SMLE Bolt Heads

[delta8672]

Greetings!

I have some SMLE 2A, the Indian manufacture, Bolt Heads which I thought would fit the No.1 Mark III Rifle.
They do not.
How many different types of SMLE Bolt Heads are in existence?
What Heads are interchangable among the various Number and Marks of SMLE and Lee Enfield?
Any information you might provide will be gleefully absorbed. Thanks!

BlueSkies! delta8672

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.

[Brian Dick]

They should fit. Remember that they need to be select fitted for proper timing and firing pin protrusion. It's not an exact science. I've fitted many new, long British SMLE bolt heads to RFI 2A and 2A1 rifles over the years.

[jmoore]

That's great news! I bought one cheap 8-10(?) years ago from Rose's dept. store 'cuz it did not have a bolt head at all. Was just going to save it for parts, but dang old Lee's about never give me any problems. Got plenty of SMLE .303 bolt heads though. Now just need an extractor!

[delta8672]

Greetings!

Am Back Again!

My SMLE No.1 MK.III Bolt has rust on/in its internal threads.

Have tried a brass brush in a drill with Kroil, the great penetrating oil, with no success.

I think a correct size and thread machine bolt used with Kroil will chase the threads and remove the rust.

Can anyone please supply the Thread Specification for the SMLE Bolt/Bolt Head?

Thanks in advance!

BlueSkies! delta-8672

[Alan de Enfield]

I have found 2 different types of bolt heads (when I was building my No1)
One type of bolt head has a 'cut out' / slot for about 1/4" up the threads (from the 'bottom') whilst the other type does not.

The one with the cut-out just would not fully screw into the bolt (it was almost as it the threaded portion was too long) but the type without the cut-out went in sweet as a nut.

Note : I just got both types out to photograph but the camera has dissappeared.

Thread form looks the same, threaded length looks the same but the one with the slot just will not screw into the bolt.
If I find the camera I'll post pics.

[Alfred]

I have found 2 different types of bolt heads (when I was building my No1)
One type of bolt head has a 'cut out' / slot for about 1/4" up the threads (from the 'bottom') whilst the other type does not.

The one with the cut-out just would not fully screw into the bolt (it was almost as it the threaded portion was too long) but the type without the cut-out went in sweet as a nut.

Note : I just got both types out to photograph but the camera has dissappeared.

Thread form looks the same, threaded length looks the same but the one with the slot just will not screw into the bolt.
If I find the camera I'll post pics.

Just the opposite here. My 1915 has the bolt head with cut out, described as an earlier type meant for a earlier type firing pin in a post on this forum some time back.
I tried a near new Lithgow bolt head without the cut and it doesn't clock in.

[Bruce_in_Oz]

Greetings!

Am Back Again!

My SMLE No.1 MK.III Bolt has rust on/in its internal threads.

Have tried a brass brush in a drill with Kroil, the great penetrating oil, with no success.

I think a correct size and thread machine bolt used with Kroil will chase the threads and remove the rust.

Can anyone please supply the Thread Specification for the SMLE Bolt/Bolt Head?

Thanks in advance!

BlueSkies! delta-8672

The thread on a SMLE bolt head is yet another "special".

The pitch is 0.050" (20TPI), the form angle is 79deg 30min, as opposed to the 55deg for Whitworth, BSF etc (and Mauser breech threads), 60deg for metric and UNF/UNC etc and 47deg 30min for BA.

If you want to chase out the thread in your bolt, find a bolt head with major damage elsewhere, grind a couple of cutting flutes in the threaded end, apply lube and go gently. I know that sounds a bit "agricultural", but unless you feel like machining up your own thread chaser tool, your chances of finding an original tool are about zero.

[RJW NZ]

Hey Delta,
Welcome to my world this weekend, trying to get bolt heads to do the right thing/s, they either jam as you wind them in (very slightly different thread), under or over rotate at the end of all the turns instead of being upright, wind in in pulses as thought the bolt is out of round but other bolt heads don't do this, etc etc.

I have a 1966 2a that does allow the early bolt heads with the slot to thread in no problems at all, but gets randomly persnickety on no1mk3 bolt heads without that slot.

Re threads; enfield threads are in house designs, not publicly used ones. In the real world, 50 -100 years later, you won't find them, ever. What threads are on 2a's I don't know but they seem mostly like no1mk3's.

ps, if you booga the bolt, go over to springfield sporters, they have them new and unserialed for less than $15, ez answer.