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Posted: 6/5/2008 12:07:02 PM EDT
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I am setting up 308 on a Dillon 550 with Dillon dies and had questions about crimping, now I have a question about COL, I did some horse trading with a friend of mine, he gave me 600 bullets (150g BT?) they are not hollow points but are solid tipped and have a cannelure grove around them. So off I go to set up my 550, I screwed the sizer/decap die all the way down until it touched the shellplate and then backed off 1/2 turn per Dillon, (checked with a case gage and with the half turn it seemed to be where it needed to be) I then moved on to the powder drop which was idiot proof to set and then I moved on to seating, this is my big question, after screwing down to the shellplate then backing off 2 turns per dillion I proceeded to set the seater plug for a 150g BT (he told me they were BTSP) the OAL in my Speer manual says to seat to 2.800" but when I do I am not even covering any of the cannelure so i called Dillon and they told me to seat the bullet to where it covers approx. 50% of the cannelure which gave me a OAL of 2.725 my speer book has a 150 BTSP set at 2.700 but does not have the cannelure ? The round looks funny with part of the line showing and I don't believe I have seen a 308 with a line around it do I need to seat further I believe covering the cannelure would put me at 2.700" as far as the crimp goes Dillon said screw it down until it touches the seated round and go 1/2 turn and be done. I hate to ask stupid questions but I am very new to reloading and don't have anybody close to go to that has knowledge of reloading my friend ordered the bullets for me of the net for some tools I had said he got them from Midway but can't find the paperwork |
| Since I handload for a bolt action long range rifle, I dont crimp the case mouths. The inconsistency of the crimps can cause a lot of variation from shot to shot. I load mine to the OAL that gives the best accuracy (that fits into the magazine). I have never had a problem with any bullets moving back inot the case which is ostensibly the reason for the cannelure. |
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length of 2.725 should be fine. Once you find a load that shoots well then you can mess with the length to fine tune the load. The sierra load data is pretty conservative so if you follow the loads listed there you are good to go. Where are you in IN? I may be able to help you if you are in the Southern IN area edited :fat fingered the keyboard |
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First off, seating to the cannelure is not required. The bullet can be seated longer and left uncrimped or taper crimped, and I suspect there are some cannelured bullets around that can be seated so the cannelure is completely covered. