03A3 2-groove vs. 4-groove & cast

[chuebner]

This may have been discussed before but are there any boolit designs that are more suited to a 2-groove barrel than a 4-groove barrel? So far the only boolit I have found that shot badly out of my 03A3 was a Saeco #315, made patterns rather than groups.

charlie

[303Guy]

Well, my two-groove Brit likes a j-word design with a chamfer which seems to prevent base distortion caused by the large bore to groove ratio. I've found cast boolits take on a poor base shape with this barrel.

http://i388.photobucket.com/albums/oo327/303Guy/MVC-201F-1.jpg I can't get this gun to shoot lead so ...

http://i388.photobucket.com/albums/oo327/303Guy/Two-GroovePP28grAR220910grBran2.jpg

[Larry Gibson]

Years back when I was shooting M1903s "across the course" (NMC) using cast bullets I found not much if any difference between 2 and 4 groove at 300 yards. At 300 yards a hard holder can begin to see an accuracy advantage with the 4 groove. Beyond that the 4 groove is indeed the more accurate given equal quality rifles and loads with the number of grooves in the barrel the only difference.

Larry Gibson

[MtGun44]

Many years ago Harrison did a big set of tests and articles on cast boolits for the NRA. He
reported that bore rider designs worked more accurately with the 2 groove barrels, apparently
due to the large support area for the bore riding portion. I have a copy of the articles in
an NRA compilation book. Personally, I have had no experience with cast in my 2 groove
1903s.

Bill

[462]

Castpics has a PDF of Cast Bullets, by Col. Harrison. Pages 23 through 28 allude to what MtGun44 mentioned. I'd paste the article, but can't get it to highlight -- reckon I reached the limit of my PDF knowledge.

My sporterized (unfortunately) four-groove '03-A3 (4-43) is in love with a very old Ideal 308291 and some Unique. Soon, it will start testing Mr. Loverin's 311466.

[45 2.1]

Many years ago Harrison did a big set of tests and articles on cast boolits for the NRA. He
reported that bore rider designs worked more accurately with the 2 groove barrels, apparently
due to the large support area for the bore riding portion. I have a copy of the articles in
an NRA compilation book. Personally, I have had no experience with cast in my 2 groove
1903s.

Bill

Bill-
I've noticed the same thing with the two grooves, the longer bore riders can be very accurate, moreso than the 4 grooves. The shorter 150 to 170 gr. loverins and shorter bore riders may show better accuracy with the 4 groove at short range, but dissappears at extended range. I've tested this out to about 600 yards...... there is a limit to testing here and it occurs when you run out of sight adjustment, the A3 sights don't go up to far.

[HARRYMPOPE]

I have shot two and 4 groove barrels in Springfields and found if the bullet fits the throat it shoots well.I dont believe the rifling type "prefers" a certain design oven another.The 2 groove barrels hold many CBA military records so they must be good enough.

George

[405]

Well I have an 03 with a 4 groove, an 03A3 with a 4 groove and an 03A3 with a 2 groove. All in original configuration. All have excellent bores. Have shot each about the same amount. All three shoot 150-165 jbullets about equally well. The 2 groove 03A3 doesn't shoot cast as well as either 4 groove. I've shot several styles of cast bullets from Loverins to bore riders. The best cast bullet by far in all three rifles is a 314299 sized to .310" at about 1500 fps. The 2 groove just doesn't shoot cast quite as well as the two 4 grooves.

Is this a statistically valid test for 2 groove vs 4 groove 03A3s- nope.

I kinda agree with 303Guy's take on it.

[HARRYMPOPE]

I stick with my 2 groove Springfield barrels being as accurate as the 4 groove barrels.Could just be individual barrels but the ones i use have been exceptional with cast.In accuracy witht he 2-grv's i expect 10 shots into 1.5" at 100 yards a good portion of the time.Sometimes i get much better but they have to hold this to shoot the match target clean with a high "x" count(even if my wind reading wont always allow it)

the 314299 also shots well in my 2 grooves but the 311467 is good but the RCBS 180 SP is best in my barrels.

