I had a rifle with a 2 Groove barrel all the time!

[Four Fingers of Death]

I have always fancied trying a 2 groove barrel with cast, but never came across one.

I bought a (nicely done) Bubba sporter M17 a few years ago very cheap and was going to re-barrel it to 375H&H, which is foolishness, but something I always wanted to do. I never took much notice of the barrel noting that it was worn out. I have never got around to doing anything about it and it lingered in the safe.

My friend rang me saying he knew a guy looking for am M17 or P14 action to build a 303/25 or a 25/06 on. I dusted it off and met him at the range today. I gave the Bbl a clean and lo and behold it is a two groover and better than I thought. The scope was set up a bit crooked and was not adjusted to suit me. I got a few 2" groups in spite of the difficulties. The guy said that he wanted to build the rifle up, but also wanted something that he could hunt with as well for a year or so until he gets around to it. He didn't think it was satisfactory and decided against it, which pleased me. I will clean it up and see how it goes once the scope is fitted correctly and loads are worked out, etc.

http://i89.photobucket.com/albums/k228/4fingermick/Bolt%20Rifles/SporterisedM171.jpg

[skeet1]

Four Fingers,
Is this a 2 groove a "03A3" barrel fit to your action? I didn't think there were any 2 groove M17s. It looks like Bubba did a decent job on this one, it looks very nice. Good shooting to you.

Skeet1

[madsenshooter]

I thought I'd read that Melvin Johnson's Company had rebarreled some 1917s with 2 groove barrels.

[Bob S]

Right. Johnson Automatics made two groove barrels for the M1917 during WW II. They are marked "JA" behind the rear sight. Rock Island Arsenal and High Standard made four groove barrels for the M1917 during WW II. Only the original barrels were 5 grooves with Enfield type rifling.

Resp'y,
Bob S.

[rhbrink]

I had a two groove M1917 when I was a young'n don't know if it was a "JA" or not too many years ago shoot pretty good though. Wish I had it back unbabba'ed off course.

[FAsmus]

Bob S;

You say; Johnson Automatics made two groove barrels for the M1917 during WW II. They are marked "JA" behind the rear sight.

Me: Sure, this is close Bob but it is behind the front sight where the "JA" is stamped.

Good evening,
Forrest

[Four Fingers of Death]

Best be getting it out of the safe and having a look, I didn't notice any markings. Then again, I didn't notice the 2 groove bbl either. I suppose I only took in the action and stock as I had planned to make scrap metal out of the Bbl.

Update: I had a good look, it looks like guy who fitted the barrel made an adaptor from the original (quite common over here). The standard barrels are 26" long, this is approximately 24.5" and has a recessed, machined crown. Soooooooooo the barrel could have came off a No4 or a springer.

There is a marking underneath about 1 1/2" from the muzzle. I looks like a P or a D or a horseshoe/arch on a bar. Check it out;

http://i89.photobucket.com/albums/k228/4fingermick/Bolt%20Rifles/20101019M17Sporter5.jpg

http://i89.photobucket.com/albums/k228/4fingermick/Bolt%20Rifles/20101019M17Sporter2.jpg

She sure is a big ol' gal!

http://i89.photobucket.com/albums/k228/4fingermick/Bolt%20Rifles/20101019M17Sporter.jpg

Gets more interesting as we go along.

[shotman]

Its kind of strange that they shoot as good as they do dont look like much rifling in them. even a brand new looks shot out
the Lyman 311413 done good in the o3a3 I had

[Bob S]

Bob S;

You say; Johnson Automatics made two groove barrels for the M1917 during WW II. They are marked "JA" behind the rear sight.

Me: Sure, this is close Bob but it is behind the front sight where the "JA" is stamped.

Good evening,
Forrest

Temporarily directionally-challenged. :veryconfu

Resp'y,
Bob S.

[FAsmus]

FourFingers;

Roger the pictures ~

I looked at my semi-as-issued M1917 - it looks very much the same as your photographs ~ less the nice sporter wood of course. The place where different gunsmiths machined off the sight ears is naturally somewhat different.

My barrel/receiver area joining is exactly like yours. The barrel is most likely as-installed by some military armory. My rifle carries the same exact "P" - looking stamp on the underside of the barrel. Mine is three inches from the muzzle - which would go right along with a barrel shortened from the original 26" to your length of 24 1/2. ~ Someone just cut it off a bit .. perhaps to get rid of the front sight band when the rifle was modified from military to sporting use.

