A new theme for the Journal

The more eagle eyed of my readers may have noticed a slight change to the layout of my Journal as it was way overdue.

I use WordPress for this Journal (I hate the Bl*g word) and although I have always ensured everything was fully up to date version and security wise I had never actually got around to changing the theme to something more in keeping with this part of decade until this evening and I do hope you like it!

The main image is our Lurcher asleep in a chair by the log pile enjoying the sun, one of the advantages of living and working in a chapel is large windows and the sun comes in through the back windows in the afternoons. There is a downside in that the heat goes out via the expanse of glass rather quickly during the winter and our wood and coal man is probably dreading the day we get this place fully insulated.

Anyway, I hope you like the change however if not let me know please as I am not 100% convinced at this stage, certainly the header image is not really shooting related and you know what they say about Lurchers, they steal things and cause fights…

The Shooting SHED F/TR “Støtteben” MkIII bipod – we are going to do another run.

We have received several emails recently asking us if we have any of our MkIII bipods in stock and if not would we consider another run so after some debate we have decided on what is probably going to be our final run.
 
The bipod is already well known internationally within the F/TR class however if you are new to the discipline here are some vital statistics for the Shooting SHED “Støtteben” MkIII
 
Main bipod assembly: 6082 T6 aluminium
Finish: Vapour honed and black anodised surfaces.
Screws: A4 Stainless Steel.
Elevations shaft: Stainless Steel
Elevation nuts: 316 stainless steel
Weight: Approximately 610 grams
Weight with optional toggle locks fitted: Approximately 674 grams
Weight of optional toggle lock 32 grams (1.15 Ozs)
Maximum recommended width: 785,0mm (31 Inches)
Maximum recommended height: 380,0mm (13.5 Inches)
 
If you would like to know more about the product and get your name on the list please email the Viking: shed@shootingshed.co.uk

BSA Martini International ‘Scope brackets

These are a small run of BSA Martini International ‘Scope brackets. I designed these brackets for the MkI and MkII with the 1-1/8″ receiver width however they they also work with the MkIII/MkIV/MkV 1-1/16″ receiver albeit with the central axis of the rail shifted by a 1/16″ which is 1.58mm. I doubt you will notice the change once zeroed if it is to be used at a fixed distance such as 25 yards/metres. The finish is satin black Cerakote and they do look nice on the Internationals.

If anyone is interested in just how much of an issue the misalignment of just under 1,6mm is at 25m I will take my socks off and have a go at the math, I might just do it anyway to satisfy my own curiosity 🙂

Today is a rifle day again, I have a couple of bedding jobs to complete plus more machining than I care to think about. I machined a couple of soft metal extended jaws for the machine vice on the Bridgeport over the weekend to improve work holding of stock during inletting a bit easier and will be putting them to use towards the end of the day. They stand an extra 50,0mm high and I machined them from 30,0mm thick Ecocast plate which is basically a 6082 with a nice finish. The hardest part is swapping the jaws out however it takes less time than swapping the vice out and squaring it up.

Best get on 🙂

EDIT – I reckon the variance of 1,58mm scope offset is the equivalent to 0.0054 MOA calculated at 100 metres and I have checked my calculations twice with the same result however it is a Monday and I am yet to start my second coffee of the day…

Ruger Precision Rifle – Rear bag rider

I have had a few enquiries of recent for a rear bag rider for the Ruger Precision Rifle so here it is as a prototype fitted to a customer rifle. This rider has a 23,4mm tube suspended from a rear plate and if it looks to be sloping up it is! The customer asked for a 10 degree angle on the rider however I opted for 2.5 degrees to keep things low. The idea of the slope is by moving the rifle forwards and back subtle changes can be made to the elevation without excessive bag squeezing.

The finished product will be anodised in black and available with a spacer to give either zero or 2.5 degree slope if requested. I will also offer it with a 20,0mm tube as an alternative so you size it to your own make of rear bag.

The bag rider incorporates the original Ruger fixings so the butt can be canted as with the original and will be made in a limited run so if you are interested or have any questions or comments please let me know.

Run out

There is always a lot of discussion about run out when it comes to chambering barrels however regardless of how well you clock in the barrel prior to taking that first cut with the reamer you need a tail stock that is aligned to the head stock because it is your tail stock that carries the reamer and reamer holder so getting this correctly aligned is important. I say important as opposed to critical as there is a glut of reamer holders designed to take out radial and angular errors when using a reamer and they all work to varying degrees however it is important to make sure your machine is as near to perfect as you can get it.

I turn a fair amount between centres and I make a point of checking the diameter of the material at both ends during an intermediate cut. Friday I performed the check and noticed around 0,1mm negative error on the diameter per 300,0mm length (.004″/12″) Which is enough to send me off for my check gauge to see what was happening.

The gauge is very simple, a round disk with a 25,0mm spigot machined on one side. The outer diameter has an M6 tapped hole aligned with the centre axis of the gauge to attach a Mercer 0.0001″ Dial indicator. To use I pop into a collect chuck, start the machine and take a fine cut off the major diameter to ensure it is concentric to the spigot and then attach the indicator. Making sure the bed and underside of the tail stock is clean I use an unused good quality #3 MT Adapter in the tail stock, move it into place so the indicator is touching the MT, lock the tails stock in place, zero the indicator at the 270 degree point, then flip it over to the 90 degree point and read the error. In theory both reading should be zero however if they not you need to make some adjustments.

Most lathe tail stocks have two hex head screws in the base which in turn screw into a block that sits on the underside and tightening/slackening one screw in conjunction with the other pulls the headstock to the left or right when viewed by above. I use two T handled hex keys and on mine turning the front screw clockwise whilst turning the rear screw counter clockwise gives a positive reading and reversing the procedure gives a negative reading.

Negative and positive is best explained thus, place a length of material between the headstock and tail stock and take a cut, now measure the diameter at the head stock and again at the tail stock, if the second reading is greater than the first then you have a positive error, if it is less you have a negative error and from this you know which was to adjust the tail stock. What I must point out is this is counter intuitive in that you would expect to be pulling the headstock towards the cutter when adjusting from the front when you are actually moving an internal floating block so the direction of movement is reversed.

Back to business, three minor tweaks and a test cut showed zero error at 300,0mm and that was to 5 decimal places so happy days 🙂

Finally, yes there are other ways of checking tail stock alignment, some a simple as a steel rule suspended between centres to using a ground steel bar however this is the way I take care of the job, moderately ‘Old school’ however it works very well for me.