PSA 300 BLK upper, any good?

[6pakzak]

Anybody try bear creek uppers?

 

[6pakzak]

Well the psa 16inch barrels are out of stock so I found a aero precision upper for 450.00 locally which seems to be a good price and looks well made, I went with the pistol length gas system and I have an extra charging handle and I'll be using the bolt I got in my bushmaster.

 

[JTComfort]

No experience with Aero here, I looked at them but went PSA, no reason other than PSA ended up being cheaper (I feel like the included BCG versus other places not including is a $100-ish difference). Their shtick is no forward assist on the upper, I don't have an opinion there either way.

Excellent fit and finish on my AeroPrecision 7.5 upper purchased on deep discount - ($200 +/-?). But, AP did not have complete uppers, so I got a PSA nitrided BCG for $80 - runs nice.

 

[JTComfort]

Anybody try bear creek uppers?

A friend has several - he likes them a lot.

 

[6pakzak]

A small base die is just that - they size smaller further down towards the base of the case, and to slightly smaller overall dimensions. They're used for actions that don't have the benefit of leverage to close the chamber - ARs, semi-autos, pumps. The forward assist is the backup for failure to close because you can smack it and accomplish the same effect as a lever/bolt.

In a bolt action as the bolt closes and the lugs lock there is a compound camming action where the bolt moves forward very slightly to lock with the bolt acting as a lever to gain mechanical advantage. If the case web is slightly oversize it's not ideal, but also not as big a problem because the bolt can lever it into the chamber easier.

You're worried that everyone complains Lee isn't a "forming" die I'm guessing? In the original method of cut-size-trim there was a 4th step of resize down with a second, potentially better die. I said use a Lee die because you could get one for fifteen bucks and size down in two steps whereas a carbide Dillon was a hundred bucks plus.

Forming Process - My Old Poor Boy Method before I gave up and started buying 300 BLK brass because this sucked

1. Cut down range brass with an angle grinder
2. Knock the burr off with a bench grinder
3. Form through a die <--- Buy a crappy Lee for here
4. Trim to length, chamfer, deburr - all by hand
5. Resize again in (Forster?) 300 Whisper die <--- Use any die here, SB or otherwise
6. Shoot, resize with the 300 Whisper die

View attachment 334602


But after seeing that jig and things changing for the better in the last ten years I would now probably do something like:

1. Resize 223 case with RCBS small base 300 BLK die and put the second shoulder on the case (SB because the case won't grow longer on future sizings if you squeeze it down tight before cutting it)
2. Cut to very close to trim length with the jig and a little chop saw
3. Trim in the LCG-WFT on a drill
4. Probably will chamber in your AR
5. Resize with whatever die works going forward. Probably a regular FL die because I've never needed a SB die before.

View attachment 334604


It seemed like after Dillon came out with the trim die it was popular to use a 223 sizing die as the decapper up front, then use the power trimmer, but I didn't have Dillon money to actually try that out back then.


I've never tried to tighten up an AR. I've also never shot a high end service rifle competition type rifle that might be accurate enough to benefit from it. It's my understanding that the Accu-Wedge is snake oil, but I've never used one.

I tried the ar with the accublock, I noticed vertical stringing, left and right was within .5 but vertical was 1.5 so I think it's moving on the accublock.

 

[QuietTexan]

I'm not really surprised, you're introducing a variable you didn't have before. The movement of a loose piece inside the rifle aside, you're probably causing something else to become the limiting tolerance and it's way out of whack. Same concept behind you can push a bullet too fast for a barrel harmonic. Something you might not be able to find without a lot of work and disassembly like the extension is out of true, the carrier is rubbing something, the bolt is unlocking at the same point in the cycle but the upper is moving in a different direction at that time now and the movement of the bolt or carrier is pushing you up or down differently. You could probably tune it out, but if taking the part out makes it stop that seems easier to me.

I get the logic behind making the upper and lower tighter, I'm just not sure it bears out in reality until all the moving parts in the upper are put into much tighter tolerance than these things are normally made to. Kind of like how no one worries about the action face being cut a few degrees off square in a factory Rem 700 because when the factory barrel has several constrictions in it and it's torqued on to where it's compressing the shoulder to the action there's no way to shoot the difference caused by the face being off. You put a brand new Bartlein on the action and don't run it it with a 1200# impact wrench like I'm assuming they do at the Remington factory, maybe the face being off all the sudden matters. There's probably some AR equivalent of that.

 

[6pakzak]

I'm not really surprised, you're introducing a variable you didn't have before. The movement of a loose piece inside the rifle aside, you're probably causing something else to become the limiting tolerance and it's way out of whack. Same concept behind you can push a bullet too fast for a barrel harmonic. Something you might not be able to find without a lot of work and disassembly like the extension is out of true, the carrier is rubbing something, the bolt is unlocking at the same point in the cycle but the upper is moving in a different direction at that time now and the movement of the bolt or carrier is pushing you up or down differently. You could probably tune it out, but if taking the part out makes it stop that seems easier to me.

I get the logic behind making the upper and lower tighter, I'm just not sure it bears out in reality until all the moving parts in the upper are put into much tighter tolerance than these things are normally made to. Kind of like how no one worries about the action face being cut a few degrees off square in a factory Rem 700 because when the factory barrel has several constrictions in it and it's torqued on to where it's compressing the shoulder to the action there's no way to shoot the difference caused by the face being off. You put a brand new Bartlein on the action and don't run it it with a 1200# impact wrench like I'm assuming they do at the Remington factory, maybe the face being off all the sudden matters. There's probably some AR equivalent of that.

I noticed a screw coming up from the reciever didn't realize what it was for till I read a few posts about AP having an adjustment screw and that's what it is, I just turned it a little and slop is gun, had to take off grip to get at it but I get what you're saying, that accublock may compress a little different every time you shoot although groups aren't looking to bad, the 1.5 was the worst out of 4 groups but I free floated the barrel and that may be helping while block is hurting but now got it solid against that scree so I'll make the same loads and see.

 

[QuietTexan]

I will admit, I did not know Savage put that screw into their lowers.

I just found your other thread: re the handguard and block, glad you got that part figured out.