[Larry Gibson]

My tests were with 311299 and 311284, they were sized .311. As stated in previous posts load development was for longer range shooting to 600 yards. Powders used were 3031, 4895 and 4831. Best accuacy for both bulllets in both types of barrels was in the 1800 - 1950 fps range depending on powder. As also noted in the previous post accuracy with both types of rifling was pretty much equal to 200 yards but at 300 yards the 4 groove barrels became more accurate with both bullets. The range I was shooting on was about 4500 ft elevation so at 2100 fps the 311299 would just stay transonic at 600 yards.

The accuracy testing was with 3 almost new M1903A4s (2 groove barrels) with the rings and scope removed and a 10X Lyman in 1" rings substituted. The 4 groove barrels were match M1903s with 8X Unertel scopes on them. Accuracy testing with standard 'A3s and M1903s proved pretty much the same at close range also but the M1903's rear ladder with peep proved more accurate at the longer ranges. Not only was the sight picture better but adjustments with an O'Hare tool were more precise and positive.

I found in most of the '03s with 4 groove barrels the 311299 was the better bullet to use at 400+ yards, especially if velocity was pushed upwards of 2100+ fps. Accuracy at that velocity was not as good as at lower velocity but 2 2.5 moa was enough accuracy for the older V targets and even then for the newer decimal 10X targets. However, these days that accuracy on the 10X target is not good enough to be competative. but fun can still be had shooting cast at that range.

All my '03s are 4 groove now including my very nice Smith Corona '03A3. I've also gone to 314299 as my bullet of choice for longer range shooting. However. 311466 is my cast bullet choice for out to 300 yards. It actually gives better accuracy in 2 and 4 groove barrels out to 2 yards than does the 311 or 314299s or the 311284. None of them shoot bad BTW.

Larry Gibson

[chuebner]

Thanks for the replies and info. You have just confirmed what I have been finding out about my 03A3 in that it really likes the 311299, 311284 and Lee C309-200. My velocities are around 1600-1700 fps. and I am limited to a 100yd range but with that I am quite pleased.

charlie

[35 Whelen]

I have a 1903A3 with a NOS two-groove barrel. The rifle is 100% as-issed and just silly accurate.
http://i60.photobucket.com/albums/h6/308Scout/Issue%201903A3/P1010007descr.jpg
http://i60.photobucket.com/albums/h6/308Scout/Issue%201903A3/314299RedDot.jpg
http://i60.photobucket.com/albums/h6/308Scout/Issue%201903A3/311291Targetmod.jpg
http://i60.photobucket.com/albums/h6/308Scout/Issue%201903A3/31129110shot.jpg

I've fired the 314299, ,311672, 311291 and 311041 and it seems to have no preference.

35W

[303Guy]

Perhaps it's time I took my mint bore two-groove out for some cast boolit trials. I'll have to make a mold for the purpose. OK, so it's not a 30-06 Springfield but it is a two-groove!;-)

[Le Loup Solitaire]

Harrison in his studies and writings on 30 cal clearly stated that "boreriders" as they are called will shoot better in 2 groove barrels. He cited Lyman # 311334 as being the best bullet. It was discontinued. Another recommendation was the Saeco 301 which suucceeded the RG4. Bores consist of lands and grooves; in the 03-A3 the lands occupy most of the circumference of the rifle bore. With a bullet having a long or "borerider "nose, the nose rides on top of the lands and is positively guided by them. The relatively short bullet body occupies the grooves. The dimensions of the bullet are important; the nose must be .301-.302 and the body must be .309-.310. If the bullet is undersize then it will slump or tilt on its long axis...in the bore and come out the muzzle in that posture with wild shooting as a result. Another noted rifleman by the name of Sears advocated "bumping up" the nose of a bullet that was undersize. He built a simple jig that allowed that to be done. In the 4 groove barrels the bullet needs a longer body that provides more bearing surface. Bullets like Lyman 311284, 311290, 311299, and 311291 etc, although they can work well in a 2 groove, seem to work better in a 4 groove barrel. There are other designs by Lee & Saeco that also do well in both 2 and 4 groove barrels. Proper bullet dimensions and fit are always key factors as well as the correctly adjusted powder charges. LLS

