Author Topic: Microgroove rifling (Read 4765 times)

PawPaw · « **on:** April 25, 2010, 03:58:59 PM »

I long ago settled on a .30-30 cast bullet load of the 311041 over 2.2 cc of my surplus 4895. This load gives me an average (of many, many shots) from my Win 94 of 1877 fps, with an Sd of 22.7 It's a good load in my Winchester. Reasonably accurate and it's what my truck gun is sighted for. I've got no problems with the load, either in leading, or feeding, or anything. No smoke, good accuracy, easy recoil,

I put the same load in my Handi .30-30 and noticed a lot of smoke from the barrel. My nose detected alox, so I deduced that the lube was burning and thought that odd. I put five shots over the chrony and got an average of 2219 fps. When I say the same load, I mean from the same lot of 100 cartridges I originally loaded and chrongraphed in the Winchester. I also notice little comma-shaped tears in the target.

So, in one rifle I get 1877 fps, in another I get 2219 fps. Interesting. And those little tears in the target - - Is the bullet coming apart?

I wrote to my buddy Junior and he tells me that the H&R barrel has microgroove rifling. That makes all the difference as it's easier to push a cast bullet down a microgroove barrel.

"Hmmm," says I and go out and slug the barrel. I find 12-groove microgroove rifling, with a 1-10 twist. (I knew about the twist rate, but I had to check.)

It seems that if I intend to shoot cast bullets through the Handi, I'm going to have to get my bullet speed down to about 1500 fps.

bikerbeans · « **Reply #1 on:** April 25, 2010, 04:10:09 PM »

Dennis,

Interesting, would this "speed limit" apply to cast projectiles and other calibers in the handi?

BB

PawPaw · « **Reply #2 on:** April 25, 2010, 04:27:33 PM »

Quote from: bikerbeans on April 25, 2010, 04:10:09 PM

Dennis,

Interesting, would this "speed limit" apply to cast projectiles and other calibers in the handi?

BB

No, I don't believe it would. It appears that my ..45-70 has a normally rifled barrel. I haven't seen any indication of problems shooting cast bullets in that caliber.

This speed limit isn't absolute, either. Lots of things like alloy and lube might help, but we're theorizing that the bullet is being "over-revved" by the barrel.

Win94 1-12 twist: @ 1877 fps = 112,620 rpm
Handi 1-10 twist @ 2219 fps = 159,768 rpm
Handi 1-10 twist @ 1560 fps = 112,320 rpm

I know that the bullet travels fine at Win 94 velocities, but the Handi has a tighter twist, so I'm going to have to reduce the speed some to learn how the Handi and the microgroove barrel works with cast bullets.

On the other hand, I 've got some loads with 115 grain 32-20 bullets that work fine in the Win 94 at about 1100 fps and I'll be interested to see how they perform in the Handi. If my experience is correct, the little bullets should fly a bit faster through the microgroove barrel.

It's going to be an interesting summer, figuring out what works and what doesn't work in the little rifle.

wreckhog · « **Reply #3 on:** April 25, 2010, 04:35:56 PM »

Handis don't have Microgroove rifling, except for the Versa Pack .22lr, or at least they never did. That 30-30 is brand new right? Hmmm. That velocity increase is huge. Like adding 4" of barrel.

quickdtoo · « **Reply #4 on:** April 25, 2010, 04:48:27 PM »

I have had 4 H&R 30-30 barrels, still have two, none have had MG rifling, nor do any of the 38 or so other H&R rifles I currently have. This has been discussed before and verified with H&R, at some time or another they may have used MG rifling occasionally, but it's not the norm unless Marlin has made some barrels recently with MG, Marlin has been making H&R barrels exclusively since late 2006, and has owned H&R since 2000, so it's always a possibility. As wreckhog stated, the only barrel that's ever been confirmed to have MG rifling is the 22Lr Versa Pack. As far as Junior's statement, it's not true as a general rule, MG H&R barrels are an exception.

Tim

streak · « **Reply #5 on:** April 25, 2010, 05:02:51 PM »

Dennis,
Is the 30-30 Handi the only centerfire that has microgroove rifling? I just bought three new .308 Handi`s and was wondering if that might be microgroove rifling. I have not had a chance to see these rifles as of yet, so cannot say if they are or not.
Anyway enjoy your articles on The "Frugal Outdoorsman" website. I have communicated with Junior several times over the past three or four years concerning some of his articles. They are all good reads! Look forward to the next one!!

lee1954 · « **Reply #6 on:** April 25, 2010, 06:30:15 PM »

