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Posted: 7/21/2010 2:47:47 PM EDT
| I have a DPMS Panther 14.5" barrel, 1 in 9", flat top M4. The frint sight base has a "B" in a diamond on it with a #2 to the right of the B in the diamond. I was told this is not an A2 Mil-Spec sight, rather a commercial sight. I bought a CAA carry handle for it and tried to get it to zero. I had to buy a taller front sight post because my shots were too high. I took it to the range and sighted it in at 25yds perfectly. Shot at the 50 - same result. Then I shot at 100 yds. The rounds were hitting about 12 - 14 " too high. The theory is the incorrect carry handle version for my front sight type. I don't really want to get into a discussion about what method of zeroing to use. My question is what type of front sight do I have and what type of carry handle do I need before I spend the $$ on something that won't work. The tech support at DPMS wasn't any help at all. What do you guys know about this issue? |
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You don't want to get into a discussion about what kind of zeroing to use but that's probably your issue.
You most likely don't have an "F" marked FSB which is proper height for a flat top upper. So you go the taller front sight post. You have elevation adjustments in the front sight as well as the carry handle. I can not see how with a combination of those adjustments you can not get it to work. Which leads me back to my first statement - your zero method is the issue. Zero your rifle at 50 yards and try again. |
| The B in a diamond with the #2 is just a forge mark. It doesn't denote what type of FSB you have. However, if it's a DPMS then it's a non-F height FSB. You also have a poor excuse for a commercial carry handle but that may not explain why you're having perceived troubles getting a good zero with your current set-up. |
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You are correct. I don't a an "F" on the front sight base. When zero'ed at the 25 it is fine out to the 50. I shot 2 quals for our agency and got 2 perfect scores, so, it works. However, at 100 I have to aim at about the pelvic region to hit upper chest. That to me seems unacceptable.
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If you shot at 25 and 50 perfectly and are 12-14" high at 100 - it is you. It doesn't matter what sight you are using, the bullets path is the bullets path, and there aint no way in hell its 12" high at 100 and on at 25 or 50.. The type of sight setup (correct or incorrect) will only affect adjustment limitations..
ETA my rough in-my-head calculations would put a 25 yard zero somewhere around 5-7" high at 100 depending on the ammo/barrel/etc |
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Warpig, yes it was an inexpensive carry handle. At the 25 off hand 5 shot groups were all within a half dollar size. So, if my front sight is a non "F" height FSB then what brand / type carry handle do I need? If I get a Mil-Spec I'll have the same problem, right?
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Warpig, yes it was an inexpensive carry handle. At the 25 off hand 5 shot groups were all within a half dollar size. So, if my front sight is a non "F" height FSB then what brand / type carry handle do I need? If I get a Mil-Spec I'll have the same problem, right? The carry handle is going to be the same size no matter what brand. A Colt or similar will be better quality, that's it. |
| Woode, actually I think you're right about the distance. I was using a standard 8" (x,10,9 black circle) 100 yard military sight in target. I put my front sight post below the black center lower than a 6 o'clock hold to get them in the black. Is that normal for a 25 yard zero? When the shots were at the highest, I was holding FSP at dead center. Sorry for the confusion. |
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The carry handle is going to be the same size no matter what brand. A Colt or similar will be better quality, that's it. No. The OP is correct. There are two different types of carry handles: mil-spec height and commercial height. Mil-spec: 
Commercial: 
His CAA handle is probably commercial height. |
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The carry handle is going to be the same size no matter what brand. A Colt or similar will be better quality, that's it. No. The OP is correct. There are two different types of carry handles: mil-spec height and commercial height. Mil-spec: http://i212.photobucket.com/albums/cc145/dieselpowrguy85/AR-15/DSCN0029Small.jpg Commercial: http://i212.photobucket.com/albums/cc145/dieselpowrguy85/AR-15/CarryHandle.jpg His CAA handle is probably commercial height. The handle or the sight assembly? |
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It sounds like you need to work on a consistent sight picture and a different zero.
