Which reamer to buy?

[tmix]

I can't wait for the AAC Blackout rifles to hit the market, so I'm going to build my own. I found a good deal on a Rem. 700ADL in .223 and I'm now shopping for a barrel and a reamer.

I know I want a 1:7" barrel, but what I don't know is which reamer I should use. More specifically, which chamber I need to go with. I want to be able to shoot the heavier 75-80gn bullets and still be able to put XM193 or Q3131 down the tube, as well.

Would a NATO chamber still give me plenty of accuracy, or should I go with a Wylde chamber?

[flip]

I don't have first hand experience but I say split the difference, Wylde.

[AirCavBob]

Wylde chamber

[Artos]

If precision is your main goal:

Use a match stainless bbl with a 1/8 twist and wylde chamber.

[silencertalk]

I would do 1:8 for 24 inch and 1:7 for 20 inch and 1:7 for 16 inch. But I could see people doing 1:8 for 20 inch - just not me.

I bet you cannot measure an accuracy difference in a NATO vs Wylde chamber. Your accuracy will come from the barrel blank and how concentric the bore is to the chamber - and also your crown.

By the way, I was just at Remington and saw actions being made. They grind certain areas. I now think anyone who pays a gunsmith to 'true' and 'blueprint' a Remington action is nuts. All you need to be accurate is the barrel done right and a decent stock and trigger - as well as a solid scope mount.

[Artos]

I now think anyone who pays a gunsmith to 'true' and 'blueprint' a Remington action is nuts. All you need to be accurate is the barrel done right and a decent stock and trigger - as well as a solid scope mount.

Boss,

When every last bit counts, sqaring the bolt face & trueing the receiver threads certainly helps shrink groups.

I understand where you are coming from and I've never had a critter tell the difference between a 1/4" gun and 3/4" gun & that point is taken. However, the paper shows a huge difference. I've also seen lots of 700 with hs stocks really improve with a simple bedding job & always suggest that first before they give up on the barrel.

Being a former benchrest guy where the game is won by .001 is where I'm coming from & may not apply for the weekend shooter. Wind flags can show you why that round jumped out of the group more than anything.

[silencertalk]

You would have to only work on the receiver and not the barrel to prove the gain.

There are not a lot of 1/4 MOA guns out there.

[silencertalk]

http://www.scorehi.com/blueprint.htm

"Blue printing an action is a term I use to mean, “to make exactly like the intensions of the blue printâ€

[Artos]

Not much you can do to factory bbl...the tube usually shoots or doesn't. If they obviously hacked the threads or had a chattered chamber a gunsmith could easily identify & clean up with a finish reamer and screw back on, yeah.

I can tell you that trueing will help a gun gain maximum performance. Problem I would have proving is did it help the factory tube. Once someone throws in the towell and trues her up, then the custom tube is installed, followed by a new stock or bedding, etc.

There are lots of 1/4" guns but not in this arena. BR is a maddening hobby and has aged me horribly. No br competitiors are using trued factory actions in the game of short range anymore. All are Stolles / Bat / Farley / Hall, etc. but a 700 can be made to shoot just as well. They just don't run the bags as well.

benchrest.com is a wealth of info if you want to consider it but making a 1/4" gun is not rocket science. Reading the wind and mirage is what drives you crazy.

I'm a big green koolaid drinker & love the 700. A 220 swift in a vssf is paradise. I was also going to challenge you on your thread where you said accuracy would be the same at 500 rounds sans cleaning but no benchrest guy would dare not clean their gun after finishing the relay and I certainly would not do it with my 700/6br...blasephemy.

[silencertalk]

I probably own a 1/4 inch gun. I have a Jim Bordon 6mm with a Nesika action. Also Nesika made me a .22-250.

But I also know someone who tested almost 1000 precision guns and he said only 5 of them were 1/2 MOA or better with factory match ammo (when 5 groups of 5 shots are averaged).

But yes, I know benchrest guns with handloaded ammo are 1/4 MOA or less for real.

I can tell you that trueing will help a gun gain maximum performance. Problem I would have proving is did it help the factory tube. Once someone throws in the towell and trues her up, then the custom tube is installed, followed by a new stock or bedding, etc.

Yes, I would need to see it tested with the same barrel and for 25 or more rounds mean radius or radial standard deviation before accepting that it helped.

