Ar15 question

[zahc]

When you handload for the AR15, do you have to crimp the bullets any different than you for bolt-actions?

It seems like there isn't any room in the AR15 mag to adjust OAL. I guess you just have to load to a "factory" OAL and forget trying to tune your OAL for rifling set-off, is that right?

[bedlamite]

When you handload for the AR15, do you have to crimp the bullets any different than you for bolt-actions?

It seems like there isn't any room in the AR15 mag to adjust OAL. I guess you just have to load to a "factory" OAL and forget trying to tune your OAL for rifling set-off, is that right?

Not really any different than bolt actions. There is the usual disagreement about which is best, taper, roll, Lee FCD, or none. I've tried both Taper and Lee, and found no crimp to be more accurate, and haven't had any problems with bullets moving with just neck tension. YMMV.

Some AR magazines allow length up to 2.3". I've found that 2.26" works pretty good in both of my 6.8 rifles, and I don't recall the length I load to in 223, but you should be able to find a length that is accurate.

[brimic]

I see lots of "service rifle" AR's at High Power matches with no flash hider.  Full 20" barrel.  They seem to think the exposed/recessed crown is greater value than the flash hider, especially since the 15+ pound rifle only gets used during peak sunlight hours in the middle of the day.

Bare muzzles are only allowed in the 'Service Rifle' category because of the 1994 AWB. You don't see M-14s without them.
There really isn't any evidence to suggest that an A2 muzzle attachment does anything to harm accuracy if installed and timed with peel washers, Crush washers can distort the rifling/bore causing minor loss in accuracy.

[AJ Dual]

Whether or not a particular muzzle device negatively or positively affects accuracy depends on a lot of variables, harmonics, barrel profile, barrel stress for a given heat, whether it's hammer forged, or button rifled, cryogenically stress relieved, how hard it's torqued down, how hard the barrel is torqued into the receiver upper, the crush or peel washer used for timing it, as mentioned above. Then there's ammo weight, the speed and pressure curve characteristics of the particular load and powder, the differences between NATO spec and SAMMI .223 brass, primer strength... goes on and on...

I'm sure having or not having one matters if you're going for absolute bench-rest accuracy, or competition, but the individual variables get to be so diverse, it's one of those black-arts kind of things where there's no broad conclusions to be drawn.

[zahc]

Bare muzzles are only allowed in the 'Service Rifle' category because of the 1994 AWB. You don't see M-14s without them.

I don't understand any part of this statement. Can you please explain to someone not familiar with the categories?

[brimic]

I don't understand any part of this statement. Can you please explain to someone not familiar with the categories?

In highpower 'Service rifle' class matches, whether they be CMP or NRA, the rifle must outwardly resemble a military issue M1 garand, M14, or M16, with some modifications that cannot be seen allowed such as a heavy contour barrel, free float tube under the handguards, precisely machined and fitted sights, weights under the stock and handguards, and a modified trigger. The rules are sort of NASCAR-ish, where the rifles have to look and and have the same external dimensions.  The '94 AWB, made  threaded barrels difficult to come by or illegal to own for those buying a new rifle, so the rules had to be modified so that civillians could buy/build AR-15 rifles for this competition. If I'm not mistaken, 'pre-ban' barrels still cannot be purchased in some states.