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Does the first shot out of your semi-auto rifle have a consistently different POI than following shots? Login/Join 
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I am confident that an inaccurate clean cold bore first group of the day with my rifles is due to me, not my equipment. My equipment is consistently capable of great accuracy. I realize that some rifles are not in this league. But I'm not discussing the poster children of spray & pray -- like a Mini-14 or an AK.

I have 2 Wilson AR15s with similar barrels, optics, and ammo preferences. I've alternated between which one I shoot first on given days. Regardless of which order I shoot them, it is extremely rare that the initial group of the second rifle is poor. But sometimes the first group of the first rifle isn't up to my standards.

I've done the same alternating 1st/2nd rifle tests with my best ARs -- one with an 18" Bartlein barrel and another with a 20" Krieger. These two ARs are truly accurate, and the results are the same.

I have 2 AR10 uppers, in 6.5CM and 6CM. When I shoot the 6.5CM as the first rifle of the day, I often see less than stellar first groups. When I shoot another rifle prior to breaking out the 6.5CM, my first groups with the 6.5CM are good. I've never shot the 6CM upper as the first rifle of the day. But as the second rifle of the day, the 6CM upper's initial groups have all been great.

Compared to bolt actions, there's a number of things going on with ARs after the bang switch is pressed. Mitigating the AR's internal parts movement, gas movement, and resulting vibrations isn't an easy thing to do out of the gate.

Professional athletes warm up before competition. Few -- if any -- can perform at there best "off the couch". In my experience, shooting is no different.
 
Posts: 7500 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
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I have experienced accuracy deterioration, POI shifts, and variable MV as I shot out barrels. Decreased MV in general resulted in lower POI at distance. MV variation increased, which resulted in vertical stringing at distance. Accuracy with quality ammo deteriorated a little at 100 yards, but with both ARs and bolt actions, it still wasn't all that bad. POI at 100 yards didn't change all that much.

*****
There are instances where the first few clean cold bore shots of the day can go wonky.
- 22lr, which is notorious for needing the barrel fouled with the ammo being used.
- Old barrels, non-free floated barrels, barrels with a fair amount of copper fouling. Like the pre-64 Winchester Model 70 my Dad gave me.
- Rifles that aren't built as precision instruments. Cut with an imprecise chamber. A lower grade barrel, with imprecise dimensions, not broken in properly.

I will also state that changing ammo in an AR can cause significant accuracy challenges. After shooting FMJ garbage, all of my match ammo requires a handful of rounds to shoot well again. And for unknown reasons, switching to and from Hornady ELD-M 73 also requires a handful of rounds to settle down into expected accuracy.
 
Posts: 7500 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
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None of my ARs are free-floated. This may very well be the main contributing factor to any first round deviations I experience. I suppose the negative effects of a non-floated barrel are exacerbated by thin barrel profiles and/or longer gas systems causing the front contact point to have more leverage on everything.
 
Posts: 1244 | Location: Northeast GA | Registered: February 15, 2021Reply With QuoteReport This Post
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I don't own any ARs that are not free floated, but I've shot a few & and shot with folks who have them. In my experience, the non-floated and pencil profile barrel ARs shoot pretty well when cold. And of course when no pressure from a sling, barrier, or bipod is applied to the handguard. I see the accuracy of such ARs deteriorate as the barrel varies from cold to warm to hot, then back again.

This topic has been discussed quite a few times in training courses at Rifles Only. Jacob Bynum (Rifles Only owner) has often stated that a cold rifle with a fouled barrel likely has the best chance for putting one round on POA -- as long as the shooter is up to the task. The advantage of free-floated, heavy profile, well chambered, properly rifled, and high-quality steel barrels is that they continue to place rounds on POA as the barrel temperature varies substantially.
 
Posts: 7500 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
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I intend to shoot the same guns again tomorrow. I am going to get more stable this time. If my high outlier disappears, I'll be curious as to what about me, as a cold shooter, makes me throw one (presumably the first) high. Actually, I'll have a spotter tomorrow, so I'll know what shot is what. If the outlier still exists, and is indeed the first shot, I'll be curious what it is about the guns. I'll learn either way. I'll group the AR10 as well, if time permits, and note any first shot phenomenon I get with it.
 
