Love those 2 groove barrels ! !

[Ben]

I agree, I'm much more concerned about the size of the group on the target down range than a few unburned powder granules in my bore.

Ben

[biggome]

I too am most concerned with accurate performance and have found my most consistant loads as far as velocity goes to be my most accurate and these always came from either fairly light charges of fast powder for the caliber or full case loads of slower than usual for the caliber powder yet high enough pressure to acheive outstanding consistancy.

Yes these are at either end of the spectrum as in using Herco in a 30-30 with light cast and H380 in a .222 Rem. with jacketed though they both had a lot in common, great groups, insanely close velocities and perfectly clean bores with not a bit of powder residue coming out of the "tapped on the bench" cases.

That being said, I usually look at the velocity spread prior to any serious target work/load development since past experience has shown to me that a rather small velocity spread which always comes along with unburned powder, can make more of a difference than I thought it ever would.

I am not saying that "dirty" loads can't be accurate or that +/- 50 fps in velocity means a "pattern" rather than a group, I am just saying that by far, my most impressive performance has come from loads that were both "clean and close" and my most unimpressive ones with cast boolits were rather "dirty" and had a wider than wished velocity spread. I have had cast loads with medium speed powder that performed fairly well and burned clean yet had quite a spread in speed over the chrono.

Accuracy tends to be a "you never know until you try it" type of deal though I still I still like to try and narrow down all the variables as much as possible.

Paul

[45-70marlin]

hey guys,
I tried Ben's load of 27.0 grains of IMR-4895 with the lyman 31141, It worked great! almost shot as well as his bullet. I will have to crony it to see what the fps is.

[Ben]

4570Marlin:

I've shot 27.0 grs. of IMR 4895 with 160 gr. - 200 gr. cast bullets from several 06's..........a real winner. I size the bullets .3105" for most of my rifles.

Glad it shot well for you also.

Ben

[Larry Gibson]

About 25+ years ago I got an Idea for what I thought would be the "ideal" .30 cal cast bullet cartridge. That was well before I had a clue as to the effects of RPM. I had a new 2 groove '03 barrel and a sporterized M1916 (made in '28 at Oviedo) SR Mauser rifle with a shot out .308 Winchester barrel (Yes I know that is a "no-no" these days but Ackley said it was ok and that was the second .308 barrel I'd shot out on that action with thousands of M80 Ball). The rifle with it's previous two barrels (one Star and one Douglas) had alway been very accuracate (MOA or better with good loads) as it was well bedded into a sporter stock, had a single stage trigger and had been converted to cock on opening (another big no-no according to Kuhnhausen but then what do I know?) which gave it a very good lock time. I computed how much 4895 given a certain case volume it would take to drive the 311284 at 2100 fps with 100% loading density using a Powley hand computor (slide rule of sorts for those who don't know about them). I then formed a couple cases by shortening a 7.62 case to .200" and setting the shoulder back so there was an '06 length neck. Had the barrel set back and chambered to that "308 CBC" cartridge. A match .308 reamer was initially used then an '06 reamer was used to finish the neck. I thought I had the perfect cast bullet .30 cal rifle.

What I quickly found with 311284, 311299, 311291 and 311041 was that best accuracy was between 1750 and 1850 fps with 26-27 gr of 4895. That "best accuracy" was still no better than what my 2 groove '03 gave me with the same bullets at the same velocities only with 2-3 more gr of powder and a dacron filler. I had gained absolutely nothing in terms of accuracy. I had only gained using 2-3 gr less powder and no dacron filler was needed. The down side was forming the 308 CBC cases. I still have the 308 CBC and it still shoots fine within the RPM threshold, just like every other rifle.

As to 2 groove barrels being more accurate with some cast bullets; I've shot many 2 groove '03A3s and have yet to find one that shoots "some cast bullets better" as the myth says. Down in the 1700-1850 fps range (hey Bass, that's smack dab in the RPM threshold) they all shoot their best accuracy. What I have found in shooting numerous of them at 200 to 600 yards with cast bullets comparing them to equally accurate 4 groove barreled '03s is that past 200 yards the 4 groove barrels are always more accurate. Look at a slug from a 4 groove barrel vs a 2 groove barrel and you'll see the 4 groove slug is still round. The 2 groove slug is oval. A bullet, given equal loads, shot out of a 4 groove is more balanced than one shot out of a 2 groove barrel and the accuracy shows that at longer ranges. Out to 200 yards its hard to tell the difference in accuracy with cast bullets between the 2 and 4 groove barrels though. I also found the same to be true with quality jacketed match bullets.

The real answer to which is more accurate lies in the answer to this simple question; how many 2 groove barrels do you see being using on BR rifles or High Power match rifles? Not to say that 2 groove barrels aren't accurate because they are. Just saying that there is nothing "magical" about them for use with cast bullets.

Larry Gibson

[Ben]

Larry:

I'm not certain about the "magic" of two groove barrels. These 2 Rem 1944 2 groove .30 cal barrels are shooting very accurately for my friend and I right now. We are enjoying our two rifles that we've built using the 2 groove barrels and having fun. I guess that is what it is all about.

