300 meter match

Today I competed in the 300 meter Robert Sandager Minnesota State Championship, and I’m pretty sure I didn’t win.

I was put in the first relay, due to start at 9am, and I was there on time, but to achieve that I had to leave the house at 7:30am, and get up at 6:30, on a Saturday. That is all beside the point though.

I have been having some problems with my rifle not ejecting cases all the way. I had trimmed my ejector spring to limit how far away my cases were thrown, but I cut off too much and sometimes it failed to eject. So I replaced that spring with another which I trimmed a little less in the hope that I would get the balance right, but it doesn’t look like I did. I even cleaned out the gas tube (which bleeds gas from the barrel to cycle the action) in the mistaken hope that it was getting clogged and that was why I was having trouble, but no. Today I had a number of cases fail to leave the rifle, which I then had to fiddle out, interrupting to my string. I think I will now get a new spring, not trim it, install it in my rifle, and accept that my cases will sometimes be found in orbit. But at least they won’t be jamming my rifle.

The weather today was cool but bright, and the winds appeared light. I think the winds were pretty light, but they were also completely baffling. The flags seemed to be indicating a light wind from about 6 o’clock, drifting a little right and left, but my rifle needed 1.25 minutes of left windage to center my group. Of course that could just be a zero issue. The guy next to me was getting the occasional 7 too though, and he was using a bleiker rifle in a 6mm caliber, so maybe I wasn’t imagining it completely.

Enough excuses and complaining though, on to my scores. There were three strings of 20 rounds with unlimited sighters and I got a 184-0, 185-3, and 188-4, for a total score of 557-7. The third string felt better than the score reflects, so I think I was finally settling in, but I’m still unhappy with my performance.

My wind reading skills still need to improve, and that’s only going to happen if I shoot more. So that is the plan.

 

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3D printed butt stock update

I have now had the opportunity to shoot my rifle with the Mk3 butt stock installed.

Last week I participated in a practice shoot at 300yds. The first detail was a rapid fire practice, and so with the Mk3 installed on my new lower receiver I got myself set up and started firing. The 2 sighter shots went okay, nothing broke and I hit the target. Then it was time to shoot the rapid fire string. The target came up and I fired my first two shots, then forgetting I had to change magazines I pulled the trigger again which only served to remind me that I needed to change the magazine. So I did that, released the action to chamber a round, and sighted on the target, but when I pulled the trigger nothing happened. No click, no first stage pressure. I cycled the action ejecting the unfired round and tried again, but nothing continued to happen, except that I cut my hand on a sharp edge on the butt stock while I repeatedly cycled the action (something to remember for Mk4).

When the detail was done I swapped my lower with the Mk3 installed for the one lent to me by George and shot the detail again, I scored 198/200. I shot the rest of the practice with the borrowed lower.

There was some discussion with George and the other shooters about my issues and the consensus was that it was an issue with my new trigger. I had been so focussed on trying out my butt stock that I forgot this was the first time I was using my new lower with it’s brand new trigger that I installed myself. On the plus side my stock didn’t break.

This afternoon I went to another practice session. It was raining so only myself and George turned up to shoot, and in the end George decided not to. I suggested that we use the 300m electronic targets so that no one would have to be out in the rain marking targets, and I decided to practice shooting from a sitting position.

This time I shot 70 rounds from the sitting position and the butt stock still didn’t break. I have been having trouble with the sitting position and I was hoping to get to grips with it. I think I made good progress.

I was still having trouble with the trigger; light strikes and the trigger not resetting after a shot, issues that I think I have probably sorted now. But the stock survived the shooting and several adjustments. I learned that despite the grid texture in the butt plate it is still quite slippery and a smooth plate covered in rubber would work better. The butt plate adjustment is slow and clumsy; I tried to do it while in position and found it very difficult.

