OAL as it relates to the length of the bullet

[rhino210]

I just reloaded some Hrndy 165gr BTSP in 30-06. The OAL is 3.3” as given by references. It is loaded in R-P cases over 50grs of IMR4064. I am new to reloading so I am working out some concepts in my mind.

I understand that if you diminish the case capacity by seating the bullet deeper you increase pressure. There is a cannelure on the bullet itself that when the bullet is correct for OAL the cannelure is about .10” above the top of the case. The rounds will be fired in a Remington 700ADL no more that two extra in the rifle at a time so crimping is not critical in regards to recoil and feeding issues can be dealt with.

Is the cannelure just a cosmetic feature of that particular bullet or is it important. My goal is 100-200yrd groups of about 2 inches or less. I am not going for cloverleaf patterns at 400yrds. Should I adjust the amount of the charge to allow the proper crimp with the shorter OAL? How do I adjust it? Are there super secret decoder rings from a secret club that has special incantations or are there simple equations for this?

I have not yet figured out the optimum case length as it relates to the lands of the bore. Like I said I am new.

Also, my father just gave me a BUNCH of steel core copper jacketed Military .308 bullets that are from de-milled rounds. The weight is 165grs each but they have a bullet length of about 0.30” longer that the regular 165gr because of the difference between steel and lead. A loaded military round measures an OAL of 3.34”

If I were to try to use the same IMR4064 recipe with the longer bullet it would almost compress the charge and to my way of thinking be bad. The manuals I have looked at don’t include a recipe for these steel core rounds.

Any one have a good recipe? Switch from the 4064 to something else? A slower powder or faster powder? OR make sinkers out of the lot.

Thanks!

 

[scrat]

WOW

i hope you did not do that all in one breathe.

jk.

ok here is the deal. i try to always press the bullet to ideal max length or close to max length. Some times the cannilure will be just a tad out of the case. if it is so be it. Thats why i have a lee factory crimp die. Why does the bullet not seat like i think it should. Several reasons. here are a few. 1. question did you full length size the cases. 2 if the answer is yes then sometimes the case will be over the case length. They your have to trim the case. 3. When triming the case it may not match the cannilure to achieve the size length you are looking for. you can either A keep it that way or B press the bullet to meet the the cannilure with the case mouth. 4. Doing this will result in higher case pressure. But it really depends at that point on the load. if you do a light load the maybe at the minimum grains then press the bullet to the cannilure resulting in a smaller case length. Then you should be fine depending on how far you pressed the bullet in. 5 Now if you maxed out the grains and then pressed the bullet in to far. Well you just create a very hot load. 6. next thing depends on the bullet being used. different brands and sizes may have the cannilure at a different position. So after that it really depends on you. When trying a new bullet try to make a dummy round without any powder this will give you an idea of what your finished product will look like without sacraficing any powder or primer. 7. you mentioned on having some bullets that are longer. This may also be ok. Depends on the bullet tip again. lets say you go out and buy some factory made bullets with round nose. or flat nose. then you go out and buy some speer spear point bullets. depending on the grain and style of the bullet the spear point bullet can actually be longer as the part that is longer is skinnier. So that point will not be touching the lands of the gun. Not so on the round nose and flat nose. they have to be right on. or below max oal. otherwise when you go to chamber the round the gun will be seating the bullet for you. Increasing your case pressure.

 

[Car Knocker]

.30 caliber bullets like you are using for .30-06 are also used for .308 Win, .300 Win Mag, 7.5x55 Swiss, etc., etc. The cannelure is in an arbitrary location, considering the multiple usages.

 

[The Bushmaster]

No matter whether there is a cannelure or not has little bearing on .30-06 as it is not necessary to crimp the case mouth of a .30-06. Ignore it...

 

[USSR]

rhino210,

Will try to answer some of your questions.

I just reloaded some Hrndy 165gr BTSP in 30-06. The OAL is 3.3” as given by references. It is loaded in R-P cases over 50grs of IMR4064. I am new to reloading so I am working out some concepts in my mind.

I understand that if you diminish the case capacity by seating the bullet deeper you increase pressure. There is a cannelure on the bullet itself that when the bullet is correct for OAL the cannelure is about .10” above the top of the case. The rounds will be fired in a Remington 700ADL no more that two extra in the rifle at a time so crimping is not critical in regards to recoil and feeding issues can be dealt with.

Is the cannelure just a cosmetic feature of that particular bullet or is it important. My goal is 100-200yrd groups of about 2 inches or less. I am not going for cloverleaf patterns at 400yrds. Should I adjust the amount of the charge to allow the proper crimp with the shorter OAL? How do I adjust it? Are there super secret decoder rings from a secret club that has special incantations or are there simple equations for this?

The OAL listed in the reloading manual is simply the length they used. Disregard the cannelure, as there is no need to crimp loads for your M700, nor is it desireable to do so. Load to the 3.3" or slightly longer (Remingtons have throats WAY out there), as long as the bullet isn't making contact with the throat.

I have not yet figured out the optimum case length as it relates to the lands of the bore. Like I said I am new.

Also, my father just gave me a BUNCH of steel core copper jacketed Military .308 bullets that are from de-milled rounds. The weight is 165grs each but they have a bullet length of about 0.30” longer that the regular 165gr because of the difference between steel and lead. A loaded military round measures an OAL of 3.34”

If I were to try to use the same IMR4064 recipe with the longer bullet it would almost compress the charge and to my way of thinking be bad. The manuals I have looked at don’t include a recipe for these steel core rounds.

Any one have a good recipe? Switch from the 4064 to something else? A slower powder or faster powder? OR make sinkers out of the lot.

If you want to seat your bullets at the optimal length, I would invest in the Stoney Point OAL Guage which I believe was just bought out by Hornady. Excellent tool, and when used with a comparator (another purchase), will allow you to measure the cartridge base to bullet ogive dimensions of your chamber. While 4064 will work fine, with the 165gr bullets, I would suggest a powder in the 4350 burn rate range (VV N160, RL-19, IMR4350, H4350, etc.). If you use the load data for the 175gr Sierra MatchKing bullet or Hornady 178gr Amax bullet with the 165gr steel core military bullets and load them to 3.34", you will be alright. Hope that helps.

Don