Seating depth/pressure

[Konigs]

I have a question regarding bullet seating and it's possible effect on chamber pressure. I'm reloading .308 with Lap cases and D46 170g bullets,Vit powder & the dies are redding comp set. Ok, having set my bullet depth and decided on powder load I'm quit happy with the results so far. I recently bought some 170g Lockbase bullets, again Lap. Still using the same powder load, only had to adjust the bullet seating depth as the ogive on that bullet is further down it's form than the D46's (but it still has to go in the mag.)and here's my question, the reloading manual
makes no distinction between either of those bullets as far as over all length is concerned but now the load is almost compressed, so ,I haven't exceeded the max loading or the OAL but have I created a potentialy dangerous situation influenced soley by bullet depth or am I worrying about nothing???? Sorry if this has been asked before but some good advice would be appreciated, needless to say I haven't been reloading very long.....nor have I fired those 5 rounds I've made up so far.
Oh yeah, the bullet is still sitting a decent distance from the chamber throat
Thanks,

 

[The Mechanic]

Re: Seating depth/pressure

In short, Yes.
Need to run them through Quickload or at least try a different manual as a cross check including using individual data from the projo mfg.'s listing

 

[desertHK]

Re: Seating depth/pressure

When you try to ram in a longer bullet into the casing, not recommended. It is better to load it a bit longer if you sitll have room in your chamber. I would strongly recommend measuring your chamber length. Different bullets have different shapes ang ogive. For a 308, the standard OAL is about 2.800".

 

[Konigs]

Re: Seating depth/pressure

Thanks guys..

 

[Konigs]

Re: Seating depth/pressure

Thanks guys..

 

[Mag 300]

Re: Seating depth/pressure

Agree with trying Quickload as a referance
Bill

 

[Country]

Re: Seating depth/pressure

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Aceshigh</div><div class="ubbcode-body">I have a question regarding bullet seating and it's possible effect on chamber pressure. I'm reloading .308 with Lap cases and D46 170g bullets,Vit powder & the dies are redding comp set. Ok, having set my bullet depth and decided on powder load I'm quit happy with the results so far. I recently bought some 170g Lockbase bullets, again Lap. Still using the same powder load, only had to adjust the bullet seating depth as the ogive on that bullet is further down it's form than the D46's (but it still has to go in the mag.)and here's my question, the reloading manual
makes no distinction between either of those bullets as far as over all length is concerned but now the load is almost compressed, so ,I haven't exceeded the max loading or the OAL but have I created a potentialy dangerous situation influenced soley by bullet depth or am I worrying about nothing???? Sorry if this has been asked before but some good advice would be appreciated, needless to say I haven't been reloading very long.....nor have I fired those 5 rounds I've made up so far.
Oh yeah, the bullet is still sitting a decent distance from the chamber throat
Thanks, </div></div>
Without the type of Vihtavori powder and the grain weight used it is not possible to say. Not all compressed loads are unsafe.
I agree with the others run your load through Quickload .
Generally speaking slow powders that you can't get enough in the case anyway can be compressed a small amount but a max load of fast burning powder might get twitchy if it was compressed.

 

[johngfoster]

Re: Seating depth/pressure

Whenever you change any component, even same wt bullets, you need to back off on your powder charge and work up again.

 

[paul T]

Re: Seating depth/pressure

Vit n550 is exellent for 175g+ weight 308 bullets, n540 for 155-175g weight.

 

[Konigs]

Re: Seating depth/pressure

The powder I'm using is Vit N140 which I think is pretty fast burning,, I'm loading at 43g at the moment. I know there are other powders, but here (Italy) there is a very patchy supply of stuff from the USA (pity but not much can do about it), so can't always be sure of availability, so decided to stick Lap stuff. At 500-800M those rounds are giving me good results without signs of overpressure or difficult extraction. Think I understand now that any change to a part of the "chain" means working back up and starting from scratch. I'll look into the N540 powder as well

Thanks,

 

[Fuzzball]

Re: Seating depth/pressure

"...have I created a potentialy dangerous situation influenced soley by bullet depth or am I worrying about nothing????"

Unless your load is at the ragged edge of safety I think you are worrying about nothing. Changing bullets will surely make some difference in chamber pressure but it's not vast. Ditto OAL unless you are going from a jump to jamming into the lands.

 

[Country]

Re: Seating depth/pressure

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Aceshigh</div><div class="ubbcode-body">The powder I'm using is Vit N140 which I think is pretty fast burning,, I'm loading at 43g at the moment. I know there are other powders, but here (Italy) there is a very patchy supply of stuff from the USA (pity but not much can do about it), so can't always be sure of availability, so decided to stick Lap stuff. At 500-800M those rounds are giving me good results without signs of overpressure or difficult extraction. Think I understand now that any change to a part of the "chain" means working back up and starting from scratch. I'll look into the N540 powder as well

Thanks, </div></div>
At 43 grains of Vit. N140 with a 170 grain bullet you are .8 of a grain under the recommended Maximum . So if it is only slightly compressed I can't see that it will make a huge difference . Most guns will take a couple of grains more than the recommended max anyway before excess pressure signs showup .