Despite my concerns that the clamp would slide around the buffer tube, it actually proved very stable. Unfortunately the buffer tube is not tight in the lower and the whole set up moves just enough to be a concern. I intend to design the Mk4 to attach to a carbine buffer tube which has a much more secure attachment to the lower, I just need to figure out how to attach the butt stock to it.

Watch this space.

The light at the end of the tunnel, and a new(ish) project…

I am pleased to announce that I have almost finished my MFA. My thesis exhibition is installed, and I have successfully defended it from my committee. I just need to edit my thesis defense paper and I will be unemployed with the letters MFA after my name. Life is good:)

A few months ago I was trying to put the finishing touches to my AR by adding an adjustable butt stock to the lower. I emailed a company who made the one I wanted, but they were all out and so I waited. After a few months I was contacted with the news that they had made some more, unfortunately the money I had set aside for it was gone.

Wandering despondently around school I happened into a room known as the XYZ Lab. It is in there that I laser etched the stock on my hunting rifle among other projects. As it happened on this day the guru of the lab, Anthony, was fiddling with a new toy. A Makergear M2 3D printer. Now, a few years ago before I departed the UK I had had 3D printers on my mind, and had considered the possibilities of printing butt plates for my Anschutz target rifle. I was very attracted by the possibilities, but deterred by the cost of the equipment.

Now here I am a few years later, bemoaning my lack of a butt stock, but here was the equipment. And it turns out the technology is easier to get your head round than you might realise.

So I have been doing some designing, and learning, and more designing, and problem solving, and I have now printed 2 complete adjustable butt stocks for my AR15. I call them the Mk2 & Mk3.

Mk1 never made it off the drawing board. Mk2 broke as I was handling it the first time. But hopefully Mk3 will make it to the range, but then it will probably break (and that will be okay).

Here are some photos.

3D printed stock, the beginning.

3D printed stock, the beginning.

This is the first part of the Mk2 being printed.

3D printed stock project, part assembled

3D printed stock project, part assembled

The Mk2 used four vertically aligned bolts to clamp the “spine” in place. This part didn’t break, but it isn’t very elegant. The five nuts you can see on the right side are press fit into the spine and allow vertical adjustment of the butt plate.

3D printed stock project, first fit.

3D printed stock project, first fit.

Here it is on the rifle.

Mk2 Broken

Mk2 Broken

Here it is broken. The rotational forces applied to the butt stock were all being restrained by this piece, but not for long. It separated along a printed layer.

Mk3 Parts

Mk3 Parts

These are the parts of the Mk3. It is a bit more complicated. I have reduced the size of the serrations on the spine and made them an even 1/4 inch long to enable specific adjustments. The clamp is now operated by two bolts and a wedge which has more mechanical force and seems to work very well, but the placement of the bolts makes it awkward to adjust. The butt plate is now curved and more ergonomically shaped.

Mk3 assembled on rifle

Mk3 assembled on rifle

I have beefed up the part that broke in the Mk2, and I plan to apply something to the top surface of the spine to give it more resistance to sliding round the buffer tube. The buttplate can still be adjusted vertically, there are three nuts in the spine (two more are inside the lower bar) and the butt plate has five points of attachment that can be used with them.

It is still not very elegant, but it is a definite improvement on Mk2. The mechanism is good, but still needs work. Once I have done some live testing I plan to reproduce it in black plastic as I have decided that the red makes it look like a toy, and no-one will take it, or me, seriously.

I am mentally designing Mk4, but also I am considering the possibilities of casting parts in metal as that will become a possibility in the near future, but will probably require some adjustments to the design.

I am still intending to purchase a professionally made butt stock as I wouldn’t want one of these to break on me mid competition.

One day I hope to have the confidence that they wont.

Hand loading, a mishap (with no dire consequences), and finding the limits.

Since getting my new rifle I decided I had to measure my chamber so that I could accurately control the bullet jump. For slow fire with 80gr bullets I have been advised to seat the bullet 20-25 thou off the lands for best results.

