di vs. piston

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HazeMK

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first off what is the difference? ive been in he military or severalm years and am very familliar with the c7 bu not with different AR designs and manufacturers. Im looking buy an AR and i want it to be quality andsimilar to the c7. Price point is around 15 to 1600 cad.

I am looking at a bushmaster an am wonderinggeneral thoughts on this manufacturer. One bushmaster has a pistion conversion kit. i really have no idea what hs means however i hear that its agood upgrade from some, and that if you ant apiston you should buy a diferent rifle which was designed for one. Wisdom and opinions much appreciated. what is DI, what is your prefernce and why? Also looking for reccommedations on models which are the best value for quality and what you receive.

Thanks!
 
There are 2 operating systems to run the bolt back to cycle the action.
Gas impingment which is what the ARs were designed with originally and works and the newer piston system that allows the gun to supposedly run cleaner and cooler.

DGI employs a gas tube that runs back to the bolt carrier and literally blows the bolt back with gas from the burning gun powder. The piston systems use gas collected at the gas port to mechanically drive a rod (piston) back to the bolt carrier to operate the rifles action.

Piston systems are all proprietary so parts from 1 maker are not operational with parts from another unlike the Direct Gas Impingement systems are.
Piston systems are well known for carrier tilt, excelerated wear on the upper and buffer tube.

Personally I would not have a piston driven AR, at least until the parts are more universal and some of the issues are sorted out. There seems to be a trend to fix things that are simple and not broken these days, all at the consumers expense.

The Bushmaster rifles are decent, they like DPMS are part of the Remington group which is part of a larger comglomerate, so in all a decent mas produced rifle that like all ARs have unlimited upgradeability.

I prefer our own AT15 rifles for overall quality but have an old XM15 Bushmaster that I won't sell simply because it runs flawlessly and is very accurate.
 
so the c7 service rifle is piston or GI ? and just to clarify youre saying that even though piston rifle conversons are sol as an upgrade they can often produce negative effects? like i said i know how the operation of a c7 works, i just don know all the terminology.
 
The C7 is a DI rifle.

If you want a piston rifle, I'd recommend a rifle that was designed for piston operation, rather than a converted AR.
 
BM is generally a 2nd or 3rd Tier AR, due to the way they batch test parts and some of their materials.

I have had BM's -- some ran great, some where lemons.

Don't buy a piston AR -- just trust me on this... IF you want a piston gun, buy a G36, Sig55X series (but not a 552), an Ak, FN FAL, FN SCAR, or even a fricken M14

IF I was going to buy a AR I would buy one of the following.
In no particular Order
KAC (I get pretty good pricing ;) )
LMT
Bravo Co.
Colt
Noveske
Larue
Daniel Defense
Stag

I've got no experience with Cdn made AR's other than Dlask (which since my mother told me not to say unpleasant things I won't comment on that).
 
KevinB said:
BM is generally a 2nd or 3rd Tier AR, due to the way they batch test parts and some of their materials.

I have had BM's -- some ran great, some where lemons.

Don't buy a piston AR -- just trust me on this... IF you want a piston gun, buy a G36, Sig55X series (but not a 552), an Ak, FN FAL, FN SCAR, or even a fricken M14

IF I was going to buy a AR I would buy one of the following.
In no particular Order
KAC (I get pretty good pricing ;) )
LMT
Bravo Co.
Colt
Noveske
Larue
Daniel Defense
Stag

I've got no experience with Cdn made AR's other than Dlask (which since my mother told me not to say unpleasant things I won't comment on that).
Click to expand...

Yeah...thanks for rubbing that in...!

:(
 
What? No love for Spikes Tactical? I'll go with KevinB that the brands he mentions are excellent...but I do like my Spikes billet quite a bit...
 
To amplify a little on what people have said, there are some parts that are more important than others. For example, you want a bolt from a reputable company, same for the barrel.

Things like the Lower receiver, assuming all your in-spec parts fit on it, matter very little to the performance of your AR15.

If you are going to buy a pre-made complete AR15 - the makers Kevin listed are all very well respected. Only the Stag and LMT are available in Canada presently with any degree of regularity.

Some of the second tier makers are also quite decent, though not as sought after as the first-tier makers.

These include the likes of Armalite and Bushmaster. Decent AR's for the price and assuming you don't get a lemon (evident on the first range trip) will perform as well as any first tier AR15 for killing paper targets.
 
