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Posted: 11/9/2008 5:52:17 PM EDT
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I am reloading 30-06 and I am having a problem with the OAL of the round. I trim to 2.484 and using a Hornady 150 gr FMJBT. When I seat the bullet for a OAL of 3.25, the canalur is well above the mouth of the case. If I seat the bullet to the middle of the canalur, the OAL is well below the suggested of 3.25. If I use Mil surplus 147 gr FMJ, the canalur sits right at the case mouth +- .03
It seems that the Hornady bullets canular is located much higher than the canalur of the Mil spec bullets. How short of an OAL can I go when I load for the M1 Garand? |
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Not sure what you are asking? What are you using to measure COAL?
Have you made a dummy round for the chamber of your grand? Generally speaking a shorter COAL will lead to a less accurate rifle. You can go as short as you want but I load my M1A to just under mag length which is .10 shorter than the chamber of my rifle so my loads are .15 shorter than max COAL for my chamber. remember the COAL in your reloading manual is the COAL that worked best for there test barrel. |
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Hornady bullets use a slightly different geometry than most, that being called a secant ogive rather than a tangent. Without going into the differences too much, seat to the cannelure and be done with it.
If you are reloading with data suitable for a Garand, there will not be any pressure issues. In bottlenecked rifle cases, deep seating DOES NOT cause high pressures as in PISTOL cases since the PERCENTAGE of case volume lost is trivial in rifles. In pistols, it IS a good percentage and WILL cause pressure excursions. |
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Hornady 7th Edition Manual lists oal at 3.185" for the 150fmj #3037 bullet.
Hornady 4th lists oal of the same bullet at 3.258" and Hornady 5th lists oal length for the same bullet at 3.260". I've tried them in M1 Garands at both lengths. I prefer the 3.185 length as it puts the cannelure in the correct place for crimping. 4th edition lists H4895 from 45.1-48.7 grains 7th edition lists H4895 from 43.2-46.4 grains for M1 Garand data but only 2600fps. The above data is just to show that maybe Hornady 7th reduces maximum for the shorter oal used. I've shot them using IMR4895 up to 48 grains at approx. 2750fps but would recommend starting at 45 grains with IMR 4895 and working up. Hornady 7th Edition lists 3.185" for regular 30-06 and also the same length in the M1 Garand section. In the Garand section they used Hornady-Frontier cases and Win LR primers in their test. |
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