O.A.C.L.for 300 win mag

dws1955

Beginner
Apr 29, 2025
5
6
180 grn. Partition spitzer in tikka 300 win mag. 5th edition nosler manual says regular spitzer goes too deep at saami o.a.c.l. of 3.340. They recommend using protected point.
Chart on Nosler web site now shows tested bullet seated at 3.31 o.a.c.l. Does this mean it’s ok to seat regular spitzer partitions a little deeper?
 
The 180e-tip is longer than other 180's and needed to be seated as such. If the throat let's you seat at different lengths, you can go with that? I only have the 180e-tips. Test lengths aren't set in stone, it only gives data based on that. I have a 243win thathas a short throat, so until I get it longer, I'm stuck with seating this. 035" shorter than published data.
 
you’re not seeing any pressure problems seating deeper?
I seated mine at 3.345 thinking it would keep it from seating too deep. Seems to fit in rifle ok but haven’t shot one yet.
 
i'm able to seat out to 3.750" which is further than it needs too be. i'm somewhere around 3.400-3.450". if you seat deeper, then pressure will go up.

at the extra .035" length you should be able to get an extra .5-1gr of powder depending on which powder is used and how much more throat is left?
 
I would first want to know if you have measured the distance to the lands in your rifle. Then, regardless of any other reference that is the max length in Your rifle for that bullet. A Partition will be different from an AccuBond for example.
Next question will be can the overall length of your max length fit in the Magazine.
If not you’ll of course want to shorten up until it does. Most of us have our best accuracy with Partitions seating them close to the lands.
I’ve never owned a Tikka, but I have owned and loaded for a number of 300 Wm, all were loaded with the traditional 180 gr. Partition.
 
I would first want to know if you have measured the distance to the lands in your rifle. Then, regardless of any other reference that is the max length in Your rifle for that bullet. A Partition will be different from an AccuBond for example.
Next question will be can the overall length of your max length fit in the Magazine.
If not you’ll of course want to shorten up until it does. Most of us have our best accuracy with Partitions seating them close to the lands.
I’ve never owned a Tikka, but I have owned and loaded for a number of 300 Wm, all were loaded with the traditional 180 gr. Partition.
Sound advice right here☝️
 
I would first want to know if you have measured the distance to the lands in your rifle. Then, regardless of any other reference that is the max length in Your rifle for that bullet. A Partition will be different from an AccuBond for example.
Next question will be can the overall length of your max length fit in the Magazine.
If not you’ll of course want to shorten up until it does. Most of us have our best accuracy with Partitions seating them close to the lands.
I’ve never owned a Tikka, but I have owned and loaded for a number of 300 Wm, all were loaded with the traditional 180 gr. Partition.
This 👆👆👆
 
I would first want to know if you have measured the distance to the lands in your rifle. Then, regardless of any other reference that is the max length in Your rifle for that bullet. A Partition will be different from an AccuBond for example.
Next question will be can the overall length of your max length fit in the Magazine.
If not you’ll of course want to shorten up until it does. Most of us have our best accuracy with Partitions seating them close to the lands.
I’ve never owned a Tikka, but I have owned and loaded for a number of 300 Wm, all were loaded with the traditional 180 gr. Partition.
I haven’t measured to the lands. What’s best way to measure?
 
There are several techniques we have used over the years most of them just frustrated me. Some years ago Hornady produced the Overall cartridge length gage. It is a two piece tool. Just saw them listed on Amazon for 29.00 you’ll also need a “modified” case, another 13.00. I’ll leave the description on how to use this to the technical report writers, but it’s easy and repeatable.
 
There are several techniques we have used over the years most of them just frustrated me. Some years ago Hornady produced the Overall cartridge length gage. It is a two piece tool. Just saw them listed on Amazon for 29.00 you’ll also need a “modified” case, another 13.00. I’ll leave the description on how to use this to the technical report writers, but it’s easy and repeatable.
Thanks salmonchaser. I’ll check the tools out.
 
Good info. Didn’t know AccuBond is longer. I’ll just use latest chart for bullet seating. My 5th edition nosler book definitely has a caution about seating Partition too deep when seating at 3.340 saami O.A.C.L. For 300 win mag.
 
Good info. Didn’t know AccuBond is longer. I’ll just use latest chart for bullet seating. My 5th edition nosler book definitely has a caution about seating Partition too deep when seating at 3.340 saami O.A.C.L. For 300 win mag.
There are two Partition bullets. The protected point is 1.180 long and the Spitzer is 1.260 long. The BT is 1.360 and the AB is 1.380, all these for the .30 cal, 180 grains
 
When I purchased my Christensen Arms .300 Win Mag I found the magazine box to be real long and the throat to be real short. I solved the problem with a good gunsmith. Now I can load to 3.600 with all bullets and longer with some of the sleek long range bullets. It did change the performance of the rifle for the better.
 
My Rem 700 300 Win Mag used to be a 7mm STW with the push feed magazine before I converted it. I would start by checking the maximum box length, and seat the 165 -180 grain bullets about .020" shorter and work a load from there. The Accubonds and Ballistic Tips can be seated long to get close to the lands without a problem, except for the 200 grain ELD -X which needs to be seated deeper and away from the lands to fit the magazine. SalmonChaser is on point
 
There are two Partition bullets. The protected point is 1.180 long and the Spitzer is 1.260 long. The BT is 1.360 and the AB is 1.380, all these for the .30 cal, 180 grains
The ogive is located at different locations on different bullets even though they may be the same weight. Different design bullets, even from the same manufacturer will have different base to ogive lengths. That’s why I think the Hornady comparator is almost a necessity.
 
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The ogive is located at different locations on different bullets even though they may be the same weight. Different design bullets, even from the same manufacturer will have different base to ogive lengths. That’s why I think the Hornady comparator is almost a necessity.
Yes, but he was talking about COAL. I only use COAL to make sure it fits the magazine. I use Ogive for seating/jump but always take into account the depth in the case. You can change the pressure signifigantly if you are not following standard safety practices
 
I would never suggest anyone disregard safety. I don’t want to see anyone injured. A BTO measurement gives a more precise point of reference for a given load. OAL specs in a reloading manual can get someone in trouble if taken as an absolute. Some sort of BTO measurement is needed.

As an example, The stated OAL in the Speer manual for 270 Win with 130 grain Hot Cor bullets gives an OAL of 3.200”. That OAL in my 270 jams the bullet .070” into the lands. I know he’s not talking about a 270 Win but the moral is the same. OAL in a given manual worked with their specific test rifle. We all have our own individual loading habits that work for us. I only speak for myself, but magazine length only comes into play after I have verified that the OAL measurement doesn’t put me into the lands. I agree that an overly short OAL can increase pressure but that’s only half the needed information. If I’m missing something disregard.
 
I would never suggest anyone disregard safety. I don’t want to see anyone injured. A BTO measurement gives a more precise point of reference for a given load. OAL specs in a reloading manual can get someone in trouble if taken as an absolute. Some sort of BTO measurement is needed.

As an example, The stated OAL in the Speer manual for 270 Win with 130 grain Hot Cor bullets gives an OAL of 3.200”. That OAL in my 270 jams the bullet .070” into the lands. I know he’s not talking about a 270 Win but the moral is the same. OAL in a given manual worked with their specific test rifle. We all have our own individual loading habits that work for us. I only speak for myself, but magazine length only comes into play after I have verified that the OAL measurement doesn’t put me into the lands. I agree that an overly short OAL can increase pressure but that’s only half the needed information. If I’m missing something disregard.
We are not arguing about BTO, CBTO. I was trying to answer the direct questions which was about COAL, and how the different bullets, same manufacurer, same caliner, same weight vary.
 
We are not arguing about BTO, CBTO. I was trying to answer the direct questions which was about COAL, and how the different bullets, same manufacurer, same caliner, same weight vary.
I didn’t mean to seem confrontational. If I did I’m sorry. It wasn’t my intention.
 
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