Parts affecting accuracy??

TXHUNTER90

New member
What all parts can affect accuracy in an AR-15 besides the barrel, trigger, scope rings and of course the human?

Worn out BCG? Barrel nut not being torqued correctly? Anything else I am not thinking of. Have a couple guys say to take it all apart and torque to specs everything.

Just at a loss, I had a bad barrel from the last company. New barrel/company and same results with a new barrel. Both barrels are above MOA with hand loads/development and factory. Both supposed to be Sub MOA barrels easily. Just seems weird that I would get 2 bad barrels in a row from 2 companies.

Thanks for the help in advance.
 
Originally Posted By: TXHUNTER90What all parts can affect accuracy in an AR-15 besides the barrel, trigger, scope rings and of course the human?

Worn out BCG? Barrel nut not being torqued correctly? Anything else I am not thinking of. Have a couple guys say to take it all apart and torque to specs everything.

Just at a loss, I had a bad barrel from the last company. New barrel/company and same results with a new barrel. Both barrels are above MOA with hand loads/development and factory. Both supposed to be Sub MOA barrels easily. Just seems weird that I would get 2 bad barrels in a row from 2 companies.

Thanks for the help in advance.

Make sure the front of the upper receiver is square. An unsquare upper bit me in the a$$ many years ago, and every upper out of my door has been squared in my lathe ever since.

Over torquing the barrel-nut can cause issues, and I like to "bed" my barrel-extension into the receiver with Loc-tite so it can't move around.

Also, make sure the timing on your barrel-nut is good. Take out the BCG, roll the receiver over and make certain that the gas-tube floats in both directions. Reach in with your little finger and push the gas-tube from side to side just to make sure.
 
In any case, don't suffer in silence. I would be happy to look at it for you. Just give us a call at the shop and we can get you fixed up.

218-444-7419
 
Originally Posted By: dtech

Make sure the front of the upper receiver is square. An unsquare upper bit me in the a$$ many years ago, and every upper out of my door has been squared in my lathe ever since.

Over torquing the barrel-nut can cause issues, and I like to "bed" my barrel-extension into the receiver with Loc-tite so it can't move around.

Also, make sure the timing on your barrel-nut is good. Take out the BCG, roll the receiver over and make certain that the gas-tube floats in both directions. Reach in with your little finger and push the gas-tube from side to side just to make sure.

Just out of curiosity - if the front of a receiver isn't square, what effects do you see on overall accuracy? Does it cause the rifle to throw groups off in one particular direction, or does it just generally open groups up?
 
Originally Posted By: cjclemensOriginally Posted By: dtech

Make sure the front of the upper receiver is square. An unsquare upper bit me in the a$$ many years ago, and every upper out of my door has been squared in my lathe ever since.

Over torquing the barrel-nut can cause issues, and I like to "bed" my barrel-extension into the receiver with Loc-tite so it can't move around.

Also, make sure the timing on your barrel-nut is good. Take out the BCG, roll the receiver over and make certain that the gas-tube floats in both directions. Reach in with your little finger and push the gas-tube from side to side just to make sure.

Just out of curiosity - if the front of a receiver isn't square, what effects do you see on overall accuracy? Does it cause the rifle to throw groups off in one particular direction, or does it just generally open groups up?

What I have found is this: 1) Generally poor groups. The first receiver that I discovered to be the problem the groups were around an inch, or perhaps just a little more.

2) I have noticed a POI shift when changing bullet-weights. The POI shift on the first one was probably 4" @ 100 yards.
 
Would higher quality uppers solve this issue? Or would squaring still need to be done? I have never squared an upper before and never have had any issues.
 
Originally Posted By: TXHUNTER90Would higher quality uppers solve this issue? Or would squaring still need to be done? I have never squared an upper before and never have had any issues.

No, there doesn’t seem to be any correlation between who makes it or how much they cost. I have had uppers in my shop from top, nationally ranked custom shops that were terrible, and I’ve had receivers that sold on cyber Monday for $29.00 that were perfect.

I will say that most, and I empathize “most” billet receivers seem to be pretty square.

When you say you’ve “never squared a receiver and never had any issues” should probably be reworded, more like: “I’ve never squared any receivers and have never had any problems that I’m aware of”. What I mean by that is that squaring the receiver is not like either turning “on” a switch or leaving it “off”. The amount of “unsquareness” is linear. You may very well have a slightly unsquare receiver, but it shot 3/4” groups, so you deemed it a success. Well, perhaps if you had squared the receiver you may have brought the group size down below 1/2”!

You wouldn’t consider taking a Remington 700 to a gunsmith to have him built it into a long-range varminter and let him screw on a new barrel without him squaring and truing the receiver...... this is the exact same thing.

Over the years I have “fixed” many accuracy issues by simply squaring the receiver. Once I had a guy call to order a barrel and told me he had a custom barrel he was ready to “rap around a tree” he was so frustrated. I asked him who made the barrel and he told me it was from White Oak Armament. I told him I would love to sell him a barrel, but John just doesn’t turn out bad barrels. He sent me the receiver, I squared it and assembled it like my full custom builds, and it turned into a laser! He ended up sending me two more stripped uppers to square and ordering a barrel!

Anyone can send me a receiver and I will put it in my lathe and square it for $15.00. It’s probably the least expensive part of the build.
 
Originally Posted By: dtechOriginally Posted By: TXHUNTER90Would higher quality uppers solve this issue? Or would squaring still need to be done? I have never squared an upper before and never have had any issues.

