I have hornady sst in 140 grain for my 270. When loading my minimum OAL is 3.280 inches. When I seat the bullet to get an OAL OF 3.280 the cannelure of the bullet is not on the rim of the case and thus not really serving its purpose for a crimping groove. It is getting very close just not on the mouth of the case. I have shot a few groups like this and gotten just over an inch. I obviously want better. Any suggestions?
loading cannelure question
- Thread starter ReloadKy
- Start date
NoSecondBest
New member
Don't get all hung up on OAL. It mostly has to do with feeding through the magazine. Too long and it won't feed....or even fit. If it's pretty close, just seat the bullet in the cannelure and shoot it. OAL is a guide, not gospel.
I load my ammo just as long as possible and still get it to fit the magazine. If it feeds into the chamber without hitting the lands I head to the range with a few loads. If accuracy meets my standards then I run with it. If not I experiment, but rarely have to mess with seating depth. If I do, I can always seat them a little deeper, even rounds I've already loaded. That way I only have to experiment in one direction.
I ignore the cannelure. Most of the bullets I load do not have them anyway. I have no idea what my OAL is.
I ignore the cannelure. Most of the bullets I load do not have them anyway. I have no idea what my OAL is.
Yosemite Steve
New member
You don't need the cannelure for your 270. You can use it if you like and roll crimp into it but I and many others have seen no benefit. Go with the suggest OAL... or find your lands and seat .020" off the lands. It was suggested to me and .020" off the lands shoots pretty good out of my gun. I get better groups closer to the lands but then my pressure starts to get too high. SST's are good accurate bullets! If you try to tweak seating depth, do it after you have found a good powder load for your gun and have read up on it.
ReloadKY said:
Hornady recommends 3.210" COL with that bullet in the most recent Hornady manual (#10 or X, as they label it). SAAMI has the .270 Winchester cartridge minimum COL at 3.065" and maximum at 3.340" for magazine fit and feed reliability. So the question is, how did you arrive at 3.280" as a minimum? It seems to be the stumbling block and is not a standard of any kind.
And if you are getting 1 inch, for hunting purposes that is as good as you need (or can use)
I never did find a bench rest set up for me when I took a shot (dang state).
It was always some kind of braced shot and a pretty fast one. AT 100 yards you would be lucky to hit within 2 inches, not to mention if you are 2 inches high at 100 (fairly standard) you would have to Kentucky windage it down at that range to be perfect B eye.
I was not aiming for a bullseye, I was aiming for a mid section.
Best my hunting gun did was 1.5 inches.
I never did find a bench rest set up for me when I took a shot (dang state).
It was always some kind of braced shot and a pretty fast one. AT 100 yards you would be lucky to hit within 2 inches, not to mention if you are 2 inches high at 100 (fairly standard) you would have to Kentucky windage it down at that range to be perfect B eye.
I was not aiming for a bullseye, I was aiming for a mid section.
Best my hunting gun did was 1.5 inches.
Forget the cannelure altogether. Just like you can ignore the 3.280" OAL(that is not a minimum length) given by Hodgdon, et al and load to the SAAMI max of 3.340". Pointy part to flat part with no ogives involved.
Forget the off the lands stuff too. It's unnecessary and your rifle may or may not like 20 thou off the lands.
Forget the off the lands stuff too. It's unnecessary and your rifle may or may not like 20 thou off the lands.
T. O'Heir,
Ah! I didn't catch that the COL came from Hodgdon. OK. That makes sense because it is a different brand of bullet, so, of course, the length isn't identical and the cannelure is not in the same place. Apples and oranges.
mikld,
If he uses the Hornady suggested length, the cannelure will be in the right location anyway.
ReloadKY,
All that Hodgdon info is for the test bullet listed. When you change that or any other component, you go back to the bottom load and work back up, watching for pressure signs, but use the manufacturer-suggested COL until you get comfortable enough with reloading to experiment more. One reason for using the manufacturer's length is will ensure the particular ogive radius they used (the nose side shape) doesn't jam into the lands of a standard SAAMI chamber, thereby raising pressure.
Ah! I didn't catch that the COL came from Hodgdon. OK. That makes sense because it is a different brand of bullet, so, of course, the length isn't identical and the cannelure is not in the same place. Apples and oranges.
mikld,
If he uses the Hornady suggested length, the cannelure will be in the right location anyway.
ReloadKY,
All that Hodgdon info is for the test bullet listed. When you change that or any other component, you go back to the bottom load and work back up, watching for pressure signs, but use the manufacturer-suggested COL until you get comfortable enough with reloading to experiment more. One reason for using the manufacturer's length is will ensure the particular ogive radius they used (the nose side shape) doesn't jam into the lands of a standard SAAMI chamber, thereby raising pressure.
That's what I do, but I measure the headspace first and seat to about 0.010" deeper so as not to impinge onto the lands.
Yes, correct. The cannelure is for semi-auto and such where the bullet may get slammed into the feed ramp and crimping can prevent bullet set back. There should be significant neck tension in all bottleneck cartridge loads such that even then a cannelure and crimping often is not necessary. I only crimp on my bulk practice 55 gr FMJ loads in .223 and 150gr FMJ in .30-06. Target bullets I do not crimp and they run fine in the Garand and AR15.
Bolt actions like your .270 should never need crimping. Maybe very heavy bullets and magnums like .458WM need crimping, I don't know, but the inertia and recoil could require it.
BTW, UncleNick has great advice on reloading and you will benefit from what he recommends any time. I doubt I have ever disagreed with anything he has said. and if I did then I just have not yet learned that I am wrong.
Bolt actions like your .270 should never need crimping. Maybe very heavy bullets and magnums like .458WM need crimping, I don't know, but the inertia and recoil could require it.
BTW, UncleNick has great advice on reloading and you will benefit from what he recommends any time. I doubt I have ever disagreed with anything he has said. and if I did then I just have not yet learned that I am wrong.
Yosemite Steve
New member
What the....?
I think what you mean to say is that you measure your lands distance first. Headspace really has nothing to do with bullet seating depth. Headspace is how much play the case has in the chamber between the bolt face and the shoulder/datum.
Don't forget it. Maybe just don't go there quite yet. There is much to be said about seating depth adjustments. Some don't like to do it and some get great results from it. Start with manufacturers' recommendations and then only tweak one thing at a time if you want to experiment.
And I concur the Unclenick is #1 helper out there!
I tried some Barnes bullets in my 7-08 and at the crimp ring accuracy was horrible. I can see a crimp ring and half another one and they punch dime holes all day. I don't crimp magazine fed bullets in a bolt action. Longer oal works for me but I have to try different oal lengths because I want all the accuracy I can get. Take accuracy over speed any day.