Friggin' bullet seating depth.

I recall an article about load development. It was for BPCR but had a good point.
What do you do with leftover less accurate ammo as you continue to work up from your best yet?
Shoot it offhand, you need the practice anyhow.
 
What bullet weight are you using? More clearly,how much of the full cylindrical portion of the bullet is engaged to the neck?
In the extreme,if you are loading 155 gr boat tails longer than 3.00,you might be making a significant compromise.

Also,long throated reamers for heavy bullets are certainly a possibility. Throat erosion is another(Though you have mentioned good accuracy)
 
I shoot a Rem.700 308 cal. It started out as a LTR 20" brl. 1/12 twist. The rifle had so much free bore the bullet was almost at the end of the case neck to hit the rifling. Would just keep to OAL of 2.800 with a Sierra 168 MK using IMR 4064. The rifle shot very accurately. After 4000+ rounds I had a Rock Creek M24 5R 11.27 twist cut at 21" barrel installed & blueprinter, The new barrel has very little leade, it shoots best with a .002 jump with F/L case sized from head to datum .002 , I check with the RCBS Precision mic. I'll remove the firing pin assembly & plunger to test the round in the chamber. The M24 barrel is 1" thick with little taper, just love shooting the rifle.
 
ADIDAS69,

Alas, you have more work ahead of you. It is true that some guns like the bullet seated to touch the lands. Mid Tompkins told a long range rifle class I took that he and his whole family of long range champions "soft-seat" their bullets. That is, he sizes the case necks so the bullet has friction light enough that you can still push it in deeper or pull it out by hand. Not too loose, but not hard. He then seats them out beyond the throat of the gun by a little and allows the act of chambering the cartridge to complete seating. He and his family have an awful lot of gold medals between them.

That said, it isn't always best. The late Dan Hackett, writing in the 1995 Precision Shooting Reloading Guide, described a 40X in 220 Swift that he was loading for by 0.020" off the lands, thinking that was best. It shot half inch 5-shot groups on average, which, as a benchrest shooter he did not find adequate, but nothing he did could improve on that. Then one day when he was switching to a shorter bullet, he accidentally turned the micrometer adjustment on his seating die the wrong way and wound up with 20 rounds seated 0.050" off the land before he noticed the error. He debated pulling the bullets, but decided instead just to shoot them for trigger practice. To his astonishment, he had two groups that were 0.25 inches and two true bugholes in "the 1's" (0.10" to 0.1999 range)

Berger had a similar experience. You can read about it here. In some guns they've found their secant ogive bullets seat best jammed into the lands, but in others 0.020, 0.050, 0.080, or even as far as 0.125 off the lands do best. So you just can't know until you try.
 
I think my method for bullet depth is better.

Seat a bullet in a sized case, make it long.

Gently (and I mean very gently) move the bolt forward.

It will stop before closure, if stuck, gently tap the bolt handle with a plastic screw driver handle in the OUT direction. .

Move back the bullet .020, try again. Repeat.

Some bullets will stick in the lands, gentle tap on the bolt handle gets back out.

Make sure that the bullet is not shorter after you get it out than it went in, you have cammed it a bit.

Simple, easy and effective.

While I do not suggest using loaded bullets I do, but we want people to be safe so I don't recommend it.

Of course I also recommend keeping your finger off the trigger unless you really want it to go boom to.
 
I just size a case, gently split the neck and seat a bullet nose first into the case.

After adjusting the set up so the the bullet can move fairly easily, close the bolt slowly, open slowly, and you have a flat base in which to take your measurement.

An easy way to get bolt face to lands for future use. I usually do this at least 2 times to establish a consistent measurement.

After that, I always seat bullets using the case head to ogive dimensions and keep 0.020" as that clearance for starting purposes.

I never use an OAL or COAL measurement.
 
when seating touching lands in my 700 ,it leaves about 1/16" above boat tail to hold bullet, which I considered not good
 
cptjack
Had the same problem , just set the OAL to the listed length for the bullet your using and work on powder charge with .5 grain differences . When you find a good load fine tune. Shoot 5 shot groups , start low on the powder. For target shooting you don't need a hot round.
 
