basic reloading question

[jason269140]

If a bullet is reloaded .007" into the lands will that create more pressure or less. (will it even be significant). Also, the people which push the bullets up that far, do they have trued actions and barrels in order to get away from the "jump" of the round going off?
Thankyou all in advanced

 

[427Cobra]

Re: basic reloading question

In the lands is more pressure, and most have aftermarket barrels with a custom chamber.

 

[jason269140]

Re: basic reloading question

does this sound right then. I'm shooting a 338LM 700 police. I reloaded 210 swift scirocco @ 89 grains of H4350. (My hodgon data manual says it's safe). I normally start out my reloading .005" or .010" back but this time I wanted to start up close. (reasons unknown now) so I left them .007" long but upon chanbering them the bullets slide back to zero. so I shot them and felt alot of bolt stinking. however the primers weren't flattened like I'm used to seeing on my savage 22-250 when I was load tuning. Could anyone explain all of this to me. and why would being in the lands add up to more pressure when the rifle powder is going to push it down there anyway? Are you referring to more of a gap or the burning powder to expand into before there is a pressure drop or is it the alignment of the bullet to the barrel getting offset because the casing can't center itself? Once again thankyou all for your help

 

[jason269140]

Re: basic reloading question

bump?

 

[Victor N TN]

Re: basic reloading question

Starting with the bullet touching or rammed into the lands, will cause a taller pressure spike at the first of the ignition series when the primer is first popped. If you have a chamber set up for that and have ammo that has been brought up from lower limits it can be a good thing. If you just start out making changes and not researching it properly before, you can get into serious trouble with "jam" loads.

Loading the bullet off the lands allows it to start moving before the bullet "jams" and starts the pressure spike. This gives a slightly less pressure spike in the overall picture.

Get a few books on handloading and do some research before shooting the loads you already have loaded. If you pierce a primer with that handfull of powder there is going to be consequences of some kind. Maybe more than just a scorched cheek.

I would advise getting a Lyman's Handloading Manual and reading all the information between the data chapters. If you feel that is beneath you, look in the back of a Precision Shooting magazine or Sinclair's Catalog and buy a copy of "The Benchrest Shooter's Primer". It leaves the beginning stages and gets in depth real quick.

 

[Innovative]

Re: basic reloading question

+1 That's great advice from Victor N TN.

I <span style="text-decoration: underline">never</span> recommend jamming the lands (especially for tactical shooting), because whenever you extract a loaded round, the bullet can stick and leave you with powder spilled all over the place. The accuracy gain (if any) is usually too small to measure.

- Innovative

 

[Greg Langelius *]

Re: basic reloading question

I generally try to develop my loads so there is no contact. All the above reasons apply. Sometimes accuracy concerns dictate otherwise, but I'll only willingly go with contact if nothing else works and the difference is truly and necessarily significant.

Greg

 

[jason269140]

Re: basic reloading question

thanks for the knowledge guys.

 

[Fuzzball]

Re: basic reloading question

Victor: "Loading the bullet off the lands allows it to start moving before the bullet "jams" and starts the pressure spike. This gives a slightly less pressure spike in the overall picture."

Expressed another way, allowing the bullet to get a running start before hitting the rifling somewhat flattens the peak timeressure curve. Wheither or not that's "good" for accuracy depends on the rifle and cartrige specifics, it's not a clear cut thing at all.

 

[Fuzzball]

Re: basic reloading question

Victor: "Loading the bullet off the lands allows it to start moving before the bullet "jams" and starts the pressure spike. This gives a slightly less pressure spike in the overall picture."

Vic is right.

Expressed another way, allowing the bullet to get a running start before hitting the rifling somewhat flattens the peak timeressure curve.

Wheither or not that's "good" for accuracy depends on the rifle and cartrige specifics, it's not a clear cut thing at all. But, seems MOST factory rifles do shoot better with a decent running start, .030" or more.

 

["Partridge"]

Re: basic reloading question

word to the wise.it is very easy to ruin a good rifle by not decreasing your charge ,and then working back up to where you want to be.if you put a max load that is not touching the lands,and then seat the bullet to touch the lands with the same charge.i would not be the one to shoot it.