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Old December 27, 2013, 09:48 PM   #26
SR420
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Bart B. Supressors and accuracy. . . . .


While nobody's offered any explanation as to exactly how a supressor improves accuracy...
.....................

Quote:
A properly designed blast baffle will strip and deflect much of the bottle-shaped blast of high-pressure gas that envelops and pursues the departing bullet. For this reason, one can logically expect an increase in practical accuracy when a properly designed suppressor has been installed.

Also, the weight of a heavy steel unit tied to both the center and end of a rifle barrel does beneficial things for harmonic barrel vibration - dampening out much of it. These two factors greatly increase the practical accuracy potential of a suppressed rifle. The properly suppressed rifle becomes very stable and reliable. Larger internal clearances reduce the likelihood of baffle contact in the event that the suppressor or barrel get slightly damaged or bent.

Also, the M21A5 that shot sub MOA groups @ 1000 yards was a semi auto built on an LRB receiver.
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Old December 27, 2013, 10:08 PM   #27
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You've asked for opinions so I'll give you one. If I was you, based on your price range I'd get a LM&T MWS or a Knights.

But for me I'd get a S&W M&P 10 with its 18 inch barrel, 5 R rifling, melonite barrel and ambi controls. For far less money.

No doubt the LM&T and Knights are outstanding guns, but I'm not an armchair commando. If the S&W isn't as accurate as I like it to be I'll change the trigger and if necessary the barrel and still be way ahead monetarily.
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Old December 27, 2013, 11:05 PM   #28
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I tend to be a bit length yin my decision making process, especially when I am forking out some real cabbage. LOL

Based on all the inputs, my favorites have been narrowed down to the Sig 716 Patrol FDE in 16", the POF .308 in 18 or 20" or either the M1A National Match or Super Match (wood stocks)

My goal is to get the rifle, sling, scope and mounts, bipod and suppressor for under $3,500 - 3,700.

Part of me wants to get the most badass rifle out there and take it out to the range and shoot MOA's around everybody there, but my ex-sniper friend has already brought Major Tom back dow to reality with a firm, 'Dave, 99.75% of all great shots are due to superb marksmanship, the remainder goes to a quality firearm properly maintained. Basically, with any good solid quality, out of the box, off the production line rifle, he said he will shoot my butt off the range every day, each day and forever more until I train to the point where I reach his skill level, which was over a decade in the making.

So, he told me, 'Get a good solid platform, with great customer service in case there is a hiccup or you just have question, and is made of quality parts. You can tweak almost any rifle and then bring it to 6 MOA at 1,000 yards and sub 2 MOA at 300-400 yards with high end ammo and lots of practice.

Basically "Learn your firearm young Danielsan"! Remember, you are a beginner and beginners don't shoot off flies testicles at 1,000 yards, they hit any part of a full size body target and think, 'Gotcha' and are happy. He told me to start shooting the wings off dragon flies at 25 yards and then move out at 25 yard increments. :=)

So, my final choices are:

1) Springfield F716 Patrol FDE 16.1" barrel .308 $1,859
2) POF .308 in 20" barrel $2,500
3) M1A National or Super Match .308 $1,900 to 2,450
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Old December 27, 2013, 11:21 PM   #29
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http://www.gunbroker.com/Auction/Vie...Item=382397715

http://www.gunbroker.com/Auction/Vie...Item=382724315
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Old December 27, 2013, 11:45 PM   #30
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HoosierDave, nobody's going to shoot MOA at 1000 with any of those rifles and the ammo you have. None of those rifles are that accurate with even the best handloads. The best of the M1A match versions with Federal Gold Medal Match would shoot about MOA at 300 yards; at 1000 it could easily be 2 MOA. Group size ain't the same all the way down range.
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Old December 27, 2013, 11:49 PM   #31
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If you are shooting within 10" at 1000-yards, you are shooting 1-MOA or less.
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Old December 28, 2013, 08:03 AM   #32
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If all shots fired don't go inside 10 inches at 1000, it's not MOA accuracy that far away. You'll need no worse than 1/3 MOA accuracy at 100 yards to do that.
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Old December 28, 2013, 09:23 AM   #33
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This thread seems to be all over the road, but I gotta bite...

How, exactly, does the rifle/ammo go from being capable of "x" accuracy (measured in m.o.a., if you like) at 100 yards, to "x+?" at any further given range?

I'm lost in this differentiation.

Beyond 100 yards, external influences on the bullet become the overriding factor in accuracy which for practical purposes don't exist at 100 yards.

