Bullets touching lands?

[leo158]

What's the worse thing that can happen if the bullet is touching the lands? What's the reason to just keep the bullet just off the lands?
Thanks again, Dan

[keeki]

nothing will happen, some handloads are crushed into the lands

[Elkbane]

The issue around "just touching" the lands is that there are manufacturing tolerances in bullet dimensions. Sometimes the distribution of dimensions is a typical bell shaped curve and sometimes its a bimodal distribution (like a two humped camel). If you are shooting bullets that have a +/- 3 thousandths variation, and you set your seating dies to touch the lands "on average", then some of the bullets will be "jammed" by 3 thousandths and some of them will be "jumped" by 3 thousandths. The effect of this will show up on target.

IMO, you either need to have them jammed or jumped, in all cases well in excess of the bullet's natural manufacturing tolerances.
Elkbane

[DanSavage]

The other danger would be, say you have worked up a good load that is off the lands and that load is near max pressure for that rifle and you seat the bullet out more to touch the lands then it could all the sudden be too much pressure for the rifle.
I always like to see how a load shoots jammed in the lands, so I will work up the load starting with the bullet jammed, when I settle on the optimal charge weight, I can safely move bullet away from the lands to fine tune it.

Regards,
Dan

[benfranklin]

nothing will happen, some handloads are crushed into the lands


Well,I say your full of crap....Just yesterday I went to the range with my 22-250
55 grain v max jamed into the rifleing..35 grain of H 4895 Shot 3 at 250 yards.
Bolt opened a little hard..Group fantastic..3/4 inch..No 4 shot blew the primer..
No 5 shot Case stuck in chamber..Had to come home and run a cleaning rod
in to remove case..Blew the ejector apart...Some don't tell him nothing will happen..
This was not a max. load neither according to the Hodgon manual...I can still shoot
the rifle,but the shells do not eject on their own.New spring and plunger on order..John

[keeki]

you can pop primers, split necks, stick cases and bust ejectors with the bullet .200" off the lands. Fact is that what happened to you had nothing to do with the bullet being crushed into the lands, it had everything to do with too much pressure. Sure the closer you get to the lands the higher the pressure is gonna be, so you gotta start low and work it up

[Eric in NC]

nothing will happen, some handloads are crushed into the lands


Well,I say your full of crap....Just yesterday I went to the range with my 22-250
55 grain v max jamed into the rifleing..35 grain of H 4895 Shot 3 at 250 yards.
Bolt opened a little hard..Group fantastic..3/4 inch..No 4 shot blew the primer..
No 5 shot Case stuck in chamber..Had to come home and run a cleaning rod
in to remove case..Blew the ejector apart...Some don't tell him nothing will happen..
This was not a max. load neither according to the Hodgon manual...I can still shoot
the rifle,but the shells do not eject on their own.New spring and plunger on order..John


Dang benfranklin - kind of harsh.

Well if you didn't work the load up jammed in to the lands the problem is YOU! You can work a good load up jammed into the lands and nothing will happen. You will get to max sooner than if it was off the lands is all.

If you just pulled that load out of your #$% and tried it without working it up from the start jammed into the lands (not loading to the COAL the manual said) you asked for trouble.

That load is over max in my manuals BTW.

Sounds like you need to learn a bit before calling someone out.

[keeki]

told me something when he said the first 3 were sticky bolt, the 4th popped a primer and he still shot number 5 ???

[benfranklin]

well You can bash me all you want..This load was worked up slow..A sticky bolt
does not mean high pressures..It could be from using fireformed case as well..
I have shots hundreds of loads with fire formed cases and had a thight bolt lift..
Any tighter than normal chamber will do the same thing..But I now for a fact if
you have a bullet into the lands,your gonna have a higher pressure reading..
After 40 some years of loading and match shooting this is the first primer I have
ever had blow like that..And if you know anything thing about some powder they
DO get hotter in warmer conditions..So don't be telling people nothing will happen.

[benfranklin]

told me something when he said the first 3 were sticky bolt, the 4th popped a primer and he still shot number 5 ???


tell me what it told ya? Thats why some rifle have some free bore in them to let out thye pressure..You should have know that... ??? ??? ???

[keeki]

whatever dude. Pressure blows primers not bullets. If your gonna deviate from the loading manual when it comes to oal, you cant go back and use the loading manual for everything else. So please dont throw that "this was not max load according to hodgdon manual" crap out there because it also wasnt correct oal according to hodgdon manual

[keeki]

shouldve never shot number 5 if number 4 popped a primer

[big honkin jeep]

The only time I have ever had sticky bolt lift from a fire formed case was when it was over length leading to high pressure.
I have several rifles I neck size for and load em long. I let the bolt fully seat the bullet jammed into the lands. It leads to very consistent seating depth and very good accuracy for me.

[Grit #1]

You know that a lot of this also depend upon the caliber in question. Some overbore and/or small case capacity cartridges are very sensitive to minor changes. The .223 rem and 22/250 fall into this category. The 220 Swift is really sensitive!! Larger bores are not so sensitive, like the 308 diameter bore. I've never been able to get enough powder in a 308 Win case to get a real high pressure problem. That is my experience.
Best regards,
Grit

[Dennis]

I've never been able to get enough powder in a 308 Win case to get a real high pressure problem

I HAVE :o


shouldve never shot number 5 if number 4 popped a primer

I also agree with the above! Especially with the first three being sticky! Been there!

[Trent]

well You can bash me all you want..This load was worked up slow..A sticky bolt
does not mean high pressures..It could be from using fireformed case as well..
I have shots hundreds of loads with fire formed cases and had a thight bolt lift..
Any tighter than normal chamber will do the same thing..But I now for a fact if
you have a bullet into the lands,your gonna have a higher pressure reading..
After 40 some years of loading and match shooting this is the first primer I have
ever had blow like that..And if you know anything thing about some powder they
DO get hotter in warmer conditions..So don't be telling people nothing will happen.



Just because you created an over pressure load does not mean that it was caused by the bullet being jammed. It is entirely on you. Jamming bullets is very standard practice. You must work up the load properly.

[benfranklin]

All the data came from the Hodgon manual,except for the oal...35 grain is not max neither..

[keeki]

obviously its over max! Cant change one part of the recipe without changing the rest of it

[Grit #1]

i'll give you an example of a short throat raising pressures to the point of trouble. I developed a load for an AR15 23 grains of Data 220 and a 62 grain SS109, Winchester brass, Remington small rifle primer. Granted Data 220 is on the fast side for the 5.56/223. I fired this round over 500 times through my A2 match rifle, Kreiger match barrel, with no problems what so ever. Then I decided to try that load in another AR-15, an A3 flat top with a Kreiger varmint contour with a .223 chamber. First round blew the primer right out of the case tying the gun up. I could not find the primer right away because it was stuck to the bolt face. The metal around the firing pin dent flowed into the firing pin hole! At first I was kind of dumbfounded. What the F!! Then I realized that the only difference between the two uppers was that the A2 had the match chamber for single feeding the 80grain VDLs, very long throat, and the A3 had the .223 chamber which has a really short throat were the bullet is almost touching the rifling. In this case the short throat raised the pressure to a dangerous level, and the longer throat did not. Bullet seating depth can make a difference. So in my humble opinion all of you are right to a certain extent.
Best regards,
Grit

[benfranklin]

Thank you Grit John FWIW I tried that same load this morning 2 rounds is all with the bullet jamed into
the rifleing.First shot hole in Primer,second blown primer----Two shots with the bullet about ..099 off the lands...No sign of pressure at all....So tell me what caused it? John