Monday, June 20, 2016

Okay you schmart peoples..... put your thinking cap on for this one.....


The PSA 18" Wylde upper was.... disappointing.... in the accuracy department.  Shoot five rounds at 100 yards, find three holes within an inch, and the other two wandering around within four inches or so.

62 grain Federal green tip made four inch patterns, as it does from every AR I own.  PMC and Federal 55 grain FMJ, as described.  A few exactly on point of aim, the rest go walking away from the party.

This afternoon after work, I began the process.  I pulled the free float tube and checked the barrel nut for being loose.  It's massive, and SO tight I'll need a bench block and a big wrench to loosen it.  That will be happening, but not tonight.

Moving on, I pulled the flash suppressor to look at the barrel crown.  Loosening the cage took hammer blows on the wrench till I got 1/2 of a turn.  After that, finger tight.  Yes, I am not comfortable with what that tension may be doing to the last 3/4" inch of the stainless barrel.

Looking at the crown, I found this:



What am I seeing here?  It LOOKS like the muzzle was crowned at 45 degrees, and then the barrel rifled.  Or..... am I seeing bullet jacket fouling from the 50 or so rounds I fired yesterday?

I'll be scrubbing the barrel, and re-crowning this muzzle before I shoot it again. It won't have a flash suppressor or break on it when I shoot it next.

Thoughts?


9 comments:

Daddy Hawk said...

The crown is possibly a small part of the problem, but if be looking closer at the torque on the barrel nut. I forget where I saw it, but someone did some thorough work up on a Ruger 10/22. it was fascinating how much impact the torque on the action to stock mounting screw had on accuracy. Over an MOA better just tweaking the ft.lbs. on that one screw alone.

thinkingman said...

Howdy:
Some thoughts- YES Federal Green tip is NOT accurate in ANY of my AR pattern rifles, not even the "varmint gun" 24" stainless bull barrel never ending parts rifle project that has evolved slowly to a heavy beast that LOVES SMK 69 grainers. The Fed Green is also FILTHY to shoot for me. Muzzles of mine look like the photo of yours, right down to the crowning; never saw anything wrong with them. 55 gr "standard" ammo give me the same good groups except for flyers you described: I have done MUCH better with decent bullets and hand loaded ammo when shooting for groups, instead of shooting for effective hits ( a 5 inch circle at 200 yards would be called fine by most ). The varmint rifle can print pretty little cloverleafs at 100 yds w 69 gr.match ammo; benchrest guys would scoff, but that's their game, and they do better than that.
You did alert me to an important point- DONT trust that just because something came to you assembled, that it was done correctly.

mc said...

I look forward to your findings since I recently put together an AR with parts procured from same sources as you.

Glen Filthie said...

Barrel heat, Carteach? Is there any order to the wanderers?

Carteach said...

Thinkingman, you make good points. If this was a factory bolty, I would never assume it should shoot well (under 1 moa) with the first random boxes of budget ammo I picked up. Somehow, I DID expect something like that with this AR. I have no excuse for that.

Glen, I doubt it. No.... no pattern to the fliers. A few random from every group went walkabout. I'll go through the rifle and see what I can find, and then start looking at different bullets and loads.

Daddyhawk.... excellent point. I WILL be looking closely at that.

Anonymous said...

Hey, what's with all the green tip hate? My RRA barrels love 'em. Always about 1" groups @ 100 yards. I think it's the 1/9 twist that makes it work. 1/7 is ovér stabilizing for the greenies.

Glen Filthie said...

I do okay with sporting rifles but these AR's and semi autos baffle me. None of mine have shot heavy bullets well. The tight twist guns I had shot nothing well... I got 2.5 MOA out of them and got frustrated with them.

Then I bought a 7.5" Stubbie AR for gits and shiggles.... And shooting prone with my outhouse reloads it consistently groups 4~5" at 200m. I haven't benched it or done any load development yet either. This gun is a 1:9 twist. I am in the same boat you are CT, except I got it the other way around. This pocket rifle shoots like a house on fire and I can't explain it either...

Long Island Mike said...

CT, just ran across this thread on a local forum. Should be of interest to you and your project. I draw your attention to the post by DSI. This is an AR manufacturer here on Long Island. It addresses their testing of Wylde chambers and the results.

http://www.longislandfirearms.com/forum/topic/160417-223-wylde-question/#entry1935049

Carteach said...

Interesting Mike. I'll be loading those heavier bullets when I get the time.