I have an OAL gauge like the one in this picture:

Hornady OAL guage

This gadget works with a specially modified case that screws on the front and holds the bullet. I also own a bullet comparator which attaches to my caliper to enable me to measure a round from base to ogive instead of base to tip. Bullet tips are not consistent, but the ogive is. I decided to buy a new digital caliper that could be zeroed and give me true measurements. The comparator adds about an inch otherwise and the measurement becomes a bit abstract.

With a little experimenting and a few fails I managed to develop a technique with the gauge that gave me consistent measurements. I had read in one forum that best results could be achieved by tapping the back of the rod lightly with a piece of wood to ensure the bullet is engaged with the rifling. When I tried this my results varied more than I desired (a couple thou each way) so I settled on tapping lightly with the rod itself. This way I managed to achieve variances of less than 1 thou.

I came up with an average of 1.978 inches base to ogive using a Nosler 80gr bullet. The next step should be to subtract the required jump from this number and seat bullets to that depth, however the first time I did this I had a “brain fart” and added 20 thou instead of subtracting. I didn’t realise my mistake until I was on the way to the range. Luckily it is easier to seat bullets deeper than to pull them out and my error had no serious consequences.

In my recent efforts to load more ammunition with the 80gr bullet I have been finding it hard to get a really consistent seating depth. I have the press set up with a quality die but the bullets seating depths are varying from 1.956 – 1.961″ (my base to ogive measurement to achieve a .020″ jump is 1.958″). I don’t know if this is an error in my process, my press and die, or my calipers. I would be interested to hear any opinion on this. I have managed to reduce variation by trying to always use the same pressure and speed on the press arm, but this implies to me there is flex in the press and I didn’t think that would be likely.

A thou here or there is probably not significant in the end, but I am still curious. I know reloading can become an endless (and expensive) pursuit of consistency, the ends some shooters go to in search of accuracy blows my mind.

Rapid Fire Success

Last summer and a bit into Autumn I was attending NRA High Power practice shoots at MRC. If you recall on my first attempt at shooting rapid fire (10 shots in 70 seconds at 300yds prone) I got all my shots into the 10 ring. The second string was not quite so good. During one of the last practices I managed to do it again, but this time in both strings.

Second rapid fire string - Autumn 2014 practice

Second rapid fire string – Autumn 2014 practice – 300yd prone.

This picture is of my second string. Needless to say I was pretty pleased.

Now if I can just get the hang of the 200yd sitting and standing shooting I might be able to get somewhere in this discipline.

New rear sight (pimp my rifle) & Shooting Results: 300yd High Power Practice

I saved my pennies and got myself a rear sight (the one I was using was a loaner). I chose a Centra that was intended to attach directly to the rail on top of my AR, which it did. Here is a picture of it attached to my AR:

Centra Match Rear Sight

Centra Match Rear Sight

I took it with me to a high power practice at Minneapolis rifle club but I didn’t arrive as early as I had intended; which turned out to be a good thing because I figured out a very simple way to transfer the zero from the loaner sight to the new one.

I attached the new sight on the rail in front of the loaner and with the loaner set at my 300yd zero, adjusted the new sight until I had its aperture lined up between the loaner and the front sight rings. Then I removed the loaner and slid the new one back into position. It worked well because my first shot was in the 9 ring.

After sighters we shot a couple of rapid fire strings (in both strings the last round jammed, I think my bullets are seated slightly too long), I scored two 98/100. Then we shot a 20 round slow fire string. Below is my scorecard (which I discover is not quite the right one for 300yd slow fire, despite what it says).

300yd slow fire scorecard 2nd Sept 2014

300yd slow fire – 2nd Sept 2014

(I didn’t record the elevation as I hadn’t adjusted the scale plate at that point).

Pretty nice I thought: although I have to ask what is up with shot number 8, I dropped the same shot in my last slow fire string.

I will have to watch that one next time.