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Bullet seating depth for 336 30-30

10K views 38 replies 22 participants last post by  jwleeper 
#1 ·
Any you handloaders out there for the 30-30 load ever check seating depth when doing test firings for your tightest groups. Have searched every where on here and find no posts about this. Cannot believe no one has brought up this subject and am just about ready to handload for this round and wondering how you guys find distance to lands...for a bolt many ways to do but for a lever want to know how some of you do this. For my bolt guns, I just take a fired case from my gun and insert a bullet and bite down on it ever so lite...and carefully insert in the chamber with the case inserted by the bolt closing and ever so carefully pull the bolt back and take the case out of the bolt and..if all goes real slow and careful, you will see that the bullet has been pushed back into the case and you can take your readings as to how long round is now...do this several times to get a good reading. Also, measure your case before you insert into chamber and you will see when taking case out how far it has been pushed back in by the bullet as it is touched by the lands. Now, with the Marlin lever, can the lever be taken out and the ejector be removed so as bolt can be inserted with the case and bullet to get this reading. Have just bought a 30-30 and know that seating depth has to have an effect on accuracy, just as a bolt gun.
 
#2 ·
Right. I'll be interested to see the responses here. I know what you are talking about with regards to bolt guns as I am just getting into ogive to cartridge base measurements and experimenting with VLD that are jumping into the lands a bit.

Everything I have learned stresses that magazine fed rounds (bolt, semi, lever) need to be loaded within spec. So are you after a single feed round here or are you wanting to experiment with OAL while feeding from the tube?
 
#10 ·
Right. I'll be interested to see the responses here. I know what you are talking about with regards to bolt guns as I am just getting into ogive to cartridge base measurements and experimenting with VLD that are jumping into the lands a bit.

Everything I have learned stresses that magazine fed rounds (bolt, semi, lever) need to be loaded within spec. So are you after a single feed round here or are you wanting to experiment with OAL while feeding from the tube?
Cthulhufan, am wanting to know what others are coming up with on the OAL while feeding from the tube...the Hornady LEV in 160 grain especially. Have purchased couple boxes of said ammo, and want to duplicate or better the accuracy and speed of this round with reloads and was hoping others would chim in as to what they are seating depth is best in their guns...then have a general idea what others are coming up with. Have a couple of loads from others as to powders and grains and chromo speeds...but no one eludes to the seating depth.
 
#3 ·
Mar Nut... for the lightweight plinkers without a cannelure I did the same measurement on the 336 as you describe for the bolt gun... only had the bullet stick once in the lands and backed off the "crimp" just a bit and the bullet came out with the case. cycled the action slowly with the lever and it worked just fine... I seat the bullet a hair short of where the bullet contacted the lands and am good to go. for bullets with cannelure, I seat to the cannelure and call it good.
 
#4 ·
I don't see why you couldn't take the extractor off to do it... Thing to consider is COL and if it will be too long to work/cycle in the action/tube? Youll have to make a couple dummies and see what happens!? :hmmmm:
Other members will be along soon to give advice on this topic...

Good luck
BloodGroove4570
 
#5 ·
Forgot to mention that..about the length of the rounds being too long for all to fit in the tube...kinda like a bolt with the magazine fed...must also fit the magazine also. Still, there has to be a set OAL for each gun..all are different...for the tightest groups. Papa vid, the cannelure on the Hornady LEV bullets the ammo already factory loaded even has different seating depths...at least the 2 boxes I have purchased have different depths. Now loading like 150 and 170 bullets without the cannelure there is no way of knowing where the correct depth would be without firing for the tightest groups or loading rounds for a maximum length to fit all in mag. tube...back to the same thing with a bolt gun fed by a mag...sometimes you can only load so long if will not fit mag. or you only single feed rounds into chamber. May be a mute point, but I find it hard to believe that loading every round to a certain depth for your gun would not have an effect on accuracy...and once you find it for that bullet and what your gun is telling you it likes...that is when things will come together. Haven't received my gun yet...hopefully tomorrow and will be doing some reloading for it when I can....but you can bet the farm on it that there is a seating depth that it likes for any or most different bullets you feed it.
 
#9 ·
I did the same but with a 168 grain Hornady Amax... Utter failure and *not* worth the trouble.

I do get what the OP is after here and I guess it's going to be a trade off, probably, right. You have to try and find the optimal cartridge length that still cycles through the magazine and action. Just like a bolt gun, this is going to be an individually unique characteristic to any particular gun.

I'll stop rambling now but this is a very fun topic. Can't wait to see where this thread ends up.
 
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#7 ·
interesting... I never measured a factory round but it makes sense... I'm a new reloader (only a year under my belt) and started with spitzer point (all I could find) so measured to the lands. was loading one at a time as recommended... measuring was the only way to find seating depth with the spitzer as seating to the same OAL had the ogive into the case mouth. I got good acuracy (I think) with this method. I did not crimp these rounds since the bullets did not have a cannelure. I ran into a few that did not seat deep enough, pulled a bullet with the lands at the range and had to go back and reseat the remainder of that lot.

I have been reloading cast for the past few months and was happy to have a cannelure so I could crimp and load in the tube. accuracy is pretty good, and I have the next batch loaded to test once the weather cooperates.. I don't mind shooting in the cold, actually prefer it, but single digits is just too cold...

I read the other day that jacketed bullets react better to bein seated close to the lands where cast react better with a bit more jump to the lands... only one source (and I can't remember where) so maybe some folks here can weigh in on this thought as well.
 
#11 ·
This thing helps take some of the guess work out of the equation.
View attachment 91648
+1, been using one for years. For calibers I don't have the modified case, I size a case, cut two slits in the neck with a cut off wheel in my Dremel and use that as an OAL gauge. :top:
 
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#12 ·
It's not possible to alter the OAL in a lever action because of the maximum OAL function length which is shorter than the distance to the lands in many rifles.
 
#13 ·
OAL is slightly different in each chamber. The best way to find this is to seat a bullet to standard OAL and the coat the bullet with soot from a kerosene lamp and the carefully seat by hand and then close the bolt and the remove carefully and inspect the bullet to see if the lands left a mark on the bullet and if not the try again with the bullet set out more until the marks are left on the bullet and the set the bullet seat down 1/2 a turn +/-


I had to write this three times before I was able to post! It would always say I do not have permission, why is this? I would be able to post more if this did not happen???????
 
#14 · (Edited)
I honestly don't see the point of this in a lever gun.

They are not Target guns, the bullets they use are not Target bullets and inside 200 yards accuracy is usually more than adequate if you just seat to the cannelure. By the way, almost every bullet maker has a 30 caliber bullet designed just for the 30-30 with the cannelure specifically located for optimum seating depth. Much research has gone into the location of that cannelure and I've found it to be correct on all of the bullets I've tried so far. I find my time is better spent experimenting with bullet weight and powder type/charge.

I guess it could be interesting to try working up a pure Target load just to see what a gun is capable of but if it requires single feeding I see no real use for hunting.
 
#17 ·
The "textbook" answer is to leave the bullet long, chamber it, letting the lands seat the bullet, extract it, and measure. Subtract .010in and that will be the supposed seating depth. It's not an absolute as some bullets work better with no bullet jump, others like a running start to the lands. Keeping in mind that some chambers are so long that you will barely have any bullet seated to reach this length ( I have several this way), also anything you are gaining may very well not be worth it, as it may cause other issues like feeding or extraction. The 30-30 round is an established dimension and manufacturers of ammunition and weapons have designed their products to perform around those dimensions. That being said, it's your gun and your time! This is all part of the sport, enjoy it. I know I do.
 
#18 ·
The "textbook" answer is to leave the bullet long, chamber it, letting the lands seat the bullet, extract it, and measure. Subtract .010in and that will be the supposed seating depth. .
The problem I had with this method is that the bullet tends to stick in the lands giving a false, longer length. I had this happen several times which is why I got the OAL gauge.
 
#24 ·
I trim my 30-30 cases below minimum. So any bullet with a crimp groove that is where it will be. 30-30 when carefully crafted hand loads will produce outstanding accuracy. When learned it is a 300 yd deer rifle.
 
#25 ·
Hi Swany, I just want to make sure that I understand what you are saying. So you trim your case below minimum and still seat the bullet in the crimp groove, so if I understand what you are saying, your loads by design are going to be well short of the lands? Sorry, I just want to make sure I understand.

