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Posted: 11/6/2010 4:16:15 PM EDT
| I have a Century 74. Occasionally I will have a round hit the target which is elongated. Now, my first 74 did not have rifling, and I have seen holes in paper which were completely sideways - a perfect profile shot of the bullet. What I am getting in my current rifle is just some elongation in about 1in 5 or 10 rounds at 25 yards. Mostly with Wolf 60 gr Hollow points. Surprisingly, it seems to do better with the 70 gr FMJ. I even got some today with 50 gr milsurp. My question is, is this necessarily keyholing if it is just a little elongated, since the bullet wobbles a little in flight? I am a mediocre (at best) marksman, so I can't really tell if it is affecting my accuracy. Would an absolute keyhole necessarily put the target completely off target or way out of a group? What I am getting is still falling within my "group". Should I be very concerned about "elongation" in 10 or 15% of my rounds which might be caused by normal in flight yaw. How can I tell if its a barrel issue or just normal ballistics? |
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I really don't think you should be seeing any elongation unless you are hitting debris along the way. It sounds like your barrel isn't exactly right, but better than some. Shooting some 53gr surplus stuff may make the key holing worse.
I got an In Range built TGI gun a year ago and I have not seen one single keyhole using only surplus out to 200 yards. |
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I have a Century 74. Occasionally I will have a round hit the target which is elongated. Now, my first 74 did not have rifling, and I have seen holes in paper which were completely sideways - a perfect profile shot of the bullet. What I am getting in my current rifle is just some elongation in about 1in 5 or 10 rounds at 25 yards. Mostly with Wolf 60 gr Hollow points. Surprisingly, it seems to do better with the 70 gr FMJ. I even got some today with 50 gr milsurp. My question is, is this necessarily keyholing if it is just a little elongated, since the bullet wobbles a little in flight? I am a mediocre (at best) marksman, so I can't really tell if it is affecting my accuracy. Would an absolute keyhole necessarily put the target completely off target or way out of a group? What I am getting is still falling within my "group". Should I be very concerned about "elongation" in 10 or 15% of my rounds which might be caused by normal in flight yaw. How can I tell if its a barrel issue or just normal ballistics?  Almost NONE of your information about ballistics is correct..
All "rifles" have rifling grooves in the barrel , and properly dimensioned bullets fired from a properly dimensioned barrel will NOT hit a paper target "sideways" as long as they are still spinning and have reasonable velocity. What YOU have experienced is due to MISMATCHING of bullet weights and profiles to RIFLING TWIST. This happened because the MFG STUPIDLY used the wrong barrel on your first AK74. 
Read through the AK forum posts and you will find lots of info about this. |
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I have a Century 74. Occasionally I will have a round hit the target which is elongated. Now, my first 74 did not have rifling, and I have seen holes in paper which were completely sideways - a perfect profile shot of the bullet. What I am getting in my current rifle is just some elongation in about 1in 5 or 10 rounds at 25 yards. Mostly with Wolf 60 gr Hollow points. Surprisingly, it seems to do better with the 70 gr FMJ. I even got some today with 50 gr milsurp. My question is, is this necessarily keyholing if it is just a little elongated, since the bullet wobbles a little in flight? I am a mediocre (at best) marksman, so I can't really tell if it is affecting my accuracy. Would an absolute keyhole necessarily put the target completely off target or way out of a group? What I am getting is still falling within my "group". Should I be very concerned about "elongation" in 10 or 15% of my rounds which might be caused by normal in flight yaw. How can I tell if its a barrel issue or just normal ballistics? Almost NONE of your information about ballistics is correct..
All "rifles" have rifling grooves in the barrel , and properly dimensioned bullets fired from a properly dimensioned barrel will NOT hit a paper target "sideways" as long as they are still spinning and have reasonable velocity. What YOU have experienced is due to MISMATCHING of bullet weights and profiles to RIFLING TWIST. This happened because the MFG STUPIDLY used the wrong barrel on your first AK74.
