Seating depth of cup and core bullets

21 November 2022, 01:35

A custom rifle? I spec my reamers so the chamber will allow me to have the bullets I use to be able to kiss the lands if necessary and fit the magazine. I'm in agreement with Saeed about seating depth in a hunting rifle. Never seen it make a difference. A good hunting rifle, for deer, should shoot 1 moa with a cold, hot, clean, or dirty barrel.

21 November 2022, 11:46

Saeed

Under hunting conditions, and I mean proper hunting walking in the field, the biggest problem is the shooter.

I have seen very good shots, who couldn’t hit the proverbial bard door from inside!

21 November 2022, 16:11

p dog shooter

quote:
A good hunting rifle, for deer, should shoot 1 moa with a cold, hot, clean, or dirty barrel.

Heck a 2 inch gun will kill the most of the deer you'll shoot at.

21 November 2022, 16:12

p dog shooter

quote:
Originally posted by Saeed:
Under hunting conditions, and I mean proper hunting walking in the field, the biggest problem is the shooter.

I have seen very good shots, who couldn’t hit the proverbial bard door from inside!

Then why would one consider them very good shots.

22 November 2022, 02:36

miles58

quote:
Originally posted by ledvm:
This rifle has detaching magazines (clips for those who use that term).

I like the rifle except that it is a 1.5 MOA rifle for me. THIS has been a disappointment for me. But, it is a lightweight, 20” barreled sporter. Maybe that is as good as I should expect??? It will shoot about everything to 1.5. I have not tried beyond magazine length loadings as it is strictly a hunting rifle for me and I have just steadily been on the quest for that sub-MOA hunting load.

I would not accept that. What I would do is to Load some to .050 off, .030 off and some to .o2o off If the accuracy drops in for you then it appears that it's that long throat giving you trouble and your choices to correct that are first to find a bullet with an ogive that it likes better, that may or may not place the bullet closer or further off the lands. Or, the rifle needs to go see a gunsmith and shorten that throat up.

I had a Remington 700 that I did that damned dance with Remington that you did. It went back home twice. I finally just bought a different barrel and had it fitted and it has shot more or less everything well ever since. If you are married to Partitions then you will probably have only the gunsmith option.

22 November 2022, 03:17

crbutler

Sounds kind of like the song and dance I got from one manufacturer.

3 shot groups, and 1 out of 20 made their statement.

“It’s in spec”. “You can’t shoot.” “Buy better ammo.”

Sent them a target with 3 3 shot groups next to 3 5 shot groups out of a .416 Rigby. The .416 groups were 1/2MOA one holers. The .223 groups were all 1.5-2” groups.

I still have that rifle somewhere. Can’t see fit to sell it to someone when it’s that bad.

Sometimes you just get a lemon. Of course, I also think that a MOA rifle means that it always shoots MOA, barring you screwing up the shot… which you know you did.

I’d ask the company to send all the targets if they claim Federal GMM is that better- I haven’t had trouble equalling it or bettering it with like components.

22 November 2022, 05:35

JTEX

quote:
Originally posted by ledvm:
JTEX,
If I get time that works for you…I am going to drive down, bring components, and let you load for and shoot that thing and see if it is better for you.

23 November 2022, 16:28

ledvm

quote:
Originally posted by miles58:
quote:
Originally posted by ledvm:
This rifle has detaching magazines (clips for those who use that term).

I like the rifle except that it is a 1.5 MOA rifle for me. THIS has been a disappointment for me. But, it is a lightweight, 20” barreled sporter. Maybe that is as good as I should expect??? It will shoot about everything to 1.5. I have not tried beyond magazine length loadings as it is strictly a hunting rifle for me and I have just steadily been on the quest for that sub-MOA hunting load.

I would not accept that. What I would do is to Load some to .050 off, .030 off and some to .o2o off If the accuracy drops in for you then it appears that it's that long throat giving you trouble and your choices to correct that are first to find a bullet with an ogive that it likes better, that may or may not place the bullet closer or further off the lands. Or, the rifle needs to go see a gunsmith and shorten that throat up.

I had a Remington 700 that I did that damned dance with Remington that you did. It went back home twice. I finally just bought a different barrel and had it fitted and it has shot more or less everything well ever since. If you are married to Partitions then you will probably have only the gunsmith option.

