It seems, based on the discussion here, and everyone's extracurricular research, that any gun that experiences a (verified, no-shit) non-shooter-influenced first round POI deviation is just an improperly built or ragged-out gun that ought to be repaired, replaced, retired from service, etc. It has no place in the competition arena, and certainly no place in a professional's armory, when precision and consistency is a priority. So, there's really no more discussion to be had; though I'll happily continue to participate in wherever this thread goes. If any of my AR15s do experience a shift that is outside my control, it's certainly because of how they're built.
KSGM, that is a good article to clarify terms. Thanks! Makes following along this thread ( and others) better.
Fritz, in your observations of cold shooter-induced first round POI differences, are any more prevalent? Is a high, low, left, or right shift more common? I have been making it a habit lately, of going to a spot at 430m, having not shot at all that day, and firing five rounds at the steel. So far, I have been unable to conquer the first shot phenomenon; there's always an outlier, doubling or tripling the overall group size. I decided what I'd like to do, if I were to free-float the gun, but it's expensive, and I'm not entirely sure it'll work, so that's not happening in the near future. I intend to continue these cold five-shot exercises, and perhaps I'll start to see some improvement, as I hone the first shot focus. The circumstances have me seated, with my rifle poked through a grid-wire fence, resting on a segment of said wire. Not a perfect, scientific, "control" environment, but it's what works easy enough that I'll do it with regularity.
Also, it's certainly agreed-upon that an unfloated gun's accuracy is compromised, but does an unfloated gun suffer more from first shot shift phenomenon? Shots 2-5 in this morning's group were inside eight inches, which is certainly acceptable accuracy, for me, inside the boundaries of this gun's philosophy of use. If I could bring that first shot in there, I wouldn't even consider floating the barrel.
Unfortunately, my thrown shots aren't consistent from day to day. But I do have a few patterns.
Horizontal stringing is almost always due to sloppy trigger control. It's less prevalent in my bolt action rifles, as I believe the lighter and crisper triggers accept a little slop with dire consequences. A POI shift to the left almost means that I put too much of the index finger on the trigger, causing the pull to be to the left. Instructors have called this the "Captain Hook" pull. I can easily do the same thing on a Glock. This is probably the more common error for me with an AR.
A POI pull to the right is generally because I put too little of the finger on the trigger, and/or that my trigger hand was right of center on the grip. This probably occurs more with my bolt actions than my ARs.
I try to mitigate both of the trigger issues with dry firing, just before going to live ammo. The goal is to do multiple trigger presses and make certain the sights don't move from the POA. Not even a bit of movement. To quantify in angular terms, a great trigger press has less than 1/4 MOA, even less than 1/8 MOA movement of sights on target.
I rarely miss low, like in once per blue moon. The great thing about this is that when shots fall low, I have a big warning sign. This is how I've first noticed barrels getting shot out -- MV falls and bullets impact lower than expected at distant targets.
I've struggled off an on over the years with vertical stringing, especially with ARs. Multiple issues here:
- I've had scopes mounted a little low for me. The critical thing is for me. Cheek welds are personal, and I find I'm more consistent with a weld where I don't bury my face into the stock. Such a position is more comfy for long strings and more time behind the gun. It also means I don't press down on the gunstock with my cheek, which throws the round high.
- I've shown poor control of the rear support. Both with beans bags on prone, and with basic buttstock-on-shoulder for shots from barriers. Better shooters and instructors noticed that I relaxed my bean bag grip hand (prone) or my shoulder (barrier) just as I broke the shot, which dropped the buttstock and sent the round high. I now tend to use firmer rear bags and I grip them a little tighter. The shoulder-supported issues are a little more challenging, but I try to focus on maintaining body position all the way through the recoil cycle.
Bottom line -- I'm not a ransom rest or a lead sled.
I’ve seen this discussed before, agree, there can be something to the phenomenon.
The simple solution is to test your gun, yourself. After that, you have your answer.
The only gun I tested clean verses ‘fouled’ is my Knight muzzle-loader. This is also set up for deer hunting with average shots from 50-125 yards.
Of course a M-L can have more serious fouling than any centerfire rifle. My normal procedure was to pop off a few 209 primers to get the slightly fouled bore.
