.223 chambers and throat length AR15

[constructor]

I need a little input on the AR15 .223 or 5.56 chambers.
The maximum load length that will fit in the mag is 2.26.
If I load 55gr Noslers or 69gr sierras the pi of the ogive is at the case mouth. Most seem to shoot the wylde chamber which has .060 freebore. Does this .060 jump hurt the accuracy?

Derrick Martin built my first barrel back in 92 and he told me if I was going to shoot mag length 69s I should go with a short throat .223 reamer.
I know the long throat allows hotter loads but again does it hurt the accuracy and why is everyone going againest the .020 jump rule? VLDs are an exception but would be worse if they shoot better stuffed in the lands. Thanks

 

[memilanuk]

I think it's possibly a carry-over from NRA HP type shooting... short mag length loads for 200/300yds, and the jump really doesn't matter that much,you're shooting it out of an AR, not a benchrest gun where the difference between 0.100 and 0.200" groups will take you from the top to the bottom of the pack), but w/ the longer throat you can seat the 80gr VLDs out to the lands,or 0.020" off if you prefer for Sierras) w/o taking up so much of the limited case capacity.

 

[billmo]

Milanuk, Does the Sierra 69 gr. HPBT seem to shoot better from a Wylde chamber seated at .020 than at .010 from the lands?

 

[constructor]

Milanuk,

Are you saying they load mag length on the short course and single feed on 600yds?

 

[memilanuk]

billmo,

Dunno. As far as I'm concerned, the 69gr SMK is a mag-length bullet, and thats where I put it: 2.250" so I have some clearance room in the front of the mag,having the bullets bind in the mag isn't fun). I don't worry about if it's 10 or 20 thou off. It's a short range round, and shoots disgustingly well without all the fussing about.

constructor,

Yes.

YMMV,

Monte

 

[billmo]

Which bullet shoots best at long range in the AR-15 .223? Right now I am not mag. feeding. I am shooting with the SLED. But I may want to shoot from the mag at some point and time so I will keep that in mind. Thanks, Bill

 

[memilanuk]

Bill,

There's a pretty wide selection... I've had good luck w/ the 80gr SMKs and Noslers,shoot the same but cheaper), and am looking to try some Bergers in the upcoming season. Some folks like the 90gr bullets,if you have a fast enough twist - 6.5, or a 'true' 7)... I have a little bit of experience w/ the 90gr SMKs, but not enough to say more than they work. Whether they show enough improvement over the 80s to justify the hassle... is debatable.

YMMV,

Monte

 

[billmo]

I have a Rock River Arms A-4 Varminter 18 " bbl with 1-8 twist. The only bullets I have tried are the Sierra 69 gr. and it did really good at 100 yds. I shot a .574 5 shot group my first outing with it. I have Berger 75 and 80 s and 75 gr. A-max but never loaded any of them. Got to get going and see what this thing will do. Have you tried or do you know of anybody that has tried one of Robert Whitley's 6mmAR uppers? I'm looking for accuracy comments. I just sent him the money for one so I hope that thing shoots as good as he says it does. Thanks, Bill

 

[memilanuk]

6mm BR or 6mm AR? Two different critters.

A shooter around here had a spacegun upper in 6mm BR,slow fire only) for a while, just because he could. It shot pretty well, but I think a lot of that had to do w/ the nut behind the trigger.

No first hand experience w/ the new breed of short sixes that feed thru an AR, other than what I've read on the 'Net.

Monte

 

[billmo]

6mmAR Yea, you got to driv' em straight and apply very little pressure if you want it to shoot good groups. O K Man, thanks for the info. I guess I'll find out soon enough whether it was a good move or a bad one. Bill

 

[constructor]

I'm shooting a 6mm Banshee which is a grendel necked down to 6mm with a 25 degree shoulder and rebated rim so I can use the stronger 6.8 bolt. It's a shooter i'm just waiting on a new barrel to try something different.

 

[billmo]

Sounds like it is close to the 6mmAR. This case is also a necked down Grendel. Don't know about the shoulder demisions yet. If it will shoot as good as all the other little 6 mm's that I have tried, I will be happy for sure. I have a 6 X 47 Shehane Custom built rifle which is a necked down 6.5 X 47 Lapua with the shoulders blown forward just a tad and I really enjoy shooting it. Thanks, Bill

 

[billmo]

Robert says I will be getting my 6mmAR upper tomorrow. I am very anxious to get this thing on the bench. Will post results as soon as I shoot this puppy. Bill

 

[memilanuk]

Sounds good! Might start a new thread since we've done drifted from the .223 path just a big

 

[billmo]

Yea, I think we did. I will crank up a new thread on that one man. Thanks, Bill

 

[billmo]

Did not get to shoot my 6mmAR today. Took my 6.5-284 instead. Too much pressure from the "bolt crowd" if you know what I mean.Oh, well there will be another day for that. Bill