Posts: 1244 | Location: Northeast GA | Registered: February 15, 2021Reply With QuoteReport This Post
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the linked article in the first post is concerning Smallbore as in Rimfire,
and one or more of the folks posting mentions that they don't know if what the OP is doing will have the same results or causation with centerfire,,



when I shot Service Rifle, (floated AR, 20 inch HB) , and I was just an poor Expert, I never really noticed a cold shot difference,

once in a while I would shoot a 2 group target, as in a few rounds clustered away from the rest, but I know that was shooter error , or a changed in position, not the gun or ammo

I also shot moly for years, (it was a thing) and did not clean my barrel after each match, sometimes not after several matches and never had an impact shift or issue that I could not blame myself for, however I would pull and clean the bolt ,



back to the link, I find it curious that folks clean the 22's so often, and so thorough,

I bought a couple small bore rifles from a competitor many years ago, and he advised me to not clean a bore until accuracy dropped off,

and years later on of the founding members or the Club I belong to would show up and shoot Smallbore practice while I was practicing SR positions,
he told me the same, don't scrub it till you have to, the rifle will tell you when it needs it (referring to 22lr's)



https://www.chesterfieldarmament.com/

 
Posts: 9837 | Location: Beach VA,not VA Beach | Registered: July 17, 2007Reply With QuoteReport This Post
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Further responses from experienced shooters seem to reinforce that the first round, "cold bore" shot deviation is a myth. How has something that is seemingly untrue become so entrenched in shooting lore? The bench rest shooter I spoke with said many events he attends go so far as to ignore the first shot entirely. Why? Do they accept the fact that the shooters are typically responsible for goofing that first shot, and opt to discount it, as opposed to holding competitors to higher standards?
 
Posts: 1244 | Location: Northeast GA | Registered: February 15, 2021Reply With QuoteReport This Post
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I've avoided this discussion since Fritz is the master of long ranges (we can't shoot those here normally). But a couple of points one specific to KSGM. What the heck? free float the barrel you seriously can't be worried about accuracy issues if that step isn't taken Smile. My personal experience is that I don't trust a just cleaned rifle barrel, it never does exactly what I expect. So when accuracy counts they are fouled. And I always store them that way so they are GTG out of storage. To the above none of the long range rimfire that I know (we shoot 300y in .22lr) guys clean until its absolutely shown its time. I have also experienced the ammo change issues that fritz notes so I never count on measuring accuracy right after an ammo change, but normally I don't change ammo anyway. All FWIW and no possible redeeming value.


“So in war, the way is to avoid what is strong, and strike at what is weak.”
 
Posts: 10375 | Registered: October 14, 2004Reply With QuoteReport This Post
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Hahaha. I certainly knew the free-float comment would come from someone. I have yet to assemble an AR with accuracy as a top priority, and I am not necessarily wondering why these particular guns aren't shooting tighter. On the day that inspired this thread, I was puzzled as to what may have caused the "flyers" that opened my groups up from an acceptable ~6" to 9". I can get carried away with a discussion for the sake of learning more about the subject in general, and not necessarily as it specifically applies to what inspired it. That is what has happened here. I do still hope I can apply some lessons learned to improving my experience with these builds though.
 
Posts: 1244 | Location: Northeast GA | Registered: February 15, 2021Reply With QuoteReport This Post
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KSGM we trade comments on the subtleties of many topics like flash, NV, suppression etc.. But let's just get to the point. If you have an acceptable accuracy standard and you are not building guns and your technique to meet it, then its all on you.
I suck at shooting. I know that. I hang around with people who do not suck. They demonstrate that to me every time we shoot. That's a plus as all the time I learn things. But I expect the guns that I shoot, with me shooting them, to deliver a certain (self defense) level of accuracy every single time. first shot, last shot, every shot, cold, hot, suppressed, not suppressed, etc. etc. If the basic accuracy of the guns/ammo/shooter involved is not what you want you need to adjust the combination. My first suggestion is normally you work on the shooter, but you are an experienced shooter, so maybe its time to work on the gun and ammo. Again all FWIW>


“So in war, the way is to avoid what is strong, and strike at what is weak.”
 
Posts: 10375 | Registered: October 14, 2004Reply With QuoteReport This Post
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Much good discussion, but as a (perhaps) final comment, it is much more generally accepted that there are significant differences between how 22 rimfire and centerfire rifles react to prolonged shooting and bore cleaning.




