The rifle is a 96 mauser in 6.5-284 Norma. Getting ready to relaod for the first batch of cartridges for this rifle. I used Hornady's lock and load gauge to determine my actions maximum COAL. It came up with 3.000 on the money. I just finished reading Lyman's reloading manual on the 6.5-284 Norma and they state that the COAL is 3.228. Can there be that much of a difference between my rifle and the data supplied by Lyman?
COAL: Book Length Vs My Action
- Thread starter onelastshot
- Start date
Coyotefurharvester
Silver $$ Contributor
Depending on the brand/weight/type of bullet, your overall cartridge length could vary more than 0.200 inches. There is an ammo manufacturers max length standard also.
I'm using Hammer Bullets, I'm not aware of any printed data that they've published.
The re-loading manual shows the numbers for that particular load. Your numbers will vary and most likely will not be the same.
Get a wood dowel that will fit down the barrel, 1/4" will work for you. Close the bolt and run the dowel down against the bolt face, mark the dowel at the crown. Then stand the gun on it's muzzle and drop the bullet of choice down the chamber and it will seat in the throat. Hold that bullet from moving then run the dowel against the bullet, mark dowel. Measure between the marks. You have a COL with that bullet (they can vary) not including any jamb.
Coyotefurharvester
Silver $$ Contributor
Typically the monolithic bullets like to jump more than cup and core bullets.
shoot4fun
Gold $$ Contributor
While I am not familiar with Hammer Bullets, I see they appear to have long bearing surface and short noses.
They also appear to share the pressure reducing grooves with Barnes monolithic BUT I would not start anything near the top suggested powder charges in your Mauser with bullets of that design and composition.
This is good advice and I would add every monolithic I tried wanted quite a bit of jump.
Yes, there can be a significant difference this why one of the first things I do when I get a new rifle or change to a new bullet is measure the base to ogive of that bullet for that rifle.
For example, the SAMMI spec for a 243 Win is 2.710. Sierra lists a test load COL of 2.650 for their outstanding 85 BTHP. That works fine in my Remington 700 and 7 but won't chamber in my Tikka or Browning X Bolt. The jam COL is 2.630 in those rifles for this bullet. Thus, I seat at 2.620 for both.
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For example, the SAMMI spec for a 243 Win is 2.710. Sierra lists a test load COL of 2.650 for their outstanding 85 BTHP. That works fine in my Remington 700 and 7 but won't chamber in my Tikka or Browning X Bolt. The jam COL is 2.630 in those rifles for this bullet. Thus, I seat at 2.620 for both.
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Thanks for the response. Yes, it is a small ring Mauser. My intention was to start a grain lower than the minimum posted by Nosler and work my way up from there. I've been cautioned regarding the strength, or lack thereof of the 96 Mauser as opposed to the 98 Mauser. I may even start 1.5 grains lower than Norma's posted numbers.
More than one person has cautioned me on the powder charge, I will keep pressures much lower than I originally planned. I'm also going to start with more jump. Now, I've got some bullets to pull.
What you need to know is that because you are already forcing yourself to load rounds 0.228 shorter than published data, your combustion chamber is considerably smaller. This alone is going to drive the pressure up. I agree with your strategy of loading under minimum but I don’t know how much below minimum spec you can safely load. My suggestion would be to use the data and load to their length with their bullet. You’ll have to measure to see if it even fits into the chamber and doesn’t jam the bullet into the lands. Don’t worry about magazine length yet. You have to establish a baseline first. Another suggestion is to download Gordon Reloading Tools software. It’s free. It allows you to adjust COL, run different bullet and powder choices and let it predict pressure and velocity trends BEFORE you attempt to build a safe cartridge. The load data you are using is INVALID because you aren’t using the exact same conditions and therefore it’s really a dangerous situation from the start. It doesn’t take long to get the software loaded and plug in your adjustment. You can change the max pressure warning and it’ll take the guesswork out of your situation. Within the software you can choose OBT. Optimal Barrel Time will allow you to adjust your real chronograph velocity measurement into their predictions and it then recalibrates real world data you observed and adjusts the pressure and velocity predictions. This alone is so important. I find that when I use GRT and it’s OBT and push my pressure up the cases exhibit pressure signs really close to the predictions as long as I make all the needed adjustments in the cartridge. I’m only recommending this because I fired thousands of rounds attempting to do similar and once I got the software it moved me into the right direction (I was pretty far off) and got me really accurate in much fewer shots. My situation is like yours except I’m long instead of short and using published data, I continued to be slow and I was using the wrong powders. Now my rounds are efficient, fast and safe and they are very accurate. The OBT predictions for accuracy don’t give me accurate loads. You can see if OBT works for your combination to make accurate loads but I just use it for pressure safety. My 223 and 308 loads are long and I use 2 grains more powder than published maximum and I’m confident they are safe. Just be careful with what you’re doing because shorter COL produces a lot of pressure really quickly and I don’t want you to take any risks until you get comfortable with the load.
Thanks for the response and the great information. Ive downloaded Gordon reloading tools software (going to take a bit to get acclimated) started my ladder test two grains lower and increased the bullet jump.
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