If you are running into adjustment limitations, maybe you have the wrong carry handle.. But your problem is that you are way high at 100 and on at 25/50 - that is your zero and possibly your sight picture. Try this ballistics calculator and check the "Zero at Max. Point Blank Range" box. It will even spit out a zero for your rifle that will keep you within X" out to however many yards (no holdover/sight adjustments if your not going for extreme accuracy) You can switch to whatever sight you want, you can even use a 50 powered scope... if you zero at 25, your going to have the same exact problem. Ballistics 101. |
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Woode, actually I think you're right about the distance. I was using a standard 8" (x,10,9 black circle) 100 yard military sight in target. I put my front sight post below the black center lower than a 6 o'clock hold to get them in the black. Is that normal for a 25 yard zero? When the shots were at the highest, I was holding FSP at dead center. Sorry for the confusion. 25 yard zero is a poor zero. 50 yard zero has the smallest hold under/hold over distances throughout the travel of the round. |
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Ok??? I read somewhere and was told that there are Mil-Spec and "commercial" brands of these also and that they are different heights? Especially the ones coming from China. No??? Either way, it's not the issue in this case. The 25 yard zero is the problem. |
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The carry handle is going to be the same size no matter what brand. A Colt or similar will be better quality, that's it. No. The OP is correct. There are two different types of carry handles: mil-spec height and commercial height. Mil-spec: http://i212.photobucket.com/albums/cc145/dieselpowrguy85/AR-15/DSCN0029Small.jpg Commercial: http://i212.photobucket.com/albums/cc145/dieselpowrguy85/AR-15/CarryHandle.jpg His CAA handle is probably commercial height. The handle or the sight assembly? The sight assemblies are the same, but they sit slightly lower on commercial height handles. |
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A couple of things that I was thinking as I read through these:
There is no such thing as a commercial front sight. There is a standard or non "F" and an "F" marked front sight base. Both are military spec, just used at different time periods. The non "F" is the earlier version, but still used by some manufacturers. You have a standard or non "F" front sight base. The difference between the two is not overall height, but the height of the shelf that the post sits in. Sometimes on carbines with flat tops and carry handles the rear sight can be too high for the shorter shelf non "F". This makes zeroing at 25 difficult, usually hitting high because the front sight post runs out of upward travel. To remedy this you can use a taller front sight post or a different carry handle. This does not appear to be your problem since you can get the POI correct at 25 yards, so it's good with exception to the low quality carry handle which may or may not be adding to your problem. Carry handles do have two heights. They look alike, but the cradle that holds the sight can be adjusted a little lower on what's referred to as a commercial carry handle, like Bushmaster. The Colt's don't go as low. Again, that is an explanation of sights, but as woode pointed out it's probably not the problem. Sighting in at 25 will give you a higher POI at 50 and even higher at 100. I got 2.25" higher at 50 and about 6" higher at 100 using basic 55 grain ammo in a ballistics calculator. This is applicable if your point of aim remains consistent at each distance and you don't hold under. Try the 50 yard zero or simply adjust your POI about 1.25" low at 25 and you you should be within about 2" from 10-100 yards, actually farther. Note: There was some other stuff about the carry handle pointed out while I was typing. Plinkr415 is right about the carry handle. I agree with CT and woode that the problem is the zero distance and consistent hold/shooting skills. |
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If I don't change my settings from 25 yard to 100 yard, my zero would be off. But not to the extreme his is. That's what I was getting at.
On department rifles, we zero'd at 50 yards with buis. At 100 it might be off 2-3" but not 14". That doesn't make sense to me no matter what sight he is using, unless adjustments are being changed. I guess I'm just not understanding 
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1st off, thanks for your expertise to everyone. Your advice is great. I am going to start from scratch, with the sights I have and an extremely consistent sight picture, and, as many have suggested, do a 50 yard sight in and write down every impact point at each distance. I'll post the results after this weekend. I'll continue to check back to see if there have been any other posts with suggestions or other insight until then. Thanks again. |
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AZ, of the two pictures plinkr415 posted, which looks like your CAA? If you have the commercial height carry handle then you should use the standard height front post. If you have the milspec then use the Bushmaster 0.04" taller post.
I agree that if you're zeroed at 25 meters then you should only be about 7" high at 100 - not 12". A 50 yard zero should keep you within approx 2" of POA from 0-230 meters. |
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It is even at the top of the carry handle like the Mil-Spec picture. The sight assembly sits even at the top even when bottomed out. As I mentioned earlier, I think I was exaggerating a little on the hight over my POA. It seems more like about 7-8" not twice that. However, I'm going to double check that this weekend and report back with results. |
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It is even at the top of the carry handle like the Mil-Spec picture. The sight assembly sits even at the top even when bottomed out. As I mentioned earlier, I think I was exaggerating a little on the hight over my POA. It seems more like about 7-8" not twice that. However, I'm going to double check that this weekend and report back with results. You're using the correct combination, then. As stated earlier, you're most likely having aiming issues. |
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Woode, actually I think you're right about the distance. I was using a standard 8" (x,10,9 black circle) 100 yard military sight in target. I put my front sight post below the black center lower than a 6 o'clock hold to get them in the black. Is that normal for a 25 yard zero? When the shots were at the highest, I was holding FSP at dead center. Sorry for the confusion. If this is thecase nothing is wrong with your rifle. 5 to 6 inches high with a 25 yard zero is the norm. re zero at 50 yards and try 200 report back. |
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If you have a DPMS upper half, why not just get a DPMS carry handle? Wouldn't solve the problem?
