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Speed wins (.308 Question)

momo_

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Minuteman
Jun 16, 2014
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So I have heard alot of the recent podcasts and I follow Franks reasoning of Faster and lighter with regards to bullet selection.

With this in mind I want to look at trying something new with my .308, I have a Tikka T3 CTR, .308, 20" factory barrel 1:11 twist. I am shooting like many others out there the 175 SMK and I am getting 2580fps with my handloads. I use my rifle for plinking steel and now the local precision rifle competitions that I just started.

I am looking at the Hornady ELD Match range of bullets as they are easier for me to find than the Sierra, I would like any advice on what to look between the 168 ELDM and the 155 ELDM for my application.

Secondly Frank mentioned with Bryan something about the 168 grain bullet, and it was mentioned that these where optimized for 300m, I dont fully understand the history around this and is this something I need to stay away from as it is problematic or are these issues that have been resolved with this grain bullet?

Much appreciated and thanks Frank for always opening up our minds to different ways of doing things
 
I've just started listening recently.

The 168 SMK is the bullet they were referencing I believe as it is known to not transition well through transonic. I don't know how the ELDM 168 flies but I am certain the info is out there.

Check out the normalizing factor information with Josh Kunz podcast. There is some good info that will shed more light on the lighter faster subject.

Example: your 175 has a f1 listed at .496 at 2580 fps. BC x MV = 1280 normalizing factor.

A 155 ELD would be .461 x 2800 = 1291.

If you can drive the 155 to that 2800 or higher (my 16" is pushing fgmm 175s to 2450 and handloaded 155s to 2730) then it should do better in the wind. There are more details but give 236 a listen.

I grabbed those bc values from the manufacturer website so at your exact MV they are likely different.
 
momo... I've hit paralysis through analysis on this. As my supply of 155 Amax dwindles, I'm looking for a better option.

I'm shooting a Rem LTR 20" 12-twist barrel, so higher velocities aren't really an option. I've narrowed it down to the 175smk, 168eldm, 178eldx, or 155 scenar L. Main focus for me is bucking the wind from 400-800 yards. According to JBM, the 178eldx wins but the 168eldm looks like a good compromise.

Guess i need to listen to podcast 236.

Can some of you more experienced 3-0-haters help us out?
 
We were talking the original 168gr SMK, not the newer variants

Many bullets have changed over the years, minor improvements etc, so the numbers even by weight will vary so you have to put it in context by saying 168gr SMK vs the other more modern ones.

A 308 is hard to talk about in this context because we focus on the middle more than the ends. In other words a 175gr is not light or heavy in this discussion, it's the better middle-ground solution. You can get great(er) performance out of a variety of bullets if you load them right. Like a 185gr Juggernaut. With the right powder, speeds are no problem.

Most people with a 308 do the same thing everyone else did the day, week, year before. We do the "military" load of the 175gr around 2575fps because that is what the military does. Sure velocities change all day, but the thinking is the same. 175gr and you are done.

Consider the discussions I had with the 185 load, instead of Varget, or 4064, I use 2000MR for the 185 and velocities will be better than a factory 175. That means it's a better overall load, and I went heavier than a 175, or 168, but it's lighter than a 208 or 190

30 Cals are stacked deep in choices. So we are not really debating heavier or lighter, but bouncing the middle based on the potential, which usually revolves around barrel length.

Remember the Gladius was originally a Tight bore 308 at 18" long designed to push a 175gr at 2600fps, that is pretty optimal for that weight. If the barrel was longer or shorter, I would want to look at mixing things up
 
Thank you for the knowledge.

After listening to the podcast, you talk about getting to the 2800 mark on velocity to realize BC, but it's on the 6.5 and not the 308. Not sure if that makes a difference or not, but assuming that is the min velocity we're looking for... since the OP and I are shooting 20" barrels with less than 10 twist, hitting 2800 isn't likely with a mid to heavy weight bullet. So the numbers on JBM telling us BC always win (the farther you go) isn't always true?? In our case, speed would be better than the heavies??

My 155's are going 2670. That's close to the "150 fps" below 2800 you referred to to where it's better to chase velocity.

It makes sense. I wish i had the time and resources to verify for myself. As much as I'd like to shoot the 178 or 185, OAL mag length will rob me of velocity even further, so the lighter/faster wins again (in our case).

