Effect of hot barrel on POI

[villiers]

My groups tend to widen when the barrel heats up. But so does my ability to concentrate. And my eyesight diminishes too

[Son]

I asked the questions yesterday for good reason.... now I have a little time and am at home, I can expand on my thoughts

Using the sling can and will string your groups vertically if you cannot use the exact same tension every time. Even the service shooting pam says not to use the sling

Attachment 72226


The foreend is supposed to contact the barrel at the Nock's form, for an inch either side of the inner band and for at least four inches back from the muzzle. Take a look at an undisturbed factory fitted foreend on a No1 MkIII*

Attachment 72227

The inner band does nothing if the foreend is fitted properly. It and the barrel centering stud under the muzzle along with the two tiny lugs in the muzzle hole of the nosecap are there to help control the accuracy if the foreend bedding fails (foreend warping) and nothing else. You should be able to shoot a No1 with only the foreend fitted with the trigger guard, no inner band, no barrel centering stud, no nopsecap, no handguards and shoot the same POI as the complete rifle does.

If you can, try the same shooting program off a sandbag without the sling and see what happens. It is not unusual for a little vertical stringing from cold to hot, but I am suggesting any more than three inches from the first shot to the tenth shot means you may have a problem. I have several No1 rifles that don't vary more than about 2" no matter how hot they are. Trouble is, there can be a lot of work t5o achieve this, and even then there is now way of being sure it will ever improve... they can be that fickle!

[CINDERS]

Another not mentioned one if you have just fired a string say 10 rounds in 5 minutes then you may get the next string not long after of say 10 x 1 shot 2 second exposures then as a finale a 10 shot in 1 minute the only break being the time it takes to score and patch the targets Oh and waiting for the Mausers.

We then induce a heat haze from the wood as believe me when we shoot in 40 degree heat and crank out the rounds the heat from the wood rising up certainly affects what you see 3-4-500m away, slight variations in head hold with the No.1 sighting if the blade is not exactly level with the top of the rear sight notch will also move the POI down (If it is higher than the back sight notch) So as suggested do a timed event using sandbags or just take your time to do it to get a correct sight pic each time.
As we all know when you have the mad minute close is not good enough, a friend and I tried it once in the mad minute he aimed as best he could and got off 15 I rattled them out had a rim over after the 4th clip went in which cost seconds to cure which left me only enough time to put a 5th clip in got off 25 and beat him by a couple of points.
Probably by sheer volume of rounds but his slow and steady was accurate enough to show that it is better to get it right, me I had a ball as that is what makes the lee so good and that is slinging lead.

[30Three]

Thank you all for taking time to answer and share your experience. It seems I have to find some range time and workshop time to check all this out.

[Gil Boyd]

But Son, I think the issue raised was only in competition, as I read it. Sandbags wouldn't be allowed, so tightening down right across the board is Marksmanship Principles well honed and tested over centuries of sniper deployment.............it will always tighten a group, but one can't help someone who doesn't maintain the same point of aim, using these principles IMHO

[Son]

But Son, I think the issue raised was only in competition, as I read it. Sandbags wouldn't be allowed, so tightening down right across the board is Marksmanship Principles well honed and tested over centuries of sniper deployment.............it will always tighten a group, but one can't help someone who doesn't maintain the same point of aim, using these principles IMHO

My suggestion to try the rifle off bags was only to test if the vertical stringing was caused by uneven tension on the sling upsetting the bedding different each time.
No point going looking for an accuracy problem in the rifle if the problem is in the technique. The rest is only to demonstrate that the standard SMLE, correctly bedded, was never meant to be fired using the sling... quite likely for that reason. Basic marksmanship training for this rifle, from the pam says no sling.
Specialist sniper rifles are a whole different ball game, in most cases.... but I can tell you the most finicky of my rifles is this regard is one of my HT's. If the barrel is touching the nosecap on the two points at the muzzle at 10 and 2, the group sizes more than double. When using it in comps I used to test it with a feeler gauge before an event and have had to put a strip of thin packing in the ensure there is no contact on more than one occasion. That is what worked for that particular rifle.

[30Three]

I had a bit of luck yesterday and bought a nice AJ Parker 9G sight for this rifle. These don't appear for sale very often in France. However it does not have the fixing plate for the No1 rifle.
So now I need to find a fixing, or make one. This will allow me to shoot this rifle in modified class and keep the No4 in the standard.
My plan of action for the rifle is:
1, check if anything has come loose
2, re-oil the surfaces of the wood with linseed oil, to make sure it's not thirsty.
3, use graphite powder at barrel contact points with inner band and front sprung pad
4, check the spacer length (after oil has soaked in) and fit at knox (nocks,) form
5, check nose cap contact
6, test it on a sandbag and prone without a sling.

[muffett.2008]

Zed, here's a couple of pic's of what you want.
Attachment 72246Attachment 72247Attachment 72248

[30Three]

thank you Muffet. That's a nice collection. I take they screw into original bolt holes with longer screws. What thread are these? Is it BA like No4's or are they special?
Let me know if you want to sell any duplicates

[martins8589]

thank you Muffet. That's a nice collection. I take they screw into original bolt holes with longer screws. What thread are these? Is it BA like No4's or are they special?
Let me know if you want to sell any duplicates

One on ebay.au atm

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Or used guns https://www.usedguns.com.au/Product.aspx?p=75461