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cycle problems

Posted: Sun Mar 25, 2012 12:30 am
by sniiped
i realize there aren't many who have purchased a 300blk from pws that come here, but if there are any, did you have cycle problems? i took mine out today for the first time and i couldn't get it to feed. i believe it was short stroking on me. i was using factory ammo Remington 115 grain. i tried different magazines and it happend with all of them. i could rack it just fine and get it to load the next round but it wouldn't do it on it's own. as far as internals it's all stock. i emailed pws, but figured i'd try here also incase any of you may have ran into this. thanks.

Re: cycle problems

Posted: Sun Mar 25, 2012 12:56 pm
by newfan
I have the PWS MK109 300blackout on a PWS pistol receiver and I took it to the range this Friday. I had the same problem with the exactly the same ammo, Remington 300 BLKOUT 7.62x35mm 115 gr Close Tip Flat Base. I tried 3 different mags, Pmag, Victory and GI, and it had the same problem. I took out the carrier bolt assembly, and re-oil it and still the same problem. Since I have two PWS pistols, I swapped out the receiver, and had the same issue.

Another post indicated maybe problems with the spring, and maybe use a lighter spring. Here is the link.
viewtopic.php?f=136&t=79229

I only had one PMAG that day, and based on another forum, I need to try out multiple PMAG to figure out which one the 300 BLKOUT ammo likes. I'll give that a try this week, and also call PWS to get an answer. If you get a reply from PWS, can you also post their reply.

Thanks.

Re: cycle problems

Posted: Sun Mar 25, 2012 9:56 pm
by rill
I just got a 16" PWS 300 upper and mine seems to do the same thing, short stroke and no bolt hold open, although I am running REM subsonics with my SWR Trident 9mm can. I have only tried a 20rd. Pmag so far with a std. .223 buffer and spring.

I really haven't had much time to mess with it, but thought I would mention my experience on here as well...

Re: cycle problems

Posted: Mon Mar 26, 2012 12:07 pm
by BLdtylry
Check your gas blocks and gas hole on your barrel. Sounds like it's either not lined up or too small.

Re: cycle problems

Posted: Fri Mar 30, 2012 12:14 am
by sniiped
So far they want me to try a higher grain bullet. Taking into consideration which gun I have (mk116) I'm thinking I can put a "softer" buffer spring in there or take a standard one and trim it down so it has less resistance. I'm searching around the net and I'm seeing buffer springs for as low as $3. Any one know of a buffer spring that is slightly softer than a standard buffer spring? Any input and help with this is greatly appreciated. Also, would a heavier or lighter buffer be another option? Thanks again.

Re: cycle problems

Posted: Fri Mar 30, 2012 3:44 pm
by Taseal
sniiped wrote:So far they want me to try a higher grain bullet. Taking into consideration which gun I have (mk116) I'm thinking I can put a "softer" buffer spring in there or take a standard one and trim it down so it has less resistance. I'm searching around the net and I'm seeing buffer springs for as low as $3. Any one know of a buffer spring that is slightly softer than a standard buffer spring? Any input and help with this is greatly appreciated. Also, would a heavier or lighter buffer be another option? Thanks again.
Honestly, shouldn't it just work? 300 BLK is always advertised as "change the barrel and you're good to go"

if you have to try higher grain bullets, change out buffer springs... It's kind of self trouble shooting which you shouldn't have to do for a $1200 upper don't ya think?

Re: cycle problems

Posted: Fri Mar 30, 2012 5:12 pm
by jason
Is it a short barrel?
I had trouble with my 9" barrel shooting weaker rounds. With the PNW 147gr rounds and my own homemade 145gr FMJBT w/ 14.7gr H110, it cycles fine.

Re: cycle problems

Posted: Fri Mar 30, 2012 5:33 pm
by 300newb
Gas port alignment, SA vs FA bcg, buffer weight, all can affect the cycle. All rifles can be different, same with ammo batches. I used to have a couple of ruger pistols, same model, same year, one would not work with the bulk pack, one did.

Re: cycle problems

Posted: Sat Mar 31, 2012 12:26 am
by sniiped
made progress today. the instructions from PWS say to keep the bcg pretty dry, and i was listening until last night. i got everything (minus the piston) lubed pretty well, and today it gave me zero problems. I'm going to contact PWS let them know it worked for me. I figure once the rifle is done breaking in, it shouldn't be a problem any longer.

Re: cycle problems

Posted: Mon Apr 16, 2012 4:37 am
by sniiped
went out again on friday. tried the gun dry with 130gr ammo, and it was short stroke after short stroke. seems like it's either run the gun wet or send it in so it can be looked at to run how it's supposed to. i plan on sending it in in july after i get back from my vacation.