I have my model 70 intransit to Pacnor right now and think I may be light on my profile after looking around here. My plan was to "duplicate" the factory 375 H&H contour, but now I am wondering if that will be to light. I picked the number 5 contour because at 24" it is the same muzzel dia as the 375 +/- .72.
It looks like the 1 in 10 is the twist to use, as I want to be able to use pistol bullets and the 500s for serious work. I am not too concerned about the weight (that is a secret that we will have to wait until the revel on

Does anyone have a factory 470 cap that they can check the muzzel dia to make sure that I am not in left field.

Thanks Guys.

That is perfect.

I would consider 0.725" to 0.750" to be the ball park, and no heavier for sure.

Trim that barrel back to 23" and you will be over 0.725".

I really like your choice of twist. Perfect!

Rip can you help a rookie out here. My options are 1-10, 1-16, 1-38 in a 6 grove and 1-18 in a 8 grove. With all the disscusion about twists around here I am a little confused, but assumed (and we all know what happens then) more is better than less on twist. What are the drawbacks with too much?
BTW I left it 24 to match the 375 (got to have a matched pair you know)

I used a Krieger barrel for my M70 in 470 Capstick. Krieger's #6 contour, cut off to 24" is just a bit over .750 at the muzzle. That has worked out well for me. That heavy barrel will make the rifle a bit nose heavy, but if you put a 13oz mercury recoil reducer in the stock, it will balance out nicely. The rifle weighs a little over 10 lbs. with 2.5x Leupold.

David, what twist rate do you have and what bullets do you shoot?

FWIF, if I was building one of those, I'd use the lightest contour I could get and when the rifle was complete I'd add weight under the barrel channel in the stock by endmilling a groove and adding lead shot epoxied in to keep them stationary.

It's easier to add weight than remove it and this way you can adjust the balance point a bit.

My 404 was built that way and I have no regrets at all.

quote:

Originally posted by vapodog:
FWIF, if I was building one of those, I'd use the lightest contour I could get and when the rifle was complete I'd add weight under the barrel channel in the stock by endmilling a groove and adding lead shot epoxied in to keep them stationary.

It's easier to add weight than remove it and this way you can adjust the balance point a bit.

My 404 was built that way and I have no regrets at all.

Idahoelk101,
Good advice from vapodog. That is why I like your contour choice. Add lead in the forearm and/or butt to balance if you want the rifle heavier.

My 470 Capstick is .750" at the 26" muzzle and is too heavy and long. It has a 1:10" twist McGowen barrel. Pic of target:


I think the North Forks are now .475" but mine shot the .474" without keyholing, that's for sure.
I know for a fact that the Winchester Custom Shop used 1:10" twist on their 470 Capsticks, and so did A-Square, the originator of the cartridge.

There are no drawbacks to the 10" twist in a 470 Capstick.
I have a 1:16" (Pac-Nor) 470 Mbogo and wish I had made that a 10". The 1:16" was the fastest twist they offered back when I ordered.

My Winchester M70 Classic Super Express was rebarreled from .375 H&H. With glass and pillar bedding, secondary recoil lug on barrel, standard Winchester factory sights, barrel band sling base, Leupold QRW scope bases and the 26" sporter barrel that is 0.750" at the muzzle, it weighs 10.25#. Too heavy. A 2.5X Leupold and QRW rings is all the scope I want to add to that weight.

You have chosen wisely. If I were doing it again, I would use the same barrel length and contour, as in your opening post. AND A 10" TWIST.

Rip, thanks for the confimation of my choices. The stock choice that I have made for this will take care of the weight issue, so I think that I should be good. One more question you mention on your target that you have your load crimped. I was planing on the CH4D dies, did you have a special crimp die made?

my pac nor 470 a.r. barrel (capstick clone in a std. action but better )

is a 1 in 10 twist 24" and i chose the heavy palma contour to keep muzzle flip and recoil to a minimum.

i would suggest a heavier barrel so you can shoot more and from the bench will be possible without too much "ooh, thats gunna leave a mark"

idahoelk101,
I used the RCBS dies, 3-die set:
1. De-cap and Size full length. Trim to uniform length: 2.840"
2. Expander/bell case mouth just enough to start the bullet in.
3. Seat bullet to desired depth with no crimp then crimp in separate step with the same seater die body screwed in a bit more, and seater plug backed off.

I needed no special crimping die for this one. Never hurts to have an extra die like the Lee Factory Crimp. The 470 Capstick "ghost shoulder" grips the bullet very well, and that is built into the standard dies.

idahoelk101

If I remember correctly, the twist rate on mine is 1:14. At the time I purchased this barrel, that was the only twist that Krieger offered.
I shoot North Fork Flat Points. Swift A-Frames, Woodliegh solids and soft points (all 500gr) with no problems and it shoots all at about 1 moa. In fact there is very little shift in POI when switching bullets.
I have also worked up a practice load with some 400gr Hornady pistol bullets at about 1800fps. They shot very good with light recoil. My only complaint about them is it is difficult to seat these bullets without crushing the case mouth. I even tried expanding the case mouth more, but no help.

For initial load workups and practice ammo, I found that the Hornady 375 basic brass is a less expensive route to take than Bell or some other brand of brass. There is no head stamp, the cases are straight walled and very close the the correct finished length. All I had to do was run them through my FL die. The case volume is almost identical to my Bell brass.

quote:

Originally posted by idahoelk101:
Rip can you help a rookie out here. My options are 1-10, 1-16, 1-38 in a 6 grove and 1-18 in a 8 grove.

1:10.

That is what the 470 capstick was designed to use by its designer Art Alphin. The relatively fast twist reduces bullet yaw and therefore enhances penetration in big game. And if someone tells you to use a slow twist to reduce pressure, don't believe them. Somochem proved that to be a fallacy with lab experiments.

I'd do it as light as I could stand to have it... that is, i hate carrying a 10+# rifle around, but sometimes lighter is bad.

ask GeorgeS, the bigbore moderator, what his is, as I believe it's an 18, and I think that the normal for the 470mbogo (which goes even faster) is generally a 14, though some 16s are running around.

We'll have a head to head on the 470 AR, 18 vs 10, here in a a month or two, to understand them a little better.

Me? I prefer a touch faster than the minimum required to stablize the bullet, which is why I choose an 18 twist, rather than a 20 or 22

jeffe