish regimental headspace gauges in the United States. There are more of these here now than 12-15 years ago when I got these direct from Sweden. Looking at the comparative measurements between the Swedish gauges and American SAAMI gauges is quite revealing. The military "field" gauge is quite a bit longer than the SAAMI gauge. Many/most m/96 will fail a SAAMI no-go but pass a field gauge. Over the years/decades there were different technical orders concerning headspace gauging. The figured on the page below are from a technical order dated 1948. That's 50+ years after the system Mauser was adopted in Sweden.

http://dutchman.rebooty.com/headspace.html

I'm not one of those who use plastigage or scotch tape or beer cans to check headspace. I use headspace gauges. And with 6.5x55 I feel very fortunate to own this set of military gauges as it gives me a leg up on the big picture with these rifles. Looking at the actual gauge lengths you'll see that your rifle could fail a SAAMI field gauge and still be within spec according to Swedish military standards. But you can't possibly be sure what's going on until you drop that 3.35mm gauge in the rifle. It's .0035" longer than the SAAMI field gauge.

Overall I think you're going to be ok with the fire forming methods mentioned above. Especially so when talking about cast bullet load levels. About the worst case scenario is you'll wear out cases faster.

Dutch

[jh45gun]

Wait until you get the bolt and see. The Swedes made in my opinion the best Mausers out there in the 93 to 95/96 platform. I have an old Model 93 Spanish Frankenstein gun that we bought cheap as incomplete guns with no bolt and the bores were sewer bores. We ordered complete bolts for 35 bucks at the time and I ordered a used barrel since I could not find a new one at that time they were drying up in parts. We put every thing together and it head spaced perfectly. Could not believe it had a gunsmith friend check it out and he gave it a clean bill of health also. So you may get as lucky as well.

[MtGun44]

Dutch,

Your gage info matches my comments, which is based on a lot of experience with "excessive headspace" guns.

I say "Headspace is overrated." Meaning that you can get away safely with a lot looser headspace than
most folks (including SAAMI) think is good. The rub comes in reloading because the cases are stretched
a LOT on the first firing and if resized to normal dimensions will fail SOON, possibly at the second firing.
With careful die setup that does not push the shoulder back, these "excessive" headspace guns can be
useful for the hobby shooter and get acceptable case life. The other point is that having a head
separation is not particularly dangerous if one recognizes it and doesn't manage to ram another round
into the chamber with a case half already in it.

I am not at all sure it is possible to close the bolt this way, but idiots being as ingenious as they are, I worry.

Of course, having a ruptured case extractor available is REALLY helpful at these times.

Bill

[wallenba]

You could also just make some cases from 270 Winchester. Shorten the case just a bit. Then with a trim die set high, just run them down a bit at a time until they chamber. Lock the die down there. You might have to turn the necks, then maybe not. You will have to cut the necks shorter.

Just for laughs take a look at my post about my type 99 Arisaka. This is an extreme case of headspace problem. I was told it was a 7.7 Jap., it was actually a 30-06 ICL Caribou wildcat chamber. Post #7 shows what I got away with. http://castboolits.gunloads.com/showthread.php?157397-Unknown-chamber-in-my-Arisaka!!&highlight=arisaka
In the pic, the one on the left is my 7.7 handload, the middle is one reformed after firing. The one on the right is a 30-06.

So I think a small bit of excess headspace in a moderate to low charge would not be much of a problem. Just neck size after.