How often do Police snipers check their scope zero.

[yanici]

Any SWAT or Police snipers on here? Or, maybe you know some. When accuracy really counts and that rifle scope needs to be right on can these guys count on the scope to be accurate. Big differences in temperature plus all the bouncing around in the case seems like it would be a cause for concern about a shift in the zero. I know my scoped rifles stay pretty much right on but they're not constantly being moved around and are in a stable environment.

 

[TheWookie]

Any SWAT or Police snipers on here? Or, maybe you know some. When accuracy really counts and that rifle scope needs to be right on can these guys count on the scope to be accurate. Big differences in temperature plus all the bouncing around in the case seems like it would be a cause for concern about a shift in the zero. I know my scoped rifles stay pretty much right on but they're not constantly being moved around and are in a stable environment.

I'm not, but I know a little about the questions you're asking.

Most of the guns that these police snipers use can take a little bumping around, if they couldn't they wouldn't want to use them. So, to have one in the back of a squad car or whatever bouncing around from time to time isn't going to change the dope. The guns are in padded hard cases, or at worst a soft-shelled carrying pack.

But based on other things how often do guys check the cold bore? I dunno, so many variables....

Factors such as temperature, ammo, and other variables mean the dedicated police sniper might do it often. Some SWAT snipers are not dedicated, they're on the street each day waiting for a call-out, they might not shoot/practice as often. Other's, might be on a dedicated SWAT team, and they can shoot daily, if they want. If anything just for sustainment and to keep sharp. Either way police snipers have good dope for every possible scenario with their guns.

And, keep in mind that most police sniper scenarios are around 50 - 150 yards -- so as long as the gun is designed to hold sub MOA - when it comes time to use it, no matter what circumstance they should have confidence that they can effectively engage a target regardless of when the last time they cold-bore-zeroed.

Anecdotally - I saw a DMR or modified M14 with an Unertl scope, in a padded gun bag, get partially run over by a civilian deuce-n-a-half - right after it happened, we took the gun down-range and set it up on the 100 yard line, and with the first shot it was on target, not bad considering it had been partially run over by a truck.

Just my two cents...

 

[Supermoto]

Temp will not affect a quality scope. Sighting in would only be needed when they change to unknown loads. The shooter should know his dope for all weather conditions and distances

 

[bpm990d]

At typical police ranges a change in the density of the air from 59 degrees to 100 degrees is only going to change the trajectory a small fraction of an inch.

I ran it on Sierra Infinity 6 and Bryan Litz's Point Mass Calculator. At 150 yards the difference was .02 inch for a 168 gr. .30 cal. bullet at 2600 fps.

B

 

[TheWookie]

Temperature doesn't have as much of an effect up close, but....

At 300 yards there is 1 MOA change in elevation per 20 degree change in temperature.
At 600 yards there is 1 MOA change in elevation per 15 degree change in temperature.
At 1000 yards there is 1 MOA change in elevation per 10 degree change in temperature.

http://www.geocities.com/teamonegear/sniper_formulas.htm

Temperature can have a much greater influence, more than just muzzle velocity, (which will depend on the cartridge temperature and the sensitivity of the particular powder to temperature changes) temperature affects air density, which affects drag and thus trajectory.

 

[Jose]

Temp will not affect a quality scope. Sighting in would only be needed when they change to unknown loads. The shooter should know his dope for all weather conditions and distances

+1

I know my rifle and my loads in any clime and place.

 

[Jose]

At 300 yards there is 1 MOA change in elevation per 20 degree change in temperature.
At 600 yards there is 1 MOA change in elevation per 15 degree change in temperature.
At 1000 yards there is 1 MOA change in elevation per 10 degree change in temperature.

http://www.geocities.com/teamonegear/sniper_formulas.htm

Temperature can have a much greater influence, more than just muzzle velocity, (which will depend on the cartridge temperature and the sensitivity of the particular powder to temperature changes) temperature affects air density, which affects drag and thus trajectory.

Good dope.

 

[bpm990d]

I have seen those numbers before in the SEAL sniper manual .pdf that is kicking around the internet. Do they correlate well in your experience? My zeroes never seemed to change quite as dramatically as those.

