Is there Ever to much neck clearance.

[hoz53]

I know this question has been asked here before, but Im asking it this time in terms of safety. Whats the largest neck clearance you have ever observed? Ive been loading for a 95 mauser lately with original barrel. loaded round neck dia. is .312--- fired neck dia is .326-- thats without accounting for springback. So thats .014 clearance overall or .007 per side. I havent observed any gas blowback and the gun shoots ok for what it is. I know brass life will suffer but thats ok. Any other reasons i should be concerned. Thanks

 

[CJ6]

Other than brass life .....No.

 

[hoz53]

Other than brass life .....No.

ok thanks

 

[RegionRat]

You pretty much stated your case very well, old Mil-Surp chamber designs were generous in order to balance accuracy, reliability, and economy. That the shoulders and necks were generous in the chambers was trading away some potential accuracy for reliability and economy.

Hitting tighter dimensions does two things, it costs more, and it means the system is less tolerant to contamination or imperfect ammo. You will typically see "looser" chambers on old military designs that became tighter when the accuracy crowd comes into the scene and starts tweaking reamer dimensions. Just look at how many variations there are on neck dimensions in 30 cal rifles over the years once Bench Rest folks wanted their own reamers.

Your brass will work harden a little faster, but if you are careful with your prep processes when it comes to FL dies and expander balls, those old Mausers can be amazing. If necessary, you will want to learn about annealing. This is a place where a Redding Body die, with incremental shell holders, and a Lee Collet die combo can really shine.

 

[hoz53]

You pretty much stated your case very well, old Mil-Surp chamber designs were generous in order to balance accuracy, reliability, and economy. That the shoulders and necks were generous in the chambers was trading away some potential accuracy for reliability and economy.

Hitting tighter dimensions does two things, it costs more, and it means the system is less tolerant to contamination or imperfect ammo. You will typically see "looser" chambers on old military designs that became tighter when the accuracy crowd comes into the scene and starts tweaking reamer dimensions. Just look at how many variations there are on neck dimensions in 30 cal rifles over the years once Bench Rest folks wanted their own reamers.

Your brass will work harden a little faster, but if you are careful with your prep processes when it comes to FL dies and expander balls, those old Mausers can be amazing. If necessary, you will want to learn about annealing. This is a place where a Redding Body die, with incremental shell holders, and a Lee Collet die combo can really shine.

OK-- well this gun does shoot pretty good. and i havent done what a person would call load development. I dont need any better accuracy from it than im getting. Im using starting loads which is probably all i ever will use in this old gun. I do have a bench source and annealed this brass I have. Its pretty old and i got a few splits, but cant really expect more out of it. i did forget to say this is a 7x57 though it could have been figured out. Ive ordered new brass but who knows when ill get it. Ill look into the collet die some more. Thanks Much

 

[RegionRat]

To waste a little time... Some of the biggest surprises I have ever had at the range, was when I helped friends do load development for their old Wooden Guns for CMP competition. At some point, Dennis DeMille and several others made up a new game called vintage sniper. It caused a lot of the old guns to come out of the closet and get put back to work.

I got a big surprise when helping with Swedish Mausers. They are not 7x57, they are 6.5x55 Swedish. I brought guys out to my club's range and we ran load development tests like ladders out at 600 yards. These old (over 100 years) guns with their sloppy military chambers and rusty old bbls took some modern match prone guns to school.

The Swedish sniper guns were plucked out of the crowd, not specially built. So I am sure there are some that don't shoot as well, but I have seen several regular ones for the 200 yard line games that also shoot well inside the 10 ring out to 600 yards.

 

[dellet]

There are two different 7x57 chambers and bores. Basically SAAMI and CIP. The old European chamber and bores were set up for a thicker brass, and a .285 diameter bullet. Neck diameter was .321” from memory, that might have been with a cast bullet.

There might have also been some other slight variation to the chamber that I do not recall, it’s been a long time, but it’s worth checking the bore size.

 

[hoz53]

To waste a little time... Some of the biggest surprises I have ever had at the range, was when I helped friends do load development for their old Wooden Guns for CMP competition. At some point, Dennis DeMille and several others made up a new game called vintage sniper. It caused a lot of the old guns to come out of the closet and get put back to work.

I got a big surprise when helping with Swedish Mausers. They are not 7x57, they are 6.5x55 Swedish. I brought guys out to my club's range and we ran load development tests like ladders out at 600 yards. These old (over 100 years) guns with their sloppy military chambers and rusty old bbls took some modern match prone guns to school.