Can you show me one example where someone did a proper controlled test and documented the improvement? I am sure people must have done such tests, but I never saw the results posted which makes me think they are not successful very often.

[Artos]

[quote="rsilvers"]"Blue printing an action is a term I use to mean, “to make exactly like the intensions of the blue printâ€

[silencertalk]

I know. I was just quoting that guy to show he was in conflict with his own statement. He was not even doing what he claimed was his goal.

Personally I would not want my receiver threads enlarged to require custom barrel threads.

Question for you....

If you make a barrel hand-tight - how much farther can you turn it to torque it to the proper spec? 1/4 turn? 1/8 turn?

I am asking because I want to make my barrels headspace when hand-tight and also when they are wrench tight. That way, I can change barrels by hand and shoot.

[Artos]

I probably own a 1/4 inch gun. I have a Jim Bordon 6mm with a Nesika action. Also Nesika made me a .22-250.

But I also know someone who tested almost 1000 precision guns and he said only 5 of them were 1/2 MOA or better with factory match ammo (when 5 groups of 5 shots are averaged).

But yes, I know benchrest guns with handloaded ammo are 1/4 MOA or less for real.

I can tell you that trueing will help a gun gain maximum performance. Problem I would have proving is did it help the factory tube. Once someone throws in the towell and trues her up, then the custom tube is installed, followed by a new stock or bedding, etc.

Yes, I would need to see it tested with the same barrel and for 25 or more rounds mean radius or radial standard deviation before accepting that it helped.

Can you show me one example where someone did a proper controlled test and documented the improvement? I am sure people must have done such tests, but I never saw the results posted which makes me think they are not successful very often.

Do you have any wind flags?? You owe it to yourself to play with some and that gun. You will need to put a good 36x - 45x glass though.

I have had two Borden 6ppc's built on Stolle Pandas and two 6pp's Halls. 3 of the 4 were .25 guns...albeit only on good days as I was not a good wind doper. My main hunting rig is a Borden 280AI and the 6Br is a Borden / 700 / Mike Bryant clone. Borden sleeved the bolt and did some other experimental mojo to the action that I let him experiment with back in the 90's.

I would love to get Jim on here and set us straight but I could prove lots of 1/4 guns are out there just by posting the results of the supershoot for the past several years.

I don't remember any tests of trueing & then checking accuracy with the factory tube but would be fun to see if any actually had or challenge some of the better smiths to do as such. They are a crusty bunch and would probably scoff.

[Artos]

If you make a barrel hand-tight - how much farther can you turn it to torque it to the proper spec? 1/4 turn? 1/8 turn?

I am asking because I want to make my barrels headspace when hand-tight and also when they are wrench tight. That way, I can change barrels by hand and shoot.

It's a big window but will not condone on hand tight cuz I've had them back out. I've seen shooters and smiths say not to worry and suggest 70lbs-150lbs!! Try this: Hand tight and put a pencil mark from the bbl to the lug / action and play with various torques. I bet your index is in the +/-1/4" advance from said mark and pretty much stops in the same place repeatedly...unless you stand on it of course which you don't want to do. A lot of shooters use this pencil mark to repeat their torques at the range but I just winged it and never had any problems.


I like the Davidson bbl vise and Kelbly rear action wrench for that work. When I did my switch bbl stuff, I would just go for feel & my guess is I was way closer to 70lbs but they were all in the smaller case ppc family. The big bores or 1k yard game, I would want to crank on harder.

[silencertalk]

My Bordon gun has a Leupold 40x or 45x benchrest scope on it. The Nesika has a Nightforce that is I think 36x.

I don't remember any tests of trueing & then checking accuracy with the factory tube but would be fun to see if any actually had or challenge some of the better smiths to do as such. They are a crusty bunch and would probably scoff.

For sure as it would destroy their gunsmithing business. They would not be able to charge people to do things that don't help.

The bolt face is larger than the rim of the brass. I don't see how it would matter if the receiver threads were shifted 0.003 (width of human hair) off center because the shell would still be square against the bolt face.

I do think it matters if the bolt face is perpendicular, but I think they probably are. Those critical areas are ground at the factory.

So, take a great barrel and stock and put them on a Walmart Remington 700. Shoot 30 rounds carefully with a 36 power scope. Then send the action to a gunsmith and have him 'blueprint it.' Then reinstall the barrel and stock, and shoot 30 rounds. I bet you it does not improve the group.

