|
Forum Rules | Firearms Safety | Firearms Photos | Links | Library | Lost Password | Email Changes |
Register | FAQ | Calendar | Today's Posts | Search |
|
Thread Tools | Search this Thread |
June 19, 2020, 09:22 AM | #1 |
Senior Member
Join Date: October 30, 2016
Posts: 211
|
Magazine or undergassed?
History:
I purchased a Bear Creek Arsenal 20" upper in 350 Legend. I attached that to an A1 configured lower. I only had 57 cases (Range pickups). I loaded Armscorp 147 Grain FMJ-RN ahead of 28 grains LiL' Gun and a CCI 400 primer. Accuracy was good, but more to the point of this, cycling was normal. About 45 rounds fired with zero malfunctions. Now: Since I only had 57 cases and Starline was saying the end of July before my order comes in I ordered some Winchester. I ordered the 147 FMJ. I began experiencing malfunctions immediately. I loaded 3 rounds at a time of 20 rounds in a 5 round DuraMag 350 Legend magazine. The first round would strip and feed normally. The second would go bolt over brass and not feed at all, but then fed normally when the action was cycled. The third round went nose up into the barrel extension. The bolt did not lock at all except when cycled manually. I noted that in comparison to my reloads the Winchester ammo of the same weight recoiled noticeably less. I think what I'm seeing is an under gassed situation. Notably the factory round is not producing enough pressure to cycle the bolt. I think an experiment would be to pull some of these factory bullet, replace the powder and taper crimp the bullet back in. Thoughts? |
June 19, 2020, 10:14 AM | #2 |
Senior Member
Join Date: March 2, 2014
Posts: 11,789
|
My guess is magazine feeding issue--the factory win 145 is a bit on the shorter COL side and also really has a truncated flat nose, so my guess is your getting some pitching up of cartridge on feed, especially if the problem seems to occur around the same round count. They may be the same thing--but I use CMMG 350L mags.
__________________
"Everyone speaks gun."--Robert O'Neill I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk! |
June 19, 2020, 12:24 PM | #3 |
Senior Member
Join Date: October 30, 2016
Posts: 211
|
Could be. But I pulled 20 rounds. Checking 5 I found a range of charge weights of 19.6 to 19.9 grains of some light grey ball powder. It looked nothing like WW296.
Dropping 28 grains of H110 in we will see what we see. |
June 19, 2020, 06:36 PM | #4 | |
Senior Member
Join Date: March 2, 2014
Posts: 11,789
|
Quote:
__________________
"Everyone speaks gun."--Robert O'Neill I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk! |
|
June 19, 2020, 08:37 PM | #5 |
Senior Member
Join Date: October 30, 2016
Posts: 211
|
Data for this new round is sparse. 357 Maximum date crosses over so I'll have to look at that.
|
June 21, 2020, 03:42 AM | #6 |
Senior Member
Join Date: February 17, 2009
Posts: 1,089
|
https://www.google.com/search?client...4dUDCAs&uact=5
Seems to me I have read about issues with Winc. 145gr FMJ factory loads. |
June 21, 2020, 04:51 AM | #7 |
Senior Member
Join Date: March 2, 2014
Posts: 11,789
|
The short throat of the 350 L is not tolerant of any "intrusion" by the case. But what REALLY is bad is the headspace tolerance of .01" (Fortunately PTG's gauges stopped at .007" with their no-go gauge.)--that might be OK for a revolver but that's asking for trouble in a rifle. I discovered early on that a manufacturers barrel could be in compliance with SAAMI specs but still result in unsupported case heads--certain cases--like starline's--could have the base of the case up to the top of the web unsupported depending on what side of the tolerances the chamber was cut. PCC's typically cut a radius into the breech face of the chamber to assist a flat-nose or "stubby" pistol bullet to feed into the chamber with increased reliability (that's what I have on the 350 L barrels I bought for AR's).
__________________
"Everyone speaks gun."--Robert O'Neill I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk! Last edited by stagpanther; June 21, 2020 at 08:03 AM. |
June 21, 2020, 12:55 PM | #8 |
Senior Member
Join Date: November 27, 2009
Location: Zona
Posts: 423
|
But the OP’s issue is with feeding cartridges out of the magazine which has little to do with chamber dimensions. That information is good to know though.
.
__________________
.22LR - .223 - .22-250 - .243 - 6mm REM - .25-20 - .25-35 - .25 BB - .250/3000 - .257 WBY - .260 - .30 M1 - .300 BO - .30 Herrett - .300 Savage - .32 H&R - .303 - .338-06 - .338 WM - .35 REM - .38-55 - .45 LC - .45-70 - .50-70 |
June 23, 2020, 09:09 PM | #9 |
Senior Member
Join Date: October 30, 2016
Posts: 211
|
Today I shot AA1680, the rifle ran fine. It ran fine with H110 (crappy accuracy) and with Lil' Gun. As soon as I switch to the Winchester load it does this crap. Defiantly short stroking wit that load.
Former lots reported popped primers and even case head separations. This seems like they over compensated. |
June 25, 2020, 06:06 PM | #10 |
Member
Join Date: June 5, 2012
Posts: 27
|
Armednfree:
What is the COL and bullet weight on your loads? |
June 27, 2020, 03:30 PM | #11 |
Senior Member
Join Date: October 30, 2016
Posts: 211
|
Actually I just loaded some 180 grain Winchester SP's. The book says 2.11 but the best my dies would do is 2.17. Fed and shot great though. Then I shot some of the Winchester stuff, same old crap. I ended up single loading them.
|
June 28, 2020, 01:25 AM | #12 |
Junior Member
Join Date: September 14, 2019
Posts: 5
|
try changing the recoil spring. i had this same problem with 224 valkyrie.
|
|
|