[nanuk]

could the difference on longe range accuracy, as found by Harrison et al, be a reflection of improper sizing?

I too have read some of Harrison's writing and I find that the boolits are ALWAYS sized.

yet as has been shown to work well, by many a member here, that fitment to the THROAT is far more beneficial to accuracy than sizing to the groove.

I have't read Cast Bullets, by Col. Harrison, but have read exerps and other articles published by him, and I don't recall him EVER saying anything about fitment to the throat.

I've got a LE4 with a 2groove, appears mint, that I have used hunting with J-words, and have yet to slug it, but I have moulds that should work.
Where did I leave my Rowntuit?

[Larry Gibson]

The difference in long range accuracy certainly is tied to "fit". However, in the case of 2 groove vs 4 groove consider the 2 groove is just squeasing the bullet from 2 sides when the bullet enters the barrel. The bullet comes out "oval" shaped. With a 4 grove barrel the bullet is squeezed evenly on all sides and comes out basically round. There is a greater potential for slightly more imbalace done to the bullet via a 2 groove than with the 4 groove.

Which is more accurate? Ask yourself this; since 2 groove barrels are less expensive and quicker to make (the reason they were used) then why aren't commercial barrel makers using them? Why aren't benchrest or HP shooters using them if they are as accurate? The answer is; they aren't "as accurate" a or more groove barrels.

Larry Gibson

[45 2.1]

As for an available boolit for the two grooves, try the RCBS 308-165-sil with a near max load of Unique. Shoots quite well in them.

[30calflash]

Very interesting info here. However I have a short one to ask. What about 6 groove 03A3 barrels? Early S-C barrels were almost all 6 groove. The land to bore ratio is higher than the 4 groove, not as high as the 2 groove.

Does anyone recall anyone using a 6 groove with cast?

[303Guy]

There is a barrel manufacturer here in New Zealand who makes a three-groove target barrel. Tru-Flite, they're called.
Look up this link; www.truefliteriflebarrels.co.nz (http://castboolits.gunloads.com/www.truefliteriflebarrels.co.nz)
Best of both worlds maybe?

[45 2.1]

Here is an article about the government testing resulting in the adoption of two groove rifling.............. it's an interesting read.

http://www.remingtonsociety.com/rsa/journals/two-groove

[Ben]

45 2.1 :

That is some FINE reading. I have several 2 groove barrels. I've never found a thing wrong with a 2 groove barrel ( which BTW, is clearly confirmed in your article ).

Thanks for taking the time to post the article, I enjoyed reading it very much.

Ben

[Char-Gar]

I find that article very interesting, thanks for posting it. It sorta confirms what has been in the back of my mind for years now.

We spend lots of time on these gun boards going back on forth ,on what is better, worse or whatever. Most of the time we are working on theory and not what happens on the range.

When we do talk about what happens on the range, none of us use enough different rifles to come to any real conclusions. While our experience is often valid and well documented it is just the difference between a few rifles, and that difference could be caused by any number of factors. Often the conclusions are little more than guess work, or choosing our favorite option over the others.

When we see a test like the one in the link, we get an idea of what a real conclusion looks like drawn from a real test. Unless we have worked in the firearms industry, I doubt if any of us have every really tested anything. We shoot and give our experience and conclusions. Our conclusions are very premature and far from being conclusive.

