Advanced Marksmanship Question with "first round flier" for AR

[zhonghh]

First, I've read some threads in this forum and found at least 2 threads that are related to my question of "first round flier" of AR. But none of them are specific on this topic (just related) and none of them gives a sure answer to this question. So I think it is OK to post a thread dedicate to this question.

My observation:
This is for my AR-15 with wylde chamber 1:7, target at 100 yard.
Last weekend, I did the following test:
1. Tested 4 different loads with 3 kinds of bullet: Hornady 75gr HPBT, SMK 77gr HPBT, SMK 69gr HPBT.

2. For each group, I loaded 3 rounds in a 20-round magazine. I closed the bolt for the first round by using the bolt catch. After the last round, bolt group will be stopped by the catch.

3. For two loads, I put two groups in one target: after I finished the first 3 rounds, I loaded the magazine and then immediately shot the second group. The time between the two 3-round groups is about 1 minute.

4. For one load, I put a 3-round group and a 2-round group together with approximately 1 minute loading time between them, to form a 5-round group.

5. After finishing a load (either one or two 3-round groups for that load), I waited about 5-10 minutes to start the next load's group.

Result is:
The first round of a load's group is always a flier around 7-8 clock direction. And this is true for all 4 loads.
The load that has two sub groups, the first round of the second group is NOT a flier. Only the first round of the first group is flier.

My thoughts about the observation:
1. In some other threads, people mentioned different way of closing the bolt for the first round may cause the “first round flier” but also they affirmed that by using the bolt catch to close the bolt, this problem will be gone. And this is exactly what I did. Also, for loads with two sub-groups, the first round of the second group is not a flier, and the second group employed the same way of closing the bolt for the first round. So it should not be a problem of how I closed the bolt.
2. Because I used 4 different loads with 3 different bullets, and this “first round flier” is true for all of them, it should not be a problem of loads.
3. I believe I have paid equal attention to the first round of a load as to the rest of the group, and for the 2nd group of a load, the first round is not a flier. I don’t think shooter is a problem of this (I am not a good shooter, and you can take this as: the first round is really bad, but the rest are just normally bad).
4. The only thing I think that may cause the problem is the long time of rest between loads. The time between first sub-group and second sub-group of a load is relatively short, and the first round of the second sub-group is not a flier. The time between two loads are long (as I check targets), and the barrel could cool down a lot. But I don’t know how this will affect the first round.
I’ve been searching for answers on the internet for a while. I found I am not the only one who has this problem. And I think this “first round flier” is a very important issue since a lot of times, you only have one shot to do the job (like hunting). If first round is always a flier, no matter how accurate and consistent the rest rounds are, it is useless. I found this forum has the most knowledgeable members so I hope people here can help to solve this mystery for me and for a lot of other people who have the same question.
Thanks.

 

[Sterling Shooter]

Re: Question with "first round flier" for AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ARgeek</div><div class="ubbcode-body">First, I've read some threads in this forum and found at least 2 threads that are related to my question of "first round flier" of AR. But none of them are specific on this topic (just related) and none of them gives a sure answer to this question. So I think it is OK to post a thread dedicate to this question.

My observation:
This is for my AR-15 with wylde chamber 1:7, target at 100 yard.
Last weekend, I did the following test:
1. Tested 4 different loads with 3 kinds of bullet: Hornady 75gr HPBT, SMK 77gr HPBT, SMK 69gr HPBT.

2. For each group, I loaded 3 rounds in a 20-round magazine. I closed the bolt for the first round by using the bolt catch. After the last round, bolt group will be stopped by the catch.

3. For two loads, I put two groups in one target: after I finished the first 3 rounds, I loaded the magazine and then immediately shot the second group. The time between the two 3-round groups is about 1 minute.

4. For one load, I put a 3-round group and a 2-round group together with approximately 1 minute loading time between them, to form a 5-round group.

5. After finishing a load (either one or two 3-round groups for that load), I waited about 5-10 minutes to start the next load's group.