It might be interesting to check the size of the bore & groove diameters of your barrel. The Johnson barrels are known for their precise dimensions; Mine is pretty much exact at 0.3080/0.3000 ~ with only enough wear at the throat to just accommodate the nose of my RCBS 30-180-SP that measures 0.3005.

As I mentioned in the thread "A two-groove M1917?" some time ago, the quality of this barrel seems to be along the lines of a Douglas Premium; don't toss it on the scrap-heap yet!

Good evening,
Forrest

[Four Fingers of Death]

I was shooting Winchester factory loads the other day and doing no good. I will have to set the scope up properly and persist with this big ol' gal. I will save the good amo and dust off a bit of Lake City MilSup I need to get rid of these and use the cases. It is old ammo and has the odd FTF, which makes it no good for competition). I will to get it percolating first and then clean up and try some cast.

Slugging is always a good idea!

I was off track with the barrel, thinking it was an adaptor, but I didn't have time to be moving half a ton of junk to get at the safe where the M17s are kept and I definetly didn't have time to pull the wood of them either (something I am always reluctant to do, they shoot, so I leave them alone!).

Thanks for the info FAsmus, big help.

[NoDakJak]

I bought four of the two groove Johnson Arms barrels for the P-17 about thirty years ago. At that time they cost virtually nothing. Who wanted two groove barrels when new Springfield, four groove barrels could be purchased so cheap. I have owned about a dozen P-17s but none of them had two groove barrels. In the late fifties and early sixties I was buying them for $29.95, new straight out of the cosmoline. 1903a3s cost another ten dollars. Almost all of them shot better them my 1903s. Every one of them exhibited excess headspace by modern standards. I believe that this was because of the cock on closing combined with them being designed to use in the blood and of the European trenchs. Neil

[Four Fingers of Death]

The Brits felt that the work of extracting the case and recocking the action was best spread over the opening and closing, rather than combined at teh opening of the bolt I suppose. Makes sense, but I never considered how it would affect head space.

I will have to give this matter great thought. It is late and I'm tired. Hmmmmmmmmmmmm!

[FAsmus]

Gentlemen;

When I first got this M1917 I bought 50 new R-P cases for it. I was amazed to see as I fired test loads in them that the primers were backing out way too much for my taste. ~ Keep in mind that I very seldom FL size and certainly not when beginning with new brass.

The problem ( I think ) is due to a heavy firing-pin fall combined with relatively hard primers. The cases are being hammered into the chamber hard enough that the shoulder is driven back slightly and the low pressure of the cast load isn't enough to expand them back, but IS enough to push the primers out somewhat.

I bought a replacement mainspring and have been cutting off about 1/2 coil every time I go shooting. The theory being that I'll either begin running into miss-fires or the problem will go away.

In the mean-time I have fixed the primer back-out by lightly oiling each cartridge before firing it. This is completely contrary to jacketed shooting but seems to work for this particular rifle and load.

The primers in question are the "MagTech" brand, made in Brazil that I bought during the primer shortage. They are reliable and provide consistent ignition for accurate shooting but I got curious one day and measured the thickness of the cup material; I found that it is 0.005 thicker than our standard Winchester LRMP cup material. This is quite a bit and may well be the whole source of the problem.

Good morning,
Forrest

[cobbmtmac]

Four Fingers,

I would certainly encourage your interest and experimentation with your newly discovered Two-Groove!

I have 3 SpringField 03's and have built several for family, Sons and Grandsons. Also, I have unbubba'd a few over the years. Two of my personal Springfields are Mark I's. One has a Two grove barrel that is stamped; "Santa Fe Springfield Sporter MK1, Golden State Arms Corp, Pasadena, CA" and cut to 22". I have a Nikon Buckmaster 3X9 scope on it.

This one is a tack driver and has always out shot my Four-Groves, not by much but I believe just a little better. I have dedicated it to hunting, but when I was shooting cast, it would produce a 1" and sub 1" MOA fairly often, using 16 grains of 2400 behind, originally a Lyman 311284 and more recently an Ohaus 30-190-S.

My hunting load is 53.5gr of IMR 4350, using a 165gr PSP. Each of the last 3 years, I have checked it at the range before hunting season with 2 shots touching each other dead center, 1&1/2 " high at 100yds. I have never tried to produce a 5 shot group thinking it might jinks the fact that I have never had to make ajustments. I am sure one of these days I will probably see what I can do.

