- Messages
- 62
- Reactions
- 28
So I just got back from pushing ~300 rounds though my 8.5" FM barrel, Anderson lower, FM bolt, Matrix arms side charging upper, with a Armaspec Stealth SRS9 buffer.
For those of you that don't know what it is, It lets you shoot 9mm with a standard AR15 lower (with a 9mm upper) - you don't need to buy an expensive dedicated 9mm lower and if your AR15 lower is SBR'd you can still run 9mm through it without having to buy a $180+ magwell adapter.
TLDR: it works but with a few problems with 30 rounds and 1 round in magazine, the built in feed ramps are flimsy and flops back to block the bolt.
#1 It does not like to have 30 rounds or 1 round: It would literally not chamber a round with 30 in. It's as if the bolt just glides right over it and says "nope, too stiff not, gonna try son, GL next time". Could be my FM bolt as I don't know the tolerances involved to allow a bolt to glide over a round and close but not strip a round. Maybe its a oddity with a frankenstein of parts like my AR9. Tried to test with a NFA 9mm bolt that my buddy has but that proprietary bolt will just not work with the Endomag period.
#2 It does not like to chamber the last round: Most of the time it would not chamber the last round in the mag, BUT WOULD LOCK THE BOLT BACK like it did shoot a last round. I have a hunch that the part of the follower that engages the bolt hold is too tall and the last 9mm round is not large enough in diameter to press it down far enough to avoid pushing up the bolt hold lever.
#3 Fears of That floppy feed ramp hitting the bolt confirmed. It is way too floppy and would often bend back into the middle which puts it right smack in the middle of the path of the returning bolt. The bolt has smacked it a few times causing a misfeed and It is pretty worn from this abuse (happened about 5 times). Not sure how much more abuse it could take before it breaks off as it is pretty floppy now. They need a stiffer polymer that allows just enough elasticity to clear the magazine lips during installation but that is not so flimsy that it just flops back into the path of the lower bolt assembly group when it is cycling.
It works but it is rather annoying to run and there is certainly no sense of confidence in it; I got through my cheapo 115 gr ammo however without blowing myself up so take that fwiw. Im getting more in through a buddy and will have a larger sample size to test but I'm not very fond of them after today.
Hoping someone that doesn't have a frankenstein AR9 upper can test this out to reassure me that it's just my upper and that I didn't waste my money on another order of 3
. I really wanted this product to work.
For those of you that don't know what it is, It lets you shoot 9mm with a standard AR15 lower (with a 9mm upper) - you don't need to buy an expensive dedicated 9mm lower and if your AR15 lower is SBR'd you can still run 9mm through it without having to buy a $180+ magwell adapter.
TLDR: it works but with a few problems with 30 rounds and 1 round in magazine, the built in feed ramps are flimsy and flops back to block the bolt.
#1 It does not like to have 30 rounds or 1 round: It would literally not chamber a round with 30 in. It's as if the bolt just glides right over it and says "nope, too stiff not, gonna try son, GL next time". Could be my FM bolt as I don't know the tolerances involved to allow a bolt to glide over a round and close but not strip a round. Maybe its a oddity with a frankenstein of parts like my AR9. Tried to test with a NFA 9mm bolt that my buddy has but that proprietary bolt will just not work with the Endomag period.
#2 It does not like to chamber the last round: Most of the time it would not chamber the last round in the mag, BUT WOULD LOCK THE BOLT BACK like it did shoot a last round. I have a hunch that the part of the follower that engages the bolt hold is too tall and the last 9mm round is not large enough in diameter to press it down far enough to avoid pushing up the bolt hold lever.
#3 Fears of That floppy feed ramp hitting the bolt confirmed. It is way too floppy and would often bend back into the middle which puts it right smack in the middle of the path of the returning bolt. The bolt has smacked it a few times causing a misfeed and It is pretty worn from this abuse (happened about 5 times). Not sure how much more abuse it could take before it breaks off as it is pretty floppy now. They need a stiffer polymer that allows just enough elasticity to clear the magazine lips during installation but that is not so flimsy that it just flops back into the path of the lower bolt assembly group when it is cycling.
It works but it is rather annoying to run and there is certainly no sense of confidence in it; I got through my cheapo 115 gr ammo however without blowing myself up so take that fwiw. Im getting more in through a buddy and will have a larger sample size to test but I'm not very fond of them after today.
Hoping someone that doesn't have a frankenstein AR9 upper can test this out to reassure me that it's just my upper and that I didn't waste my money on another order of 3
. I really wanted this product to work.