The reason I want Partitions right now is that I am cat (mainly leopard) hunting with that rifle and I want a softer cup and core like effect on impact…but want the reliability of through and through penetration the Partitions offer. Just my thoughts FWTW.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
J. Lane Easter, DVM

A born Texan has instilled in his system a mind-set of no retreat or no surrender. I wish everyone the world over had the dominating spirit that motivates Texans.– Billy Clayton, Speaker of the Texas House

No state commands such fierce pride and loyalty. Lesser mortals are pitied for their misfortune in not being born in Texas.— Queen Elizabeth II on her visit to Texas in May, 1991.

23 November 2022, 16:38

Saeed

Lane,

Don’t listen to arm chair writers, who are totally ignorant of actual hunting in the field.

I have many lions and leopards with either Barnes X, or my own Walterhog bullets.

Every single dies within a few yards.

This year shot two lions and one leopard with my Walterhog bullets.

3 shots.

3 dead animals.

Shoot any bullet that shoots well in your rifle.

In fact, as a personal preference, I would avoid partitions completely.

I would use a mono copper for everything.

Been doing it for so many years, with complete success.

03 December 2022, 17:24

LeonKomkov

Saeed, I know I'm a bit late to this thread, but I wanted to thank you for your insight regarding seating depth. I've spent years fiddling with seating depths, powder varieties, primer types, loads, etc. and while I found various "sweet loads" for various rifles, I have to admit there was no consistency to my findings --- more trial and serendipity. After reading your post stating that you always loaded to OAL, used large magnum primers for load over 30-06, and then simply varied charge, I realized my system had too many variables. Understanding that you've done a lot more reloading and shooting than I can hope to do, I spent the last several weeks ignoring bullet seating depth, and focusing solely on charge. The results are fairly remarkable in terms of efficient development of accurate loads. Sorry for the lengthy fan letter, but your post regarding seating depth came at a perfect time to clarify my path forward. Thank you.

16 December 2022, 23:38

McKay

quote:
Originally posted by ledvm:
quote:
Originally posted by Atkinson:
What dpcd said, and btw a NOsler partition is not a cup and core bullet, its a super premium bullet, and one of the first..the word partition is the first clue..

Just a double ended cup with an unbonded core of lead in each.

This, not a "super premium". Shot many, decent bullets. Lost cores in some on recovered bullets. Certainly better bullets out there now days. Was a great bullet 50-60 years ago. If you like the "partition" aspect I would buy an A-Frame every day of the week over the Nosler.

16 December 2022, 23:44

McKay

quote:
Originally posted by Peter Connan:
quote:
Originally posted by Saeed:
There is no way in HELL you can change the seating depth by 0.004" and notice any difference!

NO WAY!

Just opened a box of Sierra 168 MK bullets, and measured the length of ten random bullets.

I use a laboratory grade micrometer which I use here in my workshop.

1.2115"
1.206"
1.1905"
1.211"
1.204"
1.1895"
1.210"
1.199"
1.1985"
1.209"

Even the above sample shown here there is a difference of 0.022" in length.

Youtube has an incredible amount of utterly stupid videos on shooting.

There are some channels by professionals which are very good.

But the majority of "look at me" idiots are totally pointless.

Go measure the same bullets from base to ogive, and you will notice they are a lot more consistent.

Agreed the only time I measure an overall length is just for a quick check for magazine fit. After that always measure to Ogive. Don't know of any bullets except for those made on a lathe that will measure consistently to the bullet tip.

17 December 2022, 20:50

Puddle

I've loaded Partitions for only 3 .30-06s. 2 factory rifles and one custom. And only loaded the 180 grain Partition.

In all 3 rifles I began 0.020" off the lands, which was always within the magazine box limits. The 2 factory rifles ended up grouping best at ~0.040" and the custom rifle grouped best at 0.020".

This was with loading the 180 grain Partition, depending on the rifle, to an average MV of 2690 - 2750 fps.

BTW, I agree with one poster - if you like Partitions, then go with the A-Frame.

31 December 2022, 22:30

Atkinson

I require most of my rifles to shoot an inch, and most loads to the same POI..WHY!! I have no idea and it makes no difference to start with for a hunter or his rifle, a 2" gun will kill the same number big game from coy8otes and Javalina up..A goood Varmint rifle needs to shoot half inch to 3.4s" but you can get by with 1.5 I betcha..

31 December 2022, 22:37

Atkinson

The Nosler is a double ended cup and core???, well eloquent and cute but Im not buying it..It is also the bullet by which all others are measured by, why because it works, I can say the same for the Rem corelokt, Ww power point, and they don't have a partition, Sounds like "monolithic chatter" , BORING!!

