OAL for 100 grain BT in .25-06 Help


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Eb1
October 13, 2011, 01:16 AM
Nosler lists 3.250, but that seems a little long for the 100 grain bullet.

I shot two 5 round groups at 3.240", and they were scattered using 51 grains of IMR4350.
I am thinking the OAL could have been the issue. What are do you guys load OAL to using the 100 grain BT? I am thing 3.020" or 3.100". The Rem 100 grain Core-Lokt are around 3.020", and they shoot a consistent 1" to 1.5" group. Perfect triangle groups with the occasional .8" or less. Am I loading them to long?

Advice is greatly appreciated. Thank you.

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gamestalker
October 13, 2011, 01:45 AM
All actions are diferent, but many prefer a longer OAL. So far, every high power I've ever loaded for has performed excellent when I seat up to the lands. But again, this is very firearm specific, and I've been told even more so with a lot of the newer production rifles. Some have more tapering at the lands also.

Eb1
October 13, 2011, 01:52 AM
The 115 gr CT BT shot great at 3.260, but the 100 gr doesn't seem to be happy loaded to the lands. That is why I mentioned the group size with the Remington 100grI should be safe loading to the shorter length with the 100 gr Nosler Bt right?

GooseGestapo
October 13, 2011, 08:41 AM
A good rule of thumb when loading shorter bullets in a cart/chamber where it is difficult to get the bullet to seat out to touch the lands is to seat it such that there is at least the bore diameter length of bullet shank in contact within the case neck.

Rick Jamison outlined this technique back in the early '80's in a magazine article.

I've used this technique many times. Most lately with a .257wbyMag. As most know, the Weatherby's have a very long throat termed a "free-bore". This allows the bullet to jump a distance before it engages the rifleing which lowers chamber pressures and elevates velocities. This can also lead to a loss of accuacy potential.

By seating the bullet a little deeper, you ensure concentricity with the bore, which ultimately is the reason for seating the bullets to "touch" the lands, as this centers the axis of the bullet with the center of the bore.
I have a .257Roberts with the so-called 3" chamber. This requires the bullets either be seated far out, or with at least .26" of the full diameter shank of the bullet in contact with the case neck to improve concentricity. I've gotten 1/2" groups with my 1983 E.R.Shaw barrel in a M98 military Mauser Custom, with 75gr Hornady H.P.'s seated with .25" of shank in the case neck.
I've gotten sub-moa with both 85gr and 100gr Nosler Bal.Tip's so seated. With the 115gr BalTips, I can seat them out to "touch" the lands, but choose to seat them a little deeper to lower the pressures in this "ancient" bolt action. Accuracy dosen't seem to be adversely affected.

FWIW, my .257wby, though it pre-dates the MOA monicker and guarantee, it shoots sub-moa with most of my hand-loads, and the only factory ammo I've ever shot through it. It was the Norma 100gr Spt.s that are seated quite deeply. Five went into a neat .70" group with 3 touching. Same POI as my handload at approximately same velocity with 100gr Hornady SPT's seated a tad longer......Factory ammo chrono'd 3,450fps from the 24" bbl. About 100fps slower than cataloged from a 26" bbl.

Eb1
October 13, 2011, 10:38 AM
@ GooseGestapo,

Thank you for that information. I was thinking loading out that far was the issue. I was also having large variance in velocity.

I will load up a batch loaded .257 into the neck, and give that a try. My rifle has a large throat. Even @ 3.260 I was not into the rifling using the 115 grain Combined Technology Ballistic Tips, but they shot pretty good loaded out that far.

Your information is very much appreciated.

BrainOnSigs
October 13, 2011, 11:12 AM
Is your rifle single shot or mag fed?

Eb1
October 13, 2011, 11:42 AM
It is mag fed, and 3.260 fits the mag with the 115 grain bullets.

ranger335v
October 13, 2011, 11:57 AM
The max magazine length will be 3.260" for any bullet you use so that would be your practical max OAL.

The OAL 'could' be part of your accuracy problem but there is no valid 'rule' for OAL in anything. First find an OAL that will feed and chamber, then develop the charge for best accuracy at any shorter OAL you may desire. Test other seating depths around that length but don't jam an established load into the lands.