[Larry Gibson]

Yup, it's an interesting read alright but is it correct? No I don't doubt the results of the tests but if the 2 groove barrel really is superior at short and long range then why are we all shooting 2 groove barrels in all our rifles today? If the 2 groove barrel is superior in accuracy, quicker to produce and less expensive then the benchrest shooters and the High Power shooters would be using it. They are not.

I've shot numerous 2 groove M1903A3s over the years. I built my own wildcat cast bullet cartridge rifle using a new 2 groove 'A3 barrel because everyone thought it was more accurate for cast bullets. It isn't any more accurate than any 4 groove barrel out to 300 yards and is less so beyond that. There are numerous high end replacement barrels made for the M1903 for the matches at Camp Perry, none of them are 2 groove.

As I stated before shoot cast bullets in either out to 200 yards and you won't see much difference in accuracy. Shoot at 300 yards and you will begin to see the difference in accuracy with cast bullet loads that are pushing it to remain sonic at 500 and/or 600 yards. Shoot at 400 - 600 yards and you'll definately see a difference with cast bullet accuracy between 2 and 4 groove barrels.

Otherwise if you are content with shooting "the load" low end cast bullet loads or medium range cast bullet loads at 200 yards or less this is all a moot discusion, just use whichever barreled M1903A3 you have, cast, load and go shooting and enjoy:smile:

Larry Gibson

[45 2.1]

When we see a test like the one in the link, we get an idea of what a real conclusion looks like drawn from a real test. Unless we have worked in the firearms industry, I doubt if any of us have every really tested anything. We shoot and give our experience and conclusions. Our conclusions are very premature and far from being conclusive.

Yes... but some of us have reached those same conclusions. There have been several threads about this same thing and the same people have stated their own side several times. It is quite apparent who those people are. All one has to do is decide who has given information that relates what actually goes on in the real world and who hasn't .............. and from that decide what you yourself will do.

[sundog]

Yup, and I am sure glad that history played itself out the way it has with respect to the 2-groove 03A3s. The are extremely fine cast boolit launchers! I have one that when decosmo'd appeared to be unissued, i.e., brand new. It now has easily 6K+ rounds through it, ALL CAST. It just seems to get betterer and betterer.

[Char-Gar]

Bobby... My post was not directed toward anybody, just general musings on gun boards in general. Tis true that when folks experience coincide it is an indicator of something. I was just thinking about folks who feel they have "proved" something. They may have proved it to their own satisfaction and to the satisfaction of some others, but that still is not proof in a conclusive sense. It takes far more testing than any of us do to reach that level of certainty. To be certain there are thing I am convinced are true and do not hesitate to say so, but I always consider the possibility my experience is not the be all and end all. Hence the disclaimer I have at the bottom of all my posts.

[Char-Gar]

Yup, and I am sure glad that history played itself out the way it has with respect to the 2-groove 03A3s. The are extremely fine cast boolit launchers! I have one that when decosmo'd appeared to be unissued, i.e., brand new. It now has easily 6K+ rounds through it, ALL CAST. It just seems to get betterer and betterer.

Corky, I can say a hearty AMEN to that! I own 2 03A3s now plus a Krag I rebarreled with a two groove 03A3 barrel. I have had a half dozen more 03s and 03A3s over the year and all have been sterling cast bullet shooters be they two groove or four groove.

One type of rifling may or may not be superior to another, I just don't know as my experience has not shown any superiority.

I wouldn't want the guy who has a 2 groove to come to this board and go away thinking he has a clunker, when he indeed has a fine cast bullet rifle. It may not win the 1,000 yard match, but that isn't an issue for most of us.

[303Guy]

I noted that the testing was done by marksmen shooting off the elbow with hand held positions. That's a test of shooting skills more than rifle accuracy. But the fact that a marksman using a two-groove that had endured 16,000 rounds could still hold his own proves something.

