1943 British Evil Assault Rifle questions
1. If the Enfield No. 4 Mk. 1 rifle bolt head length is .630″ (the No. mark on the bolt head is illegible), is that more likely a No. 1 or a No. 2 bolt head?
2. What are the likely consequences of firing a bolt action rifle with excessive head space? (The rifle failed the No-Go gauge test, field gauge test not done)
Thanks in advance.
August 16th, 2007 at 4:11 pm
1) Don’t worry about the bolt. It is not an issue.
2) If the rifle failed the go-no go test, you’re probably fine but I would do a test with a field gauge. You’re at the outside limits of headspace if you’re closing on the no-go gauge.
Get a field gauge. If the bolt closes on the field gauge, do not shoot it. Get a new bolt and get headspace into specs.
The danger is case head separation or case rupture with excessive headspace. Head separation is an annoyance. Case rupture is the danger. If the case ruptures due to excessive movement within the chamber, those hot gases suddenly have a route out of the chamber other than through the barrel. Then the bolt blows up with your cheek next to it.
August 16th, 2007 at 4:43 pm
You get this:
http://www.posterboard.tv/firearm_misc/303_oops.jpg
Though, I didn’t even know that had happened until I opened the bolt…
August 16th, 2007 at 4:45 pm
That’s what could happen. You don’t want that.
August 16th, 2007 at 4:48 pm
Here:
0 .620 to .625″
1 .625 to .630″
2 .630 to .635″
3 .635 to .640″
Found on a forum so doubt the veracity; I trimmed the post off because there was some obviously spurious advice.
August 16th, 2007 at 4:52 pm
Jeez, let’s see if I can’t finish my thought with *one* more post.
*twitch*
Anyways, if it’s measuring .630 then it’s likely to be a #2. Last time I checked you won’t get metal to stretch by putting it under compression loads…
August 16th, 2007 at 6:00 pm
Isn’t that also called “Fire-forming” casings?
August 16th, 2007 at 6:46 pm
Fire-forming? Only if you’re loading up 11×8.0R 🙂
August 16th, 2007 at 9:19 pm
So excessive headspace may allow the cartridge to rupture, which vents the high pressure gases into the headspace, and the bolt may not be strong enough to withstand this pressure without the assistance of the cartridge expanding against the inner walls of the breech.
This is, what I feared.
Thanks everyone for your assistance.
August 16th, 2007 at 11:03 pm
The guys on Enfield forum gunboards.com can answer EVERYTHING Enfield. They know it all.
http://www.gunboards.com/forums/forum.asp?FORUM_ID=44