Headspace question.

[jmoore]

Ummm, GBinSC stated as did Brian Dick that his headspace is fine. Sooo, how much RADIAL EXPANSION is tolerable given worst "case" scenario using non-embrittled (relatively new, let's say) virgin brass cases or non-reloaded ammo?

I'm thinking that the degree of thinning could, possibly, be less, but I'm open to some computer modeling or actual hard data.

Oiling the case won't affect radial expansion, so leave that bit out!

[Surpmil]

Ah, the good old "maximum return to the shareholders"; not forgetting the executives and directors of course...

Naturally they'll make the cheapest case they can safely get away with. They would in fact like nothing better than to find a case that could only be safely fired once.

And if you asked, I'm sure they'd say that is their feduciary duty, to cheapen the product to the lowest point the market will bear without significant loss of sales. And they'll keep cheapening it until they reach that point. It's all very scientific, but sadly fails to take into account the loss of product and corporate reputation and consequent loss of customer loyalty. Anyway, that doesn't happen for several quarters, so why worry about it, eh?!

[jmoore]

You're not helping GBinSC, Surpmil! Let's try and help the new guy...

Email the mfg and tell 'em its a safety concern- If it is...


BTW I'm all on board w/Prvi Partisan- spent probably $6000 on their ammo and components last year. Already burned through a pile of it, too, so working more overtime today and tomorrow to feed the habit...

Just hope Cereberus or some such doesn't buy them out due to their success!

[Edward Horton]

Ummm, GBinSC stated as did Brian Dick that his headspace is fine. Sooo, how much RADIAL EXPANSION is tolerable given worst "case" scenario using non-embrittled (relatively new, let's say) virgin brass cases or non-reloaded ammo?

I'm thinking that the degree of thinning could, possibly, be less, but I'm open to some computer modeling or actual hard data.

Oiling the case won't affect radial expansion, so leave that bit out!

Mr. jmoore

Oiling the case WILL affect radial expansion, especially when the case can't grip the chamber walls, so lets leave this part in



And here is your "RADIAL EXPANSION of cartridge cases" and all the math and graphs you could possibly want.

Ballistics: Theory and Design of ... - Google Books

I even found this graph for you on cartridge pressure ring diameter, but this won't help much because Brian Dick already said GBinSC Enfield is safe to shoot.

[jmoore]

Much better. Thanks!

Wile E. Coyote and Marvin the Martian are good too! Just not at the same time.


Book's a little price-y but looks worthy of adding to the collection. Haven't updated recently in this area, 1900 or thereabouts is the vintage of my other big ballistics book (the one NOT in German at any rate).

ETA: Mind you, I don't know when I'll have time to sit down and cipher. The oil would REDUCE localized stretching in this case, would it not?

[jmoore]

GBinSC, if you are satisfied that your rifle is OK, will you please excuse us whilst we ponder your question in some detail on the Ammuntion Forum?

I'll create a new thread in the forum shortly, and move this discussion there, as it isn't specific to Enfields anymore...

Go here!:

Maximum Safe Radial Expansion for Brass Cased Rifle Cartridges - Military Surplus Collectors Forums

Link above: the line disappears if nothing's below it.

[torana68]

]
The rubber o-ring holds the case against the bolt face when fire forming your cases at "ZERO" head space.

[With the rubber 0-ring you have NO grease or oil on your cases and NO added extra bolt thrust and possible damage to your Enfields.

(You also have the added benefit that the o-ring doesn't care what your bolt head size is or what your head space setting is at)

Hi,
A nifty idea, can you advise what effect this has on accuracy and is there any recorded change in velocity?
regards
Roger
Australia

[jmoore]

Welcome torana68, be prepared for more than you asked for! (The regulars have seen it quite a bit before, but its very interesting the first time.)

ETA Perhaps Mr. Horton would be so kind as to create some useful links to past discussions.

[GBinSC]

Well, it appears that a few apologies are in order. First, I apologize for not answering any of these posts sooner, as I have been away from my computer for a few days. Second, I should have included what type of ammo I was using (DUH). Third, the question I asked was not meant to start a firestorm. Fourth, my asking the question was in no way an indication of lack of confidence in Mr. Dick or anyone else. As I told him, I shoot Garands in CMP matches and this is my first Enfield. I'm trying to get all the information that I can about these rifles.
That being said, the ammo in question is Rahway Green surplus from the 1950's. I've included a photo.
[/IMG]
With that out of the way, thanks to all that posted, especially those who included cartoon characters in their posts, that brought back a lot of pleasant memories.

[jmoore]

Sorry to hog the conversation, but we do have some spirited members, they like to nip/bite at each other a little in greeting. Gets out of hand sometimes.

Your fired case looks altogether ordinary. Shouldn't worry about, I think.

Please do let us know how it shoots for you.

There's quite a bit of discussion on this forum concerning fore end bedding methods and such as well, if you want to go that route. (Very little tolerance of "glass" bedding, though!)

Try using the search function to see how much pops up! Feel free to ask whatever questions that arise.

Lucky you to have Brian Dick relatively close at hand!