In order to participate in the GunBroker Member forums, you must be logged in with your GunBroker.com account. Click the sign-in button at the top right of the forums page to get connected.
Options
30-06 load data ??
joshmb1982
Member Posts: 8,929
im getting ready to start developing a load for my 1903 A3 and am seeing something that doesnt make sense to me. ive got info from a lyman 49th loading book and a 5 page chart from the imr website. the book lists the COL at 3.340. and the info from the website lists the COL at 3.300. in checking some factory ammo i have on hand that ammo is between 3.600-3.640. im leaning towards copying the factory ammo in OAL. but why do the books list it as being so much shorter?
also i have those comparators hat mount on the calipers to measure he length from the ogive. what lengths do you stay within?
also i have those comparators hat mount on the calipers to measure he length from the ogive. what lengths do you stay within?
Comments
I am not suggesting you can shove a bullet into the case all the way nor am I suggesting you can leave a bullet out with only a hair holding it.
The books will list them according to the bullet length being used. Some bullets, like the 125-130 grain bullets are too short to reach longer (standard) OAL's others like the 200 Grain SMK are very long and can only stick out so far and still feed from a magazine.
FWIW try 46 grains of IMR 4895 with a 168 SMK bullet. It has proven very accurate in many 1903A3's
the magazine has quite a bit of room in front of the bullets so i dont think that is much of a concern. can i go wrong using the factory load as a starting point as far as length?
That said, a number of manuals list the "tested at" length at something shorter than that, esp with the lighter and roundnose bullets.
Are you sure you're measuring correctly. I have never seen factory .30/06 ammo that long--It is seldom as long as the maximum of 3.340 except in military ammo.
what i have on hand for now is imr 4064 with a 175 gr fmj-bt bullet.
the magazine has quite a bit of room in front of the bullets so i dont think that is much of a concern. can i go wrong using the factory load as a starting point as far as length?
Sure, no problem, 3.340 is the standard OAL, if the bullet you have is the government match BT it can use the same loads as the 168 SMK. I have shot many thousand 174BT's through a 30-06 with very good results.
First, will it fit and cycle in the magazine? Too long or in some cases, too short, it won't.
Second, you don't want to crush the bullet against the rifling except in some cast bullet applications.
Third is pressure. Seat too deep with a high end load, you run into pressure problems. Seat too shallow with a load with a slow powder and lighter bullet, not enough pressure is generated on ignition to get a complete burn or good consistency.
Given your component choices, I would seat them just deep enough to feed down into the mag and see, using a dummy round using no powder/primer, if this will seat without bumping the rifling lands. If you can't close the bolt, it's too long. Keep adjusting the seating die down until it will both accomplish the goals in points one and two. You now have an OAL tailored to YOUR rifle, generally optimum for best accuracy.
Given your component selection, point 3 should take care of itself. 4064 is fairly easy to touch off and you're going to have to seat a 175 gr bullet deep enough to get proper neck tension to enable proper feeding, so it won't be too shallowly seated, but you won't be seating deep enough to cause pressure issues with good published loads.
In this rifle i found that the bullet hits the lands at 3.645(with the comparator). i backed off to 3.635 for my starting point. which is at ~3.200. this fits in the magazine and feeds fine. gonna head to the range in the morning and try em out. i started with 46.5 gr of 4064 and maxed out at 49.5. ill let everyone know if i blow myself up or not. [:o)]
ohh and also yes these are mil spec 175gr fmj-bt match bullets. hopefully ill get some decent results.