Shallow rifling -1:48 twist.

[montanadan]

I read the post by John L. Hinnert(forgive me if I miss-spelled his name)about barrels ,depth of rifling,twists and patches.I would like to hear his thoughts or anyone elses' on shallow rifled barrels with 1:48 twist.I was shooting a .451 rb and .007 patch in a Pedersoli(S-270)Penn. rifle.It was a absolute bear to load but shot very well out to 50 yds.I just tried .445 rb and .010 patch same powder charge no difference(way easier to load),went to .440 rb .015 patch same charge but had to raise my rear sight.Tried the .445 combo at 100 yds(off hand)50grns. Swiss 3fg,shot a 38.The wind started coming up,so I did not try it again.As a "rule of thumb" more ball, less patch,I really do not know.How do you know when your at the point where the patch is skipping the rifling(losing grip).Example,to much of a powder charge or not enough patch?Many thanks to all that have helped in the past...Respectfully Montanadan

 

[roundball]

How do you know when your at the point where the patch is skipping the rifling(losing grip).

I've never seen that happen.
IMO, based upon my personal experience, and side by side tests between my own TC 1:48" and 1:66" barrels, I believe the notion that round balls are inaccurate in 1:48" twists to be an old wives tale...a properly fitting patch/ball combination, using manufacturers published load data for their rifles is not going to skip rifling.

I've driven my 1:48's with the same maximum round ball powder charges published by TC that I use in my 1:66" RB barrels, and would have to study the targets closely to decide which barrel shot which target....includes 45's, .50's, and .54's.

At 100yds from a bench rest, I've gotten groups as small as 1+7/8 with 1:48" twist, with the average in the 2.5"-3" range, using:

90grns Goex 3F
Oxyoke wonderwad
TC .018" pillow ticking
Hornady .440, .490, .530 balls

:results:

 

[montanadan]

Roundball-thanks for the response.Are TC's shollow rifled? Pedersoli,I think is only .008" deep.I wanted to try and shoot 200yd target off sticks,probably a stretch for this rifle.Pedersoli does not list a max.charge for this rifle,I think they proof them at 90grns?Probably going to stay with .445rb's,and experiment with the patches and powder charges(if the wind ever quits blowing).Respectfully montanadan

 

[roundball]

Roundball-thanks for the response.Are TC's shollow rifled? Pedersoli,I think is only .008" deep.I wanted to try and shoot 200yd target off sticks,probably a stretch for this rifle.Pedersoli does not list a max.charge for this rifle,I think they proof them at 90grns?Probably going to stay with .445rb's,and experiment with the patches and powder charges(if the wind ever quits blowing).Respectfully montanadan

I've read that TC 1:48's are .006"...(I need to mic my own barrels, eh)...and I have miced my 1:66's at .010".

 

[bob1961]

I've read that TC 1:48's are .006"

i called T/C to find out what the rifling depth was and they told me it was .006"....cause i was looking at some conicals that were .512 dia. and needed to know if they would work in my T/C's 1-48" barrel....so the bore at the tops of the lands are .500 and bottom to bottom are .512....in a .50........bob

 

[LRB]

In the mid seventies, I had a .45 cal. TC Hawken that would consistantly shoot 1/2" groups off a bench rest, at 50 yrds. The load was 60gr. 3f Dupont. .010 to .011 cotton flannel patch, and a .451 ball. Remington #10 caps. This was with the open sights. Odd, but to keep it that tight, I had to change the nipple every 100 shots. I sold a new one to a customer, and it would do 3/8" groups consistantly, useing that same load. He was a preacher. He must have been a good one.

 

[adbranaman]

I just resently aqquired a 45 Penn. Pedersoli. i bought some .445, but I'm thinking about buying a maxi(mini) bullet mould. I plan on buying some bullets first and comparing them with the round ball. any one have any suggestions on the best type or style to get.Must be able to obtain a mould of it too.Lee has a solid based 200[url] gr.in[/url] the Log Cabin Cat.Is there any experience with this? I have yet to even shoot this gun,so I'd like to get as much info as I can before I do. :thanks:

 

[montanadan]

Roundball-I would like to say a late thank you for your help and load suggedtions(also White Buffalo).The 100 yd targets(off hand)have always had the upper hand with me,I practice shooting them more than any other targets.I have been playing around with Swiss B/P loads in this Pedersoli 45 cal(S-270).My load for these targets is as follows,50 grns,Swiss 3fg,.010 patch,Rws 1075+(no practice shots).NMLRA 100 yd targets single bull(the big one) I shot a 45(with three in the ten ring),single bull Buffalo(this target I always seem to choke on)shot a 38.The small single bull shot a 42(one in the ten ring)the rest in the 8 ring.I cleaned between each target,patch lube was Stumpkillers liquid MOOSE JUICE(did not wipe between shots)only five per target.I owe all my success to this forum(web-site),this is the best I have ever done on these targets.I am 60 bad back,and two really bad knee's.I know they are people here who probably shoot better just "foolin" around.Many thanks again...Respectfully Montanadan P.S. there was no wind! this is a big deal out here.