300BlkTalk

chach3 wrote:

AR-300 wrote:If you aren't willing to buy headspace gauges, you can rent them for like $8

I rented gauges just now. I didn't know that you could do that. Thanks for the suggestion

glad to be of assistance, hope it works out for you!

chach3 wrote:I don't have headspace gauges. The barrel didn't do this when I sent it to them. I can't justify paying $54 for something that I will use once and then sit in a drawer. I trusted that the manufacturer would get it right and I wouldn't have to deal with this crap.

once used, headspace gauges cannot be sold to anyone else. ever. remember that. it is very important.

bani wrote:once used, headspace gauges cannot be sold to anyone else. ever. remember that. it is very important.

Last night I did some tinkering with my barrel trying to figure out why it was sticking while I wait on the gauges to come.

I have realized that 99% of the ones that stick are Lake City brass. Non Lake city brass seems to chamber and extract fine.

I should be getting the gauges early next week, so I will be able to get a definitive answer.

chach3 wrote:Last night I did some tinkering with my barrel trying to figure out why it was sticking while I wait on the gauges to come.

I have realized that 99% of the ones that stick are Lake City brass. Non Lake city brass seems to chamber and extract fine.

I should be getting the gauges early next week, so I will be able to get a definitive answer.

tried my PSA barrel tonight and got the same, some specific manufacturer ammo (PNW if i remember correctly) jammed the bolt pretty good, i had to use a screwdriver to open it. remington seemed to eject fine.

fwiw my barrel passed the headspace no/no-go checks fine.

either some ammo is on the large side, or the PSA chamber is really tight.

bani wrote:tried my PSA barrel tonight and got the same, some specific manufacturer ammo (PNW if i remember correctly) jammed the bolt pretty good, i had to use a screwdriver to open it. remington seemed to eject fine.

fwiw my barrel passed the headspace no/no-go checks fine.

either some ammo is on the large side, or the PSA chamber is really tight.

I actually fired mine last night to check it out. And I put about 35 rounds of various brass/bullet combinations. Here were my loads that I fired:

110 Hornady V-Max made with LC Vrass 18.0 H110
110 Hornady V-Max made with Federal Brass 18.0 H110
125 Sierra OTM made with LC Brass 18.0 H110

Everything fired and ejected fine. The headspace gauges are being delivered today so I will check it tonight, but I have a feeling it is going to pass. Just a tight fit like you said.

The PSA chamber diameter is less than he AAC chamber in my Micro7 (since fired brass from the PSA will fully chamber in the Micro7, but Micro7 fired brass will only chamber 2/3 the way and stick)

I LIKE a tighter chamber as it will make brass last longer, is sometimes a little more accurate. It may not be as forgiving with ammo at the upper, over the spec limit. This is why some machine guns have sloppy chambers so they will be much more reliable when very fouled, but kill brass.

just got back from the range, the barrel functioned fantastic

tried a bunch of different ammo for function testing, here's my results.

PSA 16" barrel, unsuppressed, full auto BCG, DPMS lower w/stock carbine buffer+spring
CMMG 175gr subsonic - would not cycle
PNW 125gr match - worked
PNW 147gr range - worked
PNW 220gr defensive - worked!!
Remington 115gr - worked
Remington 220gr subsonic - would not cycle

PSA 16" barrel, unsuppressed, semiauto BCG,DPMS lower w/stock carbine buffer+spring
CMMG 175gr subsonic - would not cycle
Remington 220gr - cycled, would not lock back on empty

when will these barrels be back in stock?

bani wrote:when will these barrels be back in stock?

If I had to guess, I'd say the FN factory in SC is still playing catch up. Couple of months ago there was a run of uppers in stock so hopefully it wont be long. I'd like to see the 8" barrel come back.

My 16" upper that was handed down from my father has about 300 rounds through it and other than some 180 gr subs that failed to lock the bolt back, it's been flawless.