I can understand how a two-groove might not be the best at longer ranges because of the way the bore swages the boolit. My two two-grooves have straight taper throats which is different to my other rifles so I couldn't do a true comparison as I would only be comparing throat designs.

To me the issue of two-groove bores is driving lands. As long as the groove impression doesn't open up from torque thrust, I see no reason why two-grooves should be inferior.

[Multigunner]

This passage from the Remington society site is very misleading.


On December 26, 1836, Major General Millar, Director of Artillery - British Army, said this about two-groove rifling after considerable testing of their new Brunswick P-1837 Percussion rifle:

"It was as accurate as the others at short distances and superior at long distances. There was no difficulty in handling or loading it. It shot correctly for a longer period without cleaning. The greater smoothness of the barrel made it less likely to wear away than those with projecting bearings and lands."

The Brunwick is a muzzle loader which used a belted ball that was a mechanical prefit to the two groove rifling.
It may very well have been more accurate than the contemporay multigroove rifled barrels firing patched balls of the same large caliber, at least when loaded hurredly by the average soldier under combat conditions rather than a patched ball rifle loaded carefully by a shooter more experianced with his rifle.
The competition for the Brunswick at the time were military grade rifled arms that used various less than optimal methods of insuring that the ball took to the rifling, such as a steel rod in the chamber with an undersized unpatched ball driven against it hard enough to deform and swell the bullet and other mechanically fitted bullets which were more difficult to load properly in fouled bores. Some used tiny pegs that engaged more narrow multiple grooves and got less purchase than the wide belt. The belted ball was much easier to start into the bore than these other bullet types.
None of this carried over into the cartridge era as an advantage except the broader lands being less prone to damage during cleaning.
When steel cleaning rods were still in use more modern milspec rifle barrels used under combat conditions were damaged during cleaning than by wear or erosion of any number of rounds likely to be fired.
A common damage pattern in the late 19th and early 20th centuries was when less well trained conscript troops more familar with muzzle loading sporting arms pushed the cleaning rod in at the muzzle all the way to the bolt face, either with bolt closed or open, and the steel rod then twanged by vibration of contact beat against the lands at mid point of the bore. With the longer barreled rifles this damage wasn't easily spotted during inspections.

If I were designing a militia type firearm of .30 caliber I'd probably choose a two groove bore for its greater resistence to damage through ham handed cleaning practices. A slight lessening of accuracy potential would be a trade off for greater likelyhood of the bore remaining reasonably accurate despite abuse by citizen soldiers with unknown and widely varying levels of skill in caring for firearms.

The Three groove bores mentioned earlier might be a better compromise.
Bores with an unevven number of grooves or even numbers that are multiples of three were believed to be more accurate than four groove or eight groove bores, and tests during the early 19th century seem to bear this out.
Like the tripod being more secure and flexible in holding a pot level the uneven numbered grooves were more likely to be filled out equally with bullet nose and base remaining centered.

[Larry Gibson]

I would not want it misconstrued that my comments on accuracy differences between the types of barrels with cast bullets at longer ranges is meant to dissuade anyone from having or shooting cast bullets in a 2 groove barrel. Quite the opposite; I have two 2 groove barrels myself and shoot lots of cast out of them. I also have had numerous 2 groove 'A3s over the years and found them quite satisfactory with cast bullets. As the thread took a tangent as to the accuracy difference I simply stated my observations based on my experience over the years shooting cast bullets at long range in both types of barrels.

As to the OPs original quest as to a cast bullet "design" being better suited in one or the other I also gave my observations to that; it is the Lovern design 311466. Though I use the 311299/314299 at longer range the 311466 has proven the more accurate cast bullet design to 300 yards than the 311299 design in most 2 groove M1903A3s I've shot it in. Not surprisingly, the 311299 is generally the more accurate cast bullet in the 4 groove barrels also. It does not hold up as well as the heavier 311299s which have higher BC for longer range shooting though.

