I just got a sinclair concentricity gauge. I am trying to minimize runout but I'm not sure what my goal should be. On my 7 saum I'm using redding s bushing fl die and have foun if I loosen the bushing 1/4 turn it gives the least runout. Also if I size slowly it helps also. I seat with forrester comp die. Can anyone tell me what level of runout to try and achieve?
-
Having trouble using the site?
Contact support
Acceptable runout?
- Thread starter medium rare
- Start date
If you can live with <100% of your necks getting resized (and I can,) it's always best to free-float the bushing.
This being said, TIR of .002" (that's .001" up and .001" down) and under for traget/match grade ammo seems doable and .004" TIR for casual/plinking/practice ammo.
Whether you can see the difference on paper, is an entirely different matter.
Chris
Use the Redding bushing dies myself and don't usually check for runout because usually have little to none. Also, I believe the assembly instructions for the dies say to back off 1/16th of a run so the bushing can center itself. 1/4 turn may be a bit much but if it works have at it.
Think the spec I have seen quoted for runout is that as long as it is under .006 it is good enough for most purposes although none is obviously best.
I have dropped a couple loaded rounds and then checked them for runout. They were definitely a bit out of spec so I just run them back through the die and they are good to go. If you have some that are beyond acceptable, give it a try.
Think the spec I have seen quoted for runout is that as long as it is under .006 it is good enough for most purposes although none is obviously best.
I have dropped a couple loaded rounds and then checked them for runout. They were definitely a bit out of spec so I just run them back through the die and they are good to go. If you have some that are beyond acceptable, give it a try.
Last edited:
I had the die a 1/16 of a turn back but I was getting .004 or so. I backed out 1/4 and got .001-.002. Then when I go to seat some of them stay with the same runout and some get worse. I can't figure out what I'm doing in the seating process to get inconsistent results. I checked the seater plug and it fits well with the 180 hybrids. I guess I will keep trying different things.
When I check for runout with my Hornady gauge Im looking for anything less than .003", anymore and Ill correct it right there, nice thing about the Hornady gauge.
I only check my Benchrest ammo.. .003 or higher goes to sighters. 0.00-0.01 for relay then .001-.002 for shootoffs. (better shootoff ammo don't help of you don't get to shootoff).
for AR or tactical out of magazine I don't bother checking as standard operation will torque the bullet around during feeding.
for AR or tactical out of magazine I don't bother checking as standard operation will torque the bullet around during feeding.
Try setting the bullet as straight as possible before seating. A technique I use is set the bullet then raise the ram just enough to apply light pressure and straighten the bullet. Lower the ram slightly then seat the bullet.
One bullet loading method I've used with good luck for years is to seat the bullet 1/2 way..then lower the ram just a bit and spin the case 180 degrees and then finish seating the bullet.
I approach it like I'm bolting on a head. Raise the ram a little, release, spin ~160°, repeat. Basically make a 5 point star.
I have both Sinclair and RCBS gauge and prefer to be no greater than .002-.003 out when reloading for my TRG in 7mm08. I did do a test with some of my ammo that was found to be out by .004 and .005, the funny thing is that I didn't see a noticable difference while shooting paper at 100 yards off of a bipod. So I guess it really depends what you are going to do with the ammo.
Scott
Scott
The magic number to try and stay under is .003" I have talked to the folks at RCBS and they said when they tested it they couldn't see any accuracy differences below that but started to see it change as you get worse. I tested a lot of my rounds too and saw the same thing. I have always had to seat bullets with a Wilson Straight Line Seater to get them consistently around .001"-.0015" I have never been able to seat any bullets that close with any type of reloading dies that screw in a press. I have both a Bonanza Co-Axial and Rock Chucker, it makes no difference/does it no better sizing or seating. I talked to a lady at Redding once and she said to always loosen the expander ball run a case into the die and pull it back out. Then, when the expander is in the neck tighten it. That helped get more concentric necks/bullets.
I had a chance to try this and it works. Out of 50 rounds there was only a handful that measured >.001" and all were less than .002". Thanks for a great tip.
At 100m I have found even 0.005" of runout did not affect a 3 shot group that measured in the 0.1's. What about longer ranges? Well, when Minnesota winds finally calm down I'll tell you. But I have not found runout to affect my loads to this point. Obviously it does affect in some way, but just doesn't seem to translate onto paper.
I appreciate the advice share so far. Very useful, especially the loosening of the expander ball then tightening during resize.
I appreciate the advice share so far. Very useful, especially the loosening of the expander ball then tightening during resize.
Bruce Baer (king of the 60 pound 1000 yard bench rest rifle) says he can't see any improvement in accuracy below 6 thou runout....If Bruce cant see it...it just isnt there.
For me I shoot for 1 thou or less, but this is just to still the voices....No they aren't real, but the have some damn good ideas!
For me I shoot for 1 thou or less, but this is just to still the voices....No they aren't real, but the have some damn good ideas!
As little as possible. I measure them and the ones that are over 10 thousandths usually go in a blaster ammo box but I find that's pretty rare and only happens when my necks start to go.
I have a Lee collet die I use for seating my .308 ammo. I have it mounted in a dedicated RCBS press and it does not get removed. After I prep the cases, I put them in the shell holder, put a bullet in the mouth and turn the case as it goes into the die. I get about .001 TIR on my ammo. Some don't like the Lee stuff, bit thisnworks for me.
A few months ago, I had some 175 SMKs loaded that had about 6 thou turnout. I shot several groups with them and some ammo of the same recipe, but with very little runout. The higher runout loads bested the low runout stuff. Go figure.
A few months ago, I had some 175 SMKs loaded that had about 6 thou turnout. I shot several groups with them and some ammo of the same recipe, but with very little runout. The higher runout loads bested the low runout stuff. Go figure.
I have no idea, and haven't checked runout since I blind tested runout against accuracy and was totally unable to correlate runout to any degree of accuracy, probably over ten years ago by now.
I can't say runout is unimportant, all I can say is that given my skills and my rifles, I can't make it do anything either good or bad for my marksmanship. YMMV.
I can't say runout is unimportant, all I can say is that given my skills and my rifles, I can't make it do anything either good or bad for my marksmanship. YMMV.