20 January 2023, 00:31

Atkinson

These days to keep life simple I will seat a bullet to fit the magazine then do from there, I will blacken the neck and shoulder with a match on the case before priming. then set the headspace to allow the gun to feed, then set a bullet out a good ways and seat it to touch, then a bit more until it reaches little or no resistance and loads freely, I don't care about seating depth. test the load for accuracy, it usually ver good so I chronograph it and Im done. I require a 1 inch group with a bolt gun, scoped, and same witih irons...On a lever gun I ok withh a 2" to 3" gun scoped and with irons..Sometimes these figures change if I really like the gun..I played the reach for the holy grail of accuracy as it was interestion and fun, gained not much..today I just want an accurate rifle for big game and coyotes..

20 January 2023, 17:46

Bill Leeper

For a hunting rifle, I just load to fit the magazine and hunt. A lightweight rifle is easily influenced by shooting technique. The hold can affect accuracy a lot. I hardly ever shoot a hunting rifle from a benchrest position. If shooting from a bench, I often shoot off my elbows. I don't shoot a lot of 1/2" groups this way, but I get a pretty good idea of how I and the rifle will perform in the field.
A lightweight 308 is probably going to be used on big game inside of 300 yds. A 1.5 moa rifle will probably not make your heart go pitter-pat, but it will flat clobber a deer at 300; this assuming you can hold that well. Regards, Bill

21 January 2023, 01:10

Stonecreek

quote:
A 1.5 moa rifle will probably not make your heart go pitter-pat, but it will flat clobber a deer at 300; this assuming you can hold that well.

Bill Leeper's assertion seems valid:

Assuming that the shots of a 1.5 MOA group are reasonably equal distance from the point of aim, then the "circle" in which a 1.5 MOA rifle would strike at 300 yards is about 4.5". This means that each bullet would be within approximately 2.25" of the point of aim. Hitting a deer-sized animal within 2.25" of point of aim will almost always result in a fatal wound.

21 January 2023, 22:43

Atkinson

quote:
Originally posted by Atkinson:
These days to keep life simple I will seat a bullet to fit the magazine then go from there, I will blacken the neck and shoulder with a match on the case before priming. then set the headspace to allow the gun to feed, then seat a bullet out a good ways and seat it to touch, then a bit of back off and perhaps more until it reaches little or no resistance and loads freely, I don't care about seating depth. test the load for accuracy, it usually very good so I chronograph it and Im done. I require a 1 inch group with a bolt gun, scoped, and same witih irons...On a lever gun Im ok withh a 2" to 3" gun scoped and with irons..Sometimes these figures change if I really like the gun..I played the "reach for the holy grail" of accuracy as it was interesting and fun, gained not much..today I just want an accurate rifle for big game and coyotes..

21 January 2023, 22:47

Atkinson

I agree Bill, but do the load work and sight in off bags on the bench rest then shoot from all off hand options, off hind legs, sitting, kneeling or whatever you deem fitting..Hunting ? grab a rock, or a limb or tree trunk, Natures bench rest if its available!

21 January 2023, 23:38

Heym SR20

What you want is consistency in pressure and in particular in pressure before the bullet starts moving.

If you seat the bullet right on the lands there is plenty of, and consistent, resistance from the lands before the bullet starts to move. I believe some bench rest shooters load up with almost no neck tension and load bullets long, so that they are actually pushed back into the case as they are chambered. This may give very good accuracy, but would be a bloody stupid thing to do with hunting ammo.

Instead I always full length resize the case, load bullet to COAL, or if there is a cannelure to crimp into then that provided its seats shorter than COAL.

And then I use a decent crimp so that:

1) Bullets don't move in the case when in transport or under recoil

2) There is a a very positive hold of the bullet that allows a good level of pressure to build before the bullet is released from the case.

You now have ammo that will chamber in pretty much any rifle of that calibre, will shoot well and survive the rigours of hunting.

22 January 2023, 01:47

ledvm

That^^^is pretty much exactly what I do.

22 January 2023, 04:54

Bill Leeper

Speaking of crimping; I have seen much more consistent velocities with crimped ammo and like to crimp when I can as well. Most of the bullets I use do not have a cannelure, so I have to forgo the crimping. Regards, Bill

22 January 2023, 05:03

ledvm

I use Lee factory crimp dies and usually crimp all.

25 January 2023, 23:58

MARK H. YOUNG

Lane,

You might try 130 TSX. Even in your short barreled 308 you should get 3000 fps. At leopard ranges that bullet will open and kill the leopard very quickly. Additionally the TSX bullets tend to shoot better when not loaded close to the lands.

I completely understand your preference for NP's and I agree they are a great cat bullet but I've had many clients shoot leopards with TSX bullets and they just work fine. A leopard kills easily.

Mark