Noob to rifles has some questions

[ghbucky]

Here is my rifle

This is the red dot optic I have on it


I fired 5 reloads I had made up for pressure tests individually with a few minutes between each shot.

After that I was working today off of a front rest and working on getting the rifle zero'd at 25yds at an indoor range.

I was tracking in pretty straight line up the middle of the target (IP was low, but windage was right in the middle) as I would fire a shot, bring the target in to see where the IP was, moving the elevation up 3 clicks, run the target out, rinse and repeat.

I think I fired 5 factory Federal American Eagle 5.56 55gr when it seemed like the elevation stopped raising the IP. I'm having a hard time believing that the RDS can't reach a 25yd zero, any ideas what is going on there?

Following those shots, I ran a new target out and fired 3 shots in succession, using the same breathing cycle and trigger press. When I checked those shots, they were not at all what I expected, the grouping was probably over an inch wide.

I'm guessing that what is happening is that hand guard is screwing with the barrel as it heats up? It never got super hot, and I only shot a total of 25 shots over roughly 30 minutes.

How do I know when the rifle heating is going to start impacting accuracy?

 

[stagpanther]

My guess is that you have something loose someplace. I never get hung up on tight groups at 25 yds with an AR--I only shoot once or twice to get a "ballpark" idea of where the shot lands and then move out to 50 and 100 yds--if I'm sighting in that way. I have had several AR's with "glacier guards" that will do sub-MOA at 100 so ignore the "gotta free float or else your accuracy is crap" stuff. However, movement can be subtle--play between the upper and lower--buttstock riding up and down on the buffer tube, one I'm especially prone to is not duplicating the hold shot to shot. All that can throw your shots off. I did have a 6.5 grendel barrel I bought from Andersen once that didn't shoot worth a fruitloop though. Also I assume you thoroughly cleaned the gun when you got it--sometimes people just run right out and blast away without doing that. My guess is you'll figure it out and everything will be fine.

 

[ghbucky]

one I'm especially prone to is not duplicating the hold shot to shot.

Given my lack of experience with rifles, this is something I'm willing to believe is the issue.

 

[TXAZ]

I’d suggest you “Benchrest “ the rifle next trip to the range, and ensure your rifle is steady and sight isn’t wiggling.
Sled or sandbags that will give you a baseline.

 

[ghbucky]

I’d suggest you “Benchrest “ the rifle next trip to the range, and ensure your rifle is steady and sight isn’t wiggling.

I was using a front rest. Because of the indoor range, I didn't have the option to do a full sled type set up.

 

[Shadow9mm]

There are a couple things I can think of.

One, something is loose most likely scope rings.

second is the scope adjustment may be sticking. that is my guess. I have 2 ways to fix that.
a one is shoot 5 rounds per test group and ignore the first
so the scope will settle.
b the second is to tap the turret a couple times to help settle it, I usually use an
empty mag.

option 3 is paralax. i have had some issues before but most red dots don't generally have too much issue. basically if you dont have the dot in the center of the tube your point of impact may change. you can test this next time you shoot. shoot a group with the dot centered. shoot a group with the dot at the right edge, left edge top and bottom. your group may shift around on the target.

Last option 4, your rifle might not like your reloads and just be giving you larger groups. you can tweak charge weight and seating depth to dial a load in. in general the most accurate loads seem to be a little below max. for example my current load has a max of 25.6. however that gives me 1 to 1.5in groups at 50yds. i dropped down to 24.8g, same everything, just less powder, and it will shoot 1/2in at 50yds.

 

[ghbucky]

option 3 is paralax

I didn't seriously consider this. I'll pay closer attention to this on the next range time. Thanks!

 

[Bart B.]

How do I know when the rifle heating is going to start impacting accuracy?

When shots start hitting in one direction from where the first few go.

Properly built rifles won't do that.