This is a great thread that I find very interesting. I have not been reloading very long so this is all good info. I trim my cases to 2.028" per my lyman book and my hand loads length is different depending on the bullet,
125 sierra gn fn/hp = 2.415"OAL,
Oregon Trail 170 gn fn= 2.515"OAL

As a comparison here is some factory ammo
140 gn Hornady Flex Tip 2.579" OAL,
160 gn Hornady flex tip 2.536" OAL,
170 Gn Fusion fn= 2.500"OAL,
150 gn Federal fn = 2.500"OAL,
170 gn Rem Core Loc RN = 2.495" OAL.
My lyman books says 2.550" is max OAL It also has very different OAL's listed for most of the reloads in it.
So my question is why aren't they all the same OAL for best consistency and hence best accuracy? Dang it :hmmmm: Now I have all these questions.
 
#26 ·
Marlin bore dimensions and free bore measures vary quite a bit between model years and the pre and post ballard/micro groove years.
Cast bullet designs vary even more. For any of my guns 1893,36s and 336s, OAL is adjusted to be just short of the lands.
Touching the lands does nothing for hunting accuracy, and engraving lands is impractical (Pain in the butkus) with a lever gun;
 
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#28 ·
Hey RHP, you said:

"Just an FYI if anybody tries one and can't find the caliber modified case you need, Hornady used an odd size thread, it's a 5/16" 36 NF tap."

Have you actually tried a tap that size?

Reason I ask is I took my tool into work and had our machinist measure the threads and he decided it wad probably a proprietary thread dimension a tad under the 5/16 size. He told me a 5/16 36 would probably work but thread engagement would be less than ideal. I ordered a tap that size but have not used it yet.
 
#31 ·
.

Swany is right on. One reason that you don't see much on seating depth on this forum is most of us have found that seating depth is a non issue in the search for accuracy in these lever guns. Seating to the cannalure ( anyone have the correct spelling?) is important in bolt guns, not in lever guns as far as I have been able to determine. But then, shooting bolt guns and shooting lever guns with cast bullets are as different as tennis and handball, anyway.
 
#32 ·
"Crimp Groove" "Cannelure" spell check won't recognize it.
 
#33 ·
I know this is an OLD thread, but if anyone is wondering what the thread size on the Hornady OAL gauge, it's metric. M8x.75.

As far as seating depth goes, isn't base-to-ogive the most important measurement since that's what contacts the lands? I'm just getting started on reloading but this is what I've heard and it makes sense (since it applies to all bullets).
 
#35 ·
I know this is an OLD thread, but if anyone is wondering what the thread size on the Hornady OAL gauge, it's metric. M8x.75.

As far as seating depth goes, isn't base-to-ogive the most important measurement since that's what contacts the lands? I'm just getting started on reloading but this is what I've heard and it makes sense (since it applies to all bullets).
I love these old threads.
Thanks for the thread size.
Your just getting much to esoteric for lever guns,
In a lever rifle the cartridge must cycle thru the magazine to be usefull.
One can single load long boatailed bullets but they it may take removing the bolt to unload if unfired. That gets hinky in a competition.
 
#34 ·
@marginwalker Each 30-30 Lever is it own animal. I have one that patterns the 160ftx bullets like a shot gun ( 8 inch groups at 50 yards). Others have had great success with it. I have tried seating depths, multiple loads, you name it. The 160 ftx bullets do not work in my gun. That same gun shoots 150gr Corelokt bullets in a 1 inch group at 100 yards. I spent quite a bit time measuring and setting the COL for 2 thou off the lands. I did not see much difference in accuracy. For that gun, it seems that bullet weight and velocity plays more of a role than anything else.
 
#39 ·
Marlins are for the most part a moderate range hunting rifle. They are not a bench rifle to shoot 1/2 in groups or compete with. If you are getting 3 shot groups 2 in or under at 100 yds it certainly is a good hunting rifle with accuracy for the job. It is way more important the rifle function for 3 quick shots, if needed. A good bullet seated to correct length to function and crimped properly is more important. Just the thoughts of an old man with Marlinitis.
Have a great day.
Jim
 
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