I ran into the same problem when I replaced the carry handle on my CMMG rig with a ARMS #40-A2. I needed to buy a taller front sight post due to the CMMG FSB not being "F" marked. |
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You are correct. I don't a an "F" on the front sight base. When zero'ed at the 25 it is fine out to the 50. I shot 2 quals for our agency and got 2 perfect scores, so, it works. However, at 100 I have to aim at about the pelvic region to hit upper chest. That to me seems unacceptable. You'll be hitting high at 50yards - but still well enough to qualify depending on your agency's qualification system. But zeroing at 25y POA=POI will produce rounds striking some 6-8" high at 100y (assuming M193). That's just basic ballistics here nothing to do with the sights. If you're striking higher either your using a lighter/faster moving round or you are having control issues (i.e. need more training & practice). If you want to keep the trajectory flat, then you need to either zero at 50 yards OR zero at 25 with the point of impact being some 1 1/4" LOWER than your point of aim. That will fix your problem. |
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It is even at the top of the carry handle like the Mil-Spec picture. The sight assembly sits even at the top even when bottomed out. As I mentioned earlier, I think I was exaggerating a little on the hight over my POA. It seems more like about 7-8" not twice that. However, I'm going to double check that this weekend and report back with results. You're using the correct combination, then. As stated earlier, you're most likely having aiming issues. I agree with plinkr415, it sounds like you have an A2 height FSB so do need the Bushmaster 0.04" taller post (already installed) to use with your milspec height carry handle. All should be well as far as mechanical zero and now you can fine tune the zero. Now how good the CAA sight is we don't know but if it's of reasonable quality and you can hold zero at 25 and a little high at 50 yards then it should group well at 100 as well. If you're about 7" high at 100 then everything sounds normal. Also assuming the CAA carry handle is ok you might be able to reindex it using Molon's RIBZ to have a 100 yard zero plus the IBZ 50/200 yard zero plus the standard 25/300 battlesight zero. Though using a commercial height DPMS carry handle would work with the A2 FSB with the short post, you're probably better with the taller post you've installed since down the road you may go with a quality 3rd party BUIS and you can expect it to be milspec height. |
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Shooting at the 100 was off a bench rest sitting in a locked down rifle rest. With all due respect, control issues and sight picture aren't the issue. As I said before, I won top shooter at our last carbine class without the aid of any rest other than the 4 shooting positions; obviously prone being the most stable. I'm going to do a 50 yard zero this weekend and try it again. I'll report back either Sunday or Monday night. |
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RESULTS !!! I went out today to a different site since I had limited time, so, I didn't have the same bench rest as before. I took a camping fold-out table that is fairly stable and sand bags. I took a target frame / stand that I made and my Archer's Choice Range Finder to be sure of the distances I was set up to shoot from. I set my carry handle rear sight to the 6/3 setting (not the "z” setting) and shot at a target with a single 1” black circle in the middle from the 50 yard distance I ranged from the table. I shot several 5 shot groups and adjusted my front sight up 2 - ¼ turns (½ turn total) to get my groups zero'ed in. My average POI distance from POA was 7/16”. I can live with that. I went up to 25 yards to see how far off, above or below my POA, I would be at the closer distance. My average POI distance was 1 1/4” below my POA with an average 5 shot group size of just over 1/2”. Again, I can live with that. Next, the true test. I went back to 100 yards. I shot at a 7 1/2” black circle on white target. My 5 shot groups averaged 3 1/2” POI above my "6 o'clock hold” POA at 100 yards. I am very happy with these results!! I will never go back to a 25 yard zero! (Unless someone has a REALLY, REALLY good reason I haven't heard yet) The next test will be to go out to the Range I went to before so I can shoot out to 200 yards, then, out to the open desert for 300, 400 plus yards to test the rear sight markings with this carry handle. Thanks to everyone for the advice. This is THE place for good info! |
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