I have a 308 handi, and it like Lee 180gr better - want to get a 200 gr mold.. To get the 120gr to shoot I seat the bullet in the rifling and pack toiletpaper in the case to hold the powder in the case,, or just grip the base of the bullet ... I checked the speed once and I'm shooting 160 gr lead no gas check at just under 1400 fps.. the 180's a little more powder. mostly SR 4759 --- I'm almost sure I have bottom rifling..
I haven't real found a tack driving load yet

Does the 30-30 shoot lighter cast any better? Dan

trotterlg · « **Reply #7 on:** April 25, 2010, 08:27:53 PM »

I know nothing of the other questions (except the versapack) but the little commas on the target are the results of the bullet failing. I had (have) the same little marks when I shoot a 17 Remington, 25gr bullets at top speed out of a 1 in 9 twist barrel on my savage. Loading a half gr. more makes the bullets turn to dust before they get to the target. Larry

gcrank1 · « **Reply #8 on:** April 26, 2010, 07:44:23 AM »

FWIW, my 30-06 and 30-40Krag (not H&Rs, but 1:10 twist) have been doing very well with 180ishgr. cast at about 1450FPS (chrono).

PawPaw · « **Reply #9 on:** April 26, 2010, 01:47:13 PM »

I couldn't stand it, so I went out and slugged that .30-30 barrel again. Sure enough, it's still got 12-groove microgroove rifling. This Handi was purchased NIB earlier this month. It's a Hunter model with the pallet-wood stock and it has an Ilion roll mark. And microgroove rifling.

So, I went to the cabinet and got out my .308 Ultra. Slugged the barrel. It's got 6-groove conventional rifling.

Here's the .30-30 slug. Sorry about the lighting, it's the best I could do at the time.

Here's the slug from the .308. It's got conventional rifling.

Aint that interesting?

wreckhog · « **Reply #10 on:** April 26, 2010, 01:56:35 PM »

Wow! Got an outside diameter on those?

PawPaw · « **Reply #11 on:** April 26, 2010, 02:07:06 PM »

Quote from: wreckhog on April 26, 2010, 01:56:35 PM

Wow! Got an outside diameter on those?

Yeah, those bullets are Lyman 311041, sized to 0.309 and pushed through a .308 bore. Naturally, the rod deformed the bullets, one at the base and one at the nose.

quickdtoo · « **Reply #12 on:** April 26, 2010, 02:34:30 PM »

Ya didn't have to slug it again, I didn't doubt ya, it's just that it isn't the norm as Junior led you to believe, other than the discontinued Versa Pack which has been confirmed as having MG rifling, yours is the only other one ever seen here.

Tim

PawPaw · « **Reply #13 on:** April 26, 2010, 02:53:40 PM »

Quote from: quickdtoo on April 26, 2010, 02:34:30 PM

Ya didn't have to slug it again, I didn't doubt ya, it's just that it isn't the norm as Junior led you to believe, other than the discontinued Versa Pack which has been confirmed as having MG rifling, yours is the only other one ever seen here.

Tim

I know that, Quick. The first slug didn't turn out too well, and I wanted another try at it to try to get some pictures. Then, of course, I had to slug the .308, just to see.

I think it's interesting that the .308 has conventional rifling and the .30-30 has MG. Of course, they have different roll-marks, too. However, we've got firm proof that Ilion is using microgroove in at least some of their .30-30 barrels.

quickdtoo · « **Reply #14 on:** April 26, 2010, 03:03:50 PM »

This is just my guess, but as short supply as barrels have been in the last year or so, it's not surprising Marlin is taking a shortcut in making barrels, instead of running their barrels and H&R barrels, making one big run of .30 cal barrels to satisfy both H&R and Marlin..... wouldn't it be nice if they'd make some H&R 444s and 45-70s with Ballard cut barrels....to save money of course!!

Tim

bikerbeans · « **Reply #15 on:** April 26, 2010, 04:01:57 PM »

Hi All,

I just sent a new, unfired 30-30 barrel, Serial # CBA, to a GBO member. Sent him a PM regarding the MG rifling, maybe he will see if another one of these got out of the barn.

BB

petemi · « **Reply #16 on:** April 26, 2010, 11:59:36 PM »

I'm the culprit that got Biker's .30-30 barrel. I'm going to compare it to my Marlin 336 .30-30 that is Micro. I doubt the Handi is. I'll letcha know.

Pete

PawPaw · « **Reply #17 on:** April 27, 2010, 12:07:26 PM »

I cross-posted this on my blog, and Junior, in comments, tells me that all three of his Handi barrels are microgroove. He says in this post:

Quote

All three of my Handi-Rifle barrels are microgroove. That's an old 44 mag, and semi-old 45-70 20" and 45-70 32".

This is getting curiouser and curiouser. I'm going to have to get my .45-70 barrel down and see what type rifling is in there. I had assumed that it was conventional, but now I don't know.

