Mega Rad Gun Thread

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Particle Bored said:
various DPMS lower "generations?" Looks like there's gen 1, 2 & 3
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assuming you mean the LR-308 DPMS variations.

Gen 1 is entirely unique and requires a Gen 1 bolt carrier group, barrel nut, upper receiver, receiver extension, buffer, action spring, and bolt catch and various pins (typically things are Gen 1 when marked LR-308). Gen 1 is noticeably longer than Gen 2 or 3 and is the most common one you will see. it is based on the Panther Arms AR-308 model they made shortly before being bought by DPMS. the lower on the early "high" Gen 1 lower receivers has an internal reinforcement and a unique measurement for the lower parts that will not work with any Gen 2 or later, or "low" profile upper receiver. this gen comes in two heights (low and high) which refer to the receiver height for scope rings. the "high" version is meant for weaver-style medium height rings (3/16" rail "thickness") while the "low" version is the same height as any other 1913 rail (1/8" rail "thickness"). High profile Gen 1 must be fitted with a Gen 1 lower. an Aero Precision M5 is "high" profile and will work, but an FAR-10 will not (low profile).

Gen 1 "high":
Screenshot 2022-02-04 002327.jpg


Gen 2 (or GII or Gen II) is shorter front to back than the Gen 1, has captive receiver pins which are unique to it, uses far more AR-15 compatible parts for both the upper and lower, but still uses some unique upper parts. they can be easily spotted by the flared magazine well if it's OEM DPMS, but if it's a clone, the lower will always have the typical AR-15 rear take down pin detente inserted from the rear (the Gen 1 is inserted from the bottom). you can also just eyeball the amount of receiver "hanging off" the back above the pistol grip, the Gen 1 being noticeably longer than the short AR-15 length on the Gen 2. PSA PA-10 upper will work on a Gen 2 DPMS lower without much issue, but the reverse is not true and it's also not ideal. the Aero M5 and PA-10 are both sort of DPMS Gen compatible, but they also do not interchange at all.

Gen 1 vs Gen 2 uppers. Notice the difference in radius and lug position:
Screenshot 2022-02-04 002500.jpg


Gen "3" DPMS is a combination of Gen 2 and JP and PRI parts to make a match rifle to replace the LR-308T and LR-308 Match and Match Stainless. they are pretty much a Gen 2 with a unique upper, barrel nut, barrel, and barrel profile with matched BCG and buffer/action spring with tuned triggers OEM from CMC. they aren't really a "generation" so much as a specific competition rifle series since there was never a Gen 2 version of the older national match rifles from Gen 1.

CMMG DPMS LR-308 Gen 1 compatible lower, works with any DPMS Gen 1 upper:
21354.jpg


PA-10 lower and Aero M5 upper will not function because the PA-10 lower has a unique buffer system:
Screenshot 2022-02-04 003029.jpg


Aero M5 lower with DPMS Gen 1 upper, functional but not ideal, and probably will have issues:
Screenshot 2022-02-04 003402.jpg
 
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Does anyone have any data on just how fast bullet fragments are traveling when inside a target, specifically in the case of M193? I have seen video of fragments popping exiting the top of gel blocks at what appeared to be a good clip but to my knowledge there exists no data on just how fast they are moving.
 
MrJokerRager said:
Is the CMMG's 22lr BCG conversion system for AR-15s reliable as far as plinking goes?
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Depends on the rifle, friend of mine couldn't get it to run right on his. Bought it off him for extra cheap and ran it fine on my end. It's okay if you don't have any dedicated .22 rifles, but otherwise just a novelty.
 
