Is it alright for a bullet to be touching the lands to shoot?
- Thread starter stoop14
- Start date
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Follow proper load work up procedures ( I have some info on my website).
Bullet location relative to the lands are used in all manner of configurations. As long as the powder charge vs bullet is correct, it will work.
Work up from published starting loads.
Jerry
Bullet location relative to the lands are used in all manner of configurations. As long as the powder charge vs bullet is correct, it will work.
Work up from published starting loads.
Jerry
Usually it is the other way around. You start with standard overall length for that bullet/brass combination then you work your way up slowly while checking for signs of too much pressure. You want to measure the overall length of when the bullet is touching before you want to start testing handloads.
Take an unprimed empty resized brass case and with a bullet seated out somewhat further then standard overall length, color the bullet jacket with black felt pen. The bullet should have scrape marks on it from the rifling when chambered into a rifle with the bolt fully closed. As long as the bullet isn't crimped it should move back into the case. Reseat the bullet making the overall length shorter by small increments and recolor the bullet until the rifling no longer makes a significant mark on the jacket of the bullet. With a bolt gun this method works the best. Hopefully this makes sense.
With reloads, when touching the rifling, it can cause a serious peak in pressure that might cause serious injury to the shooter or at least destroy your firearm. Also, I never go less then the standard overall length listed in the reloading manual because that can cause a compressed load and also cause serious pressure levels. Hopefully this makes sense. Be safe. Don't just take my words for it. You can also educate yourself by reading the reloading manuals. They often have reloading tips in a section of their manual.
Ya I read a few and I did the marker trick then set the say seating die a a few thousands back but I'm still touching the lands and my powder load is where the manufacture says, I'm running 175 smk bullets with 43.5 varget. The OAL is 2.934 cases ad trimmed to 2.005. It's not the top node and no I'm not crimping.
lol - dont worry about ur rifle blowing up with the bullet touching the lands. as long as you stay with in the max recommended powder gn.
just go read mystics webpage.
To answer your Q as well, Yes. We usually start at touching the lands, than figure out what gn of powder will work best, than go back to the oal and start working down to find your optimal length.
just go read mystics webpage.
To answer your Q as well, Yes. We usually start at touching the lands, than figure out what gn of powder will work best, than go back to the oal and start working down to find your optimal length.
- Location
- Prince Albert, Sk
The SMK's have a fatter profile, ogive. They definitely hit the lands much before any other bullet I have loaded.
tactical lever
CGN frequent flyer
- Location
- Fox Creek, Alberta
I'm not good enough to tell the difference, but I believe I heard somewhere that it's actually a little more consistent to be just off the lands. This way if one is a slight bit longer, maybe due to brass varience or bullet or maybe you just didn't over cam. You'll always be "just off the lands" and have a more consistent pressure curve.
Maybe I'm making stuff up and the really hardcore guys will say that there is no varience in their ammo.
Maybe I'm making stuff up and the really hardcore guys will say that there is no varience in their ammo.
This is why we use a tool called a comparitor to check the oal after we seat a bullet.
Measures from the ogive.
Try various OALs relative to the the lands and use the OAL which shoots the smallest groups. A survey of top .308 Win. BR shooters by Precision Shooting magazine stated the majority used loads with bullets into rifling. This increases pressure so you may have to lower powder charge, but it usually uniforms SD.
Regards,
Peter
Lapua in Canada
Regards,
Peter
Lapua in Canada
- Location
- Somewhere on the Hudson Bay Coast
I prefer the bullet to have contact with the lands. This is simply the best way to uniform the bullet pull weight which has a significant effect on accuracy. If you work up to your maximum load with the bullet in contact with the lands, you can't get surprised by a pressure spike as you adjust the seating depth of your bullet, as any slight adjustment you make to your OAL will reduce pressure rather than increase it.
Factory guns have long throats. I doubt very much you will be able to use a magazine with a match bullet and have it in close proximety to the lands.
VLD bullets - as a rule of thumb - work best jammed 15 thou or so past first land contact. Non-VLD/Tangent Ogives work well almost anywhere, but they tend to work better off the lands.
Forget COAL measurements off the meplat, they mean absolutely nothing. (If you set up a die to seat a bullet, try measuring the COAL and you will find tremendous variation from round to round, but measure off the Ogive, and there will not be) The ogive measurement is what counts. THAT is what contacts the rifling. There are huge OAL differences in base-to-tip bullet measurements. Get a caliper from Canadian Tire and buy a bullet comparator from Sinclair et al for the caliber(s) you are using.
VLD bullets - as a rule of thumb - work best jammed 15 thou or so past first land contact. Non-VLD/Tangent Ogives work well almost anywhere, but they tend to work better off the lands.
Forget COAL measurements off the meplat, they mean absolutely nothing. (If you set up a die to seat a bullet, try measuring the COAL and you will find tremendous variation from round to round, but measure off the Ogive, and there will not be) The ogive measurement is what counts. THAT is what contacts the rifling. There are huge OAL differences in base-to-tip bullet measurements. Get a caliper from Canadian Tire and buy a bullet comparator from Sinclair et al for the caliber(s) you are using.
