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Posted: 11/22/2016 10:24:05 PM EDT
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I'm sure this has been covered before but my search has not turned up what I need. I've got a AR15 upper that's throwing rounds all over the target and it appears it is very picky as to ammunition.
I'm loading 55gr Hornady FMJ and my question is should I use my Hornady Overall Length Gage to determine where the bullet touches the lands and then back off a few thousands? Or should I just concentrate on C.O.A.L. since it's got to fit in the magazine? After measuring a few of my current loads (2.240) I may be a little short for this rifle's preference. |
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Unless you have a custom chamber you'll never get close to the lands with 55gr anything... Hornady fmj generally shoot very well out of any gun. Unless you're using the wrong powder, or, trying to push them really slow or way to fast I'd look for something mechanically wrong. Barrel tight? Using a muzzle brake? If Yes, try without it. Scope or irons? Could be a lose mount/bad scope issue. |
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The first reply is absolutely correct.
Even if you could seat those 55s out you can't go beyond about 2.250" anyway because that's the maximum OAL that will fit in the magazine. You definitely need to look elsewhere for the cause of the inaccuracy. Does the rifle shoot other bullets better? If it does you may want to try different loads. There is always the chance too that your rifle simply does not like that bullet. Motor |
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Quoted: I'm sure this has been covered before but my search has not turned up what I need. I've got a AR15 upper that's throwing rounds all over the target and it appears it is very picky as to ammunition. I'm loading 55gr Hornady FMJ and my question is should I use my Hornady Overall Length Gage to determine where the bullet touches the lands and then back off a few thousands? Or should I just concentrate on C.O.A.L. since it's got to fit in the magazine? After measuring a few of my current loads (2.240) I may be a little short for this rifle's preference. Cover your load in great detail, maybe we can spot the problem. |
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Thanks for all the quick replys. This upper does not have iron sights, but I have tried 2 different scopes, both with quality mounts, and both that shot well on other rifles..
Before I go any farther I'll try the recommended OAL and use a couple of other powders. I just can't imagine that any rifle wouldn't shoot (with a fair degree of accuracy) the Hornady 55gr FMJ-BT bullet but I may have one. thanks again |
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Let me make a take it or leave it suggestion.
Depending on the bbl twist, try to get your hands on some match grade ammo in the appropriate weight for your twist. If you can chronograph the match loads and if they also work well, then we know there is nothing otherwise wrong with the rig when fed good ammo. Then we can try and get that specific bullet to work at its best. If good match ammo isn't working well in the rig, it may be a waste of time trying to get these particular bullets to group. |
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Please give us more information, you my have one problem or multiple problems Length of barrel ( short barrels are more difficult to get a tight pattern with ) brand of barrel ( some brands are very picky ) twist in barrel ( with a fast twist you should be using a heaver bullet ) 223 chamber, 5.56 chamber, Wylde chamber or other ( some chambers are notoriously picky ) what type of trigger and pull weight on trigger ( a good trigger will tighten up your groups ) what brand cases ( some are better than others )( mixing brands is not good for tight patterns ) what powder and how much ( some powder/ primer combinations are difficult ) what primer ( some ball powders need a magnum primer especially in cold temperatures ) are you having trouble getting a good repeatable cheek weld when looking through the scope( and that is something you need ) how was the rifle supported bi-pod ? shooting bag? none ? how does it shoot with factory ammo |
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Quoted:
Please give us more information, you my have one problem or multiple problems Length of barrel ( short barrels are more difficult to get a tight pattern with ) brand of barrel ( some brands are very picky ) twist in barrel ( with a fast twist you should be using a heaver bullet ) 223 chamber, 5.56 chamber, Wylde chamber or other ( some chambers are notoriously picky ) what type of trigger and pull weight on trigger ( a good trigger will tighten up your groups ) what brand cases ( some are better than others )( mixing brands is not good for tight patterns ) what powder and how much ( some powder/ primer combinations are difficult ) what primer ( some ball powders need a magnum primer especially in cold temperatures ) are you having trouble getting a good repeatable cheek weld when looking through the scope( and that is something you need ) how was the rifle supported bi-pod ? shooting bag? none ? how does it shoot with factory ammo 16" mid-length PSA barrel chrome moly 1:7 5.56 NATO Geissele 2 stage (don't know pull weight) free float handguard cases are mixed Lake City bulk Hornady 55gr FMJ-BT powder AA2200 23.5gr WSR primer not shooting in cold weather no problem with cheek weld shooting off front rest and bags I've shot with a few factory rounds and it did shoot better. The hand loads I'm shooting through it were just developed for plinking and have performed acceptably in similar barrels for many years. I'm not looking for sub MOA 100yd groups. I want to use the bulk Hornady bullets (for cost) and just need to do some work with another powder and hand pick some cases. I just got some TAC so I'll try that first. |
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Sounds like you have a very nice rifle !! A 1/7 twist will work better with a heavier bullet usually that twist barrel will through the lighter bullets every where ( they are over stabilized, or spinning to fast ) The accuracy node for that weight bullet in that barrel is very small and hard to find ( some have done it ) Try a bullet weight of 62gr to 77gr ( 75 or 77 would be best ) at magazine length ( 2.260 for metal magazines, 2.250 for plastic magazines ) ( in your first post you mentioned setting your bullets closer to the lands ) The 80gr bullets are longer and were made for single loading into the rifle through the ejection port ( too long for a magazine ) they are the ones that can be loaded to a length a few thou. off the lands ( do not worry about those now ) ( the 5.56 NATO chamber is very long, but is very forgiving and will shoot a wide variety of bullets ) Your trigger is good, and I recommend a pull weight of 3 1/2 lb first stage and a pull weight of 1 lb for second stage for a total of 4 1/2 lb ( 4 1/2 lb is what ARs need to be competition legal )( you never know what is in the future for you ) Sounds like you are and will be using a ball powder A magnum primer will give you a more consistent and complete burn ( an inconstant or incomplete burn will put bullets all over the target ) If factory rounds shoot better than your loads I suggest you go to a heavier bullet and a magnum primer ( with the ball powders ) I have several ARs ( one with a 14 1/2 inch, 1/7 twist ) they all shoot very good with my load 223 for ARs 69gr Sierra MK LC case 25.3gr Varget powder ( a stick powder ) CCI BR 4 primer COAL 2.260 ( after I worked up the load I found it was Sierra's accuracy load for 69gr MKs ) |
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What is your trim length? Deburring case necks? Crimping? How much? Sorry but I just don't have the case data on those loads. they were mildly crimped with Lee Factory crimp die. That's why I stated earlier I'm going to have to start from scratch and keep close track of the loads on this rifle, so I can present detailed info. |
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Quoted:
Sounds like you have a very nice rifle !! A 1/7 twist will work better with a heavier bullet usually that twist barrel will through the lighter bullets every where ( they are over stabilized, or spinning to fast ) The accuracy node for that weight bullet in that barrel is very small and hard to find ( some have done it ) Try a bullet weight of 62gr to 77gr ( 75 or 77 would be best ) at magazine length ( 2.260 for metal magazines, 2.250 for plastic magazines ) ( in your first post you mentioned setting your bullets closer to the lands ) The 80gr bullets are longer and were made for single loading into the rifle through the ejection port ( too long for a magazine ) they are the ones that can be loaded to a length a few thou. off the lands ( do not worry about those now ) ( the 5.56 NATO chamber is very long, but is very forgiving and will shoot a wide variety of bullets ) Your trigger is good, and I recommend a pull weight of 3 1/2 lb first stage and a pull weight of 1 lb for second stage for a total of 4 1/2 lb ( 4 1/2 lb is what ARs need to be competition legal )( you never know what is in the future for you ) Sounds like you are and will be using a ball powder A magnum primer will give you a more consistent and complete burn ( an inconstant or incomplete burn will put bullets all over the target ) If factory rounds shoot better than your loads I suggest you go to a heavier bullet and a magnum primer ( with the ball powders ) I have several ARs ( one with a 14 1/2 inch, 1/7 twist ) they all shoot very good with my load 223 for ARs 69gr Sierra MK LC case 25.3gr Varget powder ( a stick powder ) CCI BR 4 primer COAL 2.260 ( after I worked up the load I found it was Sierra's accuracy load for 69gr MKs ) I understand what you are saying I'm aware for good accuracy the heavier bullet is the answer. However, I have so many of the Hornady 55gr that I need to at least find some load that will work for plinking. That same load I'm having trouble with in this rifle does pretty well in a Bushmaster and Delton with same twist rate. My Geissele trigger is nonadjustable but feels fine to me. I don't think that's playing any factor in my problem. I have some Wolf magnum primers I've never used so I'll give that a try. Thanks for all the input. |