So, how can one state that the hardware is "X m.o.a." at 1000 yards, when it's impossible to quantify and account for this (unless one had a "houston warehouse" that was 1000 yards in length)?
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Old December 28, 2013, 09:59 AM   #34
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If all shots fired do go inside 10 inches at 1000, it is MOA accuracy or better at that distance.
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Old December 28, 2013, 10:05 AM   #35
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tobnpr, one way groups enlarge is muzzle velocity spread. A .308's typically going to have bout 2/10ths inch drop difference between a given bullet leaving at two velocities 50 fps apart; that's 2/10ths MOA. At 1000 yards, the difference in drop's about 20 inches; that's 2 MOA.

Another way is the small spread in BC's bullets have. Even the best match bullets are not all perfectly balanced and they'll wobble different amounts spinning as fast as they do. The more they wobble, the more drag they have. As drag increases, BC drops. So, even if 20 of them leave at the exact same speed, a 1% spread in BC causes a spread in how much the slow down and drop. It's typically not more than a couple inches at 1000 yards. If those bullets are deformed enough when fired, they'll have more spread in BC and the vertical shot stringing at long range will get bigger.

A third way is the atmosphere. It's not all the same density from muzzle to target. Thicker air slows down bullet speed more than thin air. It slowly changes as those subtle air currents move it around. It also changes a bit with air temperature. And even slight wind speeds are not the same from the line of sight to the maximum height a .308 bullet goes above it; about 11 feet above at 550 yards or so for a 1000 yard zero. On different terrains, the wind speed that high above the line of sight will be 30% to 90% faster than at the line of sight.

Groups at 100 yards open up about 10% for eacGh 100 yards further with the best stuff making them. Lesser systems will have a greater amount of group angle subtension as range increases. Best way to see it is compare the benchrest records for aggregates at 100, 200 and 300 yards. They get bigger in MOA's as range increases. Same for 600 and 1000 yards.

All the groups are about zero MOA at the muzzle, aren't they?

But there's an exception; positive compensation due to barrel whip in the vertical axis and muzzle velocity. Some barreled actions (the Brit's .303 SMLE's for example) have a lot of whip in the vertical axis. Their cordite loaded ammo has a wide muzzle velocity spread as the left on the muzzle's up swing just before it reached its peak. Bullets leaving slower left at a higher muzzle angle than faster ones that left slower. At long range, this improved accuracy. But accuracy suffered at short and mid range targets where M98 Mauser barreled actions shot that .303 ammo more accurate than at long range. No wonder the Brits did so well in long range competition when that arsenal ammo had to be used.

If long range accuracy tests are done just before sunrise when the winds are calm and it's cool enough to see bullet holes in targets, that's the closest thing to a "Houston Warehouse" for 1000 yard tests.
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Old December 28, 2013, 10:34 AM   #36
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HoosierDave1967

So, my final choices are:

1) Springfield F716 Patrol FDE 16.1" barrel .308 $1,859
2) POF .308 in 20" barrel $2,500
3) M1A National or Super Match .308 $1,900 to 2,450
Of the three, I would probably go with the POF.
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Old December 28, 2013, 02:52 PM   #37
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I bet it was the same internet commando told everybody back in '04 that the renewed use of the M14 was just a stop gap measure that would only last a year or two...
The Army still hasn't figured out a uniform SDM rifle yet. I think having so many platforms in the mix (M4, M16, M110, M14 EBR) has worked so well that everyone is afraid to settle on a single system.

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Old December 28, 2013, 06:47 PM   #38
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Well said, Jimro.
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Old December 28, 2013, 06:52 PM   #39
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Thanks to everyone for their input. I have decided to go with the POF .308 in a 20" barrel with a LT706 QD Swivel Mount Combo and a Horus H59 Raptor 4-16x50 scope, all for less that $3,700, within my original budget.

I really liked the M1A but the Super Match and M21, but just decided on the POF. I also liked the LaRue OBR and PREDOBR and the GAP-10, but did not want to wait for many, many months.

Happy shooting to everyone.
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Old December 28, 2013, 07:31 PM   #40
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The Army still hasn't figured out a uniform SDM rifle yet. I think having so many platforms in the mix (M4, M16, M110, M14 EBR) has worked so well that everyone is afraid to settle on a single system.

Jimro
We know how smart those DD purchasers are. They're buying F-35 fighter jets for $135 million dollars each, which have no opponents, yet the poor grunt on the ground has an M14 that was cutting edge in 1962. I can't help but question the judgement of anyone that thinks that's a good thing.
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Old December 28, 2013, 07:42 PM   #41
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Eppie, both the AR10 (M110) and M14 (MK14EBR-RI) were cutting edge in 1962.
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Old December 28, 2013, 07:44 PM   #42
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Inspirational POF pic.