Best accuracy comes from a balance between the rifle and chamber, the barrel and how it's bedded, the powder and charge, the bullet and the jump to the lands, etc. There are far too many interacting variables to say 'do this and get that' about any of it.

Experiment.

Eb1
October 13, 2011, 03:21 PM
I understand that. I was just needing some reassurance of the seating depth that far below max OAL.

I have always had good luck with loading to the canalure, or loading right off the lands, but this time it seemed very excessive @ 3.240 is actually what I loaded the bullet to. So I wanted to go 3.02, or somewhere around there, but was hoping to get others OAL loading .25-06 with a 100 grain BT.

There are many variables. Many.

quartermaster
October 16, 2011, 06:34 AM
25-06 is my favorite caliber. I have 3 remmies in diiferent models and shoot 100 gr Nosler ballistic tips in all. My seating depth varies in each one as the chambers are different. My method for determining seating depth is to determine the max length by using a oal guage, which is not 100% accurate, but a good starting point. Then I seat a dummy round a bit longer and try chambering it. I keep seating it deeper until it chambers. Then I know this is my max coal. I start my test loads at .010 off the rifling and shoot groups seating progressively .003 deeper each time until I fing the sweet spot.

I have found IMR 4831 to be the most accurate powder for all 3 of these rifles with high velocities.

Good luck

41 Mag
October 17, 2011, 06:02 AM
Back around '87 or so when I purchased my first 25-06 I went through quite a few loads before settling on one for the 100gr pills. Turned out that with the 100gr Nosler seated to 3.250" over a decent charge of IMR-4831, they shot into tiny clusters at 200yds. I went on working with different bullets and simply by accident, I managed to load some 115gr Partitions with out changing the seating die from the setting for the 100gr bullets.

What followed was that I found every bullet I wanted to shoot, regardless of powder used, brand of bullet, or composition, would shoot bug holes set to this depth. To this day I haven't found any other setting which will produce the accuracy from this rifle with any load I have tried. I, at one time, had the 100gr and 115gr, BT, Barnes X, and Nosler Partition, all loaded with the same load per weight, and all would shoot into a combined group of less than 1.5" at 200yds, taken individually they would all easily fit under a nickel.

Call it what you want, but 3.250" with the BT works for me.

Today the daughter has claimed the rifle, and the load she is using shoots the same powder charge as what I used for the 115's with RL-22. She is using the 110gr Accubond and it continues to shoot those same type groups. These two were shot simply to check the scope at 250yds with a howling cross wind after being cleaned and one fouling round seen low.
http://i49.photobucket.com/albums/f285/41nag/Shooting/P4220201.jpg

This type group is so typical and repeatable with this rifle that more shots are simply a waste of components and barrel.

steve4102
October 17, 2011, 08:13 AM
Nosler lists 3.250, but that seems a little long for the 100 grain bullet.

Nosler does not list OAL for any of their loads tested. They only list SAAMI OAL Max, which means very little to the handloader. If your Nosler Manual is #6 go to page 43 and read how Nosler recommends you find the proper OAL for your rifle.

41 Mag
October 17, 2011, 11:38 AM
My Lyman 48th list a max OAL of 3.250" in the drawing on the top of the page, but for OAL's listed in loads it is 3.155 for the 100gr Sierra SP.

In my notes with that particular Sierra bullet I have listed IMR-4350@52grs (**MAX LOAD**), and seated to 3.150". Data from Sierra Technical Line, listed as Accuracy Load.

I can say this about it, I tried several powders, primers, and seating depths before I buckled and called Sierra on it. I had been given several boxes of the 100gr SP's and really wanted to use them. First work up to the mentioned load I got one hole groups. This said, after the first deer I shot with one, I decided that there were better bullets to be used with this rifle.

Rokman
October 17, 2011, 11:13 PM
My loads with 100 grain Nosler btips work great at 3.250" with RL19, RL22 and IMR4831. I loaded them somewhat shorter and a little longer and that length just fit for my .25-06.

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