Custom .35 caliber barrels

[Marlin Junky]

Here's a question for you guys that are long time .35 caliber casters/shooters:

If you could have a single bore/groove dimension that would handle all manner of commercial molds from 38Spl wadcutters to 250+ grain moose boolits, what would it be? Is the .350/.358 standard a good compromise or should I go with .349/.357, or is there an even better alternative... such as .349/.358? This barrel will only shoot softer cast boolits (BHN 9 to 14) and even though Marlin made excellent early .35 Remingtons for shooting cast, I think their .349/.359" would be a bit wide in the grooves for today's molds. Unless I'm mistaken I can have any twist that's reasonable since the barrel is a custom rifled job. I was thinking about a 15" twist in case I want to go a bit heavier than 250 grains.

MJ

[MT Gianni]

I would get the barrel I want and one mold to fit it. While they are similarly dimensioned I reserve my pistol molds for pistol and my rifle , 200 gr +, for rifle. Gianni

[GrizzLeeBear]

For the 35 Rem. I would stay with the standard .350/.358, you usually have to compromise or adjust your boolits because a barrel is something other than those dimensions. I would not go smaller on the bore because some excellent 35 cal. boolits have .350 bore riding noses like the RCBS 35-200-FN, which is just about the perfect boolit for the 35 Remmy. I would not go smaller on the grooves because a lot of molds drop right at .358 - .359 which means you have a good chance of being able to cast boolits that need little or no sizing, which can be good for accuracy.
One thing I would add, since this is a custom barrel. I would pick the boolit I wanted, the 35-200-FN would be a good one, and load a few dummy rounds with the boolit seated so the crimp groove is in the correct location. Have the smith chamber the barrel so that these rounds would chamber with the boolit close to the lands, but not jammed into them. A standard 35 Rem. chamber has a very short throat and can cause you to have to seat boolits deeper so that you can't crimp in the crimp groove.

[Marlin Junky]

How about the number of grooves? Mike Bellm tells me that 3-grooves is becoming popular with match shooters and would definitely give a solid bite on lead bullets. That comes as a complete surprise to me.

MT Gianni,

I'm looking for more versatility than that. I at least want to be able to center punch a porcupine with Lyman 358156 out to 150 yards or so.

MJ

[Bass Ackward]

But if you are concerned about land height, you are obviously concerned about drive area getting a good bite on the bullet. Lets see.

3 lands X .004 is .012.
4 X .004 is .016
6 X .004 is .024

Notice a pattern? And if you believe that bullet unbalancing distortion has an affect on HV accuracy, then you obviously want narrower lands that also occur with more rifling. (assuming that it can be made well without sacrificing rifling height which is the real problem.)

So it depends on what you believe what you should accept.

[felix]

Pick an odd number of lands. Seems to be a little more friendly in practice. Taller the lands, the less demand on the lube. Always. ... felix

[johnly]

Based on my experience it would be the same as the 50's era Ballard rifling used in Marlin rifle barrels.

http://castboolits.gunloads.com/showthread.php?t=24067

John

[Marlin Junky]

OK, I'll ask Bellm if there's anyway I can have 5 or 7 grooves.

What about .3580" in the grooves and .3480" across the lands? With seven grooves this would virtually be a Ballard rifled 336 except for the fact that old 336's were claimed to be .349/.359".



MJ

[Bass Ackward]

I believe that on levers, groove sizes are kept larger as a method to control pressure, friction and thus vibration. That's why lead does so well in a lever.

So if you wanted to shoot jacketed, it might be better with the larger groove. Plus, the larger groove is going to give you a smaller or tighter relationship between the throat and the groove. Good for a camming bolt, but not necessarily desirable for a lever. So you may want to check out what his reamer is going to cut to answer this question.