quote:

Originally posted by sigfreund:
It would be interesting to start a thread discussing the errors in books, fiction and nonfiction, about ballistics, etc. Nicholas Irving’s books are a cut above most I’ve read, but as I recall there is even one howler in his first. Unfortunately I didn’t note where it was, so it would take some searching to find it again.

I don't know if you're talking about Nick's first version -- the rapidly produced, pre-sales to the public version. I have a signed copy somewhere in my book pile, but it would take a lot of digging.

The number of errors in grammar and spelling were interesting, as were some of the descriptions of scenes. I saw a final version in a library a few years later, and realized the editors did their work. Still, I like the first version. After shooting with Nick Nick for 5 days, the original book version just seemed more....real.

I totally get spelling errors and grammar, etcc. But conceptual, fundamental errors; that's different.

quote:

Originally posted by NikonUser:
[quote]I dial 200 yards into the elevation turret of my bullet drop compensator, then add an extra two half-minute clicks. This will accommodate the acute angle of incidence and high humidity./quote] That's on page 13 in the prologue.

What? That's exactly the reverse of what he should have done. Higher humidity makes bullets go faster because water vapor is less dense than air. Also, we was positioned above the target which means he would have to reduce the distance. Now, I never worry about angle of aim because I shoot horizontal to the ground in competition, so maybe I have that wrong and I'm happy to be corrected, but the high humidity thing is plain wrong.

+1 on the humidity point. Furthermore, at 200 yards with a modern center-fire chambering, the elevation compensation for humidity is really small. And the author states he added 1 MOA to the scope. 2" is a lot of change on a 200 yard target, especially when the change is going in the wrong direction.

I don't claim to be a high-angle shooting expert, but I have gone through the classroom discussions, and I've shot some down angles at shorter distances.

I attended Rifles Only's helicopter assault course a few years ago. We used AR-15s, shot from chopper heights of maybe 15-100 yards, with most down angles from about 10-30 degrees, with target distances from 50-200 yards. Our ARs were sighted in at 50/250 yards, so we could roughly shoot POA/POI for the courses of fire. None of us students had to adjust our elevations to hit targets.

Messing around at the end of the day, we got to eradicate turtles that were infesting one pond. The chopper hovered around 50-60 yards off the deck (that height didn't spook the turtles too badly), we shot at down angles of around 60 degrees. None of us needed to change our aim for the down angle.

Three times this year I've competed in steel matches where we had somewhat steep down angles to small targets. The first was maybe 30 degrees down to 3"x5" diamond-shaped targets at 70 yards. My 6.5 Creed is zeroed at 100 yards, which means it's also pretty much sighted in at 70 yards. I held zero elevation and whacked both diamonds dead center in elevation. Next we transitioned to a pair of 200-ish yard targets, with a down angle of about 20 degrees. I dialed my normal 200-ish yard dope and whacked the targets dead center in elevation.

A few weeks ago the match had a 70 yard target with a down angle of 30-ish degrees. I dialed zero, held center of target, and whacked center of target. The shooters who futzed with elevation still hit the target, but just barely.

*****
Now, say, 45 degrees down on a 600 yard target is a whole different animal. I would have to consult my compensation tables for anything along this level of complexity. But for the bulk of us, shooting at more moderate distances and angles, elevation compensation is right up there with spin drift and coriolis.

Yep, I agree that at 200 yards any possible difference in humidity would have negligible effect. I think it was a throwaway comment, and that made the whole sentence suspect. In reality, to compensate for humidity change, a half-MOA click on the scope is way too big so, his scope could not handle it.

When preparing for Ottawa, I found that the difference in humidity from say 100% to 20% was a small fraction of an MOA at 1000 yards, something like .2MOA. At 200, it would be undetectable.

I'll rely on you for the adjustment do to the shooting angle, but something told me it was also negligible at 200 yards.

Thanks for all the replies and information guys, I found it quite interesting and educational.

To the point about shooting at an angle, I remember reading an article about shooting up and down hill and if my memory serves me right the impact will always be HIGHER in both instances when compared to a level shot. So assuming the author knows the humidity is really negligible I'm not sure why the author would raise the bullet impact another 1 MOA when in fact it should have been lowered.

A quick google search found the article:

http://www.millettsights.com/d...phillanddownhill.pdf

fritz, your angled shooting experiences are well explained in that article.

quote:

Originally posted by jljones:

quote:

Originally posted by Napalm:
my Agency sends us to the Countermeasures Tactical Institute sniper course at Camp Williams, UT where we get to play w/some of the Reserve SF guys.

Is Doug still teaching it? I've taken a couple of their road classes in years gone by and it was taught by a couple of Kentucky State Troopers. (now both retired from the state police)

As of a couple years ago - Doug was still teaching it... And my partner and I were slated to go this year.

That being said, I have yet to attend the Reno PD regional sniper course. They were slotted for the same time of year (spring), and I opted to go to the RPD school - as I have not gone to that one yet.

Naturally - the RPD course initially got cancelled, but was ultimately rescheduled. The RPD course is scheduled to go in a couple weeks (Sept 11-15), and I/we will be attending...

quote:

Originally posted by NikonUser:

quote:

Originally posted by Wreckless:
1 moa for our Swat team was the minimum standard.

Understood. What kind of distances are we talking about here? And also, what shooting positions?

Not being a smart donkey, just trying to learn about stuff. I know absolutely nothing about sniping, LEO, military or otherwise; I'm just an old paper puncher.

One MOA is 1" at 100 yds, 2" at 200 yds, etc. We shot qualifications four times a year and familiarizations (zero checks) monthly at 100 yards. The qualification course is here:

http://www.state.nj.us/lps/dcj...rearms_2003final.pdf

Wreckless, thank you for explaining about MOA, I'm somewhat familiar with it.

I read the pdf to which you link and got the answer I was looking for, which you also stated in your reply. This is at 25, 50, 75 and 100 yards, with a scoped rifle.

I guess that's right in line with everything else about LEO snipers here, 100 yards or less.

Thanks again.

You are welcome. When I was certified as a sniper I attended two different schools at different times. Both were held at Fort Dix miltary ranges in NJ at distances up to 300 yards. First school was from a private security contractor, Peregrine Corporation, and the second was by the FBI who used USMC Scout/Sniper trained agaents as instructors.