With my M-L any difference wasn’t enough to matter. It puts saboted bullets very close at 75 yards. Even though I shoot Blackhorn 209 powder, I much prefer to keep the bore clean as long as possible.
I hear ya. Nor am I; and I seldom shoot from highly reinforced positions. I do find it interesting that you don't make mention of a descending shift, outside of barrels becoming worn. My first shot deviation is almost always low. Perhaps my body has some sort of flinch reaction to that first round, that drops the muzzle, and then disappears for the remaining rounds fired, as the recoil impulse is no longer something new.
More shooting is about all I can do. Thank you fritz, and sourdough, for more worthwhile contributions.
An interesting observation. One of the demonstrators in an MDT video mentioned wanting to try more of a “jaw weld” rather than cheek weld, and after considering that I decided that my putting too much pressure on the stock could explain some of the results I’ve seen with my shooting. I’ve moved the cheek rest of one of my rifles down but I haven’t had an opportunity to shoot it much to see if it would help. I respect your comments, and if it’s something you believe might be an issue, it certainly makes it all the more worth my time and effort to examine.
“So let’s speculate, a word that sounds like an activity that should be—and once was—done in private.”
Cheek welds are personal -- what works for one shooter may not be so good for another.
My understanding came from a summer where I was struggling with consistent accuracy and POI. I carpooled to multiple matches with a very talented buddy, and conversations ran their course over the many hours on the road. My biggest consistency issues were with an 18" barrel AR15 -- a rifle which had performed extremely well in prior years' comps. Lots of things were going on, but the items which final came to the table were:
- In 2 different multi-day matches I ended up with not-so-fun carbon ring buildups just forward of the chamber. I poo-pooed the concept in prior years, when fellow competitors blamed big misses in certain stages on the infamous "carbon donut". No longer. I found as this barrel got older, it occurred more regularly. I'm now quite cognizant about feeling for a constriction when I run cleaning patches down a barrel. In my experience, the carbon donut is an indicator that throat wear is increasing. I also noticed this on my 6.5CM barrel #2, as it repeatedly developed small carbon donuts just prior to pulling it.
- The barrel on this same 18" AR essentially went tits up on the 2nd day of match later that summer. Shots were falling below the 300-400 yard targets, and I couldn't figure out why. As above, I really don't miss low on targets as long I'm not a dope with dope. When I returned home and really cleaned the barrel, I saw that MV was down and accuracy decreased noticeably. I had my 'smith install a new barrel, and he stated the throat was pretty bad.
- Again with this 18" AR, my 100 yard zero was changing from one month to the next, as I practiced at home. The rifle sports a older (but high quality) Nightforce scope and a solid NF mount, so this didn't make sense. In the prior year I changed out its A4 stock to a Magpul UBR. I never really got uber comfy with the UBR stock, even though I kept telling myself it's the best stock for this AR. My shooting buddy noticed that I tended to squash my check down onto the buttstock to obtain the best scope sight picture. And voila, from barriers I tended to push the buttstock down and throw shots high. I ditched the UBR for a lower CTR stock, and all was good. Furthermore, I slightly lowered the cheek piece on some rifles, or went with slightly taller rings on others.
Bottom line -- my cheek gently rests on my buttstocks now, rather than pressing down onto them.
I hope that will help me, and again, thank you for your discussion.
“So let’s speculate, a word that sounds like an activity that should be—and once was—done in private.”
Shot a group with each of the rifles this morning. I friggen goofed the third shot out of the second gun, and I knew it. Other than that shot though, the groups were consistent; no outlying low shot in either. I was focusing on very limited forces applied to the gun, both on the buttstock and the handguard. I rested the front end on the fence wire, just ahead of the delta ring, hoping that may mitigate negative effects of the non-floated setup. I will continue to apply this attitude, and see what happens. Unfortunately, most situations likely necessitate propping the handguard on a further-forward point.
Shot a cold group at 530 meters yesterday, with the 16" non-floated, rifle gas, with Leupold 6HD and 77gr Sig ammo yesterday. I was resting on a backpack, laying in the prone. All hits; torso-sized steel; twelve inch spread. I am growing confident that I am beating back the cold shooter effects I experienced before. I am also quite pleased with the system's performance. Taking the shortcomings into account: non-floated, "GI" trigger, no bipod or rear bag; I think that performance is quite good, for a "fighting carbine"; it's right at 2moa.
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