Result is:
The first round of a load's group is always a flier around 7-8 clock direction. And this is true for all 4 loads.
The load that has two sub groups, the first round of the second group is NOT a flier. Only the first round of the first group is flier.

My thoughts about the observation:
1. In some other threads, people mentioned different way of closing the bolt for the first round may cause the &#147;first round flier&#148; but also they affirmed that by using the bolt catch to close the bolt, this problem will be gone. And this is exactly what I did. Also, for loads with two sub-groups, the first round of the second group is not a flier, and the second group employed the same way of closing the bolt for the first round. So it should not be a problem of how I closed the bolt.
2. Because I used 4 different loads with 3 different bullets, and this &#147;first round flier&#148; is true for all of them, it should not be a problem of loads.
3. I believe I have paid equal attention to the first round of a load as to the rest of the group, and for the 2nd group of a load, the first round is not a flier. I don&#146;t think shooter is a problem of this (I am not a good shooter, and you can take this as: the first round is really bad, but the rest are just normally bad).
4. The only thing I think that may cause the problem is the long time of rest between loads. The time between first sub-group and second sub-group of a load is relatively short, and the first round of the second sub-group is not a flier. The time between two loads are long (as I check targets), and the barrel could cool down a lot. But I don&#146;t know how this will affect the first round.
I&#146;ve been searching for answers on the internet for a while. I found I am not the only one who has this problem. And I think this &#147;first round flier&#148; is a very important issue since a lot of times, you only have one shot to do the job (like hunting). If first round is always a flier, no matter how accurate and consistent the rest rounds are, it is useless. I found this forum has the most knowledgeable members so I hope people here can help to solve this mystery for me and for a lot of other people who have the same question.
Thanks.

</div></div>

First, I think you're a real smart guy. Your analysis of this and other shooting phenomena will get you to the highest shooting plateau.

It's all about the bore-it's condition is changing, from heat mostly; and, the effect may or may not have any meaning, depending on whether the first shot is important and how you account for the first shot.

 

[BlackStar]

Re: Question with "first round flier" for AR

My suggestion would be to record the data on your “first round flyer” with all 4 loads, in all conditions. This will give you a first round zero and then use your shot group data to build a group zero. (cold bore zero idea) giving you two zero’s or a semi accurate hold off.

Not really an answer to your question, but a simple solution to the hunting/ first round flyer issue.

Personally I have never experienced a first round flyer with an AR, not to say that it’s not common. I just never experienced it personally. I use a wylde chamber 1:8 twist with Mk262 and the only problems I have found, is when the actual bullet is scarred by the chamber, ejected and then re-chambered. In this case the bullet will always be a wild shot, normally in the 8 ring.

 

[Greg Langelius *]

Re: Question with "first round flier" for AR

Coupla things:

First; Sterling is right. Each round goes down a bore with different conditions.

Just as every round is an entire match, all by itself; <span style="text-decoration: line-through">if a part of the sequence is consistently off, shoot it high,</span> and get on with the rest of the string.

<*> Updated <*> If your first round is consistently going to a different, but predictable, POI, use estimated Kentucky Windage to put it into the same POI as subsequent rounds can be expected to go. I'm certain this ploy is obvious, and only state it to sorta be thinking aloud. Anything that's consistent and predictable isn't really a deviation, but rather; it's more like an old friend, for whom we are happy to make allowances

Second...; there is no second...

If you know what doesn't work, you're that much farther ahead of the game.

Shooting is as shootings does, but only if it does it consistently. If it ain't consistent; it ain't part of the lesson...

Thus endeth the lesson...

Greg

 

[Ted Howard]

Re: Question with "first round flier" for AR

How the bolt closes on a charge handle and how it closes on a fired shot is different, as it was explained to me. Only way to know is to single feed every round to test this theory. I found it to be true. I also could find the same results as you if I am reading what you are doing. Yes load developing was a pain single feening an AR, but I did it. I would place the round all the way into the chamber then close the bolt via latch. Seemed to work. But then back to the deal, Its an AR I dont single feed AR's. So you know your first shot out of an AR just as you do your Cold bore shot on your bolt rifle. $.02 please !

