Hodge Defense 14.5" mid-length barrel, gas port purportedly 0.74" or 0.75", made a little tighter for M855A1.
LMT Enhanced BCG
Ammo will be M855 (not A1), Mk262, or Mk318, but all 5.56 NATO stuff (no .223)
So the gas port is “tighter”, and the LMT EBCG will take it a bit further in that direction. I IM’d Jim Hodge on Facebook and he said it might be a little much, but to try it.
So it is generally understood that increasing buffer weight will help “tame” (if you will) an over-gassed barrel. Does the reverse hold true, i.e. a strangled gas release can be assisted in function by decreasing buffer weight? The modern standard seems to be an H2 buffer. If cycling is an issue would trying an H or even carbine buffer serve to alleviate that? I guess a good indicator of a “sweet spot” would be proper cycling and then lock-back on an empty mag, correct? Yes, I know extreme cold weather could alter this, but it does with a lot of weapon functioning, not just AR’s.
I only ask this because sometimes, when it comes to weapons (and AR’s in particular), what you think would be obvious isn’t always the case.
So in this case the “weaker” ammo is in fact full-pressure 5.56 NATO loads, not over-pressured M855A1. Nonetheless a “weaker” load than the gas port was designed for. Since I’ll start with an H2 I have two more steps downward to play with (H then standard carbine buffer).
I know eliminating the LMT EBCG would un-complicate it, but it’s NIW and I want to use the damn thing (not to mention pricey also)! I also like them so would like to find a way to make it work in this setup if possible.
Per the list above, the Hodge gas port is 0.075". The next one up is 0.076" (several manufacturers). I’m not a mathematical or ballistic engineering prodigy by any stretch of the imagination, but I guess that 0.01" difference is close enough to be essentially the same.
I can’t recall where I read it but another source said Hodge used a 0.074" gas port. Looking at that list and with the other info, a 0.74-0.75" gas port for a mid-length is “tighter” across the board. Shouldn’t there be a difference in gas port size between a mid-length and a carbine system?
Not being argumentative at all, really trying to wrap my head around the theoretical aspect of it. Obviously the ultimate test will be sending some rounds downrange, but trying to see if this brain-exercise matches up to what I will find when actually shooting it (maybe next weekend).
You really dont need a LMT eBCG in this kind of set up. The barrel was gassed to run on a mil-spec BCG and H2 buffer with 5.56 pressure ammo suppressed and unsuppressed.
I’m not sure how gas port size and location was originally determined. Was it based on engineered models and trial & error? With the exception of the mid-length system Colt seems to have figured/worked out some of the best data and specs. Today with higher quality ammo and the suppressor trend some manufacturers are reducing gas ports. For example Daniel Defense reduced the gas port on the MK18 to .069 from a .083. Mind you that .083 was a request by SOCOM which is widely known now to be over gassed but .069 is what Colt determined was best on their 11.5 carbines back in the 1970’s. Sionics RGP 11.5 has a .063 gas port and though its advertised as for suppressor use only it cycles full power ammo unsuppressed all day long. So How are optimum gas port sizes determined today? I’m not sure if anyone knows as in yeah this is, we’ve tried everything already. Computer engineered models might test the many variations possible but until those theories are validated with live fire under varying conditions I don’t think we know for sure.
My intent is to run 20 rounds each of Mk318 and Mk262. I also have 20 rounds of M855A1 I found at a gun show a year or so ago that I’ll use. I’ll start with the M855A1, as spec’d with an H2 buffer. Then I’ll move to the other two types of ammo. If I have troubles with cycling or lock-back (which I would only anticipate with the Mk318 and Mk262) then I will try an H buffer. If still having issues I will drop to a carbine buffer. If problems persist I guess the LMT EBCG goes back into storage! I have a lot of Mk318 and Mk262 so that is why I will test them subsequent to the M855A1, which I only have 20rds of.
Obviously this wouldn’t be a test of the rifle’s overall reliability given the uber-low round counts, but should give me an idea if the LMT EBCG can be used with this setup, even if I have to change buffers to make it so.
This is a very poor reason to use it in this setup. The EBCG was designed for a specific purpose that’s well outside of what you’re trying to use it for. I mean you can make a square peg fit into a round hole… if you have the right tools. Probably easier to use the right peg. PM me a price on the carrier if you’re that tired of looking at it.
No, as stated previously I have not. I will soon though, and will definitely post my results. The main gist of my question was whether going in reverse with buffer weights for less gassy barrels works like adding buffer weight for over-gassed ones, i.e. is the theory reversible?
I have 6 BCG’s in storage. All but 2 are “standard” setups except for the coating/finish of a couple (a Colt standard, a Colt with a chromed Colt bolt in it, a Cryptic Coatings Mystic Black one, and a Sionics NP3 one). The other 2 are LMT EBCG’s. If this experiment peters out then so be it. If I can get the Hodge barrel to run with an LMT EBCG and do so by playing with buffer weight then that’s awesome. This is a new Colt 6920 OEM with the barrel replaced by the Hodge one. It has a Geissele SD-C trigger in it also. It’ll be a keeper. I just want to see what I can make work.
The answer to the question is very much a “yes”. Gamers (not being derogatory) do this all of the time, to the point of also reducing carrier mass. These guns run on the ragged edge of reliability, however.
The reason I say it is useless to discuss an unfired rifle, outside of specing one out before building, is there are many variables than gas port and buffer weight that affect function in a duty-grade rifle. Without first shooting the rifle, it is hard to judge what the optimal set-up will be outside of a factory rifle. I would grab Federal XM855, H buffer, Sprinco white spring, and regular Colt carrier and go from there. It’s a boring, but thoroughly vetted, combination.
The answer to your question is yes. Same principal as using a lighter buffer as underpowered .223 in a gun ported for mil spec 5.56. Will it work in your particular set up? I dunno. Maybe, maybe not. Sounds like you’re just tinkering for the hell of it.