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Old December 28, 2013, 10:52 PM   #43
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To original poster. I own a POF 308, although I've only had it a couple of weeks, so I haven't put a lot of rounds down range yet.

I really like the rifle and have no regrets, but there are a couple of things you should know before you buy.

The good - 1 They are very well made with high qualtity parts.

2 Piston does keep the rifle much cleaner, as does the the nickel/boron coating.

3 Mine is very accurate and they do have the reputation of being tack drivers.

4 The stock trigger is excellent.

The bad - These guns are heavy in general and like most pistons tend to be front heavy. I have a 14.5 inch barrel with suppressor. I have to believe a 20 inch barrel is going to be very heavy.

Also shop around you can find these for a substantial discount below list.
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Old December 28, 2013, 11:07 PM   #44
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The bad - These guns are heavy in general and like most pistons tend to be front heavy. I have a 14.5 inch barrel with suppressor. I have to believe a 20 inch barrel is going to be very heavy.
I'm 5'8" and weigh 155lbs, I would describe myself as average size and build, and I am 59 years old. I don't find my POF heavy. It is beefier then a 5.56 (my son-in-law describes it as an M-4 on steroids). But you can't fire a .308 round with some lightweight rifle, if you did the recoil would be brutal.

When you talk about the rifle being front heavy, I think you're forgetting that you're the one with a can at the end of your barrel. I actually find that the 20" barrel makes the rifle really well balanced.

Hounddog, I'm confused about your rifle configuration. Why buy a .308 with a 14.5" barrel. The .308 is intended as an all purpose round (short and long) but your barrel screams short range. What am I missing?
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Old December 28, 2013, 11:38 PM   #45
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From the POF web site.

14.5" vs. 20.0"

8.5lbs. vs. 8.9lbs.
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Old December 29, 2013, 08:55 AM   #46
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A properly designed blast baffle will strip and deflect much of the bottle-shaped blast of high-pressure gas that envelops and pursues the departing bullet.
Does this mean that rifles without supressors have muzzle blast waves disturbing the bullet's flight?
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Old December 29, 2013, 09:16 AM   #47
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You may want to post your suppressor questions in the NFA Guns and Gear section.
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Old December 29, 2013, 09:31 AM   #48
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SR420, I'll post my questions about that claim in this thread where that claim was placed. I was hoping you might have an answer as you're the one who posted it and might want to provide some support to that claim.
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Old December 29, 2013, 09:47 AM   #49
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Eppie, actually I don't have a can at the end of my barrel.

And as far as weight is concerned, I suppose it's all relative. I have a .22 that probably weighs 5.5 pounds. And I've shot 50 bmg's that weigh 30 pounds. With a decent scope and a full mag, a POF308 with a 20" barrel is going to weigh 11+ pounds. Does that make the rifle unshootable? Of course not. But if you are used to an AR15 or a hunting rifle, you're going to notice the weight. Since I'm not sure if the original poster had ever held or shot a POF308, I thought the weight was at least worth mentioning. If he has other rifles that weigh in at 10-12 pounds, the weight is not going to be an issue. However, if he's used to 6-7 pound rifles it might be. Also, although all semi-auto 308's are going to be heavier than a comparable AR 15, my sense is that pistons in general (and the POF in particular) tend to be on the heavy side. For example, I also own a PWS in 5.56, and have shot a POF in this caliber, and the POF is both heavier and heavier in the front.

One other point I neglected to mention on the POF, the handguards/rail tend to be pretty thick. Again this may not be an issue for the OP, but is something to be aware of.

Finally, as to why a 14.5 inch barrel on a .308, I live on the east coast, so opportunities for me to shoot out beyond 300 yards are few and far between. Almost all of my shooting is between 50 and 200 yards. At these distances I really don't need anything beyond a 14.5 inch barrel. Of course at these distances I suppose I don't need a 308 at all. But by that logic I don't need 1/2 of guns I own - something my wife has pointed out to me on a number of occasions.
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Old December 29, 2013, 09:55 AM   #50
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Bart,

Thanks for the detailed response- makes a lot of sense.

So...

There's the "pure" accuracy of the rifle, what we all like to refer to when we ask "how accurate is it?", usually defined by performance at 100 yards. Seems this is how best to determine the quality of the hardware?

Then, there's the external influences of air density, wind, etc.- and variations of bullet performance driven both by it's physical characteristics, and by it's velocity spread. These account for the increased spread as range increases.
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