Yup, I slugged it. The slug shows an 8-groove barrel, with the lands being 0.080 wide and about 0.004 deep, based on my altogether fautly measuring. I'm betting that it is a microgroove barrel too.

Which explains a lot, if you read this article here.

Rustyinfla · « **Reply #18 on:** April 27, 2010, 01:04:24 PM »

According to Veral Smith in his book "Jacketed bullet Performance from Cast Bullets" the Marlin Micro barrels are similar to the legendary Harry Pope's barrels. That said they ARE accurate with cast bullets as long as the bullet is properly fitted to the bore.

And tell Junior he needs to quit slacking off and put some new material on his website. how about the further adventures of Buffler Bill?

quickdtoo · « **Reply #19 on:** April 27, 2010, 01:50:30 PM »

This is the email I got from the H&R/Marlin brand manager in Oct 2008 when I asked about MG H&R barrels.

Quote

I can't find any info that says that Marlin made any blanks for H&R using the microgrrove pattern. This past year, H&R was making some of their own rifle blanks in the larger calibers with tooling borrowed from Marlin. There is the possibility that some could have been produced during that period. No one left in Gardner to confirm.

Here's info on Marlin MG barrel history by Glenn Fryxell with some specs.

http://www.lasc.us/FryxellMarlin-MicroGroove.htm

Quote

For the common centerfire calibers, the initial specifications (circa 1956) for Microgroove barrels were as follows:

* .22 centerfire -- 16 grooves, .015" wide, .001" deep
* .30 caliber -- 16 grooves, .030" wide and .002" deep (this would be changed in 1958 to 22 grooves .024" wide, and .002" deep; and then again in 1968 to 12 grooves, .040" wide, .0028" deep)
* .32 caliber -- 16 grooves, .035" wide, and .0015" deep
* .35 caliber -- 16 grooves, .040" wide, and .002" deep (this would be changed in 1968 to 12 grooves, .055" wide, .0028" deep)

Quote

In 1972, Marlin introduced the Model 1895 chambered in .45-70. Initially, these rifles were made with 8-groove Microgroove barrels, with grooves that were .060" wide and .003" deep. The next year this was changed to a 12-groove barrel, with the other specs remaining the same. Again, groove diameter is spec-ed out at .4587", so oversized cast bullets are called for in these guns. All of these .45-70 Microgroove barrels had a 1 in 20-" twist.

Quote

As of fall of 2007, Marlin still makes a number of guns that have Microgroove barrels on them (according to the 2007 Marlin catalog posted on their website; Marlin Firearms). All of their .22 LR and .22 Magnum rifles still have Microgroove barrels. The 336s in .30-30 and .35 Remington are still made with Microgroove barrels, however the stainless 336XLR in .30-30 and .35 Remington have Ballard rifled barrels. All of the big-bore Marlin leverguns (e.g. 444, 1895, etc.) are now fitted with Ballard rifled barrels (both blued and stainless guns), as are the 1894 and 1895 Cowboy models. Interestingly, in the 1894 series, the.44 Magnum and .357 Magnum guns are Ballard rifled, but the .32-20 1894CL and .41 Magnum 1894 FG are both fitted with Microgroove barrels.

There seems to be some confusion on my part as well as others what MG barrels actually are and there are obviously more MG H&R barrels out there than previously thought, 8-groove barreled 45-70s which is what my 2008 Stainless barrel has, I've never slugged it, but it definitely has 8 grooves compared to the 6 grooves of the other four 45-70 barrels I have are. I checked the slugs that I've made in the past, one is from Pete's older overbore 44mag that I rechambered to 445Supermag and converted to an extractor for him, it has 12-grooves which agrees with Fryxell's statement....

Quote

Also in the 1960s, Marlin introduced the .44 Magnum to the Model 336. This rifle was fitted with Microgroove barrels, containing 12 grooves that were .062" wide and .0043" deep. Factory specs for the .44 Magnum barrels also called for a 1 in 38" twist, but that this time nominal groove diameter was to be held to .4315", and a bore diameter of .4230", so oversized cast bullets are once again called for. It is interesting to note that given the difference in groove width, groove diameter and bore diameter, suggesting that the .44 Magnum barrels were produced using a separate process and tooling than were the .444 Marlin barrels.

Tim

PawPaw · « **Reply #20 on:** April 27, 2010, 02:07:53 PM »

Quote from: Rustyinfla on April 27, 2010, 01:04:24 PM

And tell Junior he needs to quit slacking off and put some new material on his website. how about the further adventures of Buffler Bill?

That's my website too. Why do you think that I'm doing things like slugging Handi barrels? There's an article in the works, just as soon as I get some time to work on it. I'll get my .223 Ultra off layaway in mid May, and then I have to do some range tests, but I intend to put up an article extolling the virtue of the Handi-rifle.