Ben

[LET-CA]

It's looks like you've got a serious case of "shy" bullets; they're afraid to get too far away from each other. Nice problem!

[Ben]

LET-CA:

You'd like to shoot this rifle, it is a real shooter.
Here is a photo of my friend's rifle. I built both of them, both have 2 groove barrels in them, and both will " drill it."

http://img.photobucket.com/albums/v4...e/PICT0016.jpg

http://img.photobucket.com/albums/v4...e/PICT0011.jpg

http://img.photobucket.com/albums/v4...e/PICT0009.jpg

[stillhunter]

I have had really sweet results with a 2 groove A3 that I picked up. The gun was butchered, but the bore is near new. Try Lyman 311467 and 311284 at about 1500 fps. You will like it! I hate to think how I used to shun these two groves. Enjoy your gun..!!

[Larry Gibson]

Larry:

I'm not certain about the "magic" of two groove barrels. These 2 Rem 1944 2 groove .30 cal barrels are shooting very accurately for my friend and I right now. We are enjoying our two rifles that we've built using the 2 groove barrels and having fun. I guess that is what it is all about.

Ben

It is commonly said today that the easier to make 2 groove barrels were adopted because they still shot as good as the 4 and 6 groove barrels. While "commonly said" these days that is not quite true however. The 2 groove barrels were adopted because they still shot within accuracy acceptance standards for the M1903 service rifle with M2 ammuntion. That was a pretty loose standard BTW. While 2 groove barrels will shoot well and some appear to shoot right along side of the 4 and 6 groove barrels actual tests show accuracy is pretty close out to 200 yards but at 300 yards and farther the 4 groove barrels almost always are more accurate.

I agree about the "magic" as have found out with my 308 CBC. They shoot cast bullets about the same out to 200 yards as 4 groove barrels. I found quite a difference at 500 yards between 2 and 4 groove accuracy with cat bullets with the 4 groove barrels giving decidedly better accuracy. However, I do still have my 308 CBC and another new 2 groove barrel to use on something. Because I say the 4 groove barrels are more accurate doesn't mean the 2 groove barrels are inaccurate. They accurate and "fun" as you mention. I'll keep shooting mine.

Larry Gibson

[leadman]

Ben, very nice looking rifle. The stock is awesome. What finish did you use on the metal.
I have a CMP 1903a3 with a 2 groove that so far has been impressive. I need to get it back out and do some more "fun" work with it.

[Three44s]

Ben ...... that group needs work!!!

.......... LOL .......... and now ....... I will just go over in the corner and turn green with envy .....

Did ya have to post those rifle pictures????? Geeze!!!!

Seriously, very nice job on the groups and the gun work as well!

Three 44s

[shotman]

pat I had some for sale . I have both and cant tell one way or the other both shoot good . At 500yds I am not shooting a 30-06 so 200 yd is fine. We shot at a 1000yd range one time I think I was holding at the tree line to drop a 06 in on the board

[Ben]

Ben, very nice looking rifle. The stock is awesome. What finish did you use on the metal.
I have a CMP 1903a3 with a 2 groove that so far has been impressive. I need to get it back out and do some more "fun" work with it.

The finish is a super hard epoxy spray that is a satin flat black.

I have it on several of my rifles. No rust in wet environments, non reflective on a hunting rifle, 4 times more durable than any blued steel. If it does get scrapped it can be touched up in 2 minutes, try that with blued steel. I like it ! !

Ben

[Rodfac]

Great group, Ben and a fabulous looking rifle. How hard was it to spray? that epoxy finish? I've got a Remington 700 Classic in .35 Whelen that I'd like to use it on. I took a header down a high altitude Colorado skree slope 15 years ago and have never repaired the cosmetic damage to the bbl and trigger guard. As an aside, the Leupold 2x7 scope it was wearing was dented on the bell housing like you'd pressed your thumb into soft butter, the front sight was knocked clear off the barrel, and the stock was scratched and bruised in several places. After inspecting my extremities for breaks, I tried the rifle on an aspen knot at roughly 100 yds and the scope/rifle combination was only an inch off! Good rifle...a great shooter...and big medicine on elk and deer. Regards Rodfac

[Ben]

The epoxy isn't hard to put on , the metal needs to be 101% oil and grease free before you spray.

[94Doug]

Nice job on those rifles Ben. They look great!

[Gerry N.]

My wife calls them " Boy Toys."

joatmon :

You understand that a Springfield 1903 barrel can be rethreaded and installed on a small ring Mauser BUT NOT ON A LARGE RING MAUSER ? ?
Who will be barreling your action ?

Thanks,
Ben

How is it then that the Chileans rebarrelled thousands of Steyr made Modelo 1912 rifles, a large ring M98 action, Converting them into the Chilean M12/61 in 7.62X51mm NATO using Springfield '03 2-groove barrels the US Gov't sold them for less than a buck a barrel? I have one and it shoots very well indeed.

Gerry N.