B

 

[ShadeWPI]

Well, if they're seal numbers, they're going to be based on military issue 7.62x51mm special ball (M118 I believe) since that's what they're going to be shooting. Temperature will affect different rounds differently.

Different powders are affected differently by temperature
Different bullets are affected differently by different air densities.

 

[pbearperry]

Has anyone ever heard of a Police Sniper taking a real long distance shot?I think most of the shots are well within 100 yds most of the time.

 

[bpm990d]

Well, if they're seal numbers, they're going to be based on military issue 7.62x51mm special ball (M118 I believe) since that's what they're going to be shooting. Temperature will affect different rounds differently.

Different powders are affected differently by temperature
Different bullets are affected differently by different air densities.

The one I have doesn't specify what type of ammo. The only thing in that section mentions M118 Match (not special ball) and M80 ball. I just never thought I needed to change my zeroes by that much when the temperature went up during the day.

I always wonder about some of the stuff I've downloaded how accurate some of the manuals are. They all seem to have the correction for humidity backwards (to include the latest Army manual; 3-22.10.) I tend to think that revisions simply take the previous manual as gospel and republish without doing enough confirmatory research.

B

 

[cockpitbob]

Has anyone ever heard of a Police Sniper taking a real long distance shot?I think most of the shots are well within 100 yds most of the time.

The last numbers I heard were that the average Police Sniper shot was about 75yds while the average military Snipers shot was something like380 yards.

 

[TheWookie]

SEALs and top Tier guys get their ammo hand-loaded. They don't shoot what you and I shoot, or what the 'rest' of the military shoots. It's specifically made for the shooter, the gun, and sometimes even the scenario. Same goes for their guns, all custom.

I have seen temperature effect a round.

 

[Jose]

SEALs and top Tier guys get their ammo hand-loaded. They don't shoot what you and I shoot, or what the 'rest' of the military shoots. It's specifically made for the shooter, the gun, and sometimes even the scenario. Same goes for their guns, all custom.

Once again, having ammunition custom made to a particular firearm and a particular use is no big secret or the exclusive province of HSLD types.

bpm990, PatMcD, Derek, myself, and many others who have been sucessful in competitive shooting have been so in part because we know how to produce ammunition that is handcrafted to precision specifications of case weight, charge weight, bullet weight and OAL, meplat uniformity, cartridge OAL, and runout.

Us civilian 1000 yard competitive shooters do not get our ammo at Walmart.

 

[TheWookie]

Once again, having ammunition custom made to a particular firearm and a particular use is no big secret or the exclusive province of HSLD types.

bpm990, PatMcD, Derek, myself, and many others who have been sucessful in competitive shooting have been so in part because we know how to produce ammunition that is handcrafted to precision specifications of case weight, charge weight, bullet weight and OAL, meplat uniformity, cartridge OAL, and runout.

Us civilian 1000 yard competitive shooters do not get our ammo at Walmart.

I understand what you're saying. I should clarify for those who are mentally challenged and/or constantly feel the need to show me how big of a stick they carry - SEALs don't shoot what most regular shooters shoot. The high speed guys like Jose shoot what they make, or what is made for them.

 

[bpm990d]

Not saying they don't have the capability for that, but I'd think they would be too tired from staying on jump and dive status and PT and small unit tactics and range time, not to mention chasing terrorists to crank on a Dillon when they get home from the field. Wouldn't it be easier to just have Black Hills make it? What do they use all the MK 282 Mod 1 for?

I don't really shoot many cold bore shots, so I don't have a data book with that kind of info about temps, it just seemed to me that I was always with in a half a minute or slightly less, going from my first strings at a match in the cool mornings air to my last match on a hot afternoon. There is an interesting article in the Sierra 4th edition manual on ambient temperature affecting muzzle velocity. Not sure why they don't publish the tables that are in the reloading manual, but the short story was they were getting +126 fps when they went from 72 degrees to 137 degrees. A change of 65 degrees. When they went down to 20 degrees from 72, they lost 106 fps. It works out to ~ 2 fps/degree.