Hey, Quick! When I do that article, I'd like to link to this forum. Do you guys have any problem with that?

petemi · « **Reply #21 on:** April 27, 2010, 02:15:43 PM »

Quote from: quickdtoo on April 27, 2010, 01:50:30 PM

I checked the slugs that I've made in the past, one is from Pete's older overbore 44mag that I rechambered to 445 Supermag and converted to an extractor for him, it has 12-grooves which agrees with Fryxell's statement....
[

Tim, so you believe it is in fact a MG? You told me what the barrel slugged at. I wrote it down and can't find it. Can you give me a clue as to what size bullet to load?

Your pain in the butt friend,

Pete

quickdtoo · « **Reply #22 on:** April 27, 2010, 02:23:02 PM »

Quote from: PawPaw on April 27, 2010, 02:07:53 PM

Quote from: Rustyinfla on April 27, 2010, 01:04:24 PM

And tell Junior he needs to quit slacking off and put some new material on his website. how about the further adventures of Buffler Bill?

That's my website too. Why do you think that I'm doing things like slugging Handi barrels? There's an article in the works, just as soon as I get some time to work on it. I'll get my .223 Ultra off layaway in mid May, and then I have to do some range tests, but I intend to put up an article extolling the virtue of the Handi-rifle.

Hey, Quick! When I do that article, I'd like to link to this forum. Do you guys have any problem with that?

Yes, definitely!! That would be great, just be sure to tell Junior I didn't know what the heck I was talking about and I owe him and everyone an apology!!!

thanks,

Tim

bikerbeans · « **Reply #23 on:** April 27, 2010, 02:23:44 PM »

Pete,

Just when you thought reloading was going to be easy.

BB

quickdtoo · « **Reply #24 on:** April 27, 2010, 02:31:01 PM »

Quote from: petemi on April 27, 2010, 02:15:43 PM

Quote from: quickdtoo on April 27, 2010, 01:50:30 PM

I checked the slugs that I've made in the past, one is from Pete's older overbore 44mag that I rechambered to 445 Supermag and converted to an extractor for him, it has 12-grooves which agrees with Fryxell's statement....
[

Tim, so you believe it is in fact a MG? You told me what the barrel slugged at. I wrote it down and can't find it. Can you give me a clue as to what size bullet to load?

Your pain in the butt friend,

Pete

I'd shoot the biggest cast bullets you can Pete, it slugged .433" in the groove, so that would be the minimum to use, .434" hard cast gas checked would be best if you can find or make them.

Tim

http://www.montanabulletworks.com/pistol_bullets.html

petemi · « **Reply #25 on:** April 27, 2010, 03:45:50 PM »

Thank you sir. I wrote it down and taped it to my forhead. I wrote it down again, backward, and taped it to my forhead, so when I looked in the mirror I could find it,

Getttin old aint easy.

Pete

PawPaw · « **Reply #26 on:** April 28, 2010, 02:02:02 AM »

Hey Rusty!

I passed your request along to Junior, and he responded this morning.

Quote

Hey, tell Rustyinfla that "Buffler Bill' had operator problems. The front mag tube hanger cracked after ~200,000 rounds, and some fool thought it was dovetailed to the barrel and tried to drive it out. It wouldn't drive, so the fool got a bigger hammer. It still wouldn't drive, so the fool got a sledgehammer. It drove. Pieces went everywhere. Turns out it was welded in, not driven in.....

Heh!

streak · « **Reply #27 on:** April 28, 2010, 09:24:59 AM »

Quote from: PawPaw on April 28, 2010, 02:02:02 AM

Hey Rusty!

I passed your request along to Junior, and he responded this morning.

Quote
Hey, tell Rustyinfla that "Buffler Bill' had operator problems. The front mag tube hanger cracked after ~200,000 rounds, and some fool thought it was dovetailed to the barrel and tried to drive it out. It wouldn't drive, so the fool got a bigger hammer. It still wouldn't drive, so the fool got a sledgehammer. It drove. Pieces went everywhere. Turns out it was welded in, not driven in.....

Heh!

A prime example of a case of where " bigger is not better" ! Keep Junior awawy from hammers!!

gcrank1 · « **Reply #28 on:** April 28, 2010, 09:35:08 AM »

I always have to wonder when a percussive adjustment doesnt seem to be working.....

tturner53 · « **Reply #29 on:** April 28, 2010, 08:28:48 PM »

I have a Handi .308 Win. with 12 grooves, looks like a Marlin 30-30 barrel, just like the one at the top post. 1/10" twist. I haven't had a chance to try it yet, just got it. From what I've read the MG types require a very good fit and more speed to shoot cbs well. We'll see.