need boolit diameter help

[curmudgeon]

I have a Swedish black powder rolling block in 12.7X44mm caliber. The groove diameter measures 0.502 inches. What is a good bullet diameter to try and where can I buy them (I don't cast - yet).

Thanks.

[montana_charlie]

Somehow, I have this feeling that you measured a 'groove' in the slug you pushed through the barrel. That would correspond with the top of the land, or bore diameter.

Measuring the 'ridges' on a driven slug will give you 'groove diameter' of the barrel. Are you still sticking with that .501" measurement?

While Googling in an attempt to find an answer for you, I ran across this...
"This is where I buy my cast bullets. I have used bullets from 6.5 mm to .50 caliber and have been most pleased with quality, price and service. I use his .511 offerings in my Swede 12.7mm bore rolling blocks with great success. If you don't see what you want from the web site, ask Wayne, chances are he has it. Tell him Theoxrojo sent you."

The link he provided is http://www.customcastbullets.com/

Additionally, this place mentions bullets of .500, .501, and .502 diameter on it's main page. I suppose you would have to look through their stuff, or contact them for specific information on your need.
http://www.rimrockbullets.net/catalog/

BUT I SUSPECT that you actually need a bullet diameter that is closer to .511". If that is the case, they are available (like) everywhere.

CM

[enfield]

last nite I was shooting my swedish rolling block with reformed .348 brass and I think it was 11.5 gr unique ( I'm at work, cant look in my book ) and the Lee 450gr bullet ( ment for the 50-70 ) it measures about .515 . it works o.k but I do want to try it with black powder . by the way I just used cast ww for my unique loads.

[northmn]

Since I don't know crap about the Swedish caliber all I could suggest that if you are sure it is 501 diameter is to try the pistol bullets for a 500 S&W. Sounds like a foreign 50-70.

DP

[marlinman93]

Whatever the max diameter of a slugged bullet is, add 2-3 thousandths to the measurement.

[curmudgeon]

Somehow, I have this feeling that you measured a 'groove' in the slug you pushed through the barrel. That would correspond with the top of the land, or bore diameter.

Measuring the 'ridges' on a driven slug will give you 'groove diameter' of the barrel. Are you still sticking with that .501" measurement?
CM

I am a novice about these things. I have two measurements 0.502" and 0.476". I figured 0.476 was the barrel diameter before the rifling was cut and 0.502 was the cut. Therefor I called 0.502 the "groove" cut into the 0.476 bore. That is why I chose to call 0.502 the groove diameter.

Thanks for all the information you and others provided.

I have located a number of bullets in the .510 inch diameter range and will try some of them. Too bad you can't buy a few of various sizes to try before buying a large quantity.

[curmudgeon]

Whatever the max diameter of a slugged bullet is, add 2-3 thousandths to the measurement.

That would mean 0.502 + 0.003 = 0.505. Then 05.10 t0 0.512 would be too large.

[bubba.50]

i have a swede like yours. haven't slugged it but, measures about .512x.485 diam. i personally shoot 450gr. .512 diam. boolits over 60gr. goex 2f w/2 milk carton wads. this gives me 1to2 in. groups @50 yds which i think is pretty good considering that the chamber has been reamed with a 50-? reamer. question mark is because chamber is deeper than any listing in cartridges of the world. so i just use 50-70 dies & starline 50-70 brass. don't re-size & the brass lasts forever. boolits look like you could turn them with a wrench after squeezing down in that bbl. good mild load and tons of fun. hope this helps. bubba.

[montana_charlie]

I am a novice about these things. I have two measurements 0.502" and 0.476". I figured 0.476 was the barrel diameter before the rifling was cut and 0.502 was the cut. Therefor I called 0.502 the "groove" cut into the 0.476 bore. That is why I chose to call 0.502 the groove diameter.
When you say it that way, it sounds like you were right about .502 being your groove diameter. I wish I knew enough about the 12.7mm to give you sound advice.

CM

[curmudgeon]

Bubba.50:


i personally shoot 450gr. .512 diam. boolits over 60gr. goex 2f w/2 milk carton wads.

Thanks for the load info.

Based on the 30" twist I measured for my RB sporter, it can stabilize up to a 1.25 inch bullet. How long is your 450 gr. boolit?

[bubba.50]

this load has worked well for me. the 450gr. boolits are about .92 or3. i get about 1 to 2 in. groups @ 50 yds. could probably do better if my chamber hadn't been re-cut with a very long .50 cal. reamer. don't know excactly which one as it is deeper than any i can find listed in cart. of the world. also wouldn't hurt if my eyes were about 25 or 30 yrs. younger. hope you can get some thing from this. stoke'er up & let the white smoke roll. bubba.

[bubba.50]

almost forgot- if your chamber is original you may have to squeeze the boolits down a few thousandths to get them to chamber. as i said my chamber has been re-cut so no problem for me. i have also shot hard-cast 350gr. gas-checks with 4759 loads copied from 45-70 load chart for bullet weight. nice mild trapdoor safe load that is fun to shoot on days you don't feel like cleaning up after black. if your bore is like mine, try to shoot into something where you can recover boolits and you'll be amused by how they squeeze down to almost hex-shape. anyway, fun guns and a hoot to shoot. bubba.

[wrcook]

I have a Swede rolling block in 12.7x44Rmm. I am shooting a 515 slug from an old Dixie mould, using reformed 348 Win Brass, and black powder. I am getting very good accuracy at 50 yards (my range out back). My rifle is a full military, dated 1874 made by Husquavarna. Great fun to shoot.
Bill C

[marlinman93]

Cartridges of the World calls out the 12.17x44 Swede to be a .502" bullet. I would never use more than a few thousandths larger size over slugged bore size. If you want to get the correct sized bullet contact GAD Custom Bullets.
Veral Smith always said that bullets should be .001-.002" larger than slugged bore size.

[bubba.50]

i have never slugged or cast my bore but i did just check a fired slug and gas check. these were 350gr "heat treated" hard cast .511 diam. recovered from block of wood. gas check picked up half way to target. both measured .475 to .480 by .500 to .505 as bore is apparently not very true. load was imr 4759 load taken from 45-70 chart adapted to 50-70 and listed as trap-door safe. shot well and was very mild in my gun. in my limited experience c.o.t.w. is not the most reliable source of info but is good for a general idea of what you have. bubba.