Better yet - install and test that same barrel and stock on 3 Walmart Remingtons and send those actions to 3 gunsmiths who take up the challenge. Then shoot each one for groups with the same barrel and stock.

Also shoot the same barrel and stock on a BAT Remington-clone receiver.

[silencertalk]

It's a big window but will not condone on hand tight cuz I've had them back out.

I know someone who does it and said it never backs out because the right-hand twist torque it tighter as you shoot.

1/4 turn would be 1/64 of an inch which is 0.015. That is too wide to work both hand tight and wrench tight. So I would have to pick one or the other. SAAMI only allows 0.010 of headspace variation.

On the other hand, if it turns out to be 1/8 turn between hand tight and 70 fp, then that is 0.0075 and that can be worked with as you can set the headspace to be at min for 70 fp and at +0.007 for hand tight.

[widlin1]

I am not sure that 1/4 of a turn after hand tight really is .015 inch if the shoulder on the barrel and the receiver are square to threads. I bet if the shoulder on the barrel bears uniformly on the receiver then when you tighten with your wrench the threads on the barrel and receiver deform and the actual change in head space is much less than the lead of the thread would suggest. The few barrels I have chambered I did so by reaming till my head space gage stuck out the barrel a distance equal to the distance from the receiver ring to bolt face minus the barrel shank length plus 0.001 to 0.003 inch and tightening them as tight as I reasonably could never reduced the head space enough to prevent the bolt closing on the gage.

Jeff

[silencertalk]

True. So I probably can make this work.

I am now thinking lapping the lugs is one thing that would help - and that is easy to do yourself.

Has anyone done a before/after group of at least 10 shots?

I still am not convinced that re-cutting the receiver threads can help and there is a downside in paying for it and having the new threads be enlarged.

[silencertalk]

BS - 30% to 50% reduction in group size. Right..


http://www.z-hat.com/Cryo.htm

[Artful]

I bet you cannot measure an accuracy difference in a NATO vs Wylde chamber. Your accuracy will come from the barrel blank and how concentric the bore is to the chamber - and also your crown.

The Wylde chamber was designed by Bil Wylde. He is one of the original people to work on the AR15's as target rifles. The chamber is designed for both function and accuracy. Loose enough for good function and tight enough for match worthy groups.

For function is has generous body dimensions. For accuracy it has a smaller throat diameter. It also has become the most popular chamber for service rifle shooters.
Part of the reason is that John Holliger (White Oak), Satern Barrels, and Rock River, and numerous others use it as their standard chamber. A 223 minimum SAMMI spec chamber will shoot better groups than a Wylde but will not be as reliable in an AR15, but a Wylde will shoot better than NATO 5.56 standard slopply chamber.

And Robert you can test this easily - just take a tight 223 chamberered good shooting rifle and shoot your test group - then take a larger reamer like a wylde and rechamber it - shoot it again - then take a sloppy 5.56 NATO reamer and go back in again and shoot your last test group - if your right there will be no change in accuracy - but I'm thinking you will find a difference in gorup sizes. - So what do you want to bet

Oh, an I'm infamous with my friends, as I only bet when I know I have the odds in my favor.

[Artos]

Are you actually able to turn the bbl 1/4 "turn" after hand tight?? Mine went tight and then just nudged over barely advancing??

In regards to lapping the lugs, I know of several reports where br rigs completely opened up and quit shooting after having one of lugs gauled. Lapped them up and went back to bug holes. I'm no smith but this just tells me it causes the face to go awol and the need for bolt face to be square with the bore??

[silencertalk]

Oh, an I'm infamous with my friends, as I only bet when I know I have the odds in my favor.

I am strange. I tend not to do friendly bets when I know I will win.

As for 5.56mm NATO chambers being sloppy, they are not.

So many myths abound. NATO does not have a larger chamber.

.3769 at the rear and then .3553 at the shoulder, .2539 mouth for NATO
.3769 at the rear and then .3553 at the shoulder, .2540 mouth for .223 SAAMI.

.223 has a shorter throat and a tighter freebore.

I don't have a Wylde drawing handy, but it probably has the freebore diameter of .223 but the throat angle of 5.56mm and splits the difference on throat length.

In any case, I would be happy with a Wylde or NATO chamber. You should probably get the Wylde.

[Artful]

As for 5.56mm NATO chambers being sloppy, they are not.

So many myths abound. NATO does not have a larger chamber.