7/93
“So let’s speculate, a word that sounds like an activity that should be—and once was—done in private.”
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Posts: 46398 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
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I like to do some research, and narrow down a relevant reference to show for it, before I post on a topic like this. That's why I first included the link to that other discussion. I understand better now, how a rimfire anecdote wasn't the best choice, but I was fond of it because he seemed to have identified the problem, and found a cause, in his set of circumstances. In doing more reading, it seems velocity changes of less than 50fps are not uncommon, and are noted by shooters who, as it seems on the internet discussion forums, are relatively experienced. Velocity shifts like that cause about 1/2moa deviations, for these shooters, and are certainly not enough for me to notice, given my less precision circumstances.

I appreciate your vote of confidence, hrcjon, but I suspect my deviations on that day were more my fault than the gun(s) or ammo. I intend to re-engage today, with a more supportive position, in an attempt to adequately bolster what I know are pretty good fundamentals on my part. My non free floated circumstances almost certainly have some bearing, but I suspect they can't be responsible for the entirety of the shifts I experienced the other day. I'll certainly share today's experiences in this thread.

I appreciate all the good conversation here; it has been an engaging thread for me. I came across this article just now, which seems to represent a comprehensive and seasoned opinion.
https://ridgelineshooting.com/...re%20is%20the%20same.

UPDATE after shooting 12/21/22:
Well, I think I left today's session with more questions than answers. I won't bother muddying this thread any further, with my amateur observations and theories. I appreciate everyone's input and feedback, up to this point, and beyond, if you so choose. I learn a lot from you guys.

As a vague summary of today's shooting is as follows... Both of the aforementioned AR15s displayed the same grouping characteristics, but the outlier (which was indeed the first shot, out of five) hit low. I suspect this is due to my more neutral and supported position, which wasn't applying any upward pressure on the unfloated handguard. So, I need to work on further mitigation of the "cold shooter" in me. The more unsettling, but also more logical results, were out of the AR10. Everything was low. There was an exceptionally low shot (first), and then the remaining decent group was also lower than it should have been, according to DOPE. The ambient temperature was at least thirty degrees cooler than when DOPE was previously collected and confirmed, so I suspect that is playing a role in that POI difference.

This message has been edited. Last edited by: KSGM,
 
Posts: 1244 | Location: Northeast GA | Registered: February 15, 2021Reply With QuoteReport This Post
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have not shot a lot of suppressed rifle, (a few 22lrs, for giggles, not score) I am curious how much difference the suppressor makes,

as in, does the same thing happen when the suppressor is removed,

and does the brand suppressor affect accuracy?

as in if I have a Gemtech, Silencerco, or Dead Air on 3 known to accurate rifles, would either brand of silencer make a difference?



https://www.chesterfieldarmament.com/

 
Posts: 9837 | Location: Beach VA,not VA Beach | Registered: July 17, 2007Reply With QuoteReport This Post
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I think one can answer your questions partially. First it is well established that a suppressor alters the POI by some amount. But not in a way the the OP was posting about, its not some first shot change, its a change. For the record I can't imagine why one would mix suppressed and unsuppressed fire this seems completely an academic and irrelevant question. Second its also pretty well established that running suppressed at a minimum does not hurt accuracy and generally improves it. But the impact by "brand" is a more subtle question that will vary by the specific brand and specific rifle as the change relates to barrel harmonics, weight and a host of other factors specific to the combination. I've never seen a test of suppressor brands across multiple rifles (it may exist) but generally its kind of a theoretical question, who cares. Mostly one mates a specific suppressor to a specific rifle and if one changes its a permanent one. I can say from personal experience (I run surefire on semi's and TBAC on bolts) that changing the specific device doesn't do anything to POI.


“So in war, the way is to avoid what is strong, and strike at what is weak.”
 
Posts: 10375 | Registered: October 14, 2004Reply With QuoteReport This Post
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quote:
Originally posted by hrcjon:
I think one can answer your questions partially. First it is well established that a suppressor alters the POI by some amount. But not in a way the the OP was posting about, its not some first shot change, its a change.


eliminate a variable, simple as that, (as mentioned, I have very little suppressed rifle experience)

[
quote:
For the record I can't imagine why one would mix suppressed and unsuppressed fire this seems completely an academic and irrelevant question.

with respect, irrelevent answer, not where I was going with the questions, however I would guess suppressors can fail?

