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308 Win and bullet weights. When does wind become a factor at 300 yards? Login/Join 
Yeah, that M14 video guy...
Picture of benny6
posted
I want to find a good load for my 300 yard line. This will be a competition load, firing over 20 rounds for score. The X-ring is 3" wide and the 10-ring is 7" wide.

Ideally, I'd use a 130 grain SMK (or was it 135?). Either way, it's discontinued, so I'm looking for a more appropriate bullet for 300.

I've never tried the Speer 125's at 300, but they are stellar at 200. I'm wondering if they'll be sufficient at 300. I might try some on my next range trip and have them screaming along at around 2900 FPS.

I'm also considering a 150 grain SMK or a 155 Hornady ELD match.

I think it's a waste to shoot 168's and 175's at such a close distance. I'm also going to be tinkering with 169 Sierras on my next 600 yard session. I'll get some groups with those at 300 as well. The match is single-feed at both 300 and 600 yards, so I'm not concerned about seating to mag length.

Thoughts?


Owner, TonyBen, LLC, Type-07 FFL
www.tonybenm14.com (Site under construction).
e-mail: tonyben@tonybenm14.com
 
Posts: 5550 | Location: Auburndale, FL | Registered: February 13, 2001Reply With QuoteReport This Post
Green grass and
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In .308 I like 165gr. Nosler Myself.



"Practice like you want to play in the game"
 
Posts: 19827 | Registered: September 21, 2005Reply With QuoteReport This Post
Freethinker
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That’s the sort of question best answered by running figures through a ballistic calculator such as JBM.

Out of curiosity I ran a couple of loads, the Speer 125 grain TNT at 2900 feet per second under “standard” atmospheric conditions, and the Sierra 168 grain MatchKing at 2600 fps.

According to the Applied Ballistics solver, a 5 mile per hour full value wind deflects the Speer 125 grain 4.77 inches at 300 yards; the same wind deflects the 168 grain SMK 3.19 inches. The different isn’t much, but neither is a difference of 5 mph. At 10 mph the values are 9.43 inches and 6.24".

I have no experience with the Speer bullet that I gather is a varmint style, what sort of precision do you get with it? I don’t know what level of accuracy you need at 300 yards, but it seems to me that a dedicated match type bullet might give you somewhat more consistency confidence.

Ultimately of course your view of what’s a “waste” is what matters, but given all the dedicated effort (not to mention expense) you’ve put into the endeavor, getting even a little better performance from the components would be worth it if the decision were mine.




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“Cet animal est très méchant, quand on l’attaque il se défend.”
 
Posts: 47789 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
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quote:
Originally posted by benny6:
I want to find a good load for my 300 yard line.

I am surprised you didn't start with ballistics program data, such as JBM.

Putting things in perspective, your X-ring is about 1 MOA and your 10-ring is about 2.3 MOA. IMO most of the paper-target competitions take place at ranges that generally have calm winds. As opposed to western & prairie states, where steel-target matches generally deal with significant winds. The expected winds at your competition locations should be considered. If you rarely shoot with cross-wind values above 5 mph, then wind drift of various loads can take a backseat to overall accuracy.

I've shot quite a few different factory loads through my 308 bolt action. The following all have 10mph crosswind drift values of 1.7 MOA at my winter conditions. Understand that due to your lower elevation, increase the drift by about .2 MOA (i.e. to 1.9 MOA). My summer drift values at 300 yards are about .2 MOA less (i.e. 1.5 MOA).
Hornady 155 Amax
Hornady 168 Amax
Federal GMM 175

Loads with 1.8 MOA drift in my winter conditions.
Federal GMM 168
Lapua Scenar 167
Lapua Scenar 186

Loads with 1.5 MOA drift in my winter conditions.
Black Hills 168 TMK
Black Hills 175 TMK
Corbon Scenar 155
Hornady 168 ELD-M
projected loads with the new Sierra MK 169
Corbon SMK 190
Lapua Scenar 155

The on-target drift distance at 300 yards for a 1.5 MOA drift bullet vs. a 1.7 MOA drift bullet, with crosswinds of 10mph, is about .6 inches. So...1 bullet diameter for 5 mph winds, and 2 bullet diameters for 10 mph winds. In relatively calm conditions, at 300 yards, I consider load accuracy more important than bullet drift.

Unless something is wonky with the barrel and its mounting, expect bullet dispersion to be a relatively consistent circle. Look at your current impact patterns on targets. If they are generally circular, then wind (or wind calls) likely isn't the primary focus. If your patterns are an oval going 12 o'clock to 6 o'clock, then wind is the least of your issues. If the patterns are an oval going from 3 o'clock to 9 o'clock, and if you're shooting in anything other than calm conditions, then wind drift and wind calls will be extremely important.

IMO bullet accuracy comes first. If you're shooting a lot, then bullet behavior over the effective life of the barrel enters the mix. The Hornady Amax and the older SMK bullets generally shoot well in quality barrels as throat erosion occurs.

Some high-BC bullets don't play as nicely with older barrels, and/or they are very picky about the jump to lands. Sierra's TMK bullets are high on the list. From the few trustworthy reports I see about the new SMK 169, expect the same thing. There are a number of folks who praise the BCs of these Sierra bullets, but show only limited good target results with them. Hornady's ELD-M bullets seem to be one of the more consistently accurate high-BC options, although I feel a lower-BC more traditional HPBT bullet is still better as a barrel approaches end of life.

The few loads I've shot with Berger bullets are definitely accurate. I know some guys who hand-load with Berger match bullets, and they are pleased with the results.
 
Posts: 8059 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
Yeah, that M14 video guy...
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quote:
Originally posted by sigfreund:

I have no experience with the Speer bullet that I gather is a varmint style, what sort of precision do you get with it?