I understand what you said about switching powders, but since i have Varget on hand, I'm sticking with it for now.

Does it sound like I'm starting to see the light?
 
This is making alot of sense to me as I play around with the numbers. Unfortunately I am restricted to go out and do the actual testing so it's just crunching numbers for now.

@lowlight was spot on in saying that people including myself just went the 175 SMK "military" load and left it at that.

Will be looking at other powders as suggested, I just had used Varget in the past so stuck with it
 
As Frank was saying, monkeying with "The Middle" for the 308 comes from getting optimum performance to meet a fixed standard (which before Gary Anderson's win with a 308 was done with a 30-06!).

The 168 Match King was optimized for the Olympic 300 Meter discipline -- still popular in Europe but no longer an Olympic event:


What Is 300 Meter Rifle Shooting?
by Reya Kempley - Monday, August 14, 2017
What Is 300 Meter Rifle Shooting?


https://www.ssusa.org/sign-up-for-updates
"{While it remains an obscure discipline in America, 300 meter rifle is Europe’s equivalent of our high power rifle. In decades past, when greats such as Lones Wigger and Margaret Murdoch ruled the podium, 300 meter rifle was the premier rifle event in the Olympics. Men and women competed together. Smallbore shooting was considered a training event at that time. But as cities grew, firearms laws became more restrictive, and the price of centerfire shooting increased, it was removed from the Olympics. Numerous national and international competitions are still held every year, and it remains in the ISSF World Shooting Championships along with other non-Olympic events such as running target and women’s smallbore prone. The World Championships are held every four years between the summer Olympic years. The next will be held in Korea in 2018.

Today, the men have three 300 meter events: 3x40 free rifle (40 shots per position: kneeling, standing, and prone), 3x20 standard rifle, and free rifle prone (60 shots). The women only have two events: 3x20 sport rifle and prone (also 60 shots). Rifles look similar to those used in Olympic smallbore competition because the equipment rules are essentially the same. You’ll see hook-style butt plates with plentiful adjustments, aluminum stocks, and bloop tubes to extend the sight radius. The exception is the men’s standard rifle event. This rifle looks similar to the women’s standard rifle of days gone by (think Launi Meili’s gold medal in 1992) except it must have a trigger weight of at least 1.5 kilograms or 3.3 pounds. Despite the limitations in adjustability and trigger weight, standard rifle shooters can post scores well over 580 out of a possible 600—comparable to free rifle scores. Steve Goff and Jason Parker are two athletes of recent years who were among the world’s best with this rifle.

300 meter rifle competition

Left: This welcoming 10-point range in the small town of Lienz, Austria is representative of European 300 meter ranges. You may gaze upon a lovely waterfall on the mountainside between shots. Photo courtesy Reya Kempley. Right: The author and Justin Tracy at the 2013 USA Shooting 300 meter Nationals, Fort Benning, GA. Photo courtesy Tony Chow

In the glory days of 300 meter shooting, the .30-06 Springfield was the standard caliber in America. Think of shooting 40 shots per position with that recoil! Thankfully, cartridge technology has progressed since then. The most popular caliber in the world today for this discipline is the 6 mm Benchrest (BR). This cartridge offers superb accuracy, low recoil, a long barrel life, and extreme ease of hand loading. Other calibers such as 6XC and 6.5x47 have some following as well. The vast majority of European competitors shoot factory-loaded ammunition by Lapua or Norma, which is capable of shooting under half-minute groups at 300 meters. However, in this country the cost can be prohibitive (dollars per round), which leads more of us to shoot our own DIY ammunition. We can squeeze a bit more accuracy out of the cartridge that way too. If you do handload, be prepared to ogle at the piles of once-shot Lapua brass the Europeans casually dump into the range brass bucket!

The maximum caliber allowed in ISSF 300 meter events is 8 mm—though I question the sanity of anyone who would choose to shoot such a caliber! All shots are scored as if the bullet diameter is 8 mm. The black starts at the 5-ring, which measures 60 cm, or about 23.5 inches. The 10-ring is a mere 10 cm, or around four inches. Compare this to the American high power 300 yard target, which has a 10-ring of just under six inches.

