M91/30 Sniper

[villiers]

Patrick .... 70 years would make it only a tad older than my LE No 5, which I´ve never used with a scope. But even without, a good shot (maybe not me) could get them all in the black at 100 metres ... with iron sights. The old gents at 50 and 100 metres with star wars weaponry and erogenically phallic scopes are always good for a silent laugh. I like watching them spread out their paraphernalia, by which time I´m almost finished. When their targets are pulled back and are often no better´n mine, their scowl is always appreciated.

[Patrick Chadwick]

.... 70 years would make it only a tad older than my LE No 5,

Well, of course the Mosin Nagant 91/30 is basically just an upgrade of an 1890-ish long rifle, unlike the Lee Enfield No. 5, which is, of course, an upgrade of..........er...umm........ an 1890-ish long rifle?

Saturday's competition (limited to rifle models introduced before 1965, so the real black-plastic wunderwaffen were excluded) was won by a Finnish Mosin Nagant. What a bore - the guy scored 100/100. But not, I hasten to add, with anything like an original scope.

Ivan came 37th in a field of 58. Not brilliant, but no-one else was shooting an original PU3.5, or indeed an original military issue scope of any kind as far as I could see. As the round progressed, the problem was not the scope itself, but a serious loss of aiming stability through the mirage effect of the hot barrel making the target image dance around. It would not be fair to judge Ivan on that - those rifles were not intended for quasi-continuous precision fire. I think a bit of experimentation with a "cooler" charge is called for. And a touch of self-discipline to make better use of the time.

[fn111557]

Patrick, you need to hold the NEXT competition in Sept. – Oct. cold of Stalingrad! Targets should be replica WWII German helmets with stencils. Scoring is: 0 for a miss, 5 for hitting the helmet, and 10 for hitting the stencil. Also targets are presented (on a 5 second pop-up view timer) at random range of 100 to 300 meters.
Vasily Grigoryevich Zaytsev

[Patrick Chadwick]

This was Ivan's best group at the competition.

Attachment 43566

Rifle and ammo are perfect. It's just me as the limiting factor. The "0" is the kind of thing that really irritates me. You just can't score enough bulls to make up for that. And the worst is, I just have no explanation, other than I need a new set of eyeballs. Or more practice, maybe???

[bow]

Hi Patrick, could you speack about ammo you shoot? i reload with sierra 174 hpbt and vihtavuory n140. what you use? What kind of primer is best for conic case?

[Patrick Chadwick]

I use the published loading data from the Vihtavuori reloading book for N140, with a 180gn Sierra spitzer.

[bow]

Thanks. Have you ever shot 174 HPBT Match kings?

[Patrick Chadwick]

Ballistically, they should be fairly close up to about 300 yards. I.e. not identical, but in the sort of everyday correction range* for light, wind etc. that is easy to handle. A possible problem is that the throat of the MN is deep enough that the boat tail is coming free of the cartridge neck before the bullet is engaging the lands. This can actually lead to a worse internal ballistic performance and group size than with flat-base projectiles, as the gas blow-by on the bullet can cause it to be engraved with a slight skew**. Check the absolute maximum OAL you can use (with the bullet touching the lands) and if, in this position, the start of the boat tail is out of the case, stick to flat-base. That is precisely the situation with my 91/30. So the direct answer to your question is: yes I have tried HPBT, but the flat-base round-nose or spitzer types fly better in my rifle!

*Get the Sierra book for detailed trajectory values.

**I suggest that you get out your pocket calculator and work out how much skew over the length of the parallel section of an HPBT corresponds to 1 MOA. It is very, very, small.

[Patrick Chadwick]

Using the old rule of thumb:

1 MOA corresponds to 1" at 100 yds.
so
1 MOA is 1/1000" at 1/10 yd or 3.6"
and over half an inch (the approx. length of the parallel section on an HPBT)
1MOA is 1/1000" divided by 3.6 x2 or 7.2

About 1.4 tenths of a thousandth of an inch. Small enough for you?

So now it is clear why the bench-rest boys measure things like bullet run-out in the case.
And why they try to get the "slop" of the neck in the chamber down to well-nigh zero.
And why neck sizing your fired case, leaving an ever-so-tiny unsized ring at the bottom of the neck that provides automatic centering of the neck in the chamber improves accuracy.

It's not just nit-picky fiddling around - it really can make a difference - if you and your rifle are good enough.