How can I tell the difference between a No. 1 firing pin/striker and that of a No. 4?
Printable View
How can I tell the difference between a No. 1 firing pin/striker and that of a No. 4?
The rear of the No1 is flat, the No4 is rounded.
Thank you 5thBatt. Mine is rounded with a notch on the right side. Oh, I looked again and the notch is on the left..........grin.
The threads are different. I think you'll find some rounded and some flat regardless of whether No.1 or No.4.
Brian, do you have some reference to that? it states in Ian's book TLE Pg 396 that the No4 is rounded & No1 flat & that has been my experience, i do have a No1 with a rounded firing pin but it also has a No4 cocking piece which as a single unit is interchangeable.Quote:
Originally Posted by Brian Dick
We had boxes of No1 and 4 strikers and I agree with Brian. There were rounded and flat of each sort. THat of itsel;f is not an identifying feature The difference is in the thread form.
Interesting, thanks for that Peter, always good to learn :)Quote:
Originally Posted by Peter Laidler
They will interchange but only with respective SMLE or No.4 cocking pieces installed as a unit.
That's what i was trying to say but poorly re-reading my post.Quote:
Originally Posted by Brian Dick
Striker and cocking piece threads:
No4: 1/4" x 28 TPI BSF (55deg, Whitworth form)
No1: 1/4" x 30 TPI Enfield Special
Both are made to a somewhat closer fit then your average hardware-store screws and nuts.
Further to BinO's thread 10. This close thread form is to make sure that the cocking piece is a tight fit on the striker. If it ain't then you really can wave goodbye to any notion of a good pull-off. The EMER says that in order to make it a tight fit or tighten up the fit you can strike the thread on the striker with a small letter 'S' on each side!!!!! I don't go along with that - although I have done it of course. Just clean up both threads and tin them. It'll be tight enough for a good tight fit, ain't going to work loose and you'll be able to get it apart in the future without snapping the ears off the TOOL, removing, striker
As to telling the difference .. carry a 1/4 BSF nut with you to test with - or a cocking piece of known origin.
And another thing..
The REAL engagement is between the parallel "seat" in the front part of the cocking piece and the smooth, parallel tail-end of the striker.
The mating of these surfaces keeps things lined up and "rigid"; the thread stops it coming apart..
Dimensions and tolerances for the No1 components:
Striker "parallel":
0.25" Accept
0.249" REJECT
That's it; a 1 thousandths of an inch tolerance.
Cocking piece "parallel" bore:
0.25" Accept.
0.251" REJECT
Not exactly a "racing" fit!
Given the machinery and metrology of the times, I wonder how many components it took to get these sorts of dimensions correct?
.
Yep...... I hadn't taken notice of that either Bruce, It is the parallel shank and hole in the c/p that keep it all aligned! Which makes me wonder why you still find bent strikers when you test them! Oh yes...., just thought..... Some people bend them to get the two-stage pull off as an alternative to stining the bents correctly. Thanks Bruce