Chasing accuracy problems in AR build

[plant_one]

just something i dont think seen mentioned here.. but have you checked for proper clearance between gas block and handguard? just wondering if you're too close and pinging off the handguard a bit during firing flex of the barrel.

[carpenterminator]

Guys,

Thanks for the help! The Seekins handguard is huge, there's almost 1/4" clearance around the gasblock.

The upper is Cerakoted grey on top of the factory black. I honed the face to the point that half the face was black, the other half clean aluminum. Pretty cool tool from Brownells- I went back and honed and bedded two others besides the 450. They weren't bad, but they weren't great.

If it comes to sending to the barrel to Saturn, I hope they want the receiver attached... it's going to be hard to get off. In the meantime, I have to make one more trip to the range.

Best Regards,

[plant_one]

Guys,

Thanks for the help! The Seekins handguard is huge, there's almost 1/4" clearance around the gasblock.

The upper is Cerakoted grey on top of the factory black. I honed the face to the point that half the face was black, the other half clean aluminum. Pretty cool tool from Brownells- I went back and honed and bedded two others besides the 450. They weren't bad, but they weren't great.

If it comes to sending to the barrel to Saturn, I hope they want the receiver attached... it's going to be hard to get off. In the meantime, I have to make one more trip to the range.

Best Regards,

nah.. nothing the flame wrench cant fix. LocTite breaks down somewhere around 450 degrees or so heat it up and remove it if its that stuck. you can probably knock it out though from the rear with a good hardwood dowel and a hammer.

that heat issue why loctite doesnt get used for anchoring QD devices for suppressor attachment and we're stuck with products like Rockset for that application. last time i had to remove one of those that was rocksetted on i had to soak my barrel in water for the weekend while i was gone (instructions say at least 24 hours to break it down)

[Hoot]

If they don't mind, I'd leave them attached, along with the gas system and hand guard. Every picture tells a story...

Hoot

[3rdgeargrndrr]

+1 lemon barrel. I havent seen one 450 AR shoot buckshot groups; I assume you shoot only factory rounds correct?

To answer Hoot, lapping an upper is an easy process, a truing kit is sold on MidwayUSA.

[Hoot]

+1 lemon barrel. I havent seen one 450 AR shoot buckshot groups; I assume you shoot only factory rounds correct?

To answer Hoot, lapping an upper is an easy process, a truing kit is sold on MidwayUSA.

Long Time No See Joe!

[Texas Sheepdawg]

Thanks guys, it's not the barrel nut then, I can't believe that this beefy Seekins upper is cracked, I'll try a last time on a rock of Gibraltar table at a city range (I'm in the DFW area, I just like shooting in west Texas), with some basic scope rings... and then call Brownells. They say that they have a great, lifetime warranty. I imagine Saturn and Brownells get all kinds of unhappy idiots wanting replacements, refunds, etc.

Again, thanks for all the help, I'll post what happens after I can get to a city shooting range (are those even open?)

Well. Dallas is a different monkey. I’m about an hour north of Dallas and 40 minutes north of Plano.

[carpenterminator]

Hey, I think that I figured out my troubles. It took long enough

I bought a cheap bore scope for issues with a different rifle (rust pitting from weather as it turned out, in the bore of my 20 year old model 70 elk rifle). On a whim I decided to scope all my rifles, and I eventually ran it through the 450 BM. The Saturn 450 bore is really rough, and takes copper like a cheese grader. Comparing the Saturn to the barrel on my cheap, 2 yr old Tikka (that probably hasn't had a full box of rounds through it) is like night and day.

With the rough surface, the first few shots aren't bad, but it fouls quickly. When you're constantly swapping scopes, those first few shots tend to be wasted to zero the scope.

I did a mild lapping with abrasive paste when I put it together the first time, but nowhere near enough to smooth this thing. I could give it a substantial (~80 passes) treatment, but maybe I'll send Satern a picture and ask if this is just how they roll, and find out what they recommend.

[Texas Sheepdawg]

My Satern 6.5 Grendel barrel is smooth as a mirror.

[Hoot]

Bore lapping is as much art as it is science. Premier barrel (read not Satern or a half dozen others) makers hold the specifics of their lapping process close to their vest. If a company advertises that they lap their barrels and you get one that obviously wasn't, the first move would not be to correct it yourself (more art than science). IMHO, you should send it back to them to have it remedied. I have cast laps and worked out rough spots on several Savage barrels only because the don't make that claim. That said, most Savage barrels still manage to shoot amazingly well, right out of the box. There are important details in how a barrel is made, starting with how precisely their chamber is cut and how straight the bore is. Neither is a given and seem to reflect the manufacturer's quality commitment importance in the price point they are pursuing. Hammer forging on the other hand, is more science than art. It bypasses the issues that can arise from rifling cutting but brings its own set of challenges like the need for stress relieving after they are forged. The 450b is however, not a BR driven caliber. That doesn't mean you throw demand for some semblance of quality out the window nevertheless. Profs to Bushmaster for choosing to chrome plate their 450b bores. An aside from the main driving factors for that added expense, it does fill in a lots of the imperfections in the bore. Few owners shoot their 450b's in a manner that endangers their chrome plating. They do however reap the benefits when it comes time to clean them.

Hoot