Read through the AK forum posts and you will find lots of info about this. No. It is, at least partly, science. Almost ALL of my information about ballistics is verified here, and here. "Bullets do not typically follow a straight line to the target. Rotational forces are in effect that keep the bullet off a straight axis of flight. Yaw refers to the rotation of the nose of the bullet away from the line of flight. Precession refers to rotation of the bullet around the center of mass. Nutation refers to small circular movement at the bullet tip. Yaw and precession decrease as the distance of the bullet from the barrel increases." And from my AK Files post here. I never knew about this either until I read it at the supplied link. Now, what I had on my first AK was a smoothbore. Not the wrong barrel, the bullet fit. The idiots just did not put any rifling into it - not too little, none. I took it back to the seller and they exchanged it. I found it very hard to believe that a bullet which appears unstable at short ranges, miraculously stabilizes at longer ranges. Until I read those articles above. |
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No. It is, at least partly, science. Almost ALL of my information about ballistics is verified here. From http://library.med.utah.edu/WebPath/TUTORIAL/GUNS/GUNBLST.html "Bullets do not typically follow a straight line to the target. Rotational forces are in effect that keep the bullet off a straight axis of flight. Yaw refers to the rotation of the nose of the bullet away from the line of flight. Precession refers to rotation of the bullet around the center of mass. Nutation refers to small circular movement at the bullet tip. Yaw and precession decrease as the distance of the bullet from the barrel increases." I found it very hard to believe that a bullet which appears unstable at short ranges, miraculously stabilizes at longer ranges. Until I read those articles above. Have you examined many targets? While bullets may yaw slightly in flight even when everthing is working properly, the amount of yaw is so small that the hole in the target is circular and does not show evidence of keyholing. When the bullet has yawed sufficiently to leave a non-circular hole in the target, something is wrong. In any case, the answer to your question is to be found in the real world, on a shooting range where the target is 100 m/y or more from the firing line. |
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––––––- Almost NONE of your information about ballistics is correct..
All "rifles" have rifling grooves in the barrel , and properly dimensioned bullets fired from a properly dimensioned barrel will NOT hit a paper target "sideways" as long as they are still spinning and have reasonable velocity. What YOU have experienced is due to MISMATCHING of bullet weights and profiles to RIFLING TWIST. This happened because the MFG STUPIDLY used the wrong barrel on your first AK74.
Read through the AK forum posts and you will find lots of info about this . No. It is, at least partly, science. Almost ALL of my information about ballistics is verified here. From http://library.med.utah.edu/WebPath/TUTORIAL/GUNS/GUNBLST.html "Bullets do not typically follow a straight line to the target. Rotational forces are in effect that keep the bullet off a straight axis of flight. Yaw refers to the rotation of the nose of the bullet away from the line of flight. Precession refers to rotation of the bullet around the center of mass. Nutation refers to small circular movement at the bullet tip. Yaw and precession decrease as the distance of the bullet from the barrel increases." And from my AK Files post here. I never knew about this either until I read it at the supplied link. Now, what I had on my first AK was a smoothbore. Not the wrong barrel, the bullet fit. The idiots just did not put any rifling into it - not too little, none. I took it back to the seller and they exchanged it. I found it very hard to believe that a bullet which appears unstable at short ranges, miraculously stabilizes at longer ranges. Until I read those articles above. - Finding a rifle with a barrel that was never rifled is so rare that I can't recall ever reading a post about it
here , however I accept the fact that it happened to you. The ballistic effects described in the article you referenced are maximized at very short distances ( under 30 meters ) and should NOT be so extreme as to be visible by simply comparing holes in a paper target.
And even so , the heavier bullets in your NEWER rifle should be completely stabilized by a proper 5.45x39 barrel. Can you take a picture of an actual target for us ?? . |
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Yeah, I really didn't think I needed to check the barrel for rifling, and it was a shame because I looked that rifle over very well. Everything was very tight, straight, and clean. I didn't mind paying $400 for a century when I was able to handle it as opposed to pressing my luck with an unknown entity over the internet.