MrJokerRager said:
CMMG's 22lr BCG conversion system
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Rent Tin said:
Depends on the rifle, friend of mine couldn't get it to run right on his.
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man this is an entire topic in itself.

so, key concepts: .22LR is slightly smaller (.223 bullet diameter) than .223 Remington or 5.56mm NATO (.224 diameter). so conversions for the AR-15 is very straight forward, and "training" conversions for military rifles have a very long and storied history in many countries. because there is a bit of gas "leak" when fired, and because rimfire ammunition tends to be both cheaply made (dirty and/or unreliable), there can be significant issues when using a rimfire conversion - even ones that are pretty much dedicated firearms in their own right (Glock 44 for example has been really hit or miss and i've stopped recommending them as a plinker/trainer after having dozens of issues spanning a year or so of selling them).

because there isn't enough pressure from a .22LR to drive most gas systems, or even most locked breach firearms, a lot of .22LR is recoil driven in some way. in the AR-15 conversions this often results in excessive fouling of the gas system because hot, high pressure gas isn't blasting it clean after each shot. because of no gas system, a self-contained specialized bolt carrier group replacement that includes a short chamber adapter mounted to a short recoil action and rail system with action spring, typically with a magazine adapter/insert or special magazine is pretty much the entire "conversion".

due to the inconsistency of ammunition, these systems can be unreliable and are often tuned to a specific ammunition type or SKU. the major players are:

1. the old military conversions, like the M261 system used by the US Air Force and US Army (and these differ from each other slightly) which is profiled for M16's and will work in most AR-15's, but is very specific - you typically cannot mix and match magazines and the ammunition is limited to 1050 fps velocity with a bullet length 0.460-0.465" which is for the 1:12 twist of the M16/M16A1... it will work with other twists and bullet lengths, but you might need to get picky with bullet mass then, like 40gr HP or 36gr plated RN. unlike some kits or rifles, the M261 uses all normal M16 controls including locking the bolt carrier group back with the bolt catch on empty. it is not compatible with the "automatic" fire select setting though.
2. Colt Ar-15 .22LR AR-15 Conversion Kit (from the late 70's which is sort of an improvement of the M261 in handier packaging but has a "cheaper" and less durable design to keep costs low. works very well for very specific ammunition.
3. Clones of option 1 (Olympic Arms, Ceiner, Brownell's, Atchisson)
4. Clones of option 2 (CMMG, Stag Arms, S&W M&P 22, et c) with modifications like chamber profiling, brass collars for taper control, modified rails, modified carrier for recoiling mass, modified action spring and spring guide, et c.
5. dedicated rifles that are often uniquely designed but are also just greatly adapted version of option 2, 3, or 4 (example being the S&W M&P-22).
6. clones of the Ruger 10/22 or Marlin Model 60's action (itself a modified Remington Model 552) that is placed in an AR-15 shell. the Mossberg Model 715, although funnier options also exist like the Adler AP. you rarely see Model 24 clones though... Browning mafia strikes again.

generally speaking, you will want to keep with manufacturer recommended ammunition and typically it's either going to be standard velocity (for options 1 and 2) or high velocity (greater than 1100 fps) with options 3 and 4. option 4 has some special cases where you might alter the spring or carrier mass for different ammunition for "tuning" like the CMMG Echo which is designed for compatibility with full-auto lowers vs the Bravo which is not. the Echo is also good if you like hypervelocity ammunition (greater than 1500 fps typically like CCI Stingers).

the bullet mass should usually be 40gr, but this varies. too heavy can have weak ejection or failures to feed, too light can damage components of the conversion kit and lead to cushioning or bounce making failures to ejection or failures to fire more common. biggest problems with conversion kits are over or under lubricated (just like a normal AR-15, light lubrication is ideal, but not in the magazine other than a touch on the follower and spring), magazine issues, ammunition compatibility issues, and sometimes fouling issues especially on the bolt face.

you'll also want to use one or two full power .223 Remington or 5.56mm NATO to clean out the gas system after using .22LR if it's not a dedicated rifle (Mossberg Model 715 for example lacks a gas tube entirely).

AGPinochet said:
how fast bullet fragments are traveling when inside a target, specifically in the case of M193?
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not specifically when inside a target, although the rate of deceleration is incident on initial velocity at the point of impact and the nature of the impact (if keyholing or if properly entering, et c). during ideal fragmentation with M193 where velocity at the point of impact is above 2700 fps, deceleration of fragments in calibrated ballistic gelatin seems to reach zero within 10 inches with the exception of the spitzer tip, which if intact seems to reliably travel an addition 2 inches.
 