quote:
Second its also pretty well established that running suppressed at a minimum does not hurt accuracy and generally improves it. But the impact by "brand" is a more subtle question that will vary by the specific brand and specific rifle as the change relates to barrel harmonics, weight and a host of other factors specific to the combination. I've never seen a test of suppressor brands across multiple rifles (it may exist) but generally its kind of a theoretical question, who cares.

shooters tend to be geardo's on occasion, as in barrel brand A is better than barrel brand b, or sling x bets sling y, etc etc, when in honestly, they are close enough in performance that most of us will never notice or capitalize on the difference,

as an example I had a conversation, when I was a lowly sharpshooter, with a high master,
we were discussing the flavor of the month on barrels, and also about reloading , and he opened my eyes a bit,

Service Rifle you shoot known distance, and for score, the tighter the 10 or 20 round string is, and in the X ring, the higher your score,

however, as an example, the 600 rd target 10 ring is 12 inches, 2 minutes, and there are slight variations for 200 and 300,
so when shooting, the gun needs to be damn good, the ammo damn good, or at least a 2 minute gun, but there is a point where you stop chasing damn good and realize the equipment is good enough (2 minutes or better) and a shooter needs to improve him or her self,

quote:
Mostly one mates a specific suppressor to a specific rifle and if one changes its a permanent one. I can say from personal experience (I run surefire on semi's and TBAC on bolts) that changing the specific device doesn't do anything to POI.


thank you for your input and answer, hope the OP is not upset over the thread drift



https://www.chesterfieldarmament.com/

 
Posts: 9837 | Location: Beach VA,not VA Beach | Registered: July 17, 2007Reply With QuoteReport This Post
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The OP loves silencers, and approves of all silencer discussion. I see where you were going, in inquiring about potentially removing the silencer. I experienced that first round deviation across three guns yesterday: two with direct-thread silencers made by pre-S&W Gemtech, and one with an OpsINC-style OTB silencer; all quality options with solid mounting methods. I have not removed the silencers, in an effort to eliminate that variable, as you suggested. For me, the silencer is non-negotiable, and if the phenomenon were to be caused or enhanced by the silencer, I'd accept that anyway, and move on with figuring ways to compensate for the effect. My fingers and toes are more than adequate, to count the number of times, this year, that I've fired a rifle round without a silencer. Where POI shift in general with/without the silencer is concerned, one would want to document that shift; especially if the silencer has a QD mount of any kind. Quality silencers don't fail under normal circumstances, or even "wear out", but catastrophic events find a way; so it's wise to know your unsuppressed POI, even if you have no intention of ever removing it. I agree with both you and hrcjon, on the different silencer and gun combos. I like to experiment (the "geardo" in me), however hrc is right in saying a match is made, and it seldom changes. Any change that is made is a semi-permanent long term change; one rifle doesn't play host to many different silencers on a regular basis.
 
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Thanks for this thread. It’s given me much to think about even though it’s a subject I’ve considered at length before. Although I’m still highly suspicious of the accuracy of anecdotes, and not least because they seldom provide adequate information about variables, sometimes they’re hard to doubt. Then there are the confident assertions of individuals and organizations from the Army Marksmanship Unit to the Ridgeline group with their detailed claims, up to requiring “mapping” to deal with the phenomenon.

I will, however, point to something I’ve raised before: Just as if P320 pistols can go off by themselves without human intervention, there must be a mechanical explanation for how that could occur. Likewise, there must be some mechanical and/or ballistic explanation of the “cold bore” shift that doesn’t involve some shooter contribution. And since that’s an obvious given: What is the explanation? At this point I’m not convinced that any of the usual claims are sufficiently valid to accept as full explanations. Flaws and gaps, greater or lesser, become apparent in all of the ones I’m familiar with once they are subjected to detailed and close scrutiny. It’s one thing to claim that something always occurs, but if it does, there must be a why it does, and not just “Fifty million Frenchmen can’t be wrong.”

Perhaps there are multiple reasons why the phenomenon could occur, and that would be at least a partial reason for why no one thing seems to be a complete explanation, but that too seems a little weak to me. In any case, thanks again.




7/93
“So let’s speculate, a word that sounds like an activity that should be—and once was—done in private.”
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Posts: 46398 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
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quote:
Originally posted by KSGM:
So, I need to work on further mitigation of the "cold shooter" in me. The more unsettling, but also more logical results, were out of the AR10. Everything was low. There was an exceptionally low shot (first), and then the remaining decent group was also lower than it should have been, according to DOPE. The ambient temperature was at least thirty degrees cooler than when DOPE was previously collected and confirmed, so I suspect that is playing a role in that POI difference.

