Two Groove Rifling

I have a 1917 that has 2 groove rifling. I'm never sure what I'm looking at when I check the bore. I've read on the CMP site that most of the rifles they are selling now don't have much if any rifling.

I have distinct rifling in the barrel. A bullet also does not go very deep into the muzzle which is one of the tests I've seen a few guys here recommend. The bore does have some pitting but it is not what I would call a dark bore, but by the same token it's not a bright bore either.

What I'm wondering is if the rifling in these 2 groove barrels just is not as deep as what you find in a 4 or 6 groove barrel. The rifling is pretty wide and if it were as deep as other types, it would seem it might bind. So what should I be looking for here. I know the final test is shooting it which I still have not gotten around to doing so that's still the final determination.

typicaly a 2 groove barrel is a replacement barrel circa wwII. while generally its suposedly not as desirable as a 4 groove barrel 1903a4's came from Remington with both 2 and 4 groove barrels. The best advice I have been given and pass on is to simply shoot it and see what it does. and remember that m2 ball was 150 grain. I have an M1 with a muzzle and a chamber that rates about a 6 in terms of wear yet it will shoot about 2 MOA at 100 yards. 2 groove rifleing looks kinda funny until you recognise what you are looking at. the depth is the same as 4 groove too so thats not a factor either.

I re-barreled one of my M1917's with a WWII two groove barrel. It shoots as well as any rifle I have. Qualified with it during the old DCM days.

By the way this was one of the one's that came back from some Arabic country many years ago. At the time new old stock stocks and barrels were readily available and cheap. Aside from the lack of rebuild stamps, after a park job it looks like it just came from a rebuild.

My 2 groove would heat up and at about 25 rounds would lose its bedding. I then began over-shooting the target by 1-2 feet. I sold the gun.

when the barrel is streight if you crygenically temper treat the barrel it will usually hold its zero

I have a two groove on mine and it is ok with flat based bullets boatails are another story, but that is typical with two grooves

Rock Island and Johnson Automatics made 2 grooves,,they shoot just fine.

Chuck is right that two groove barrel shoot very well, some two grooves shoot better than four grooves and visa versa. I have heard that after four to five thousand rounds the grouping ability of the two grooves drops off quicker than the four grooves. I do not know for sure as I only shoot cast bullets thru mine.

To correct Chuck a bit, Rock Island never made barrels for the M17 and except for small experiments,, never made anything but four groove barrels.

The WWII spare barrels for the M1917 were made by Hi-Standard and Johnson Automatics. Ferris states the Hi-Standards had four grooves and Hatcher wrote that 81,570 Johnsons were two grooves. Johnson may have made some four grooves, I don’t remember. However, all Hi-Standards I have seen had four grooves and all Johnsons I have see have had two grooves.

45B20

I swapped stocks on my 2 groove '17. Didn't help Once the barrel hit 25 rounds it would start over-shooting the target. A nice barrel, as well. I took that rifle to Perry, long drive to make a fool of myself. I sold the rifle.

RIA made many many replacement barrels for the 1917...iv installed a few. they are only marked RIA with no date no ord, bomb..and are also 2 groove.. LA also made unmarked barrels for the 1917,, actually for the 1941 johnson. if you remove a barrel from a johnson. you can see the extractor cut for the 1917.. if you remove the receiver ring from a johnson barrel, it will fit the 1917. and vise versa..

No Chuck. Rock Island never made barrels for the M1917, they installed barrels made by others, (Remington blanks, Savage machining ) and stamped RI on them but never made barrels for the M1917. Ferris says only 2,100. It is interesting that you were able to obtain spares, were they new or were they removed from another rifle.??

45B20

My particular barrel is marked JA which I assume is Johnson Automatic. It has the ordnance bomb but no date. Is the no date unusual for these barrels?

The JA barrels were not dated. No idea why.

Were the JA barrels only made during WWII?

sorry, i dont care what Nick says in his book..iv installed barrels marked RIA just under the front sight, Nick is a great guy, but like us, isnt perfect.
Rock Island did make or at least provide barrels made for the 1917.
matter fact, iv seen 1917 barrels FS on GB, and here on this site marked RIA. no...not 1903 barrels, i know the differance.

Chuck--You installed my RIA tube on my '17. Good job, too. The RIA barrels are an odd WWII story. Remington (?) supplied blanks to Savage(?) who finished the white barrels. They were shipped off to RIA who parkerized and used (?) them in re-build. Very small number made 2100(?) and seldom seen today. The mint barrels were availabe through the DCM in the 1950's and I bought my barrel off a gentleman who got it from the DCM. Marked RIA and undated. Alot of effort to get 2100 barrels and then not use all of them in the re-build program. Whole story is untold and little known.

i dont remember if they had the REP in a box, common with Remington made barrels...just that hey are marked RIA..