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View Full Version : Carbine length AR 55grn VS. 62grn


blazeaglory
07-01-2011, 1:58 PM
hello. i did a search and could not find anything. and my question would be...

we all know that a carbine length rifle is more likely, or supposedly more likely, to have a jam or malfunction due to the shorter gas tube vs. a mid length or rifle length gas tube. now my question is in regards to ammo...

would a lower grain count help in this issue? for example would 45grn or 55grn be better than 62grn or higher in regards to helping with less malfunctions in a carbine length system due to higher pressure created by a higher grain count? like should i buy 45grn when my *** is on the line or would 62grn be fine? this is not for target shooting but rather for a SHTF type scenario or home defense when the shotty is out of the question

i was curious because i plan on buying a large amount of ammo and i would like some input on this. thanks

HK Dave
07-01-2011, 2:30 PM
You know... i see questions like this a lot...

I have NEVER had a failure in many thousands of rounds out of any of my carbine gas ARs.

It makes me curious what these malfunctions and jams are about.

The majority of what i shoot is 55 grain XM193. I sometimes shoot heavier stuff but not that often. Didn't even know 45 grain exists in 5.56.

But to make this a little more scientific... all my carbine length guns are higher end guns made by LMT, DD, BCM and the like, all are 14.5" to 16" barrels, and all are kept clean.

The only failures I've ever had on an AR were because of faulty mags.

krnrspd
07-01-2011, 2:35 PM
my carbine length ARs are a mix of DTi and Aero Precision

Never had a single issue with m855 62 gr green tip penetrator or xm193 5.56 55 grain from Lake City, Black Hills or PMC. Also haven't had a problem with remington or federal .223 55 grain. Not 1 ftf/fte!

I had put wolf down my armalite carbine length back in the day, ftf/fte 10 out of 100 at least!

Do not put the russian lacquer coated crap through your AR

Steel cased russian ok, but sometimes their primers require a little bit more force!

blazeaglory
07-01-2011, 2:52 PM
my carbine length ARs are a mix of DTi and Aero Precision

Never had a single issue with m855 62 gr green tip penetrator or xm193 5.56 55 grain from Lake City, Black Hills or PMC. Also haven't had a problem with remington or federal .223 55 grain. Not 1 ftf/fte!

I had put wolf down my armalite carbine length back in the day, ftf/fte 10 out of 100 at least!

Do not put the russian lacquer coated crap through your AR

Steel cased russian ok, but sometimes their primers require a little bit more force!

my rifle is a CMMG lower with a DTI heavy 16" upper.

thats what i was going to buy actually...but it is XM855 62grn green tip.

and on the CMMG website it says that wolf ammo voids the warranty...hehe

Josh3239
07-01-2011, 3:00 PM
Carbines are more likely to be overgassed but that doesn't mean anything. As with any gas system, it just needs to be tuned to that sweet spot. That can be done at the gas port, gas block, gas tube, or at the buffer.

In 55gr vs 62gr the weight is negligible and in velocity were talking more or less than 200 feet per second difference. The military seems to prefer their 14.5'' M4 and those work just fine. I think your overthinking this. If your really worried about pressures look into an adjustable gas block.

blazeaglory
07-01-2011, 3:23 PM
an adjustable gas block would be nice...

i just ordered this. the picture shows the "not for duty use" but the website states that the picture is wrong and the product is true milspec NATO and not rejected or whatever

http://www.cabelas.com/product/Home/Misc-Shooting/New-Ammo|/pc/105625080/c/106032780/sc/108793080/Federal-556-NATO-Ammunition-with-Ammo-Can/1218213.uts?destination=%2Fcatalog%2Fbrowse%2Fhome-misc-shooting-new-ammo%2F_%2FN-1105071%2B4294771227%2FNe-4294771227%3FWTz_l%3DSBC%253BBRprd1218213%26WTz_st %3DGuidedNav%26WTz_stype%3DGNU&WTz_l=SBC%3BBRprd1218213%3Bcat108793080

http://images.cabelas.com/is/image/cabelas/s7_218085_999_01?rgn=0,0,2000,1497&scl=5.2631578947368425&fmt=jpeg&id=3ZHcfA4SL90-H8uSkTxiPo

luckystrike
07-01-2011, 3:30 PM
55gr 62gr dont worry about it unless you are looking thru glass trying to shoot thru your old bullet holes. carbine will be fine with whatever gr ammo. I have seen no difference in reliability between carbine, midlength and rifle in my personal experience

blazeaglory
07-01-2011, 3:40 PM
sweet:D

CK_32
07-01-2011, 4:03 PM
You know... i see questions like this a lot...

I have NEVER had a failure in many thousands of rounds out of any of my carbine gas ARs.

It makes me curious what these malfunctions and jams are about.

The majority of what i shoot is 55 grain XM193. I sometimes shoot heavier stuff but not that often. Didn't even know 45 grain exists in 5.56.

But to make this a little more scientific... all my carbine length guns are higher end guns made by LMT, DD, BCM and the like, all are 14.5" to 16" barrels, and all are kept clean.

The only failures I've ever had on an AR were because of faulty mags.

Dito. I shot 800 rounds through my 16" BCM carbine with out a single hick up full rapid fire and 50% bump firing. Didn't take it easy what so ever and didn't have a single probelem shooting 55gr xm193 with p mags and GI mags...