Bullet seating depth?

[CB11WYO]

Being newer to reloading, I hadn't actually ever heard the "1 Cal. depth" seating rule. Seems like a good starting point though. I usually end up about .010" off the lands, with my guns anyway...

 

[jsdboy]

Hornady LNL detpth gauge with comparator

The manuals suggested OAL's are to keep it short enuf to feed thru most magazines.

To determline where the bullet ogive touches the lands, get a Hornady bullet comparator and read the instructions. The lighter bullets may need to be seated down so that they are not able to reach the lands. Try to keep minimum of about .01" of bullet in the neck.

There! this is the comment I have been waiting to see in this thread. All other discussion had proved fruitless for me until i got one of these babies.

And the Barnes bullet company insists that the ogive of it's projectiles be seated 50+ off the lands, and this simply can not be done on a replicable fashion without one of these gizmo's.
I find that my hunting guns prefer the ogive of the bullet to be 10-20 thou. off the land. In fact, the more powder I stuff into a case, the more i will back the bullet up.

this one tool has been the best investment in reloading stuff i have made for consistent shooting while switching up projectiles.

as for how deep to seat in the neck, if the entire neck surface of the case is not engaged with the bullet, i don't do it. Again, it has to do with consistency. statistically, there is very poor consistency with case/bullet friction with only 100th" of the bullet in the case mouth.
No, I am not a math prof nor an engineer, however a lot of shooting buds at the club are and i deem them worth listening too as these old boys can shoot circles around me.
good shooting folks!
jsd

 

[Reloader222]

Got to the following site for a cheap effective way to determine the best OAL for your rifle:
Innovative Technologies - Reloading Equipment

Go to Reloading and Shooting Tech Tips and then to Best OAL.

 

[jsdboy]

Got to the following site for a cheap effective way to determine the best OAL for your rifle:
Innovative Technologies - Reloading Equipment

Go to Reloading and Shooting Tech Tips and then to Best OAL.

THANK YOU!

I really appreciate tips on awesome and affordable reloading stuff.
the funny thing is that I would be lying if i said that i shot long range - but i have the most "accurate" out of the box Savage model 14 Euro Classic 308 I have ever seen - and it is from 'anal-yzing' all the variables

thanks again RL222 and have a great day!
jsd

 

[Whitesheep]

Wow, I know I post among giants when a 3/4" group @ 100 yrds is ho hum and 5 into a quarter sized hole at 100 yrds is not really considered good enough. Seriously, I am impressed.

As for C.O.L I agree on what has been said here and that the Hornady or other chamber length gauge is an important tool for working up loads truly customized not only to the rifle but to the bullet being loaded in a particular rifle.

In "Getting the Best Precision and Accuracy from VLD bullets in Your Rifle" Berger recommends the following:

Load 24 rounds at the following COAL if you are a hunter (pulling a bullet out of the case with your rifling while in the field can be a hunt ending event which must be avoided) or a competition shooter who worries about pulling a bullet during a match:

• .010 off the lands (jump) 6 rounds
• .050 off the lands (jump) 6 rounds
• .090 off the lands (jump) 6 rounds
• .130 off the lands (jump) 6 rounds

This is the procedure I have been following using 5 rounds (they fit in a standard ammunition box better) with good success. I use this method for all bullets manufacturers, not just Bergers. Note that success for me is 1 MOA, so if 3/4 is just ho hum for you, you may need to work within the 0.04 increments. PM me if you would like a copy of the Berger article.

I disagree with the comment about not "wasting money" on a chronograph and "backing into" the numbers using a load book. IMHO this sounds like a technique subject to large error and penny wisdom when pounds matter. A chrony is about $200 from Dillon http://www.dillonprecision.com/#/content/p/9/pid/24728/catid/32/CED_Millenium_Chronograph and with $3000 rifles and $1500 scopes the norm for what is advertized on this site, $200 for a tool seems small change for someone really interested in long range accuracy. I find also fine it important to remember that BC is an estimate as well as an average over various velocities. Read the back of your Sierra loading manual for a good introduction to the problems/issues with BC. Only real live range tests with your gun and your loads matter.

Great discussion and happy shooting to all.gun)

 

[RUMBALL]

So, I finally got around to working up some coyote/wolf loads for my .270. I'm going to try the 110 Vmax and a 90 gr Sierra hollow point.
I started with the Vmax, but when I seated the bullet to the length specified in the Hornady book (3.165") it's not even CLOSE to the cannelure. I was always under the impression that you seated the bullet to (or even over) the cannelure. What gives?
I then switched to load the 90 Sierra's. Although there's no cannelure to go by, when seated to what the Sierra book calls for (3.200"), it's only into the case by .172". Is that correct?