The Swedish sniper guns were plucked out of the crowd, not specially built. So I am sure there are some that don't shoot as well, but I have seen several regular ones for the 200 yard line games that also shoot well inside the 10 ring out to 600 yards.

i have a swedish mauser in 6.5 swede to. It has been somewhat sporterized so it has scope rings drilled and tapped on receiver. Unfortuneately someone cut the barrel to 18" but even so that thing shoots good. Ive only used surplus ammo in it and it has done well even with that. Im gonna load for it one of these days to see what it will do. thinking about it a little more, i also have a 98- ill check the neck dia on it and the swede to. Thanks

 

[hoz53]

There are two different 7x57 chambers and bores. Basically SAAMI and CIP. The old European chamber and bores were set up for a thicker brass, and a .285 diameter bullet. Neck diameter was .321” from memory, that might have been with a cast bullet.

There might have also been some other slight variation to the chamber that I do not recall, it’s been a long time, but it’s worth checking the bore size.

Yes you are right. I can pretty much tell what the chamber looks like by the fired brass but i really should slug the bore. I know freebore is long compared to what id like but i wont change that any. Ive been shooting 284 jacketed in it of coarse. dont know what ill do if its oversize. does anybody make .285 bullets? I could shoot cast sized to my bore. Its a possibility. Thanks

 

[Doom]

.3253” is the minimum chamber neck dimension per SAAMI.

 

[hoz53]

.3253” is the minimum chamber neck dimension per SAAMI.

my brass has .014 neck wall thickness, so .028+.284= .312 which should be loaded neck dia. mabie with thicker brass as dellett above said my chamber is in specs as its close to what you say. I wonder how thick of walls they used? Anyway military guns dont necessarily have to follow cip - saami do they?

 

[Bill Norris]

I've seen some factory rifles that had what I thought was excessive neck clearance but never really noticed any thing crazy going on with the brass failing at a premature rate but I guess it would affect it sooner or later.

 

[dellet]

Best I can do on my phone. This is the CIP cartridge and chamber drawing, not quite as easy as SAAMI.
Note the neck diameter/collar that converts to .325 on the cartridge max and .326 chamber min. And bullet diameter of 7.25 which would be 285 vs 7.22, 284. Grooves and lands are also slightly different.
Went through this about 20 years ago with my brother so rusty memory. He just shot cast because finding proper Bullets was a pain.
Link https://bobp.cip-bobp.org/uploads/tdcc/tab-i/tabical-en-page33.pdf

 

[hoz53]

Best I can do on my phone. This is the CIP cartridge and chamber drawing, not quite as easy as SAAMI.
Note the neck diameter/collar that converts to .325 on the cartridge max and .326 chamber min. And bullet diameter of 7.25 which would be 285 vs 7.22, 284. Grooves and lands are also slightly different.
Went through this about 20 years ago with my brother so rusty memory. He just shot cast because finding proper Bullets was a pain.
Link https://bobp.cip-bobp.org/uploads/tdcc/tab-i/tabical-en-page33.pdf

all that effort wasnt necessary but sure spells it all out. ill slug my bore to see whats up. Thank You

 

[hoz53]

I've seen some factory rifles that had what I thought was excessive neck clearance but never really noticed any thing crazy going on with the brass failing at a premature rate but I guess it would affect it sooner or later.

seems that would make sense but there could be many factors. In say my guns i shoot alot off bench i wouldnt tolerate excess neck clearance but in this old gun it doesnt matter. It just mite help me learn something is all. Thanks

 

[Bill Norris]

seems that would make sense but there could be many factors. In say my guns i shoot alot off bench i wouldnt tolerate excess neck clearance but in this old gun it doesnt matter. It just mite help me learn something is all. Thanks

U bet Bro.

 

[joshb]

Hoz: Try this load in your old Swede. This was 5 shots at 100 with my 80 year old M38 Swede.

 

[Bill Norris]

Nice shooting Bro

 

[joshb]

Nice shooting Bro

It’s all the gun! I love those old Mausers.

 

[dellet]

my brass has .014 neck wall thickness, so .028+.284= .312 which should be loaded neck dia. mabie with thicker brass as dellett above said my chamber is in specs as its close to what you say. I wonder how thick of walls they used? Anyway military guns dont necessarily have to follow cip - saami do they?

Well 5.56 is not SAAMI.

Talked to my brother, be certain to slug the bore. Old and military means some pretty broad tolerances. His bore was 286 and change, so he used 275 H&H bullets .287 for jacketed. If they are too big, you can run them through a sizing die and lose at .001” diameter easily.

Search results for: '287 diameter 154 grain spitzer soft point jacketed bulelts box of 100 bac287154'

www.buffaloarms.com

Brass from 257 Roberts tended have thicker necks for donor cartridges than a lot of American 7x57 brass. Makes sense, Roberts used the 7x57 necked down. He said the necked up brass was .016”. Old military 30.06 cases were also thick.

It fun to get the old things off the wall and on the range, even more if they shoot well. I remember him not doing so well for bench rest and targets with it, but silhouette was another story.

Hope that helps to get you going.