Question on seating depth experimentation.

[FEENIX]

Wrong! The longer the jump to the lands the less pressure you have. Weatherby uses freebore to decrease pressure and increase velocity.

This!

 

[FEENIX]

So the more you stuff your bullet into the case and decrease case volume, there isn't a corresponding increase in pressure?

As per my #2 post, I started at .015-.020" off the lands, my preference for hunting loads. Since, I ended up at .080" off the lands when I finally got the group I wanted. This means I also have to reduce my powder charges.

 

[K.E.C. Darkside]

Howdy, when I have bullets still wanting to go vertical, I have found that my powder weight still needs work.
And horizontal I need to work on seating depth. And have you tried different primers. What bullets are you using?
Berger's tend to like a jump.
Hope this helps.

 

[fruitnut]

From the link above:

Important: Adjusting seating depth to match your rifle's throat/freebore and maximize accuracy "is fine, but bear in mind that deeper seating reduces the capacity of the case, which in turn raises pressures. Going the other way, seating a bullet out to the point that it actually jams into the rifling will also raise pressures." – Sierra Reloading Manual

 

[nealm66]

What type of stock are you using? I've had to play around with different rear setups to bring groups in tighter with different stock designs. Also find with lighter magnums that a little hold on the forestock goes a long ways in some cases. Where the stock rides in the front rest, it all can make a difference if you're trying to shoot tiny. Ive lost count of how many times I've helped guys at the range realize their sling studs need to be away far enough from front or rear rests. I always ladder in and out 3thousands from 10k off jam. I do my pressure ladder first at 20k off jam. Hope this helps

 

[MarkInPA]

My rifle is Bergara B14 hunter. A Remington 700 clone. I replaced the factory stock with a Boyd's laminated stock. I think it is their platinum model. It's just a sporter or hunting rifle. Nothing you would use for bench rest. It has a fairly straight comb with a cheek piece.

I know what you are talking about with the forestock hold on the magnums and have been giving this some consideration. I'm shooting a .30-06. Not a magnum but still there is some recoil there.

I've been trying to pay attention to the sling studs too. How far do you think you need to keep the studs away from the rest? I guess that depends on how much the rifle is going to move during recoil.

What is the concept on a mechanical front rest for the adjustment to pinch the front bag closed?

Appreciate your input. At least I know that I am paying attention to things that can make a difference.

 

[nealm66]

I usually stick a couple fingers in between the front sling stud and the rest. This also helps keeps everything consistent. I always have to shoot them a bit before I can figure them out. Most of the time it's about how you'd shoot a shotgun as far as shoulder pressure and depends on a few different things on how much to hold down if any but ya just got to believe there's something there and figure them out. A stiffer rear rest would be my first attempt at your vertical but just try and enjoy the process and learn. Edited to add , maybe lay a dryer sheet down on the rear rest. Just gotta always be thinking about the recoil

 

[ShtrRdy]

So the more you stuff your bullet into the case and decrease case volume, there isn't a corresponding increase in pressure?

I'm with you on this relationship. The caveat to this is if the bullet is seated into the lands, then if you seat the bullet into the case the peak pressure will decrease as the bullet gets more jump before touching the lands -to a point.

 

[MarkInPA]

just try and enjoy the process and learn

Exactly what I'm doing. You never do know everything and there is always something new to learn. Sometimes the more you learn the more you realize there is a lot more you don't know. I guess that's what make it fun and it is part of what makes it enjoyable to come on here and share our experiences with each other.

 

[nealm66]

Well said. About the time I think I've got it figured out I end up at square one lol. Swapped a brake and tuner to make a gun legal for nationals and it's making my eyes water

 

[K.E.C. Darkside]

I usually stick a couple fingers in between the front sling stud and the rest. This also helps keeps everything consistent. I always have to shoot them a bit before I can figure them out. Most of the time it's about how you'd shoot a shotgun as far as shoulder pressure and depends on a few different things on how much to hold down if any but ya just got to believe there's something there and figure them out. A stiffer rear rest would be my first attempt at your vertical but just try and enjoy the process and learn. Edited to add , maybe lay a dryer sheet down on the rear rest. Just gotta always be thinking about the recoil

A USED DRYER SHEET.
Benchrest trick.

 

[MarkInPA]

I usually stick a couple fingers in between the front sling stud and the rest. This also helps keeps everything consistent. I always have to shoot them a bit before I can figure them out. Most of the time it's about how you'd shoot a shotgun as far as shoulder pressure and depends on a few different things on how much to hold down if any but ya just got to believe there's something there and figure them out. A stiffer rear rest would be my first attempt at your vertical but just try and enjoy the process and learn. Edited to add , maybe lay a dryer sheet down on the rear rest. Just gotta always be thinking about the recoil

I just did make this purchase. Do these serve the purpose of the dryer sheet? The front bag came very full and I question if it may be too hard. I'm considering leaving some of the sand out.

 

[K.E.C. Darkside]

Very Nice.
Everyone adjust them to their own liking.
Protecktor guys are great to work with.
Seen them at a national match last weekend. Enjoy
Ps: used dryer sheets work, ask your wife to put them in a baggie and not to throw away.

 

[Koda_]

I'm about ready to proceed with experimenting with overall length. I found a powder and bullet combination that seems to show promise at .020" off of the rifling. So, I'm going to start loading test groups by seating the bullet deeper in either .005" or .010" increments. I'm kind of curious how far you want to go by continuing to push the bullet deeper and deeper? This is for a hunting round so I definitely don't want the bullet engaging the rifling when chambered. As far as going to deep, I suppose that at some point it would become obvious that your seating too deep and I'm know that you have to be concerned about pressure the deeper you seat your bullet.

IMO, starting from .020" off the lands go forward in .003" increments no more than twice. I prefer to stay .010" off the lands for hunting ammo (technically .009"). Going back into the case go in .005" increments no more than what puts the base of the bullet past the bottom case shoulder. Always check for pressure signs and velocity changes along the way.