 

[Sierra]

Re: Question with "first round flier" for AR

Keep digging and you will eventually figure out what is causing ig. I have never experienced a flyer on the first round but I have experienced flyers on the last round in a group if it is the last round in the magazine. The bolt locks back on the last round and changes the harmonics in the gun resulting in a flyer. Not a bad flyer but if you are shooting for tiny groups it reeks havoc on you until you figure it out. It took me a little while to figure out what was causing my flyer.

 

[Sig685]

Re: Question with "first round flier" for AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sierra</div><div class="ubbcode-body">(Snip) The bolt locks back on the last round and changes the harmonics in the gun resulting in a flyer. (snip) </div></div>

That's not the reason, but we are not going to redo that thread. Search is your friend.

 

[Sterling Shooter]

Re: Question with "first round flier" for AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sig685</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sierra</div><div class="ubbcode-body">(Snip) The bolt locks back on the last round and changes the harmonics in the gun resulting in a flyer. (snip) </div></div>

That's not the reason, but we are not going to redo that thread. Search is your friend.</div></div>


One of our posters here, coming to the table with more science than most here could muster on the topic, has alluded to issues about knowing where the gun is pointed when changing from single feeding to feeding from the mag. Look for posts from Sinister.

 

[doc76251]

Re: Question with "first round flier" for AR

Not to re-hash the thread that Sterling is mentioning..... the weak link in AR (or in my case M1A) group issues was the magazines. I spent a goodly portion of 2 days testing magazines to find the 3 that I used for high power that would shoot to the same POI for thier assigned positions. You will find many HP shooters that have numbers printed on thier mags for this reason. 1, 2, & 8.

My method of testing was to shoot 4 rounds at 4 different targets.

Round 1 - Straight from the mag w/ 2 under it
Round 2 - 2nd in the mag
Round 3 - last in the mag
Round 4 - drop in and hit the bolt catch (M1A finger and fly the op-rod)

With a little bit of bullet hole annalysis you can determine what each magazine does and assign them appropriately. It takes alot of paper, alot of ammo, abunch of magazines and alot of walking but the results are worth it in the end.

Cheers,

Doc

 

[JeffinTX]

Re: Question with "first round flier" for AR

you didn't mention whether you are shooting with irons or scope, is your handguard floated or standard AR? how far out is that first round?
in my AR's for service rifle competition, shooting 10 rd rapid fire strings with a sling and iron sights at 200 and 300 yds, I have not encountered issues with 1st round flier or any substantial differences with mags. they either feed reliably or they don't. GI 20 round mags work. I expect to clean the rapids and when I don't, its going to be an error in setting the NPA, position-including proper sling tension, or missing the wind call at 300. In the rapid fire strings, we load with 2 rounds, shoot, then mag change with 8 more rounds in 60 or 70 seconds, so we have rounds feeding from an open bolt twice and two rounds firing from an empty mag with the bolt catch lacking back twice in each string of 10. the rapid prone at 300 will usually break down any flaws in shooting technique.

 

[Greg Langelius *]

Re: Question with "first round flier" for AR

Mags and initial bolt release make sense. Issues post bore transit don't, the bullet's already gone, but mag drag during feeding and lockup might indeed create differences in bolt velocity. I think it's a stretch given the small amount of bolt rotation needed to engage the bolt lugs, but it's possible.

I would use the charging handle to pull the bolt back to complete retraction and release the bolt after magazine insertion, rather than using the manual bolt release.

So how would one deal with mag issues?

