Seating depth issue

[Icallem]

While at a gun shop the other day, I was talking about a target that I had shot, not knowing what to do to make it better. Some guy stops and asks what did the target look like?

Here is what it looked like:

X – 1st shot
0 - point of aim
XX XX

He said, “Oh, we call that two holing; it is a seating depth issue”. He then walked away. Other people said he is a benchrest shooter and knows what he is talking about.
I’m shooting 168 Berger VLD’s, touching the lands. I have seated them deeper, but seem to shoot best when out to the lands.
Is there something to this?

 

[Greg Langelius *]

Re: Seating depth issue

Gun shop 'wisdom' strikes again. Two holing for sure, seating depth, I wouldn't be so sure.

My first guess would be bedding, and I could be just as right or wrong as the guy behind the counter.

I would try different depths to be sure. Personally, I like to seat with a decent jump, at least .010", but that's not a truism, it's a personal quirk. If factory ammo demonstrates the same problem, I'm guessing seating depth ain't what at work here.

If the rifle isn't bedded, it's a good thing to do whether there's a problem or not. If it is, the odds that bedding is the problem become far less.

There are other potential issues as well.

Be kind to the counter guy, he means well; and he's not paid to solve problems, he's paid to sell stuff.

Greg

 

[Icallem]

Re: Seating depth issue

Thanks Greg.
The gun has been bedded, in fact, it was never fired before that so there is no baseline to draw from. The barrel does appear to be lots closer to one side verses the other, but after 15-20 shots, it is still not in contact with the stock.
I have laid out a box of factory rounds to try. All shells to date have been reloads.
This reloading is harder than what it first appears, Berger likes to touch the lands, a-max likes to jump .020 and on and on.....

 

[Greg Langelius *]

Re: Seating depth issue

It's as hard as you make it. I've spent decades finding out that simpler is better.

I think there's a natural progression about handloading.

Folks explore all the various methods and techniques, and each eventually comes to an understanding about what's important <span style="font-style: italic">for them</span>. I'm pretty sure you'll eventually end up looking for the simplest approach that pays, and that some tradeoffs will be at its basis.

Where seating depth is concerned, I count less on getting a specific jump distance for each round, and concenrtate rather more on ensuring they either all jump or all don't.

When I do my load development, I start out with the max OAL the bullet maufacturer recommends on a generic basis, and then revisit OAL testing as the absolute last step of load development.

Often, I will have found that the recommended depth delivers respectable accuracy, and simply leave the last step off. Having a round which will serve a generic application is sometimes preferable to getting that last bit of extra accuracy that overlength seating will provide.

Part of this tradeoff, believe it or not, involves personal liability. I'm getting on in years, and the end must come sometime. When it does, I don't want my descendants having to be comcerned with any outcome that might be involved with specialized handloading allowances they are not fully aware of. For my purposes, the generic application becomes the norm. There is still plenty of room for highly acceptable accuracy within such a set of limitations. Personal responsibility, for me, demands such.

For deliberate simplicity sake, I have adopted a SAAMI-only chamber spec policy.

This policy eliminates some things. Some of them are absolutely ultimate accuracy, and others are the more arcane techniques involved with such accuracy. It's a tradeoff, my tradeoff, and I'm comfortable with it.

Greg

 

[vman]

Re: Seating depth issue

This group that you shot... what was the height difference between the top shot and the bottom four?

Was the top shot a cold bore shot?

 

[SPAK]

Re: Seating depth issue

As I'm sure you've already considered, don't forget to rule out the shooter. I've shot groups at 100 yards just like that, with seemingly two groups going on, simply from placing the trigger on a different spot on my trigger finger.

 

[Icallem]

Re: Seating depth issue

vman, the top shot(cold bore) was 1/2 inch above bull, shots 2&3 were 1/2 inch below bull, with shots 3&4 just maybe 1/4 inch to the right.

Frogman, I always consider myself as the problem. In fact, I was / am pretty proud of that group.

 

[Fuzzball]

Re: Seating depth issue

"He said, “Oh, we call that two holing; it is a seating depth issue”. ..people said he is a benchrest shooter and knows what he is talking about."

Well, I'd perhaps agree when he said "WE call that two holing..", but after that, ... maybe not.

In my exerience, and IF it's consistant, "two holing" is more likely a primer and/or charge problem. But, I ain't no club range BR or BS shooter anymore.

 

[Lumpy Grits]

Re: Seating depth issue

Fouling is changing POI/POA
Could STILL be a bedding issue, BTW.

Cheers,
LG

 

[Swan]

Re: Seating depth issue

did you happen to change powder lots prior to shooting that group?

 

[Icallem]

Re: Seating depth issue

All shells were loaded with the same lot of powder.
I have cleaned the barrel, loaded some 168 SMK with some different charges of varget and maybe will get to test them today.
I'm shooting off of a bench(due to the snow and mud), but typically shoot prone. I could be rolling the rifle one way or the other, so will work on that.
Hopefully the weather will get better and a friend will go to shoot and we can get someone else behind it.

