Barts bullets
- Thread starter Ajshooter
- Start date
Jeff,
I jam the bullet and normally end up shooting it somewhere from .003 to .012 back from jam.
I very seldom jump.
Bart
Lee Martin
Active member
Every barrel is different but my 13.5 Shilen shoots Bart's 68 gr Ultra FB beautifully a couple of thou into the lands. The amount of free-bore also matters. My chamber is a JGS 1046, which is a 1045 body with a 264 neck. Freebore is 0.060".
Set-up a practice target and try different charge weights, perhaps 0.3 grs apart. On seating depth, start 10 in and work back at four or five thousandth increments. You'll start to see what the gun likes.
-Lee
www.singleactions.com
Set-up a practice target and try different charge weights, perhaps 0.3 grs apart. On seating depth, start 10 in and work back at four or five thousandth increments. You'll start to see what the gun likes.
-Lee
www.singleactions.com
jackie schmidt
New member
If these are Ultras, and you are shooting 133, here is a tip.
Load up some and jam them to where the marks that are made on the bullet Ogive when checking the jam are twice as long as they are wide. This is a visual thing.
I know it sounds kinda ridiculous, but try it. Back when I shot Ultras, it worked pretty darned good with a .237 4 groove Krieger and a big dose of 133.
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What are you talking about? There's probably something I did along the way, and a ton of stupid stuff, but I don't know specifically what you're referencing. I'll turn it off if I can!
DeltaBravo
Member
I shoot Bart's 68BTs at 9 thou off "touch" which for me is 1 or 2 light marks, not on opposite sides of the ogive, and "jam" is defined as 4 equal square marks. This is on my 6BR with Shilen 14-twist ratchet rifled barrel and .266 neck.
Dennis
Dennis
Dusty Stevens
Hollow Point Dispenser
.009-.011 off a hard jam for me. Adjust thruout the day as needed
jackie schmidt
New member
Like many, I have found the best accuracy with Bart's Boatail darned near jumping them .020-.025 from "just touching".
I have no explanation as to why.
I have no explanation as to why.
CYanchycki
Club Coordinator
James/Jackie
Could you please CLARIFY what your or how you determine JAM?
I know the way I do a starting point for a new barrel finding the sweet spot for seating depth but for clarification what is JAM.
For me Jam is seat the bullet LONG with normal neck tension and close the bolt on it. It is more than likely going to push the bullet back in the case when you do this. When it comes to load development then there is only ONE way to go with seating depth. You cannot seat longer because in reality the lands will push the bullet back into the case.
When I find my sweet spot I never change seating depth ever. I just use powder to try and stay in tune.
Calvin
Could you please CLARIFY what your or how you determine JAM?
I know the way I do a starting point for a new barrel finding the sweet spot for seating depth but for clarification what is JAM.
For me Jam is seat the bullet LONG with normal neck tension and close the bolt on it. It is more than likely going to push the bullet back in the case when you do this. When it comes to load development then there is only ONE way to go with seating depth. You cannot seat longer because in reality the lands will push the bullet back into the case.
When I find my sweet spot I never change seating depth ever. I just use powder to try and stay in tune.
Calvin
jackie schmidt
New member
I am interested in the "just touching" measurement on a brand new chamber. I use my "thingy" to find that. I can stick a loaded round in it give it a spin, and look at the marks moving the seater in or out until I am satisfied I have found out what I want to know.
I can work from that dimension. There is nothing particularilly special about that dimension, it just tells me where I am.
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CYanchycki
Club Coordinator
Thanks
for clarifying Jackie.
That is exactly what I do. Find the just touch point and go from there.
Next question from barrel to barrel using your reamer, how much variation in the just touch point have you seen? It must be so close, right?
for clarifying Jackie.
That is exactly what I do. Find the just touch point and go from there.
Next question from barrel to barrel using your reamer, how much variation in the just touch point have you seen? It must be so close, right?
Lee Martin
Active member
I do the same as Jackie. I seat way long with mild tension and close the bolt. Number recorded. Then I slowly work back until the marks are barely visible (which is usually only a land or two...not the full 3, 4 or 6). Using a Zippo smoked bullet, when the marks are barely visible under a loop I note that as touch. It's not perfect but close enough. From there I adjust my Sinclair seater to either jump or protrude in. Of course, as you wear the lead that depth changes. That's why I re-check seating every 50 - 100 shots.
-Lee
www.singleactions.com
-Lee
www.singleactions.com
jackie schmidt
New member
I use only one brand of Barrels, Kriegers. .237 4 groove in 6mm, and their standard 308 4 groove.
Honestly, I never check them from one to the other. I depend on the reamer to duplicate the throat on each one.
Honestly, I never check them from one to the other. I depend on the reamer to duplicate the throat on each one.
Lee Martin
Active member
Calvin - you're also right about jam seating. Unless you change your bushing between tests, when you seat long the bullet still gets pushed back the same amount. It really depends if it prefers to be engraved or just touch. My Ultras seem to want marks that are just visible for a couple of the lands (ie, slight touch) to half the land width in length ("in").
-Lee
www.singleactions.com
-Lee
www.singleactions.com