For grins, I ran JBM calculations based on my own 16" AR15s with Hornady 75 Black HPBT ammo.
- Baseline of 300 yards, MV of 2625 fps, and a fairly common air density altitude of 8,000 feet. Bullet drop of 4.1 MOA, or 12.9".
- I find a 30 degree temp swing generally changes DA by around 2,000 feet. But the DA change could be closer to 3,000 if a front moves in with the temp change. So let's reduce the DA to 5,000 feet and keep MV constant. Drop of 4.3 MOA, or 13.4".
- I find a 30 degree temp drop might reduce MV 25-50 fps, depending on the ammo. So let's reduce the MV to 2575 and keep the DA at 5,000 feet. Drop of 4.5 MOA, or 14.2".

This means in the above conditions, JBM predicts my 300 yard POI dropping by .4 MOA, or 1.3 inches. In my actual experience a POI drop of 3/4 to 1 inch is the ballpark, and in all honesty I might add a 1/4 MOA click of elevation. Or maybe I'll ignore the relatively minor difference in POI when I'm shooting at steel targets.

Now for targets at 500-600 yards I will take more notice of the day's environmental changes, but even then my elevation dope adjustments will likely be no more than 1 MOA.
 
Posts: 7500 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
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quote:
Originally posted by sigfreund:
Likewise, there must be some mechanical and/or ballistic explanation of the “cold bore” shift that doesn’t involve some shooter contribution.

I have never received a good explanation of the cold clean bore shift, or maybe I wasn't paying attention. From experience, I will state that for some rifles/barrels the shift can likely be ignored.

This is barrel #1 of my GA Precision 6.5 Creedmoor, using Hornady 140 Amax. Going back to September of 2014. I was shooting in a multi-day sporting clays tournament and it wasn't my best day. Figuring my events would be done before it got too late in the day, I brought my rifle and hot footed it over to our family property. Cold clean bore, the first 2 shots from the rifle that afternoon, 577 yards. Wind from the left, 12" plates, wind drift was in the 12-14" ballpark IIRC. Dialed the normal dope elevation for these targets. A stylized version of this picture is still on JC Steel's site, as an illustration of his double post targets.



This is the 6.5CM with its second barrel, in May of 2017. Cold clean bore, with maybe 50 rounds on the barrel. Hornady 140 ELDM. My 'smith said this Bartlein was likely the straightest barrel he had every installed and expected great things from it. 5 rounds at 100 yards in .194" -- likely the best group I've shot.



In a Rifles Only course in northeastern Colorado, Nick Irving (Ranger Sniper) shot my 6.5CM bolt action cold clean bore and produced a 5-round group at 100 yards which was probably .1" -- it looked like one hole. Uncertain which barrel was on the rifle at that time.

A number of years ago, I attended at rifle course held at what was the T1 ranch in northeastern Colorado. The instructor was Frank Galli -- sniper's hide site owner, ex-sniper, and ex-Rifles Only instructor. On one day of the course, Frank asked me to get on his spotting scope, in order to spot him at 100 yards. Frank would be shooting his GAP-built 308 in a match the following week, and he wanted to confirm it was zeroed. IIRC he was using Black Hills 168 Amax. Frank's first shot was 1/4" right of the POA, and I saw the impact. I couldn't spot Frank's 2nd & 3rd shots. On his 4th shot, I realized the 1st shot hole widened by a really small fraction of an inch. Same with shot #5. His group might have measured .1" but also might have been less.
 
Posts: 7500 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
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In my actual experience a POI drop of 3/4 to 1 inch is the ballpark
That's what my benchrest shooter acquaintance said as well. Unfortunately, my results on Wednesday were lower than that. It sucks, because I worked hard on the DOPE for that gun, and had (I thought) proved it's effectiveness at least three times, since it's collection. Going to have to put in some more work with it. That gun is floated, so I have zero excuse for any first shot deviation as well. My overall goal,for the AR10, is to have data and performance that can land me a first round hit on a six inch target anywhere inside 300m. I know the gun and ammo combination is solid, and capable; gotta work on the human element.

*The (perhaps wishful-thinking) goal was, originally, to have that first round 6" target hit ability anywhere inside 500m. I don't know if that's realistic.
 
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