Author Topic: Does OAL or Ogive really make a difference? (Read 868 times)

longwinters · « **on:** April 23, 2006, 12:27:46 PM »

Well what is your experience? Actually Ogive measurements seem theoretically to make the most sense; but then I have shot similar bullets (factory and reloads) that both shoot MOA and the OAL is way different.

I have the Stoney Point comparitor and thought it would make a huge difference in accuracy . . . I just don't see it. I tend to agree with Barnsess when he says that the most important thing is getting the bullet started down the barrel straight.

Long

Grumulkin · « **Reply #1 on:** April 23, 2006, 01:26:56 PM »

Ogive measurements would actually make the most sense since the length of bullets as measured with a dial indicator is quite variable. When I set up a die, I set it up to seat close to the lands whch is essentially using the ogive as a reference. The cartridge OAL I measured before is some help in setting up but I'm not under the delusion that I can measure one cartridge and have the die set like I did before.

I think starting the bullet down the bore well aligned is the most important. The thing is some chambers may not be perfectly aligned with the bore and in such cases seating the bullet close to the lands may help in starting the bullet out right.

longwinters · « **Reply #2 on:** April 23, 2006, 03:09:27 PM »

"I think starting the bullet down the bore well aligned is the most important. The thing is some chambers may not be perfectly aligned with the bore and in such cases seating the bullet close to the lands may help in starting the bullet out right."

That is a good point and not something that I have thought of before. How would the average gun owner/shooter/hunter determine if this is a problem in a rifle?

Long

bluebayou · « **Reply #3 on:** April 23, 2006, 03:59:04 PM »

Aside from the pressure concern, I haven't seen one bit of difference in varying the OAL. I just gave up on seating differences. I meet the book's OAL and just go with that. Maybe I am just not a good enough shot to see the difference. I figure that consistency of the powder charge and the consistency of the manufactured bullets mean the most. Since I can't control the bullet consistency except with my wallet, then I just worry about reweighing every other charge.

R.W.Dale · « **Reply #4 on:** April 23, 2006, 04:11:45 PM »

My main problem is I load for some rifles that have very limited mag lengths. So when seating bullets to the max allowable lengths a inconstant bullets can lead to feeding problems.

But in the accuracy dpt I have to agree that the bullet tip plays a very small role in overall accuracy

Bullseye · « **Reply #5 on:** April 23, 2006, 04:43:02 PM »

I load to the OAL for that particular bullet in the reloading book. I have tried seating the bullet closer to the rifling which is supposed to create better accuracy but I have never seen much difference at the distances I shoot at. Maybe I am just not that good of a shot!

Questor · « **Reply #6 on:** April 24, 2006, 03:31:38 AM »

Matching the bullet to the gun is the most important thing. I've tried plenty of bullets that wouldn't shoot well even though they were apparently superior in their specifications. For example, I have a 221 Fire Ball barrel for my Contender whose rifling rate of twist is too slow to shoot many of the new .223 bullets accurately. It won't shoot any plastic tipped 50 grain bullet accurately. They're too long for that barrel. With the right bullets, it shoots into an inch at 100 yards.

Questor · « **Reply #7 on:** April 24, 2006, 03:34:58 AM »

...Oh. About OAL: It has made a difference for me, but only a slight difference. In other words, it might make a difference to a bench rest shooter, but not to a hunter.

Idaho_Hick · « **Reply #8 on:** April 24, 2006, 09:49:26 AM »

I have only tested for OAL influences in one of my rifles at this point, and I can say without a doubt that it makes a big difference in that rifle. Everything seems to make a difference in that rifle, it is the fussiest one I own and I am going to try glass-bedding it this week.

qajaq59 · « **Reply #9 on:** April 25, 2006, 12:10:52 AM »

The only time I have noticed a significant difference was in my Swiss K31 with 150 gr bullets. By varying the bullet seating in that rifle, once I had the correct powder charge, I was able to tweak the accuracy just a bit. But in my other rifles I never notice much change at all.

Steve P · « **Reply #10 on:** April 26, 2006, 06:02:10 AM »

OAL makes a difference if your gun has a magazine. You have a max OAL period. Cant fudge on that. OAL in most reloading manuals is how they set their ammo for their gun or shooting fixture. It is a good starting point, but not necessarily optimum in your gun.

On my guns with magazines, initial OAL is magazine length. I then blacken the bullet with soot or marker and chamber. If marks from the lands, I seat a little deeper until I get about a .010 jump.

On my single shots, Contenders, XP-100s, etc, I size the brass to just firmly close the action. I seat the bullet until just firmly held in the brass. Then I soot or blacken it and chamber. I check for the marks for the lands. Again, I adjust to about .010 jump to the lands. Some ammo needs tweaked from there. If it will not fit in my ammo box, I will seat a few a little deeper, check accuracy, and if within my criteria, will go ahead and seat to fit in the box. On the xp-100 once in a while you get that outstanding load only to find that the load chambers fine, but if you go to remove it from the action, it is stuck in the extractor and the bullet tip will not clear and the ejector will not kick it out. Now, do you keep that load and hope you don't have to remove loaded round, OR put quick release on bolt so removing bolt becomes easier??

Steve