You may be thinking that building a rifle and buying equipment for such a specialized event with few competitions in America is a silly proposition. But the good news is you can shoot other American high power matches as well—NRA mid-range prone matches, for example, in the “Any Rifle” category. Under these rules, you can use your entire ISSF-legal kit, including the hook-style butt plate. A 6 mm BR on a windy day may be slightly disadvantaged against other common calibers for this distance, but you’ll find the 10-ring seems huge after shooting on the challenging international target. It’s almost double the size in terms of minute of angle.
Ft. Benning Range

A down range view at Fort Benning, GA. The screens in the foreground are meant to reduce wind for the 50 meter smallbore range. Photo courtesy Reya Kempley

Two 300 meter ranges with electronic targets exist in this country: one located in Minnesota and the other at Fort Benning, GA, for the U.S. Army Marksmanship Unit. If you’re lucky enough to live near one, a few clubs around the country actually shoot 300 meter matches, often reduced to 300 or 200 yards. I have shot a very well run 200-yard reduced match in Seitzland, PA, where high power shooters without ISSF-legal equipment were also welcomed to participate.

In Europe, 300 meter ranges abound. To those of us used to the rustic conditions of outdoor firing lines, pits, and manually-operated carriers with paper targets, European ranges feel much more civilized. The firing line itself is often enclosed within a building, with large doors that open downrange. Electronic targets are the norm. Because of the higher population density, ranges include walls and baffles to reduce sound and stop stray bullets from exiting the area. A bar serving alcohol may adjoin the range.

I encourage you to give this fun and historic discipline a try! Why not get a match started at your local club? There's no need to enforce the ISSF equipment rules at first—check out the target and course of fire initially to see how much fun it can be. You might find the American high power target a smidge easier afterward, too. The USA 300 Meter Nationals and World Championships Team Tryout will be held at Fort Benning, GA, this September. Go to this link on the USA Shooting website for the schedule and program, under Rifle/Pistol Fall Selection."
 
The 168 stuck around so long because it served well in M1s and M14s at Camp Perry out to 600 yards, and in Federal Gold Medal Match was unequalled in thousands (if not tens of thousands) for the price, consistency, and availability in 308-caliber police bolt action rifles to 300.

The Sierra 175 was to optimize performance with the M14 for the 800-900-1000 yard Service Rifle Match formats at Camp Perry, shot with an M1 and 22-inch M14. That bullet also got better performance out of M118 Special Ball (formerly using a 173-grain bullet, but starting to go into the toilet as far as precision due to worn-out Lake City bullet-making dies).

As the AR-10 came aboard with its two inches shorter-than-M14 barrel, the Berger 185 Juggernaut allowed the USAMU to advance past the M14 at 1,000 yards.
 
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If you are looking specifically at 155-168 class bullet then you should take a hard look at IMR8208xbr. it is a great powder for the lighter bullets.
I use it for both 155 scenars and 168 bergers. If availability is an issue you can use AR-COMP (2nd choice)
You get excellent temp stability with good speeds your accuracy potential can be achieved with this powder
during my time with the 308win i have run the range of bullets 125 up to 215's and 8 different powders.

My precision rifle runs 168 bergers with IMR 8208xbr 26" barrel and i can get 2890fps which is above the PRS speed template you do not require SRP for these speeds I use Norma brass mag fed but COAL is 2.91
F class rifle is a specialty rig looong freebore running 215's single loading and SRP brass is mandatory

The topic of 185 bergers came up and i have to kindly disagree with Frank i haven't found a double based powder that doesn't require special attention to temperatures. N550 required a morning and afternoon load depending on the temp swings.

Here is my caveat all my testing is based on 1/2moa target at distances out to 1,000 and my requirement to have a load that stays within this requirement from 32-90 degrees during matches. This testing method has carried over for all disciplines f class and precision...2000MR may give you the desired accuracy throughout the temperature swings given your min target size

For 185's single based powders like Varget (of course) or N140 will give you the desired speed, good accuracy and temp stability.
I tried AR-COMP but there was too much pressure with less speed then the others mentions.
IMR 4320 ahh it was just ok

Cheers
Trevor
 
Im running 185’s with MR2000 in a .308 and getting 2717 fps ave and low sd’s. Ill take that all day long.
What OAL, which brass and primer, and how many grains are you using? If you don't mind sharing.