Anyway, have fun!

[Four Fingers of Death]

cobbmtmack IMR4350 is a good powder, I burnt a lot of it years ago, but I haven't seen it for a long time. I use ADI AR2209 which is essentially the same. I used to shoot a lot of 3006 (my license plates are SP3006!), but not so much nowadays. For many years, my centrefire rifles were a 223 and a 3006. Got er' done!

Looking forward to getting this rifle sorted, but have a big shoot on next weekend and it is time to be getting the garden ready for spring planting, so I'm like a one armed bricklayer in Bahgad at the moment. I have some 311291s and a few 311284s tucked away somewhere, I might give them a run if I get a chance.

[Bob S]

Gentlemen;


The problem ( I think ) is due to a heavy firing-pin fall combined with relatively hard primers. The cases are being hammered into the chamber hard enough that the shoulder is driven back slightly and the low pressure of the cast load isn't enough to expand them back, but IS enough to push the primers out somewhat.

Good morning,
Forrest

Forrest,

It isn't so much the firing pin fall as the reaction to the explosive in the priming compound. When the priming compound goes off, the gas jet has to go through that little flash hole; the pressure build-up tries top shove the brass casing forward and the primer backward. The case is shoved with some force into the shoulder of the chamber, pushing the shoulder on the case back a bit. The neck and shoulder of the case expand enough to grip the chamber walls, but the pressure is not enough to stretch the metal in the rear of the case, so the case gets a bit shorter. The primer is unrestrained, so it is shoved to the rear until it contacts the bolt face. The result is backed out primers. This isn't any cause for real concern as long as you keep those cases segregated for the light loads. Repeated firing with suitably light loads, especially in a rifle with controlled feed like the M1917 or the M1903, will shorten the cases only so far, then it won't progress any further. But shoot those shortened cases with a full-power load, and you my see some partial head separations.

I have several 50-round "lots" of FA 37 and Den 42 cases that have been fired with 15 grains of 2400 and 311291 so many times in the last 45 years that I have lost count. I keep neck sizing them with the Ideal tool, shooting with the same load; primers (Rem 9-1/2) back out a bit every time, and I never give it a second thought anymore. Even my load of 40 grains of WW II surplus 4831 with 311284 will have backed-out primers in the '03. These loads probably produce pressures less than 20KSI. The cases are probably going to out-last my lifetime.

Resp'y,
Bob S.

[FAsmus]

Bob;

Thanks for the post ~ it makes perfect sense ~ but I don't understand some aspects of this situation.

For example: I shoot pretty much the same load, (except for using a 311284), but the same primer and all in my old 1921 double heat-treated M1903 with never a pushed out primer.

Also, in my 30'06 M70 Winchester the exact same load was used with the same primers and no pushed out primers were encountered. However, the M70 (apparently) did not have a heavy enough firing-pin fall since it would not reliably ignite the primers in question. Miss-fires amounted to over 10% of the cartridges loaded! In this instance I returned to using WRL primers and the miss-fires disappeared.

Food for thought here is that these are the "MagTech" primers from Brazil. Now, I have used some 3500 of these primers by now and except for the M70 I have been perfectly satisfied with their performance. They work fine in my 7.62x51 JAP, the M31 Swiss, the M91 in 7.65x53, the M1903, the FBW singleshot etc ~ the only one that backs out primers is the M1917!

I guess the very next thing I should do in this vein is to load some WLR primers into the M1917 and see what happens ..

Good evening,
Forrest

[NickSS]

I have seen a lot of US, Canadian and British rifles with two groove barrels. In fact I have right now a Springfield 03 and a Savage Arms Made No 4 Mk 1* which have two groove barrels. I have tried cast in the Enfield using a Lyman .314" 200 gr bullet over 20 gr of AA 5744. This load shot groups of around 2 to 2.5 inches at 100 Yards and was pleasent to shoot.

[bkbville]

In an auction I bid on an 03A3 nobody wanted because the description said "barrel shot out"

In reality whoever created the description didn't realize it was 2 groove.

I got it for $300 - I slugged it at .300/.308. The rifle is mint.

I had intended to flip it for a profit, but once I held that in my hands it wasn't going anywhere.