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Wolf magnum primers only have a thicker cup not the extra priming compound you need with ball powders use another brand magnum primer If this load works in other rifles and not in this one it may be that you have a picky barrel and you will have to work up a load for this barrel I hope you can find a load they all like |
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Typically accuracy with Hornady 55's should be as good as M193 ball in a decent load and rifle. You know your rifle is designed to shoot heavier bullets. My plinking loads in my Bushmaster 1:8 are with 62 gr FMJ bullets, but I can still get M193 ball to shoot decent 2 MOA +- groups too.
I think it's possible the combination of 1:7 twist and that powder is not right. From description of AA 2200 powder - "a double-base, spherical propellant that also works extremely well in 222 and 223 cartridges with light bullets from 36 to 45 grain". I recommend you try a different powder, H335, AA 2230, W748, Varget, BLC-2 something in that arena. Recommend seating to 2.25 or 2.26 if possible, and try not crimping. |
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Why are you concerned about COL? COL is for fine-tuning only and will not change a 1.5" group into a 0.5" group. Like most "tricks" used in precision rifle, it only makes small changes (often too small to be seen by any one shooting a "normal" rifle). If the bullet is going all over the place, then the bullet is not right for that barrel. How does it shoot 55gn factory ammo? |
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Quoted:
Wolf magnum primers only have a thicker cup not the extra priming compound you need with ball powders use another brand magnum primer If this load works in other rifles and not in this one it may be that you have a picky barrel and you will have to work up a load for this barrel I hope you can find a load they all like I have only heard of Wolf SRM primers being a problem with some loads of H335. I don't think they are a problem with all or most ball powders. I use them with TAC and have had zero problems. |
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Quoted:
I'm sure this has been covered before but my search has not turned up what I need. I've got a AR15 upper that's throwing rounds all over the target and it appears it is very picky as to ammunition. I'm loading 55gr Hornady FMJ and my question is should I use my Hornady Overall Length Gage to determine where the bullet touches the lands and then back off a few thousands? Or should I just concentrate on C.O.A.L. since it's got to fit in the magazine? After measuring a few of my current loads (2.240) I may be a little short for this rifle's preference. What does throwing rounds all over the target mean? I think with those bullets, very carefully loaded ammo might get you about 2 to 3 inch groups in most cases. If you can't cite your trim or other specs, and you are using mixed brass, it sounds like you are not applying sound reloading principals, and it might be perfectly reasonable to expect something around 4 to 5 inch groups. You have to keep in mind, varying case volumes and different neck tension, among different types of brass are going to have a noticeable effect on groups. |
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What does throwing rounds all over the target mean? I think with those bullets, very carefully loaded ammo might get you about 2 to 3 inch groups in most cases. If you can't cite your trim or other specs, and you are using mixed brass, it sounds like you are not applying sound reloading principals, and it might be perfectly reasonable to expect something around 4 to 5 inch groups. You have to keep in mind, varying case volumes and different neck tension, among different types of brass are going to have a noticeable effect on groups. Quoted:
Quoted:
I'm sure this has been covered before but my search has not turned up what I need. I've got a AR15 upper that's throwing rounds all over the target and it appears it is very picky as to ammunition. I'm loading 55gr Hornady FMJ and my question is should I use my Hornady Overall Length Gage to determine where the bullet touches the lands and then back off a few thousands? Or should I just concentrate on C.O.A.L. since it's got to fit in the magazine? After measuring a few of my current loads (2.240) I may be a little short for this rifle's preference. What does throwing rounds all over the target mean? I think with those bullets, very carefully loaded ammo might get you about 2 to 3 inch groups in most cases. If you can't cite your trim or other specs, and you are using mixed brass, it sounds like you are not applying sound reloading principals, and it might be perfectly reasonable to expect something around 4 to 5 inch groups. You have to keep in mind, varying case volumes and different neck tension, among different types of brass are going to have a noticeable effect on groups. It means 5" groups at 25yds off bench. I apologize for not being able to quote specifics but this load was developed and loaded several years ago for plinking ammo in 2 other rifles, and it performed OK. As I have stated above I really can't add any other opinion or details until I follow the advice given and work up another load(s) using other primers and powders, as well as carefully measuring cases. I do appreciate the advice given and will start this project next week. I have read of many instances where a 1:7 barrel will have success with .55gr FMJ. It may never happen with my barrel but it is still worth a try. Obviously I'm never going to get the accuracy that I would achieve with heavier bullets, and in fact it may require heavier bullets to get ANY accuracy. |
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Hornady's 55 grain FMJs are superior to most bullets found in GI ammunition - saying you should be able to get "close to M193" accuracy is an understatement to say the least.
For a rifle to scatter bullets like that, I would think it's not your load, it's your barrel. How many rounds have you put through it? And as others have said, you can't load rounds for an AR that "touch the lands" without having to single load them. You certainly can't with anything like these 55 grain bullets - they're too short to hit the lands and still have anything like neck tension. |
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For a rifle to scatter bullets like that, I would think it's not your load, it's your barrel. How many rounds have you put through it? Yes, 5" at 25 yards means something is wrong with his rifle hardware. My shotgun does about that group size (smooth bore). Did the OP say he can shoot better than that? With such a large group, and not knowing the shooter's capability, you have to question everything. |
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Yes, 5" at 25 yards means something is wrong with his rifle hardware. My shotgun does about that group size (smooth bore). Did the OP say he can shoot better than that? With such a large group, and not knowing the shooter's capability, you have to question everything. Quoted:
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For a rifle to scatter bullets like that, I would think it's not your load, it's your barrel. How many rounds have you put through it? Yes, 5" at 25 yards means something is wrong with his rifle hardware. My shotgun does about that group size (smooth bore). Did the OP say he can shoot better than that? With such a large group, and not knowing the shooter's capability, you have to question everything. Well.................my eyes are getting old and I've never been accused of being a real marksman, but I can tell you I have other AR's that I can shoot good groups at 100 yds. with. Seriously, I don't think my shooting skills are the primary problem here. This is a new upper assembly so it only has about 50 rounds through it. I'm sure more rounds downrange will improve it some but still something wrong at this point. |
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Get a good AR powder and a good load, I'm pretty sure your groups will improve, I doubt its the rifle or you. However based upon your report you can understand why some of the experienced AR shooters would be concerned about the hardware.
You can shoot some "control groups" with M193 or civy equivalent 55gr loads and see how the factory ammo shoots. That should tell you a lot. I don't know how many 55's you're saddled with, but if its a big investment, you can work up a load, or try and trade / sell them. |
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A five inch group at 25 yards (assuming from a rest) leads me to believe you have a mechanical problem with the rifle, something is loose somewhere. Id suggest you look at your scope mounting first (not just the scopes), then start looking for issues like a loose barrel, loose gas block, loose receiver fit, and so on. Hold either the upper or lower only, and shake the rifle vigorously, does anything rattle?
Even my worst scoped AR from the bad old days would group around 3.5 inches at 200 yards. It turned out to have the worst fitting upper receiver ever made. It actually rattled when I shook it. Replacing the upper receiver took it down to the 2 inch range at 200 yards (rested). |
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