No Tool Seating Depth Method

MagnumManiac

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Joined
Feb 25, 2008
Messages
4,153
Holy smokes….I don’t foresee myself ever being this committed…but if you derive some satisfaction from this degree of meticulous attention all the power to ya! That’s what it’s all about, finding satisfaction in the work you’re doing (Ecclesiastes talks a lot about that :) ).

I’m probably a heretic here but I stopped trying to seat anything right up to the lands a long time ago when I realized that with my hunting accurate but not usually target accurate rifles, combined with my not bad but not at all professional level of shooting ability, it didn’t make enough difference to count. That and discovering some bullets like jumping.
I do this so that my rifles will print 10 shots into one ragged hole off a bench.
I want an AVERAGE 1/4MoA or better @ 100mtr when I am working up my loads.
If it cannot do this, the barrel goes bye bye.
I shoot Hunter class and F-class, this is from prone where shooting technique makes or breaks the outcome….bench shooting is easier than prone.
I don’t do this on every rifle I own, there’s no point doing this on a rifle that shoots on average 3/4-1MoA, it will most likely not improve the outcome if you have already found the sweet spot on seating depth.

My custom Ruger M77 MKII was a learning curve to see what outcome all the tricks in gunsmithing BR guns could bring, bar sleeving the bolt.
It shoots to an average of 3/8MoA with non target bullets, the 110g Accubond for instance. The 115g Berger will print less than .2’s on an average of 10 shots.
Rugers are not known for that sort of precision out of the box, but this 25-06 proves that ANY action can be made to shoot.

Cheers.
 

Calvin45

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Joined
Apr 13, 2019
Messages
1,391
Location
Nipawin, Saskatchewan, Canada
I do this so that my rifles will print 10 shots into one ragged hole off a bench.
I want an AVERAGE 1/4MoA or better @ 100mtr when I am working up my loads.
If it cannot do this, the barrel goes bye bye.
I shoot Hunter class and F-class, this is from prone where shooting technique makes or breaks the outcome….bench shooting is easier than prone.
I don’t do this on every rifle I own, there’s no point doing this on a rifle that shoots on average 3/4-1MoA, it will most likely not improve the outcome if you have already found the sweet spot on seating depth.

My custom Ruger M77 MKII was a learning curve to see what outcome all the tricks in gunsmithing BR guns could bring, bar sleeving the bolt.
It shoots to an average of 3/8MoA with non target bullets, the 110g Accubond for instance. The 115g Berger will print less than .2’s on an average of 10 shots.
Rugers are not known for that sort of precision out of the box, but this 25-06 proves that ANY action can be made to shoot.

Cheers.
That makes sense. If I ever need to pick someone’s brain I’ll bear you in mind.

The 3/4 moa hunting gun is more what I have and it’s what I learned to reload on, a boring ugly old savage 111 in 270 was my first. It has never printed a group I’d post pictures of and brag about, it’s never shot a group under half an inch. It’s also only encountered 2 specific loads in its entire existence that couldn’t do right around an inch or inch and half….it’s kind of boring really.

My newer savage 300 win mag has on more than one occasion shot one ragged hole groups but that’s with 3 shots not 10, and I’m fully aware they’re not the same thing at all.

One thing I’ve found to live up to the hype has been that hexagonal boron nitride. Pretty much none of the issues of moly and tungsten disulphide, and it really does seem to make loads much less sensitive to seating depth due to the reduction in initial engraving pressure (probably, I don’t actually know if that’s why, just know it works), as well as reducing point of impact differences between cold bore and subsequent shots. Not to mention I have personally found you can load to higher velocities as it allows for larger powder charges. That’s been my experience anyway. I haven’t been using it long enough to know what it does for barrel life yet.
 

MagnumManiac

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Joined
Feb 25, 2008
Messages
4,153
Funny you mention HBN, my ELR gun will only shoot my custom CNC turned solid .338” 323g bullet if HBN coated, if not it wobbles around it’s axis. The additional velocity is the key. I get an additional 100+fps from HBN.
Dabbled with it in my F-class 264 and 300, but didn’t improve on any groups.
I may look at it again in the future as I have several new projects on the SAUM & WSM cases I will be doing for myself.
Also a 33XC in the works as soon as an action shows up.

Cheers.
 

SSgt G Cody

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Joined
Feb 23, 2020
Messages
168
Location
Asheville, NC
BFD, I use a very similar method to you. I load an empty case with just a bullet very "Long", crimp lightly, Load into chamber, closing bolt. When I then remove case and bullet, I know it has been "Shrunk" to maximum chamber length. I measure OAL, make note of it, then start my reloads at .020" less than measured OAL. This allows .020 of free-bore, which is a great place to start working up my loads! This should be done for each bullet you use, and for each gun you use.
 
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