Larry Gibson

[303Guy]

... the OP's original quest as to a cast bullet "design" being better suited in one or the other ...This has led to some interesting info. For starters, I now know to go for a good bore-ride design for my mint two-groove. I might even try a harder groove engaging section to the boolit. In fact, I think this thread is taking on a 101 quality! :drinks:

[45 2.1]

This has led to some interesting info. For starters, I now know to go for a good bore-ride design for my mint two-groove. I might even try a harder groove engaging section to the boolit. In fact, I think this thread is taking on a 101 quality! :drinks:
Whats most important with the two groove is that the long bore ride nose fits the lands snugly (as in engrave the nose into the lands while allowing removal without debulleting) as the lands occupy a large percentage of the bore and keep the boolit centered. The body can be less than groove or throat diameter and still shoot quite well.

[mustanggt]

I have a SC four groove 03A3 that I shoot 314299 in sized .312 as well as shooting it in my Krag. Very accurate for me. I don't have experience with a two groove however.

[MtGun44]

45-2.1 -

Good point. I noticed that all of Harrison's sizing dimensions would be considered to be
"too small for good accuracy" today. Apparently the nose fit of the long-nosed bore riders
is overshadowing the rear fit issue. I need to find the time to go out and test my own
Springfields, not having any significant cast experience with any of them.

I presume that a Lyman M die is recommended for this kind of work. I have not tried this
particular die, although I have known about them for decades. I've just been doing so little
rifle cast boolit work that it never became a critical item. Since I may use it in many .30 caliber
cartridges, I presume that a short body die would work fine for all calibers. Is this correct?

Bill

[mustanggt]

I use the Lyman M die in 30 Long for my 06 and Krag though the Krag is shorter it still works with it too.

[45 2.1]

MtGun44;1392536
45-2.1 - Good point. I noticed that all of Harrison's sizing dimensions would be considered to be
"too small for good accuracy" today. Apparently the nose fit of the long-nosed bore riders
is overshadowing the rear fit issue. For higher velocities the body needs to be throat -0.0005" for good results. I need to find the time to go out and test my own
Springfields, not having any significant cast experience with any of them.

I presume that a Lyman M die is recommended for this kind of work. The RCBS neck expander die works somewhat better. I'm not a big fan of the step on the Lyman M-die. I have not tried this
particular die, although I have known about them for decades. I've just been doing so little
rifle cast boolit work that it never became a critical item. Since I may use it in many .30 caliber
cartridges, I presume that a short body die would work fine for all calibers. Is this correct? It will ride pretty high for some of the longer 30's. The long version works better.

Bill

[462]

"I presume that a short body die would work fine for all calibers. Is this correct?"

I've found that a long M-die body is more adaptable to a short case, than a short die body is to a long case.

[MtGun44]

OK guys, glad I asked on the M-die. I had assumed (we know what that means!) that
the short would be the best for the widest range of calibers. I'll get a long die version.

Is the RCBS expander that you are talking about just the normal pull through neck
expander? I have Bonanza, Lee and Hornady die sets, so maybe they will do OK.
I have used the Lee universal expander die up until now.

Bill

[405]

Correct about the long body die. I've found it to be more universal than the short body. I've have several types of "third die" neck expanders- RCBS, Lyman, Lee and custom type neck expanders. I don't think the reference is to the "regular" neck expanding button as found on bottle neck sizers. RCBS makes an expander similar to the Lyman. Having used the various types, I still prefer the Lyman type with the short step. It requires careful adjustment but that short step really helps me hand seat the bullet and seems to help maintain alignment during bullet seating. Many times with large diameter cast bullets the pull thru expander button on conventional bottleneck sizers leaves necks undersized (for max jbullet tension) and may cause neck runout if sizing difference too great or can cause soft alloy swaging with plain base cast bullets. Simple neck mouth belling tools can cause similar swaging down of soft alloy, plain base bullets and can be hard on brass by over-working the mouth area during each reloading cycle.