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9mm blowback vs radial delayed

Aisin

Grumpy old fuck
Joined
May 19, 2020
Member Number
304
Messages
2,610
Who is running a RD gun versus a traditional blowback? I’m pretty sure Roc Doc has one. Is it actually worth the big increase in price over a blowback setup? I have a 10 inch sbr in 9mm. I want something shorter. I am leaning towards the radial delayed.
 
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Yeah I have a CMMG Resolute and it's a nice piece, but it's had some cycling issues. They've sent me some parts to change out in the BCG, but after replacing the extractor, it still didn't cycle properly and they sent me some more replacement parts but haven't put them in yet. I was hoping they'd just send me a whole BCG, and that may be next. No love with 115 Magtech, 124 Win Nato spec, or 147g Speer Lawman.

OTOH, my side charger blowback New Frontier that I built runs like a deer.
 
Ouch. Sucks to hear that. My “dangerous” blow back Foxtrot Mike eats everything from 68 grain extreme defender to 165 grain subsonics. With the heavy buffer(10.68 ounces) it’s a completely different gun compared to when I was running an H3 buffer. The H3 buffer was almost to the point of being too light. That fat buffer really slows the bolt down.
 
OTOH, my side charger blowback New Frontier that I built runs like a deer.
Build list for the side charger? I have a Aero EPC9 lower that I'm going to build next and was looking at the NFA sidechargers for an upper.
 
Mean Arms has a bearing delay upper, seems awful expensive. I don't understand the hype/difference Bearing Delay Upper Receiver | Mean Arms

I have a shitty PSA blowback upper that runs fine. Ran into a feeding issue when I switched to the mean arms endomag inserts, finding its feedramp/round shape related. I have a magwell adapter for colt/uzi mags and its been flawless on that.
 
Build list for the side charger? I have a Aero EPC9 lower that I'm going to build next and was looking at the NFA sidechargers for an upper.
Upper, lower, BCG and 16" barrel all New Frontier. I had furniture, handguard, etc.
 

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Upper, lower, BCG and 16" barrel all New Frontier. I had furniture, handguard, etc.
Thank you. I've been looking for a solid side charging upper and for the life of me couldn't find a middle ground on pricing. Only shit I could really find was trash BCA stuff or CMMG for 3x what these New Frontier ones go for. Even the owner at the FFL I use for transfers couldn't find anything between those two price points.
 
Thank you. I've been looking for a solid side charging upper and for the life of me couldn't find a middle ground on pricing. Only shit I could really find was trash BCA stuff or CMMG for 3x what these New Frontier ones go for. Even the owner at the FFL I use for transfers couldn't find anything between those two price points.
Your FFL sucks. Foxtrot Mike is middle ground for AR9s. Side charging, LRBHO and built like a fucking tank. My 10 inch 9mm sbr weighs as much as my AR10. Oh yea, FM doesn’t have a disclaimer about their bolt catches breaking off like New Frontier does. The bolt catch on the FM lower receiver is beefing than a standard bolt catch.
 

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Your FFL sucks. Foxtrot Mike is middle ground for AR9s. Side charging, LRBHO and built like a fucking tank. My 10 inch 9mm sbr weighs as much as my AR10. Oh yea, FM doesn’t have a disclaimer about their bolt catches breaking off like New Frontier does. The bolt catch on the FM lower receiver is beefing than a standard bolt catch.
Every FFL around here sucks unfortunately. The only decent one is an 80 something year old Fudd who works out of his living room. He's charging 1/3 what everyone else is for transfers but you have to put up with shitty boomer disapproval looks for anything that looks like it was produced in the last 60 years. :laughing:

Annnd the bold killed any interest in the NF upper. BCA breaks off just the same for 1/2 the price.
 
Every FFL around here sucks unfortunately. The only decent one is an 80 something year old Fudd who works out of his living room. He's charging 1/3 what everyone else is for transfers but you have to put up with shitty boomer disapproval looks for anything that looks like it was produced in the last 60 years. :laughing:

Annnd the bold killed any interest in the NF upper. BCA breaks off just the same for 1/2 the price.
Seriously, look at a FM if possible. I bought the lower bare from Brownells. It’s the billet lower. They also have a hybrid lower that is part polymer. The upper was complete and originally was a 7 inch barrel but I swapped to a 10 inch barrel to run it suppressed. It has the SilencerCo ASR flash hider. The heavy ass KAK buffer made it a completely different gun to shoot compared to the H3 buffer I was running.
 
Seriously, look at a FM if possible. I bought the lower bare from Brownells. It’s the billet lower. They also have a hybrid lower that is part polymer. The upper was complete and originally was a 7 inch barrel but I swapped to a 10 inch barrel to run it suppressed. It has the SilencerCo ASR flash hider. The heavy ass KAK buffer made it a completely different gun to shoot compared to the H3 buffer I was running.
Already bookmarked. They came up when I was looking but I guess I never went to the actual store page. Product page doesn't list a price so I wrote it off.
 
Already bookmarked. They came up when I was looking but I guess I never went to the actual store page. Product page doesn't list a price so I wrote it off.
Their website is horrible. I didn’t get the upper from them either. Primary arms. I would go with the KAK 10 ounce buffer. 9mm has a ton of energy. More than you think. 124 grain pills will fully cycle 37.5 ounces of bolt and buffer weight out of a 2 inch barrel.
 
Your FFL sucks. Foxtrot Mike is middle ground for AR9s. Side charging, LRBHO and built like a fucking tank. My 10 inch 9mm sbr weighs as much as my AR10. Oh yea, FM doesn’t have a disclaimer about their bolt catches breaking off like New Frontier does. The bolt catch on the FM lower receiver is beefing than a standard bolt catch.
I built that NFA PCC back in 2016 not long after they were introduced. Have not had a bolt catch break, and used it in a 5 day class at Gunsite, well over 1000 rounds with no issues. Maybe they changed the design, or maybe I bought so early they hadn't had any breakages yet. I dunno.
 
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