It seems to me that the configuration and orientation of the mag follower within the mag interior would be a factor, so anything one might do to make this more uniform between magazines would be to advantage. Maybe also note that the last round feeding process may or may not bring the follower into contact with the bolt carrier and this might consequently alter bolt velocity. I might even seriously consider gluing a dummy round onto the follower, so the last round drags against a case surface, instead of a mag follower. An immobile last cartridge would probably stop the bolt as effectively as a mag operated bolt stop, and would work in such instances (with other rifle designs) where a bolt stop was not present (AK, 10/22, etc.).

Perhaps a lubrication regimen for the mag follower might also help.

Follower springs are an issue. I would compare their unstressed height and degree of straightness, and maybe come up with a way of using a trigger scale to guage compression force at full compression and at a distance about equivalent to the spring length when feeding the last round.

Follower springs made of wire probably create differences in bolt/cartridge friction for each and every round in the mag. There are other kinds of springs that can work with mag follower. The one I like is made of flat spring steel sheeting, coiled like a roll of tape. The force it exerts as it is unrolled and retracts back on the follower is nearly perfectly uniform at any depth within the mag body. I think that would be beneficial. In fact, I can't think of a better kind of spring for a lot of other rifle action mechanisms as well.

The exterior finish of case walls may have some bearing on bolt velocity, as they affect the degree of friction between the two elements.

Greg

 

[zhonghh]

Re: Question with "first round flier" for AR

Thanks for all the feedbacks from everyone. Here is some more info:
I use a freefloat handguard. I use optic: 2.5-16x42mm Bushnell Elite 6500, set at 16x. I use bipod + back sandbag. I think my aiming should be ok.

I tested single feed today: I put one round in mag and feed by releasing bolt catch.

Test result, two groups:
1. 11 rounds, 0.81"
2. 5 rounds, 0.51"

All these rounds have POI similar to the first round in a multi-round mag as I tested before. So it is pretty consistent.

Now the fact is: all first rounds are pretty consistent hit lower around 6-7 o'clock direction, while the following rounds are consistent as well and hit the bull's eye.

So I suspect this must be some feeding problem. There are several things I think may affect this:
1. buffer. I use a extra heavy buffer with some tungsen insert. I build it myself.
2. bolt. The bolt directly contact the rounds.
3. gas system. I am using a PRI adjustable gas block. Could too much or too little pressure affect feeding consistency?

 

[AQC440]

Re: Question with "first round flier" for AR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: doc76251</div><div class="ubbcode-body">Not to re-hash the thread that Sterling is mentioning..... the weak link in AR (or in my case M1A) group issues was the magazines. I spent a goodly portion of 2 days testing magazines to find the 3 that I used for high power that would shoot to the same POI for thier assigned positions. You will find many HP shooters that have numbers printed on thier mags for this reason. 1, 2, & 8.

My method of testing was to shoot 4 rounds at 4 different targets.

Round 1 - Straight from the mag w/ 2 under it
Round 2 - 2nd in the mag
Round 3 - last in the mag
Round 4 - drop in and hit the bolt catch (M1A finger and fly the op-rod)

With a little bit of bullet hole annalysis you can determine what each magazine does and assign them appropriately. It takes alot of paper, alot of ammo, abunch of magazines and alot of walking but the results are worth it in the end.

Cheers,

Doc</div></div>
Now that was informative!

 

[van462]

Re: Question with "first round flier" for AR

Have you ever tried loading 4 rounds and see if its different. Since it's a staggered mag it feeds from both the left and right side. Could the barrel extension feed ramps combined with magazine differences cause both different bolt speeds or bullet deformations.

 

[Hellbender]

Re: Question with "first round flier" for AR

Is the gun new or well broken in?

If new, check your locking lugs for contact, many AR's only have two lugs touching, and this will allow any inconsistency in loading to show up in the groups.

I lap my bolts for better contact, but 3-400 rounds of shooting will help a lot.

Your fliers should slowly get better as the bolt seats itself to the barrel extension, if this is the problem.

 

[Sterling Shooter]

Re: Question with "first round flier" for AR


Hey, just think of it as a cold bore shot.