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Posted: 2/26/2006 8:12:42 PM EDT
I still haven't been able to decide, I have been reading and researching..so here it is..im still stuck.


Lets say you were taking a intro precision rifle course..

You were taking an 18inch SPR, match barrel/chamber, tight go/no-gauage measurements....

You were shooting between 50-300yards in the great state of Texas' climate


What weight of .223 would you buy? Money isn't an issue really..

55grain BH Blue box or 73+grain BH Blue Box?

Im almost done breaking in my barrel with the 73+grainers, but it has been really fucking cold so accuracy has been not taken into consideration. I have a feeling that its going to shoot whatever Black Hills I choose, well.

But my main question is I keep hearing/reading conflicting 'reports' of 55grainers performing just as well or better inside 300yards.

But I know on a windy day, the 73+ will shoot with less windage correction needed compared to the 55grainers....

suggestions?
Link Posted: 2/26/2006 8:37:17 PM EDT
You are making this too complicated. It is EXTREMELY simple.

As a general rule - you want to shoot the heaviest match bullets, that your barrel will stabilize and shoot accurately. That is all. Period.

Now, the only thing that really matters, you left out of your post. Your barrel twist rate. If it is 1:7 or 1:8, then start with the 77SMK and try that out.

The reason you want to run a heavier bullet is for wind.... you will have less wind effect on the bullet. If you are VERY experienced with reading the wind, this will be less of an issue.

That being said - the majority of margin of error will NOT be in the ammo you choose. It will be in your general skills, and your ability to read wind.

Black Hills 52, 68, 69, 75, or 77 all will likely do well. See what your barrel shoots best, and practice with that. The 52's and 68's will be cheaper.
Link Posted: 2/27/2006 2:11:15 AM EDT
1:8 twist, sorry. so it'll handle everything.

maybe I am thinking too much about this..

this is my first precision course, hence the 'intro precision' so I should probably try to decrease and/or eliminate any factors/variables. Wind would definitely qualify on that list..
Link Posted: 2/27/2006 5:10:48 AM EDT
If a heavier bullet is moving slow enough, a lighter/faster one may have similar wind deflection while maintaining a flatter trajectory.

I don't have data comparing 77's, but here's a pseudo-M193 vs. Sierra 69 example:

Sierra 55 fmj @ 3200 fps. Max. point blank range is 280 yards, with a 240 yard zero, when using a +/- 2.5 inch above and below LOS limitation. "Drop" at 300 is 19.3 inches. Wind drift at 300 yards during a 30mph crosswind condition is 29.64 inches.

Sierra 69 Match(bthp) @ 2800 fps. Max. point blank range is 255 yards, with a 215 yard zero. Drop at 300 yards is 24.6 inches. Wind drift at 300 yards/30mph crosswind is 28.88 inches.

I would be curious how fast do 77's actually chrony in a 20 inch barrel. Drop at 300 yards? How HIGH is their midrange trajectory?

In the above example, M193 has around 5 inches less drop at 300 yards, while the "windage advantage" of the heavier bullet is LESS THAN AN INCH!

Paladin
Link Posted: 2/27/2006 7:15:40 AM EDT

Originally Posted By PALADIN-hgwt:
If a heavier bullet is moving slow enough, a lighter/faster one may have similar wind deflection while maintaining a flatter trajectory.

I don't have data comparing 77's, but here's a pseudo-M193 vs. Sierra 69 example:

Sierra 55 fmj @ 3200 fps. Max. point blank range is 280 yards, with a 240 yard zero, when using a +/- 2.5 inch above and below LOS limitation. "Drop" at 300 is 19.3 inches. Wind drift at 300 yards during a 30mph crosswind condition is 29.64 inches.

Sierra 69 Match(bthp) @ 2800 fps. Max. point blank range is 255 yards, with a 215 yard zero. Drop at 300 yards is 24.6 inches. Wind drift at 300 yards/30mph crosswind is 28.88 inches.

I would be curious how fast do 77's actually chrony in a 20 inch barrel. Drop at 300 yards? How HIGH is their midrange trajectory?

In the above example, M193 has around 5 inches less drop at 300 yards, while the "windage advantage" of the heavier bullet is LESS THAN AN INCH!

Paladin



HENCE! my confusion..
Link Posted: 3/1/2006 5:59:16 PM EDT
btt for anyone else
Link Posted: 3/1/2006 6:08:43 PM EDT
Id use 69 grain for that range if I was handloading. You will have less drop and deflection most of the time. If I was shooting at anything but paper I would use 75 grain.
Link Posted: 3/1/2006 6:12:26 PM EDT
once i get out from campus renting, i'll have a 'man room'. Handloading will be my first addition to my 'man room'

did i mention i was getting a 'man room'

I didn't consider dropping below 70grain, but it does make sense, a little of both worlds..
Link Posted: 3/1/2006 10:50:47 PM EDT
Yeah, get a couple of boxes of the 68gr and 69gr and see which shoots better in your gun. Let the ammo make the decision for you.

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