Gday I use the 90gr sierra in my tikka t3 270 and at 3.200 oal it was getting rifling marks on projectile after using a oal gauge it was 2.275 at the orgive and my oal cartridge length was actualy3.183 on the lands.
So I seated them at 3.170 oal had them loaded with 60gr of ar2209/h4350 and they are deadly accurate.
Maybe different in your rifle so start a grain or two less this is not a max load but best to work up just to be safe.
winchester brass,fed 210 primers.
Also have used 110 vmax havnt spent much time with them last test was 54.5gr of 2209/h4350 this is mild load with 1/2 inch groups im sure they could be better with some work.
Cheers
Rumball.

 

[duke75]

Bullets of the same caliber are different, as is the gun itself.
The olgave of the bullet is the largest part.
I always allow the bullet to seat where the olgave is resting in the lettie which is
just before the rifling.
The bullet is now positioned where it does not jump from the casing into the
rifling, you will see a great difference in accuracy.
I use a dummy round which I put a slight crimp just enough to hold the bullet
secure.
I then chamber the round very slowly pushing the bullet into the casing util the
the olgave makes contact with the rifling.
I slowly eject the dummy round and mark it, you now have a round that is
ideally seated.
The next thing you do is seat the bullet so very slightly further back into the casing
Don't forget the first mark you made, this is your reference point.
Give this a try you notice your accuracy has improved,

 

[MtPockets]

Wow, I know I post among giants when a 3/4" group @ 100 yrds is ho hum

Whitesheep, the problem with the written word is that you can't see the emotion in the writers head or the sarcasm in his voice. I am EXTREMELY happy with that 3/4" group, I just HOPE it wasn't a fluke.
Since that was among the first loads that I've tried for that gun, I guess we'll have to wait and see...
I have a buddy who owns a stock Sako that shoots quite a bit better than 3/4" and I'd REALLY like my old Ruger to show him what's what!
Like I said, for a stock (and very old & well-used) hunting rifle with a very old scope I'll be pretty happy if I can make it work...


Thanks for all the good info, fellas!!!

 

[MtPockets]

I think I found some powder and primers! Life is good!!!

 

[tt35]

I'm surprised noone has mentioned comparators when discussing COAL. Very cheap useful tool to measure and compare the ogive of different bullets in the same cartridge and rifle. It also removes the variable of bullet tip irregularities when measuring your sample bullet especially for hollow points. It may not be perfect in finding equivalent distance-to-lands measurements for different bullets but it gives a good starting point without starting over with the COAL length gauge. I use the "nut" comparator from Sinclair. It saves time and increases measurement accuracy at the reloading bench.

 

[tt35]

I'm surprised no one has mentioned comparators when discussing COAL. Very cheap useful tool to measure and compare the ogive of different bullets in the same cartridge and rifle. It also removes the variable of bullet tip irregularities when measuring your sample bullet especially for hollow points. It may not be perfect in finding equivalent distance-to-lands measurements for different bullets but it gives a good starting point without starting over with the COAL length gauge. I use the "nut" comparator from Sinclair. It saves time and increases measurement accuracy at the reloading bench.

 

[Whitesheep]

tt35 I couldn't agree more about having the right tools to measure COL to the ojive where it touches the lands in YOUR rifle. Even bullets from the same green box can be as much as 0.005" different in length. Yellow box variation is even greater in my experience with 7mm bullets.

I do have one rifle with very gradual leade into the lands that is difficult to get a consistent measurement of COL to ogive length. It ranges about 0.005" between just touching resistance and a full jam. Since this is far below the 0.040" steps I use in working up loads, it is more of interest than concern.

I have an article from Berger with their recommend testing for ideal COAL "Getting the Best Precision and Accuracy from VLD Bullets in Your Rifle" which is attached. The crux of this document for hunters is:

[FLOATRIGHT]Load 24 rounds at the following COAL if you are a hunter (pulling a bullet out of the case with your rifling while in the field can be a hunt ending event which must be avoided) or a competition shooter who worries about pulling a bullet during a match:

• .010 off the lands (jump) 6 rounds
• .050 off the lands (jump) 6 rounds
• .090 off the lands (jump) 6 rounds
• .130 off the lands (jump) 6 rounds

Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. The remarkable reality of this test is that one of these 4 COALs will outperform the other three by a considerable margin. Once you know which one of these 4 COAL shoots best then you can tweak the COAL +/- .002 or .005. Taking the time to set this test up will pay off when you find that your rifle is capable of shooting the VLD bullets very well (even at 100 yards).[/FLOATRIGHT

While this did not work for me in the one rifle I tried it in (T/C PH .280 Rem) after burning up most of a yellow box, it has paid off with SGK's for this rifle and others.

 

[jsdboy]

I'm surprised no one has mentioned comparators when discussing COAL. Very cheap useful tool to measure and compare the ogive of different bullets in the same cartridge and rifle. It also removes the variable of bullet tip irregularities when measuring your sample bullet especially for hollow points. It may not be perfect in finding equivalent distance-to-lands measurements for different bullets but it gives a good starting point without starting over with the COAL length gauge. I use the "nut" comparator from Sinclair. It saves time and increases measurement accuracy at the reloading bench.

check out post #10

 

[tt35]

I stand corrected, jdsboy!