.3769 at the rear and then .3553 at the shoulder, .2539 mouth for NATO
.3769 at the rear and then .3553 at the shoulder, .2540 mouth for .223 SAAMI.

.223 has a shorter throat and a tighter freebore.

I don't have a Wylde drawing handy, but it probably has the freebore diameter of .223 but the throat angle of 5.56mm and splits the difference on throat length.

In any case, I would be happy with a Wylde or NATO chamber. You should probably get the Wylde.

http://www.ar15barrels.com/data/223-556.pdf

C Base Diameter
223 Rem Match 0.3779 Wylde 0.3810 5.56 NATO 0.3816

D Shoulder Diameter
223 Rem Match 0.3568 Wylde 0.3572 5.56 NATO 0.3560

E Neck @ Shoulder
223 Rem Match 0.2510 Wylde 0.2568 5.56 NATO 0.2550

F Neck @ Case Mouth
223 Rem Match 0.2510 Wylde 0.2558 5.56 NATO 0.2550

G Freebore Diameter
223 Rem Match 0.2242 Wylde 0.2240 5.56 NATO 0.2270

H Pilot Diameter
223 Rem Match 0.2190 Wylde 0.2190 5.56 NATO 0.2180

K Base-to-Case Mouth
223 Rem Match 1.7600 Wylde 1.7726 5.56 NATO 1.7750

L Base-to-Shoulder
223 Rem Match 1.4320 Wylde 1.4316 5.56 NATO 1.4380

M Neck Length
223 Rem Match 0.2034 Wylde 0.2228 5.56 NATO 0.2180

N Freebore Length
223 Rem Match 0.0680 Wylde 0.0619 5.56 NATO 0.0500

Q Shoulder Angle (Degrees)
223 Rem Match 23.0 Wylde 23.0 5.56 NATO 23.0

R Throat Angle (Degrees)
223 Rem Match 1.50 Wylde 1.25 5.56 NATO 2.50

These dimensions were compiled directly from the published blueprints provided by the respective makers. Basic reamer drawing from Clymer's website.

http://radomski.us/njhp/cart_tech.htm

Here are just a few of the chamber reamers that I have prints for. There are hundreds of .223/5.56 chamber dimensions and I always get a kick out of people arguing over whether a rifle has a .223 or a 5.56 chamber. Just because it has a .223 chamber, does not mean it's the same as another rifle with a .223 chamber. Both reamers may say .223 on them, but they may be very much different. Also, everyone just knows the .223 is smaller than the 5.56, well the 5.56 Target chamber is smaller in about every dimension than the .223 Wylde.


The COAL for the 80 grain SMK is an ESTIMATE based on bullet empirical data and from chamber prints. The actual COAL in your rifle may be different, even though it has that specified chamber. The number is supplied to help identify a chamber if it is unknown or as an aid in selecting the proper chamber reamer (bullet seated further out means you can get more powder in the case).


Chamber Freebore Lead Angle 80SMK OAL Comments

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5.56
Target .0566 1 deg,
13 min 2.465 This was designed by a C. Hildebrandt at Savage. I believe it is used in the savage .223 rifles. I do not have this reamer, but it should work well for HP.

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.223
JGS#514 .025 3 deg,
10 min 2.435 I believe this is used by Krieger and Mike Bykowski. I use it for slow twist varmint uppers but I think it is a little short, and too steep of a lead for HP.

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.223
Wylde .0619 1 deg,
15 min 2.475 Designed by Bill Wylde. Shoots everything good, and has slightly generous body dimensions for reliability. Eats anything you put in it.

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.223
Holliger .106 1 deg,
15 min 2.530 Designed for the 90 JLK. The longer throat allows a little more velocity.

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5.56
CLE .025 1 deg,
30 min 2.450 Of course we all know Frank's rifles shoot just fine!

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5.56
Bushmaster .0250 1 deg,
30 min 2.450-
2.475 Info from Bushmaster (thanks!). These are one of the best out-of-the box barrels, and handle up to 80 gr bullets no problemo.

--------------------------------------------------------------------------------

[silencertalk]

That is very interesting. My values were the minimum allowed chamber by the spec, but not the actual reamer drawing of what companies often do.

[silencertalk]

Why is this guy being so annoying as to write an article on lapping but refuse to give any information?

http://www.gundigest.com/article/gunsmi ... ping-lugs/