The novice and the twisted receiver.

[jss]

I've read quite a few posts here regarding damaged and worn receivers but not so much on how to spot them. I'm just trying to work out why my DP is so designated. It looks to me as though the receiver is possibly slightly twisted. The point where the bolt head drops down onto the action on closing seems slightly raised. I had thought it might have been very expertly welded but I now think it is probably just slightly bent, or perhaps the area behind the raised bit has been worn down by the travel of the RH bolt lug over many cycles.
The mismatched bolt does seem to waggle around quite a bit on closing and when closed can be moved quite a lot. The areas of wear on the action have also been pitted by rust.

Is it just a matter of experience to spot damaged/worn receivers and know when they are un-servicable or are there any guidelines around for the uninitiated?. I think the EMER's specify limits for transverse bolt movement presumably tested by using the special tool.
Could the mating surfaces of the bolt lugs be relied on in some way to show up any deformities and excess transverse movement of the bolt at the front end.
I suppose if the bolt face is square with the chambered round while the lugs are in contact with the receiver and the centre line of the bolt is in line with the centre of the barrel then all is well.........................
And how much does it matter. What would happen if the bolt face is not square on to the round. Presumably the case would crumple a bit but the force would still be taken up by the lugs if the mating surfaces are in contact......
I shot one rifle a while ago with a dodgy looking chamber (I did not know at the time)and it seemed to twist on recoil such that I stopped firing immediately, or was I imagining it?.

More beginners curiosity I'm afraid so if it's too boring please ignore.

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[Beerhunter]

I. I'm just trying to work out why my DP is so designated.

Because a DP rifle was needed for training purposes. The real question is why was your rifle selected for DP'ing and the only answer to that is: because it was available. It's availability was down to the situation at the time and so the rifle could have been anything from a Service Rifle that was surplus to requirements to a piece of scrap.

In other words, it wasn't case of: "that rifle is broken, we may as well DP it. Rather: "we need some DPs what rifles are available".

[Peter Laidler]

Why your rifle is/was selected to become a DP rifle has been covered many, many times here. There are equally, as many, many reasons why. I have been involved in this from a service angle and to save me writing it all out again, I'd suggest you read it all again. Beery has it covered from the two extremes. If there's a request for, say 35 DP rifles when you only have 28 heaps of tat in stock. So you select the 28 heaps of tat and the next worst 7 and DP them!

BUT........ unless you have base workshop gauging facilities, a metallurgy lab and an experienced eye, you, the average civilian shooter doesn't know whether yours was one of the 'good' ones or one that has broken through the hardened locking shoulders or, heaven forbid, (as I have seen and certified....) been the subject of a ferocious fire.

If a dealer said to me words to the effect (and there are some on this forum who have actually heard it said...........) 'they're perfect.... only used for recruit training since they were new' then I'd ask him to say that in writing.

DP.......................... I know that there are thousands out there more experienced than me...., and wiser too but I wouldn't trust one. Any worthy collection deserves a couple but that's where they belong and not on the firing point.

I'll sit down and put my steel helmet on as there's sure to be some incoming mortar fire