My range is only set up to 25 yards so getting a 100 yard shot will be difficult to achieve w/o moving hardware around, but I might have to try it. Re: your comment about heavier bullets - I was under the impression that lighter rounds would do better as opposed to heavier because they spin easier and faster. However, I do seem to get better results out of 70 gr FMJ than I do the 60gr HP. Could HP v/s FMJ make any difference? The picture I'm attaching (or attempt to) is from the first smoothbore rifle I had to return. There is one round on that pic which is closer to what I'm getting now (the top middle round). Ok no luck on a pic attachment. How do I get a pic from my CPU to a post? |
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Create an account at tinypic or photobucket, upload, copy link to your post. Hmm. I'll try. href=http://i1124.photobucket.com/albums/l576/kick_em/th_489c8eb8.jpg" /> Well it seemed to work. That's from my first rifle without rifling. The one shot up toward the top of the target is closer to what i'm getting now, but not quite as exaggerated. |
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Create an account at tinypic or photobucket, upload, copy link to your post. Hmm. I'll try. http://<a href=http://i1124.photobucket.com/albums/l576/kick_em/th_489c8eb8.jpg</a>" /> Well it seemed to work. That's from my first rifle without rifling. The one shot up toward the top of the target is closer to what i'm getting now, but not quite as exaggerated. good group, Grats |
I'd take it back and get a refund and save up for an Arsenal or another rifle with a guaranteed milsurp barrel. The only barrels that seem to have keyholing issues with this caliber irregardless of the reason are the American made ones from Lancrapster , Century, even Smith & Wesson AR's have all had issues with this caliber.
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I'd take it back and get a refund and save up for an Arsenal or another rifle with a guaranteed milsurp barrel. The only barrels that seem to have keyholing issues with this caliber irregardless of the reason are the American made ones from Lancraster , Century, even Smith & Wesson AR's have all had issues with this caliber.Add Spikes Tactical to your list. If you consider that ST uses Lothar Walter barrels, which are top tier, they still have keyhole issue. The second batch of LW barrels are actually being rejected. American barrel makers have trouble cutting 5.45 barrels, period. |
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I'd take it back and get a refund and save up for an Arsenal or another rifle with a guaranteed milsurp barrel. The only barrels that seem to have keyholing issues with this caliber irregardless of the reason are the American made ones from Lancraster , Century, even Smith & Wesson AR's have all had issues with this caliber.Add Spikes Tactical to your list. If you consider that ST uses Lothar Walter barrels, which are top tier, they still have keyhole issue. The second batch of LW barrels are actually being rejected. American barrel makers have trouble cutting 5.45 barrels, period. Well that would be #4 all American made unfortunately. I had considered getting one of these Century AK's for myself for Christmas but I'll pass since I don't want to have a repeat of my Lancrapster less than 100 round smoothbore experience. |
why I will never buy another Century 5.45x39 gun again.
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Can you take a picture of an actual target for us ?? . http://i1124.photobucket.com/albums/l576/kick_em/a614aa01.jpg This was shot today with milsurp - I assume 50ish grain at 25 yards. I have heard that heavier rounds are harder to stabilize, however, I have had better results with 70 grain wolf milspec. Which is it? Lighter rounds should do better or heavier? Thanks. |
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I have a Century 74. Occasionally I will have a round hit the target which is elongated. Now, my first 74 did not have rifling, and I have seen holes in paper which were completely sideways - a perfect profile shot of the bullet. What I am getting in my current rifle is just some elongation in about 1in 5 or 10 rounds at 25 yards. Mostly with Wolf 60 gr Hollow points. Surprisingly, it seems to do better with the 70 gr FMJ. I even got some today with 50 gr milsurp. My question is, is this necessarily keyholing if it is just a little elongated, since the bullet wobbles a little in flight? I am a mediocre (at best) marksman, so I can't really tell if it is affecting my accuracy. Would an absolute keyhole necessarily put the target completely off target or way out of a group? What I am getting is still falling within my "group". Should I be very concerned about "elongation" in 10 or 15% of my rounds which might be caused by normal in flight yaw. How can I tell if its a barrel issue or just normal ballistics? Almost NONE of your information about ballistics is correct..
All "rifles" have rifling grooves in the barrel , and properly dimensioned bullets fired from a properly dimensioned barrel will NOT hit a paper target "sideways" as long as they are still spinning and have reasonable velocity. What YOU have experienced is due to MISMATCHING of bullet weights and profiles to RIFLING TWIST. This happened because the MFG STUPIDLY used the wrong barrel on your first AK74.
Read through the AK forum posts and you will find lots of info about this. i respectfully disagree.. he said the 70 gr were doing better.. that would lead me to believe the barrel was more than sufficent for spinning the lighter 60 gr. are the rounds JHP? i have older wolf that the lead rattles on the copper jacket |
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