Myth Busting

For #1 I only use magnum primers cause it simplifies my inventory requirements.
For #2 Those of us that shoot 100 YDS or less have probably never thought about a difference as long as it was accurate enough.
With regards to #3. Alot of hunters went hunting with the good ole 30-30 in years past. Those rounds were either RN or FP and they did tend to shoot their deer in dense brush without many misses. So the RN bullet is good for brush (at close range) came to be an excepted thing. Now testing proves inconclusive at best.
Hope I helped clear things up.

As far as boat tail and flat base bullets , I'VE ALWAYS HEARD.... (Only heard, never tested myself) Flat base bullets are slightly more accurate under 200. Take it for what it's worth.

Being in NY I have shot many a rifle a below zero temp. If you shoot regularly you shoot in all types of weather. Cold is one of them. I had my Rossi refuse to eject at about 5 below. Pesky rifle. When its warmer no problem. Never had a failure to fire at the cold temps.

higgite said:

Thomasss said:

Myth Busting

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I see the myths. Where's the busting?

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When I do "myth busting" threads, I focus on either busting or confirming existing myths with measurable factual data that are repeatable (One such is the myth busting of digital scales where we shattered myths about digital scales, even cheap ones, against beam scales) - https://www.thehighroad.org/index.p...endence-from-work.853305/page-5#post-11672875

Since there are many reloading/shooting variables, some myth busting can be more difficult as these other variables must be reduced or eliminated first. So to conduct effective myth busting (And believable by THR peanut gallery), you would have to prove how you isolated the variable you are myth busting or confirming.

Thomasss said:

1) I really question the need to use magnum primers in cold weather.
2) Second myth is flat bottom bullets are better than boat tail bullets under 200 yards. I've been told many times it take longer distances for boat tails to stabilize.
3) Third myth is round nose bullets are better at brush busting than any other kind of rifle bullet.

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1) If I was doing temperature effect on powder/primers, I would focus on actual temperature of powder/primer and not the ambient temperature. Also, I would factor in influence of chamber getting hotter and raising power/primer temperature from repeated firing.

Since powder can be temperature sensitive (or even reverse temperature sensitive), test rounds need to be kept in an insulated container/ice chest and fired before warmed by hot chamber as if powder charge is warmed, can overshadow pressure variation from primer flash/duration affected by temperature.

2) If reloading/shooting variables can be made consistent enough, holes on target with large enough sample size could show accuracy trend. But this myth busting will be heavily dependent on your ability to reduce reloading/shooting variables.

3) Unless you can produce same/consistent enough "brush barrier", effect on target group size could vary. I think this myth busting will be difficult unless you are simply conducting comparison shooting through different barriers which will be different from what hunters will encounter in real life.

Thomasss said:

1) I really question the need to use magnum primers in cold weather. I've deer hunted in Wisconsin for over 50 years. I've seen all sorts of weather. I remember about 10 years ago the radio saying opening morning was 10 below 0. I've shot 30/30, 30.06, .270, and 303 British, .300 Win Mag and have never had a problem. I hunt all day long.
2) Second myth is flat bottom bullets are better than boat tail bullets under 200 yards. I've been told many times it take longer distances for boat tails to stabilize.
3) Third myth is round nose bullets are better at brush busting than any other kind of rifle bullet.

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I recently purchased and read through this book.

https://www.amazon.com/Short-Primer...d=1&keywords=B08BDXM96W&qid=1603431188&sr=8-1

I suggest you review its contents by some means (library loan, Kindle, whatever) WRT your item #1. Your personal experience, however broad you imagine it to be, is not all inclusive. Included items are discussion of the Federal 216 "Super Magnum" Primer used in some Federal factory ammunition but not sold as a retail reloading component and tests at Norma of the 30-378 Weatherby Magnum for Weatherby, among other items revolving around real life rifle detonation events including detonation of a near detonation (whatever that is) in a 300 (Remington) Ultra Mag rifle surmised as a result of a confluence of a too mild primer used in conjunction with a large volume case loaded with a slow hard to ignite propellant on a frigid day after successful load development in warmer weather.

Note rifle propellant technology continues to progress including WRT "slow burning" powders - recent examples I can think are IMR 7977 & IMR 8133, among others.

Your item #2 I've never personally encountered prior to your posting it. However in ignorance of this suggestion, anecdotally, if I didn't land a bullet of either design on my point of aim within 200 yards it's always been due to something I did or failed to do independent of whether the bullet used was flat based or boat tailed. Also anecdotally the obverse has been true in my experience.

I have no experience to draw upon for your item #3. This has really nothing to do with bullets launched from cartridges I've fired, and everything to do with "Know your target and what's beyond". I expect my lack of individual experience in this matter to continue through my remaining lifetime.

Isn't it strange that a fact that has been proven true over the last 60 years (that flat base bullets tend to be more accurate at distances under 200 yards) is still questioned? The question you should ask to determine if it is a myth, is "what type of bullets do the benchers shooters use for 100 yard groups."

"1" I have used magnum primers and still do in 30-06 "hot" loads, not max but close, and have noticed no unburned flakes.
"2" I usually use whatever is on sale, I think I am more of a difference than the difference between flat base and boat tail bullets.
"3" If I was to have to shoot through brush I would look closely at the 50BMG, it will go through a 3"tree and keep going.

When I work up a load for a new gun I try both FB and BT bullets since most of my shooting is 300 yrds or less. In 90% of the cases I end up getting better groups out of the BT bullet. I think back in the early days before bullets became high tech it was true, but not any more with the advancement in aerodynamics.

Thomasss said:

1) I really question the need to use magnum primers in cold weather. I've deer hunted in Wisconsin for over 50 years. I've seen all sorts of weather. I remember about 10 years ago the radio saying opening morning was 10 below 0. I've shot 30/30, 30.06, .270, and 303 British, .300 Win Mag and have never had a problem. I hunt all day long.
2) Second myth is flat bottom bullets are better than boat tail bullets under 200 yards. I've been told many times it take longer distances for boat tails to stabilize.
3) Third myth is round nose bullets are better at brush busting than any other kind of rifle bullet.

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1. magnum primers in which specific cartridge? There is no general rule for use of magnum primers at or under a certain temperature.

2. My experience - mostly with 223/224 diameter bullets is that under about 250 meters, the configuration of the base is immaterial.

3. In general, immaterial. I have decades shooting 110-125 grain bullets from 30 Carbine - at 1900 to 2000 fps - no difference was noted.

3a. Around 3,000 fps (and higher) the bullet's nose configuration MIGHT make a difference, but then actual performance will depend on muzzle velocity and how sense the brush is.