 

[Icallem]

Re: Seating depth issue

 

[Icallem]

Re: Seating depth issue / Pic added

Well I got to shoot yesterday and have a target much like the previous one.
I shot with a CCB, a 5-shot group with some factory Hornady, then started this target.
All shells loaded in FC brass, Federal match primers and loaded to 3.123 with a Sinclair comp.(this is .015 off the lands), with 168gr SMK.
Range to target is 229 yards.
Group #1 is 43.5 grs Varget.
Group #2 is 44 grs Varget. Scope was adjusted down ½ MOA from group #1. Frist shot is the highest one, then second shot the next one down. I guess the scope caught up with things, as the next 3 are close up and down.
Group #3 is 44.5 grs of Varget and does appear to have the ‘two hole’ effect. Scope adjusted ½ MOA left from group #2. Prior to first shot, scope was tapped on with pocket knife.
Group #4 is factory FGMM just used as a baseline.
After each 5-shot group, I walked to the target, so barrel should have been about the same each group.
Is group 3 the two holing, or is all this on me. I think group 4 is a tough argument for it all being me.

 

[notquiteright]

Re: Seating depth issue / Pic added

Curious as to what scope and power you use.

I'd say its all you. Since we cant see you drive the rifle we cant say what little thing(s) you do open the group up. If I understand the targets looks like you do 1moa at just over 200 yards.

I have no love for berger bullets, I prefer Amax. The fed factory ammo did the best and that says alot. If I had to say your muscle control as you squeeze could use some work. You are set hard on your rear support but rocked side to side as you pulled the trigger.

With the SMK or Amax alot of the anal tweaking isnt required. Both are very forgiving and have great downrange performance.

I'd recommend a few seasons on the Amax before tackling the more sensitive VLDs. Course a few seasons on the Amax and the experience you gain might make you a Hornady fan for life.

Good Luck

 

[Icallem]

Re: Seating depth issue / Pic added

This rifle has a Sightron S111 6x24x50. It has a target dot and I think I had the power on about 10.
I am having some issue with the accu-trigger on this rifle. I have a 260 with a Shillen trigger that breaks at about the pressure it takes to pull the blade back on this one. Group 4 makes me think it could be trigger pull. They went right, ... left.

 

[notquiteright]

Re: Seating depth issue / Pic added

I have had trouble with a 'gritty' trigger on savages. Several guys who have shot other rifles and then bought Savages feel it as well. The SSS competition trigger you can buy and install yourself, the 'glock' trigger you have will require a bit of the trigger housing cut away with a dremel, REALLY helps trigger control.

I dont own a target dot scope and find when I use them I tend to look around the dot and that hurts group size.

Do you keep your face solidly on the stock for the entire string and feed the rifle without looking around? A very good coyote hunter cut his group size in half by keeping his face on the weapon during the string. he was surprized it mattered that much.

It doesnt look like 2 holing but rather just the need to refine your techinque a bit. It might help to use a simple target, one that isnt so busy. I use shoot n c's with one shot, or group depending on the drill, per circle.

Good luck, yes a gritty or stubborn trigger can mess with you if you are wanting more than minute of buck.

 

[gvanhyning]

Re: Seating depth issue

I personally have not experienced two holing from seating depth. I have experienced two holing from a broken reticle in the scope. It was a Leupold MKIV 6.5-20 and the first shot would be exact at the point of aim and second shot would be 1/2" right, third shot would mark the first or second. I was like a dog chasing a cropped tail thinking it was the loads, then me, and then I noticed the reticle seemed canted and it was. Reticle was broken so might try shots with a different scope. After reviewing your other posts if the groups are from load development, I never pay attention to groups other than to pick the best one and work from there. Looking at the photo I would take group 4 and work with that. But if you already have a standard load with another bullet, might get some shots with something you know is consistent to eliminate any mechanical failure type issues.

 

[Icallem]

Re: Seating depth issue

I do not stay on the rifle, I shoot single shot and raise my head up after each shot.
I have printed up some targets that have 10 1/2 inch dots on them. That might help get my mind off of the group and on to each shot.
I did alot of shotgun shooting over the years and they always said you have to keep the two blocks of wood together!

 

[chain]

Re: Seating depth issue

I have had a rifle do that with the root cause being brass wasn't all the same. I sorted brass better and paid close attention to what I was doing with trigger control, forearm on the bag in the same place, or same pressure on the bipod, etc. I am leaning towards this.
I haven't heard "two holing ' since I skipped across the border from Laredo years ago,I was conducting normal business with a young lady entrepeneur and she informed me that "two holing" would cost more.

 

[vman]

Re: Seating depth issue

Chain, hahahaha