Here's a target I shot with it, rested on a sandbag in prep for a match, and getting initial data. 100-9x at 200. This was a M14 EBR with a Kreiger barrel. We use the 125's whenever possible because it's a soft shooting round and will really help scores improve during the rapid fire string. It doesn't beat up your position as much as a 168 or a 175.


98-3X on match day, prone slow fire.


95-1X on match day, prone rapid fire.


I ordered a box of 155 ELD-M's and I'll compare them with a box of Sierra 155 grain Palma's that I have here as well.

The range I shoot at is on the coastline and winds pick up around 10am. Winds can be 5 to 20 MPH, depending on the weather.

The 200 yard GSVM match starts at 8:30 and finishes around 9:45

The vintage sniper match starts around 10am at 300 and we are usually shooting the 600 yard line by 11:15am. I have shot some matches where I was holding the left edge of the 9-ring to land them in the X-ring. My biggest problem I had during the last match was an elevated hear rate. My crosshairs were bouncing around too much to get a consistent shot. I may have to soft-shouler it next time to see if I can get a better group that way.

Tony.


Owner, TonyBen, LLC, Type-07 FFL
www.tonybenm14.com (Site under construction).
e-mail: tonyben@tonybenm14.com
 
Posts: 5550 | Location: Auburndale, FL | Registered: February 13, 2001Reply With QuoteReport This Post
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Reading and Learning.
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Posts: 3389 | Location: MS | Registered: December 16, 2004Reply With QuoteReport This Post
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Not specific to your question, but I have great luck in .308 single shot and bolt pistols with Vihtavouri N133 with 130 Hornady spire point.
 
Posts: 7665 | Location: Over the hills and far away | Registered: January 20, 2009Reply With QuoteReport This Post
I have not yet begun
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quote:
I think it's a waste to shoot 168's and 175's at such a close distance.

If it’s a match counting for score, I’m at a loss to see how it’s a “waste” shooting anything that performs well.
If in fact those bullet weights do perform well, I’d use the hell out of them and never look back.


--------
After the game, the King and the pawn go into the same box.
 
Posts: 3898 | Location: Central AZ | Registered: October 26, 2006Reply With QuoteReport This Post
Yeah, that M14 video guy...
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Perhaps this whole thread was an exercise in critical thinking. After reading all the responses, I think I was stuck in the "Across the Course" (XTC) mentality. Sometimes we want to ask a question, but we don't always use the most appropriate wording in the thread title. Maybe I should have just asked "Whats' your pet load for 300 yards?"

In a XTC match, the only stage at 300 yards is rapid prone. In rapid prone, just like rapid 200, you want to try and avoid interrupting your position, hence, you don't want a load that is heavier on recoil which will beat you out of position. It's not so much an issue when shooting an 223/5.56, but it becomes an issue with a 308, and shooting a M14 at that.

I have my pet loads for 100, 200 and 600 yards, but I shoot 300 the least. I was seeking data on other shooters' pet loads, if they have one, for the 300 yard line.

And as far as the ballistics programs, there's what the computer spits out and then there's experience from actual shooters. I guess I was just seeking personal experiences from shooters that have shot in those conditions, wanting to know how much wind really affected their scores at 300 and if anyone else uses a specific bullet weight at that distance.

But after re-reading and re-thinking this whole thing, yeah, why do I care about being beaten out of position? I shouldn't! The course of fire is single-feed, slow and cadenced. Recoil is a moot point! Thanks for helping me break out of this conditioned thinking I was stuck in.

Well, I hoped someone else learned from this at my embarrassing expense.

But hey, any advice dispensed by Sigfreund and fritz is always beneficial for discussion and I am grateful for them taking the time to participate.

Tony.


Owner, TonyBen, LLC, Type-07 FFL
www.tonybenm14.com (Site under construction).
e-mail: tonyben@tonybenm14.com
 
Posts: 5550 | Location: Auburndale, FL | Registered: February 13, 2001Reply With QuoteReport This Post
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quote:
Originally posted by benny6:
Perhaps this whole thread was an exercise in critical thinking. After reading all the responses, I think I was stuck in the "Across the Course" (XTC) mentality. Sometimes we want to ask a question, but we don't always use the most appropriate wording in the thread title. Maybe I should have just asked "Whats' your pet load for 300 yards?"

In a XTC match, the only stage at 300 yards is rapid prone. In rapid prone, just like rapid 200, you want to try and avoid interrupting your position, hence, you don't want a load that is heavier on recoil which will beat you out of position. It's not so much an issue when shooting an 223/5.56, but it becomes an issue with a 308, and shooting a M14 at that.

I have my pet loads for 100, 200 and 600 yards, but I shoot 300 the least. I was seeking data on other shooters' pet loads, if they have one, for the 300 yard line.

And as far as the ballistics programs, there's what the computer spits out and then there's experience from actual shooters. I guess I was just seeking personal experiences from shooters that have shot in those conditions, wanting to know how much wind really affected their scores at 300 and if anyone else uses a specific bullet weight at that distance.

But after re-reading and re-thinking this whole thing, yeah, why do I care about being beaten out of position? I shouldn't! The course of fire is single-feed, slow and cadenced. Recoil is a moot point! Thanks for helping me break out of this conditioned thinking I was stuck in.

Well, I hoped someone else learned from this at my embarrassing expense.

But hey, any advice dispensed by Sigfreund and fritz is always beneficial for discussion and I am grateful for them taking the time to participate.

Tony.


I don’t see any reason to be embarrassed. I enjoy and often learn things from your posts and the posts of the other folks in this thread.
 
Posts: 493 | Location: Upstate NY | Registered: October 09, 2018Reply With QuoteReport This Post
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