What am I doing wrong?

[EW1066]

Went to the local indoor range today and zeroed my Pentax RDS. I know that I will take some flak for using a pentax, but so be it. After chasing the the poi around the paper I finally got it on target. This was all done standing, shooting off hand. Then I started shooting three round "sets", ie run the target out to 65' shoot 3 and bring it back in. I started to notice that I had this vertical string starting. The length of the string was pretty much determined with the first 3 round group. the gaps simply filled in as I kept shooting. I feel like I must be pulling the shot somehow. So I thought I would defer to the experts here for advice.

In an effort to fill in some of the blanks these are some amplifying details.
1. The sight is mounted on a riser for co witness and both the sight and riser are tight.
2. ammo was pmc brass. I know its cheap but funds are limited and I just wanted to get some range time.
3. I built the gun.
Mega forged lower.
Mega forged upper.
CMT BCG.
Dpms LPK yea yea I know, but I bought it before I knew better.
Carbine buffer
Daniel Defense 1:7 carbine non CHF barrel
4. Since I was trying to Zero and had to do it standing all shots were "slow fire"
5. I was shooting at 65' because that is as far as the targets go at this particular indoor range.
6. The shots below the bull are what I am referring to. The first round in that overall group is the one just to the left of the bull. No adjustments were made after that round was fired

[J-Dub]

So you're trying to zero your optic while standing unsupported? Interesting.

First i would go to and outdoor range (50yds). Second, i would use sandbags or atleast a bipod. Thridly, i wouldnt use a pentax.


Oh and use better ammo if you want better groups.

[TomMcC]

J-DUB pretty much nailed it for you. If the Pentax is all you have, I guess you'll have to roll with it. You can count the shooting you did as the "get it somewhere on the paper" warm-up to the real zeroing.

BTW, I would use a smaller target for zeroing.

[EW1066]

Fair enough but please tell me how that vertical string of shots is ammo related and or related to the optic. I think it is more related to something I am doing physically when pulling the trigger. Is a pattern like this somehow indicative of an optic problem. I have had loose optics before and the poi was all over the place with no rhyme or reason. I feel like it's me not the equipment

EDUB

[EW1066]

So a 6 inch target at, just short of 25 yards, is too big ?

[TomMcC]

It could be as simple as arm fatigue. You really need to bench it to be sure.

I use a 2" at 50 yds for zeroing with an unmagnified optic.

[Omega_556]

Breathing

[jonconsiglio]

At that distance being low is acceptable depending on the zero you want. The vertical string is coming from you dipping the muzzle, my guess would be from flinching.

Get some dummy rounds and put one or two in your mag next time. I bet when you pull the trigger on that dummy round your muzzle dives a bit.

Work on a lot of dry fire at home for trigger control by focusing on a light switch or other small object. Focus on slowly pulling the trigger. Many times we forget the fundamentals when we have other goals in mind at the range.

It'll come, just practice and watch your muzzle with a snap cap. You won't flinch when dry firing so don't rule it out just because you aren't seeing the muzzle dive at home.

[Travis B]

The vertical string is coming from you dipping the muzzle, my guess would be from flinching.

Most vertical stringing comes from improper breathing techniques. Make sure you exhale 100% to your respiratory pause, hold it for a couple seconds, then you squeeze.

[Rattlehead]

Looks like you're jerking the trigger.
Go out with a buddy and have them hand you the gun after he's told you that he's not sure if it's loaded or unloaded (SAFELY and CONTROLLED). I'd recommend repeating that until you have a smooth pull loaded and unloaded.

In my experience the only way to really tell of someone is jerking the trigger is of they think the gun is going to fire when they pull the trigger.

The snap cap is also good, however if you know the gun is unloaded your trigger pull is most likely going to be completely normal and smooth, assuming you have a smooth pull in the first place that is.

Like jonconsiglio already mentioned post or two before me, dry fire safely at home, you should see an improvement at the range after a couple hundred dry fires a night.

Only when the gun is loaded (usually) do you get that knee-jerk reaction of pushing the gun away from you face/immediate jerk. That obviously makes a huge difference downrange, more so with pistols.