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Re: 7 Degree Leade?

Posted: Thu May 13, 2021 9:37 pm
by mdeland
Here is a little perspective of the 7 degree taper . These are forcing cone cutters for revolvers the top is 11 degrees and the bottom is 5 degrees . The OD is .500 and gives a good look at the taper profile of what a 7 degree leade would look like. One of these days I'll get some time to actually turn a steel plug on a 7 degree taper starting at chamber mount diameter down to bore diameter.

Re: 7 Degree Leade?

Posted: Sat May 15, 2021 10:17 am
by sandhillcowboy1
Good comparative images there mdeland. Put a 45 deg in there and will be a very large difference. So with the gentle leades pressure does not build as fast or as high compared to a 45 deg transition? I know the old Creedmoor shooters did not want the bullet to bump up quickly.

Rick

Re: 7 Degree Leade?

Posted: Sat May 15, 2021 3:30 pm
by powderburner
I have a 4070 and I’ve been trying to shoot paper patching it for about a year I’ve tried everything including a dual diameter bullet I’ve tried different watch stacks all kinds of stuff I had at throated the other day and all that other stuff disappeared it shoots regular bullets it’s used to do a diameter bullets and I don’t get any paper rings and I don’t have any problems and it cleans up with three patches I think it works

Re: 7 Degree Leade?

Posted: Sat May 15, 2021 3:35 pm
by sandhillcowboy1
I have a 40-65 with a standard chamber that shoots PP extremely well. I did get some paper rings when I first loaded for it but lengthening brass stopped it. Not saying PP is better or worse than GG , just trying to understand the thinking behind gentle leades, and what the old Creedmoor guys were thinking.

Re: 7 Degree Leade?

Posted: Sat May 15, 2021 3:41 pm
by sandhillcowboy1
powderburner wrote: Sat May 15, 2021 3:30 pm I have a 4070 and I’ve been trying to shoot paper patching it for about a year I’ve tried everything including a dual diameter bullet I’ve tried different watch stacks all kinds of stuff I had at throated the other day and all that other stuff disappeared it shoots regular bullets it’s used to do a diameter bullets and I don’t get any paper rings and I don’t have any problems and it cleans up with three patches I think it works
Do you mean it shoots PP or GG's well now?

Rick

Re: 7 Degree Leade?

Posted: Sat May 15, 2021 3:55 pm
by bobw
Dean don't do greasers Rick. Bobw

Re: 7 Degree Leade?

Posted: Sat May 15, 2021 4:29 pm
by sandhillcowboy1
bobw wrote: Sat May 15, 2021 3:55 pm Dean don't do greasers Rick. Bobw
O.K. Thanks Bob, I reread that and then thought that might be the case. My 40-65 is a Ped and I have to patch to bore to get it to shoot well with the standard chamber. My 45-110 Loomer buffalo gun and my 45-70 competition gun both have gentle leades and shoot the best of my BPCR guns;) Never a problem with paper rings and clean up like Dean said is very quick and easy. That is one of the biggest differences I noted going from standard chambers shooting grease grooves. I used to get a little lead with my .45-90 and gg bullets, never with PP.

So my question still goes, do the gentle leade/ transitions give less pressure in the round than a 45 deg transition. May be the reason some of the powders like Kik work better than Swiss in gentle transitions? Just throwing out some things. It also goes back to what the old Creedmoor shooters say about not having the bullet obiturate too quickly.

Rick

Re: 7 Degree Leade?

Posted: Sat May 15, 2021 4:50 pm
by powderburner
Had a reply but it didnt post.
Reading your post. I found the same thing before and after with the cleaning and i believe the leade allows the bullet to get more into the barrel before bumping.
When i had a std chamber 2&7/8 i could get rings on call. Just use a faster powder and ta da With 1F I could guarentee no rings as long as i matched my alloy to the charge. Using alloys of 70 # of lead and an ounce of tin up to 30-1 which i considered hard.
It may mot be for everybody but it sure makes my day when it works so well.

Re: 7 Degree Leade?

Posted: Sat May 15, 2021 5:16 pm
by sandhillcowboy1
powderburner,

Did not mean to insult you about the greasers :D I got one of the KAL TGBS molds from you at one of the Q's some years back and that bullet with my Loomer 2- 7/8 is my designated buffalo slayer, a very accurate combination with barrel sights. Also using soft alloys like Bob turned me on to. That gun has dispatched a lot of buffs and did it in good fashion. It even shot well using Bob's loads when he was here. I think the gentle leades are less persnickety.

I agree with you about the bullet bumping up a little farther down the line possibility, may create less neck tension which leads to better accuracy? That is kind of what I was after.

Rick

Re: 7 Degree Leade?

Posted: Sun May 16, 2021 7:15 am
by sandhillcowboy1
Correction, I meant patch to groove on my Ped.

Rick