Most common cause is the receiver face ain't squared up with the barrel thread axis and it has hard contact at one place around it. The cure costs about 30 dollars per rifle at the factory to fix. Your gunsmith will charge a lot more if he knows how to do it.

 

[ammo.crafter]

MOA?

Is the scope correctly mounted so the verticle adjustment and horizontal adjustment are in their correct location?

 

[Bart B.]

Is the scope correctly mounted so the verticle adjustment and horizontal adjustment are in their correct location?

I don't think that's an issue. Many left hand folks install scopes twisted 90 degrees to the left.

 

[ghbucky]

I think Shadow nailed it with the paralax idea.

My first 4 or 5 shots did exactly what I expected, with each adjustment moving the POI up the target toward the bullseye.

Since I'm new to rifles I don't really have an embedded hold and cheek weld and I was paying more attention to breathing and trigger than where I was on the rifle.

I'll find out more on my next trip.

On a side note, as a practical pistol guy I always was more concerned with quick acquisition and 'close enough' shooting. I'm kind of getting an accuracy bug though.

 

[Nathan]

I don’t think you can see heating up at 25 yds. How is this sight mounted. It should be mounted to the picatinny rail on the upper only.

It’s an Anderson....heck the barrel could be loose! Seriously, wiggle the Barrel and see if it feel loose.

Second, get the rifle in the best rest you can and pull the trigge....does the reticle move. It shouldn’t. Try centering the turrets elevation first. That should put you on a paper plate at 25 yds. If not, scope or mount are loose/broke. Likely broke. What mount?

 

[stagpanther]

I thought the op was using a red dot?

 

[jetinteriorguy]

You could try adding a front post sight and set it to cowitness with the red dot. I’ve found with mine set to cowitness with both front and rear sight it’s very easy and natural for fast accurate sight acquisition. But even just set with the front sight helped me a lot. Mine is set so the dot centers in the rear peep and sits right on top of the front post.

 

[ghbucky]

What mount?

The RDS came with a mount, I didn't make any changes to it. Pictanny.

 

[Erno86]

Perhaps you're using an inconsistent cheek weld?

For sighting in: I like to fire three shots from a cold barrel, in a fairly rapid succession, before the receiver starts to heat up -- Then let it cool.

For rapid fire strings with a high power gun: I like to run a 6 shot rapid fire string --- Then I let the big gun cool --- If the barrel is too hot to touch...it has reached the 180 degree fahrenheit mark (enough to fry an egg), which can cause heat stress cracks in the throat of the barrel.

While cooling the gun down: Try to keep it out of the direct sun...because the sun's rays can heat up the barrel on one side; giving you inconsistent groups.

 

[ghbucky]

Perhaps you're using an inconsistent cheek weld?

I think this is the simplest, and therefore, most likely explanation.

I was feeling pretty good that my first few shots looked so good. Maybe I relaxed.

I just dry fired a bit and was paying attention to stance. I can't really get a good cheek weld and still have alignment with the RDS. I'll have to figure that out.

[edit] and thanks for the detailed explanation on the heating and cooling.

 

[Nathan]

Honestly, with an RDS, cheek weld, parallax, etc don’t apply at the same level as the do with an optic.

Heating/cooling.....never seen that on an AR, but maybe somebody can share details of their testing to enlighten us all.

I would try 2 things. Grab a known good shooter and confirm your results.

Grab a known good optic and try it.

One of those should get you close.....and point out if your issue is shooter, rifle or optic

 

[raimius]

For issues at 25yds, look to simple answers. At that distance the bullet itself is almost 1 MOA. Your adjustments are only going to move the impact 1/16th of an inch per click at that distance. You won't be able to really measure mechanical precision very well. Check how you have the optic mounted. See if there is something loose on the rifle.

Pictures of your rifle and targets might help.

 

[7.62 man]

Yep it sound like something is loose.
One shot at a time don't work for me I always shoot at least 3 rounds, then go from the center of that group on a 1" grid target to do corrections on the scope.