Old M70

[Marlin Junky]

Has anyone had any luck with the old 4 groove Pre-64 M70 barrels? I was thinking about buying an RCBS 30-165 silhouette mold and shooting it out of my '06 real fast... like at 2900 fps if possible. My luck with conventionally sized and lubed 30-180FN has not been good beyond 2000 fps.

MJ

[bcp477]

I can't comment about what you asked......but I will say one thing. If you want to get to that kind of velocity (2900 fps), or close to it, your bullet alloy will have to be HARD (a high BHN). Too soft an alloy is possibly why you haven't had much luck past 2000 fps, so far. The bullets I shoot are BHN 12 - 15..... and I can't get too much past 2100 or so, before leading begins. I would think that you'd need a BHN of at least 25, to get up to 2800 - 2900 fps. No matter if you will just be punching paper.....but absolutely NO good for hunting (far too brittle). Just thought I'd mention it - in case you haven't considered this.

[docone31]

Marlin,
Get your self two push thru dies. One .308, one .309.
With either notebook paper, or computer printer paper, the 8 X 11 type, cut 1" strips across the bottom of the paper. The grain runs up and down, cut across the grain.
Make a template 1 3/8" with 45* on each end, opposite each other. Get a cigarette roller.
Soak the patches and lay one on the apron of the roller. Place the 180gn FN as you already have it, that has been sized to .308, on the patch to be rolled, with the patch 1/2 way to the nose from the bearing transition to the nose. Wrap with the roller. Remove the once soaking now damp/dry patched casting. Twist the tail, and let dry.
Snip the tail once dry, leaving just a tad on the base. Smear some Auto Wax on the nose of the casting, and size it to .309. The sizeing die will remove most of the wax, leaving a shiney surface.
Load to minimum jacketed data for whatever powder you are useing. Do not crimp! Just tension the neck. It is ok if the casting goes below the neck. I have fired many patched loads that way with no notice of accuracy loss.
You might get **** for a few loads, there will be stuff in the bore no matter how well you clean it. The patched load will remove it. Make the bore shiney also.
Try 20. See how it does.
.309 should be the size for the .30 cal. At least it is for my Ishys, O3A3, and A&B .308.
Cannot get the loads to touch at 100 yds, but I am sure happy with what I do get.

[pdawg_shooter]

I have a post on here about the 311289 at 3000fps from a 300RUM. It can be done with paper.

[Marlin Junky]

I have a post on here about the 311289 at 3000fps from a 300RUM. It can be done with paper.

I'm sure it can be done and my experience with the .35W substantiates that; however, I don't want to deal with that much recoil from a sporter weight target/varmint/predator rifle. I would like to know if my M70 barrel has the potential to deliver the goods before I get started. I don't want to fiddle with RCBS 30-180FN because it'll weigh over 190 grains in the alloy I want to use. I'd rather just start with RCBS 30-165-SIL or even a lighter caliber.

MJ

[Marlin Junky]

docone31,

Maybe your right. I should cast up some RCBS 30-180's and patch them just to see how everything fits together before investing in another mold. I'll probably just need to buy a couple push through dies and I'll be on my way. Even if I can only get 2700 fps with this boolit, that'll be faster than any hand made boolit I've ever shot. Should I go with a 50/50 alloy or are straight clip-on WW's OK? I've probably got 1/4 ton of WW metal but my plumbers lead is getting kind of low at this point.

MJ

[docone31]

Marlin, use the wheel weight. I water drop the wheel weight, then size, then wrap, then when dry size.
I have found, the heavier castings do better than the lighter ones. I cannot tell you why. They just do.
Eventually, you will probably follow what I have written down. I do not know why it works for me, it just does. Higher POA than jacketed, good clean bores.
Good luck, definately try a roller. They are cheap, and you do not have to tell anyone.

[Marlin Junky]

Higher POA than jacketed, good clean bores.
Good luck, definately try a roller. They are cheap, and you do not have to tell anyone.

doc,

POA?

Please link me up with a suitable roller that'll work for .30 cal. and all the way down to .24 if possible.

Thank you,
MJ

[docone31]

Point of Aim.
Here is a link. Easier to get them in convience stores though. Cost the same.
http://www.ryotobacco.com/page/ryot/PROD/hroll/rayo70
I do believe, it will wrap down to .22. If I had a suitable mold, I would be doing .257s with it, and 243s.
It does .308 rather without incident, a 35 should do well also. 8mm, might need to open up the opening latch. Simple, takes a minute.
When I found these machines for paper patching, It all came true.
Those paper patchers, they were RIGHT!

[Marlin Junky]

Why the 70mm roller? Why not the 79?

If the 70mm will handle from .243 to .35 why would 8mm present a problem?

MJ

[docone31]

Marlin, you could use the 79mm. It is about paper width, not thickness. Your patches are 1" wide.
The 8mm might not fit in the roller as issued. There are two grooves, one on each side. The groove with the nub, the forward side can be elongated then the 8mm can be rolled.
Most convience stores have them. I got a bunch in case I wore one out.