No, there doesn’t seem to be any correlation between who makes it or how much they cost. I have had uppers in my shop from top, nationally ranked custom shops that were terrible, and I’ve had receivers that sold on cyber Monday for $29.00 that were perfect.

I will say that most, and I empathize “most” billet receivers seem to be pretty square.

When you say you’ve “never squared a receiver and never had any issues” should probably be reworded, more like: “I’ve never squared any receivers and have never had any problems that I’m aware of”. What I mean by that is that squaring the receiver is not like either turning “on” a switch or leaving it “off”. The amount of “unsquareness” is linear. You may very well have a slightly unsquare receiver, but it shot 3/4” groups, so you deemed it a success. Well, perhaps if you had squared the receiver you may have brought the group size down below 1/2”!

You wouldn’t consider taking a Remington 700 to a gunsmith to have him built it into a long-range varminter and let him screw on a new barrel without him squaring and truing the receiver...... this is the exact same thing.

Over the years I have “fixed” many accuracy issues by simply squaring the receiver. Once I had a guy call to order a barrel and told me he had a custom barrel he was ready to “rap around a tree” he was so frustrated. I asked him who made the barrel and he told me it was from White Oak Armament. I told him I would love to sell him a barrel, but John just doesn’t turn out bad barrels. He sent me the receiver, I squared it and assembled it like my full custom builds, and it turned into a laser! He ended up sending me two more stripped uppers to square and ordering a barrel!

Anyone can send me a receiver and I will put it in my lathe and square it for $15.00. It’s probably the least expensive part of the build.

had mike do a couple for me and turn around was really fast. although the cost probably should be more money........except for me, LOL
 
Mike - I didn't know you were posting in here again, I'm glad to see it!!

Have you ever measured run out improvement on receivers "squared" with lapping mandrels, rather than trued on a lathe?
 
wow $15 to true an upper - thats not bad at all.

although its not that hard to do and the wheeler kit is only like $20 if you're a DIY kind of person.

if i didnt already have the tool, i'd be all over that.
 
Originally Posted By: VarminterrorMike - I didn't know you were posting in here again, I'm glad to see it!!

Have you ever measured run out improvement on receivers "squared" with lapping mandrels, rather than trued on a lathe?

Thanks!..... I think... Lol! I was getting burned out on the business, especially after Obama's second election. I was taking record orders every week, so instead of slowing down, it was getting busier, and I couldn't seem to change it. Then along came my new partner Matt! Matt started out as a customer, became a friend, and is now my business partner, and will most likely be the next "Dtech" When you get to be my age, you start thinking about "exit strategies" There was just no real good way for me to "step out" of my business. Now, I don't want to get out, at least for the foreseeable future. The help that Matt has brought to the table has cut our lead-times down to virtually nothing, and made it "fun" for me in the shop again! We put in more equipment, including a second lathe, to make things run smoother and take the "bottle neck" out of our production.

To answer your question: No, I have never had one of the "lapping fixtures" in my hands, and have never compared one squared by one by putting it in the lathe.
 
Originally Posted By: dtechOriginally Posted By: VarminterrorMike - I didn't know you were posting in here again, I'm glad to see it!!

Have you ever measured run out improvement on receivers "squared" with lapping mandrels, rather than trued on a lathe?

Thanks!..... I think... Lol! I was getting burned out on the business, especially after Obama's second election. I was taking record orders every week, so instead of slowing down, it was getting busier, and I couldn't seem to change it. Then along came my new partner Matt! Matt started out as a customer, became a friend, and is now my business partner, and will most likely be the next "Dtech" When you get to be my age, you start thinking about "exit strategies" There was just no real good way for me to "step out" of my business. Now, I don't want to get out, at least for the foreseeable future. The help that Matt has brought to the table has cut our lead-times down to virtually nothing, and made it "fun" for me in the shop again! We put in more equipment, including a second lathe, to make things run smoother and take the "bottle neck" out of our production.

To answer your question: No, I have never had one of the "lapping fixtures" in my hands, and have never compared one squared by one by putting it in the lathe.

you've got a lathe, and a new wonderworker in the shop - have him whip a lapping bar up and test it out
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i'd be curious myself
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i have done several with the wheeler bar and checked them on a lathe. does that count?

if that counts i will say they all were every bit as square as if they were done in the lathe. the bar works very good imo.
 
Originally Posted By: SlickerThanSnoti have done several with the wheeler bar and checked them on a lathe. does that count?

if that counts i will say they all were every bit as square as if they were done in the lathe. the bar works very good imo.

It would stand to reason that a fixture that fit snugly to the bolt-raceway, and has a perpendicular lapping surface would be accurate.

The lathe is an amazing machine, but if you don't set-up the mandrel correctly, you can actually cut the receiver face crooked. If you run the mandrel through the receiver and into a live center, then it's pretty much impossible for it to cut anything but perfectly square.

In reality, I was squaring receivers in my lathe years before any of these lapping-fixtures hit the market. Probably the only reason I've never tried one....
 
I'm going to give the Brownells lapping tool a go. I'm not building as many AR's as I used to, but I want to give it a try on one that has been giving me fits.
 
I bought one of those tools. the thing I don't like about them is the friction it causes inside the upper. So add lube you might think. the problem its too easy to get the lube mixed in with the lapping compound. I didn't like how it was working. the better option would be just send the thing to mike.

mike, I appreciate your comments here lately. I would be interested in your thoughts between barrel extension fit to upper fit, have you seen any difference if the barrel extension isn't fitting that tightly when its inserted into the upper? are you just using blue locktite on your extension when putting these together?
 
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