B

 

[yanici]

Lotta good stuff here so far. How often do you think that the police sniper rifles are checked and tested. I'm just wondering if the guns may,at times, sit in a cruiser's trunk, bouncing around, for 6 months without even being fired. Also, how about qualifying with the gun? I'd like to keep the topic on Police and not so much military snipers if you don't mind.

 

[P2A]

Lotta good stuff here so far. How often do you think that the police sniper rifles are checked and tested. I'm just wondering if the guns may,at times, sit in a cruiser's trunk, bouncing around, for 6 months without even being fired. Also, how about qualifying with the gun? I'd like to keep the topic on Police and not so much military snipers if you don't mind.

It is totally dependent on agency requirements. Additionally how motivated the designated marksman (not Sniper) may be.

Not saying they don't have the capability for that, but I'd think they would be too tired from staying on jump and dive status and PT and small unit tactics and range time, not to mention chasing terrorists to crank on a Dillon when they get home from the field. Wouldn't it be easier to just have Black Hills make it? What do they use all the MK 282 Mod 1

The shooters dont load the ammo. Right now in theater most guys are using M118LR. Within the Tier 1 units there is a capability for special made ammo, as well as custom built rifles. MK 262 was fielded for the SPR/ SDM rifles. Currently issued to select units, it is hard to get. It is to enhance the accuracy over M855. It is a phenomenal upgrade over the M855 in regards to accuracy, and terminal ballistics.

 

[Jose]

I understand what you're saying. I should clarify for those who are mentally challenged and/or constantly feel the need to show me how big of a stick they carry - SEALs don't shoot what most regular shooters shoot. The high speed guys like Jose shoot what they make, or what is made for them.

I don't need to show anyone the size of anything.

The way you express yourself in this thread leads novice shooters to think that precision with a rifle is some sort of unobtanium skill that can only be had by uber-tacticool-ninja-secret-squirrel types.

I am just setting the record straight.

 

[SgtUSMC8541]

There is a misconception out there that the FBI has done a study on LEO Sniper employment and distance of shots. They have not done one. The only organization that has since a study and then released the results is the American Sniper Association. The first study was done in 2005. Over 20 years and 219 sniper engagements, the average shot was 51 yards. Longest seems to be approximately 187 yards. (A 300 + yard was taken but no proof that the target was hit) Not all hits were fatal.

Shortest shot was 5 yards.
Most, not all, but most LEO snipers do not load their own ammo. The dept buys Match grade ammo for their use. I have a few friends who are LEO snipers. They (like we did in the military) zeroed each time they shot. The rifles were shot anywhere from once a week (for the Full TIme SWAT guys) to once a month for the "part-timers" Hope this helps.

 

[bpm990d]

Also, how about qualifying with the gun? I'd like to keep the topic on Police and not so much military snipers if you don't mind.

Sorry for the thread drift. NTOA might have some information. Not sure if you need to be a member or a sworn officer to access it.

I would guess that they need to have some type of quarterly qualification with a cold bore shot. But as mentioned earlier, totally dependent on the department.

B

 

[PatMcD]

At 300 yards there is 1 MOA change in elevation per 20 degree change in temperature.
At 600 yards there is 1 MOA change in elevation per 15 degree change in temperature.
At 1000 yards there is 1 MOA change in elevation per 10 degree change in temperature.

http://www.geocities.com/teamonegear/sniper_formulas.htm

Temperature can have a much greater influence, more than just muzzle velocity, (which will depend on the cartridge temperature and the sensitivity of the particular powder to temperature changes) temperature affects air density, which affects drag and thus trajectory.

Some powders get funny at different temperatures. W748 is one that gets a bad rap for this (although I never found it to be a problem with .308 loads). Maybe they took the worst case scenario and published it as "this is what could happen".

However, those numbers above don't correllate to anything I've ever heard of. A 6" shift in 15 degrees at 600yds is huge.

 

[TheWookie]

However, those numbers above don't correllate to anything I've ever heard of. A 6" shift in 15 degrees at 600yds is huge.

I hear what you're saying, PatMcD. I don't know what to tell ya.

But really, the topic is police snipers. So we are drifting, maybe somebody should start a thread on weather conditions and how they effect different rounds under different conditions. And then everybody with a can of spray glue can chime in on that. Good luck.