Just to clarify. The AG42B and the MAS 49, 49/56 are DI. Gas is carried rearward through a tube, where it acts directly on the bolt carrier, with a spigot and socket arrangement, and blows it back.
The AR system is ducted gas, not DI in the sense that the first two rifles are DI. Gas is ducted through a tube back to the bolt carrier. It enters the bolt carrier, where there is an expansion chamber. The gas expands between the bolt (this is why it has piston rings) and the bolt carrier. The carrier is forced rearward, the movement separates the bolt and carrier, the movement causing the bolt to rotate and unlock. The energy imparted to the carrier causes it to continue to move rearward, opening the breech, etc. There are vent holes visible through the ejection port where gas is vented after it has done its work. In addition, the bolt carrier key is separated from the spigot end of the gas tube as the carrier moves rearward. This, and the vents, compensate to a degree for some variation in gas pressure. If the AR were a true DI system, there would be no gas passage into the interior of the carrier. Anyone ever plug the passageway through the bolt carrier key and see if an AR will work with DI?
Heat and fouling are introduced into the carrier assembly. This doesn't happen with either a piston or true DI rifle.
AR piston conversions aren't trouble free. KevinB and the other posters are bang on when they suggest that if you want a piston driven rifle, get one designed that way from the get go.
If you want a rifle that resembles a C7, Gunnerlove's suggestion makes sense.
 
Didn't you say you served for many years? How do you not know this? Doesn't todays modern soldier know his/her rifle inside and out???
Click to expand...

Uhh they just shoot 'em, they haven't got a clue how they work.

I once had a half hour argument with a Master Corporal that the C7 did not in fact operate from an open bolt. I had to actually go to stores to get one to show him. The funniest bit was when he tried to pull rank on me and claim that he was right and outranked me. I replied that while he might well outrank me, that didn't make the C7 fire from an open bolt.
 
KevinB said:
BM is generally a 2nd or 3rd Tier AR, due to the way they batch test parts and some of their materials.

I have had BM's -- some ran great, some where lemons.

Don't buy a piston AR -- just trust me on this... IF you want a piston gun, buy a G36, Sig55X series (but not a 552), an Ak, FN FAL, FN SCAR, or even a fricken M14

IF I was going to buy a AR I would buy one of the following.
In no particular Order
KAC (I get pretty good pricing ;) )
LMT
Bravo Co.
Colt
Noveske
Larue
Daniel Defense
Stag

I've got no experience with Cdn made AR's other than Dlask (which since my mother told me not to say unpleasant things I won't comment on that).
Click to expand...

I would actually be interested in your unpleasant experience with Dlask Arms. I'm sure if it's an objective opinion (which may be hard for you) it's good to hear others perspectives. I'm assuming that if KAC sold a piston AR you would probably tell the OP that it's ok to to purchase piston AR's. I think the large group of people who are successfully using LWRC, POF, H&K ( to name a few) might take exception to your comment on staying away from piston AR's. I will happily put my MR223 up against anything KAC has to offer.
 
What did you pay for the MR223? My $1300 Stag has 11000 rounds through it with two stoppages (one due to me failing to seat a mag and the other a bad primer) and minimal cleaning. I have a hard time seeing how the casual user needs something better than the99.9818% reliability that a quality AR will provide.
I have not seen anything in piston driven rifles like the G36, AUG and SA80A1 that makes me want to jump on the piston band wagon.
 
How about the PWS Mk107 Diablo?
It's a piston system and it is suposed to be the cats hoop!
Any input would be great, I have one inbound!
 
There have been many reviews of piston rifles recently, but I think that the lack of universal specs and interchangablity of parts is the main problem.

LMT, LWRCI, POF, PWS, HK and recently Stag have all come out with piston guns that get great reviews, but each has come up with their own solutions to problems such as carrier tilt and excessive wear.

Until one system comes out on top, I'm not sure they'll be widely accepted.

I don't think anyone can say any of the above manufacturers make a bad product.
 
If you can get a '06 or '07 Hk416 -- they are gold.

We do make piston guns -- the PDW, and the LMG, we also made some piston SR-16's, and if someone really really wants a piston SR-16 I'll sell it to them (.gov they are select fire) - but I do not see the need, and a ton of cons.

Engineeringwise - its easily demonstrated the AR system which was never designed for a piston (other than the bolt action in the carrier), is best left without.
Unless someone comes up with a non standard AR upper - with bolt rails (really guide rails, as opposed to the bolt carrier 'pads', carrier tilt will be a problem.
 
Agreed Kevin "dont f^&k with a good design"

DI rifles that are turned into Piston guns, are never as good as a orignal designed piston gun.

the piston AR is a Fad in my mind "if its not a piston AR your D&*k will fall off ;)"
 
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