Thanks for the advice. cw308 more than once you helped me out. ,tweeked my load ,showing about 1/8 " above cannelure on another note I pay about 1/3 in taxes on 20 acres than me wife pays on 3/4 acres on in Suffolk ,live in your neighbor and made the move to upstate,,,,here the people actually wave
 
cptjack
Will be up in your neck of the woods this weekend Albany for a 65 birthday . Upstate is like Heaven to me . What caliber is your 700 ? I'm shooting a 308 with a 168 SMK bullet no cannelure , are you crimping your rounds? The barrel I have on my 308 now has just about zero free bore . My loaded rounds are 2.780 on a caliper OAL. What just popped in my mind , back in the early 70's I remember going Upstate sighting in a M1 Garand on the side of the road 3 large bolders by the road in the front with a quarry wall set back about 75 yards . At that time we were living in Astoria Queens where you could never find parking. Upstate was the closest thing to heaven. And still is , and yes the people are very nice.
 
SHOOTING 308 165 hornadys after a good load I switch to sierras ,which is more accurate qs tested in me 270 identical load but used hornady Sierra and the core lok bullet ,Sierra edged out the hornady and core lok was third. ....I am about an hour north of Albany
 
good info on seating depth

Was asking my engineer nephew to come up with a way to figure best OCW/ velocity for a 20" barrel. It's been done already. He found an article that demonstrates the importance of seating depth. Just as the shock wave down the barrel from firing the cartridge distorts the muzzle, it also affects how tight a seal the bullet makes back at the throat of the chamber. It's all timing and rocket science to me so I'll just keep working up loads a few grains at a time the only way I know how. A person could really go down a rabbit hole with this stuff.
 
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The solution to this would be simple for me. I have always made sure that the bullet was seated to a min depth of one bullet caliber. The idea as I learned it was it needed that much to hold the bullet firmly. What I found is that nearly all heavy bullet's in my rifle's, generally would make that, some ended up seating to the base of the neck. One rifle, a Rem 700 with a 100gr bullet, I couldn't get close to the lands. Problem was the magazine well was to short, I lived with it and it was fine. 100gr bullet's was all I'd ever tried in that rifle. In an old L61R Sako in 7mm mag years ago. using 160gr bullet's, the bullet went below the neck and was just off the lands. Plenty of magazine so I made up a dummy with the bullet seated to the base of the necf and had a gunsmith lengthen the chamber so that round fit just off the lands, worked like a charm.

You pretty much have to live with what you have. It sounds like you have a really long chamber and to hold the bullet at one caliber depth, your gonna have to let the bullet jump quite a bit. Weathery's all have a bunch of jump and I guess some of them still shoot well. You really need to get a handle on how long your cartridge can be. Try this, close the bolt on an MTY chamber and stick a cleaning rod down the barrel to the face of the bolt and mark the rod right at the barrel. Remove the bolt and drop a bullet into the chamber. get a new wood pencil and push the bullet until the lands stop it. Run the cleaning rod down the barrel again until the nose of the bullet stops the rod, hold the bullet in all the time. Mark the rod again and then measure the distance between the marks with your caliper. That is the length from the bolt face to the bullet tip. Make a dummy round that length, OLL. It will not chamber without hitting he lands. Seat just a bit more until the bullet no longer touch's the lands. Watch the land marks on the bullet as you go and every time you seat it deeper clean the marks by rubbing off with 0000 steel wool. Keep doing it till land mars no longer show at all. Even after you get to where you can't feel them, I've found they still show faintly, not good enough, go just a bit deeper.

Now, if your chamber is simply to long, seat the bullet to one cal depth. With the 308 the bullet will be seated to where the neck and shoulder meet. That will leave you some bullet jump, the round should go right into the rifle and chamber. Load up some rounds and shoot them and see if your rifle can live with it.

If you still don't want that jump, take a dummy round to a gunsmith and have him cut the chamber to fit the load. If you get good results after seating to the base of the neck, I'd live with it myself. I would strongly suggest you do not seat the bullet as shallow as you say and try it. The bullet there could be seated off center and you may not even notice it.
 
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