Im loading .308 Win with 46 grns of WC-846 using BL(C)-2 Data Seating a 150 FMJBT from Everglades. Seated to cannelure is .06 under COL as per most Manuals I have. Q is will that much bullet in case raise pressure to High ? Should I seat to COL and ignore cannelure?
Rifle Bullet Cannelure and COL
- Thread starter gns4me
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How long is the bullet, and how far from the base is the cannelure? Can you post a pic?
ManFromMontana
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IMHO, Cannelure shouldn't be used to determine COL as brass length and neck may vary. I'd ignore cannelure and go with COL from manual(s).
I don't think that COL changes have the same impact for rifle cartridges as they have for pistol. Pistol cases are usually much smaller than rifle, and bullet diameters, for the most part, are bigger. Thus, a small change in pistol COL changes the case volume to a much greater percentage than for most rifle cartridges.
As an example, I tested the seating depth for 80 gr. SMK's in .223 to see if there was a difference in accuracy for my rifle. IMI brass, Rem 9 1/2 primers, and the same charge of
RL15. I chronoed 10 shot groups, and the results follow:
2.520 OAL, 2588 fps, ES=81, SD=25
2.500 OAL, 2581 fps, ES=91, SD=26
2.490 OAL, 2621 fps, ES=62, SD=23
Not much difference w/r to accuracy or MV with a 0.030" OAL variation. 0.006" in a .308 wouldn't change much if the load is safe to start with.
As an example, I tested the seating depth for 80 gr. SMK's in .223 to see if there was a difference in accuracy for my rifle. IMI brass, Rem 9 1/2 primers, and the same charge of
RL15. I chronoed 10 shot groups, and the results follow:
2.520 OAL, 2588 fps, ES=81, SD=25
2.500 OAL, 2581 fps, ES=91, SD=26
2.490 OAL, 2621 fps, ES=62, SD=23
Not much difference w/r to accuracy or MV with a 0.030" OAL variation. 0.006" in a .308 wouldn't change much if the load is safe to start with.
I doubt that the bullet you are using is the same one list in the manuals.
Heck sometimes it is hard to match Hornady bullets with the data from their manual using Hornady brass trimmed to the exact length they did.! There is a lot of variance in the width of a cannelure, I would not worry about 0.06
Heck sometimes it is hard to match Hornady bullets with the data from their manual using Hornady brass trimmed to the exact length they did.! There is a lot of variance in the width of a cannelure, I would not worry about 0.06
Its 0.060 " difference The powder fill case up to the shoulder I guess thats worries me
Random 8
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Slow your roll. You are using a non-standard bullet AND powder vs published data. WC 846 is NOT commercial grade BL-C2 falling into a specific tested pressure range. You should be working up to that load with that bullet. You may be just fine, you may have far bigger problems than .06 difference in COL. Only testing will prove.
As for the cannelure, you can basically ignore for most purposes unless you are crimping. If you are crimping, the cannelure will set your COL and pressure signs if present will determine the true maximum load in your rifle/your component selection. If you're not crimping, I would try the book COL and adjust as needed for top accuracy, following load work up best practices.
As for the cannelure, you can basically ignore for most purposes unless you are crimping. If you are crimping, the cannelure will set your COL and pressure signs if present will determine the true maximum load in your rifle/your component selection. If you're not crimping, I would try the book COL and adjust as needed for top accuracy, following load work up best practices.
AJC1
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Cannalures in rifle bullets are not really useful for my loading unless it's a lever action load. Neck tension is your primary bullet holding force.
Charlie98
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That's the Hornady bullet on the R... next to the Winchester (L) and Prvi (C) bullets. Yes, the cannelure is way too high for .308. Just seat the bullet to your designated OAL and call it a day. As an aside, I seat those bullets to the cannelure only in the .30-06 for my M1 Garand... but my load is tuned to that OAL.
Charlie98
Member
It isn't, but it interesting...
My Hornady 7th has the 150grn BT-FMJ, which is close to this bullet, but not quite... but suggests a seating depth of 2.780", which is where I seat all my 145-150grn FMJ's in .308. They also have the 150grn (or 155grn... they don't specify...) SST bullet, with the much higher cannelure, and a suggested OAL of 2.735" I'll bet that SST bullet seating depth would be very similar to the mystery FMJ we are talking about here... and the Hornady data does not make any changes between 7 different bullets.
Either way, the OP should start low and work up... no matter what OAL he decides on.
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