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What’s a “good price” (in cpr) for you guys when talking about 9mm FMJ right now? I’ve been a gun owner for the last couple years but I started getting out to target shoot more actively in the last two months or so (great timing right). I’ve been buying all my ammo online pre and post Covid and I seem to average about $0.38-ish CPR but it averages out to like $0.52 CPR after shipping and taxes. I’m not exactly buying in bulk (the biggest boxes I buy are 100-250) but my cousin and one of my teachers said either of them would be willing to go halfers on a 1000rd brick
 
Nate Higgers said:
What’s a “good price” (in cpr) for you guys when talking about 9mm FMJ right now? I’ve been a gun owner for the last couple years but I started getting out to target shoot more actively in the last two months or so (great timing right). I’ve been buying all my ammo online pre and post Covid and I seem to average about $0.38-ish CPR but it averages out to like $0.52 CPR after shipping and taxes. I’m not exactly buying in bulk (the biggest boxes I buy are 100-250) but my cousin and one of my teachers said either of them would be willing to go halfers on a 1000rd brick
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In my locale, 50rd boxes of fmj are 50-60cpr, which works out to be the same if I bought it online. But the way things have been going, I'd much rather keep my buying habits offline, while supporting my local stores (and gas stations here even sell ammo).
 
Pocket Dragoon said:
In my locale, 50rd boxes of fmj are .50-60cpr, which works out to be the same if I bought it online. But the way things have been going, I'd much rather keep my buying habits offline, while supporting my local stores (and gas stations here even sell ammo).
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My neighborhood independent LGS gouges the fuck on the prices. I bought a certain 9mm striker fired polymer compact handgun of a certain verboten brand and they had it marked up roughly $70 higher than the Cabelas or academy down the street. I don’t make terrible money for what I do but it’s the same situation for the ammo they sell too. They don’t sell many “name brand” 50rd boxes and the prices are closer to $1.00/rd for FMJ than I’d like
 
Nate Higgers said:
My neighborhood independent LGS gouges the fuck on the prices. I bought a certain 9mm striker fired polymer compact handgun of a certain verboten brand and they had it marked up roughly $70 higher than the Cabelas or academy down the street. I don’t make terrible money for what I do but it’s the same situation for the ammo they sell too. They don’t sell many “name brand” 50rd boxes and the prices are closer to $1.00/rd for FMJ than I’d like
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Our Texaco down the road has just about every flavor of pistol calibers, even a selection of shit like 10mm & 5.7, which all run between $30-$50. There's even a few boxes of Russian 5.45 among all the different rifle calibers, but nothing is over $60 unless I missed it.

The place is kind of a unicorn store (but it's not alone), but a couple weeks ago I went to a couple LGS in town to check on things Their prices were roughly the same or slightly higher, except for match & self-defense stuff, and the few boxes available were in the $60-$80 range, at every store. The problem is their stock & selection was very limited or non-existent; though I was lucky to find one that has stacks of Makarov fmj ammo at a reasonable price.

All of them have websites now, but most calibers outside of range fodder 9mm, 5.56, or 7.62 are either unavailable or insanely expensive; plus the time & cost it takes to get shipped. At that point, going to a big box online retailer would be the same deal, along with having to give them all my personal information.

When it comes to guns & ammo, it's gonna be done face to face with regular cash; it may cost more sometimes, but privacy is worth more to me than convenience.
 
Jesus Goldstein said:
Scored a brick of primers the other day at the local box store; Federal Large Pistol Magnums. Components may slowly be showing back up on shelves.
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I just happened to pass an LSG I hit up and owner I'm friendly with let me take the 100 7.5 shot 12g they got. I feel 0 shame if he let me and 7.5 is fucking perfect for game birds. I can't wait to eat me some grouse.
 
If any of you niggers need anything from Safariland, got a 20% off your order coupon for their website: GUNTALKMEDIA22Q1.

Of course compare the discounted price with amazon depending on what your lookin at.
 
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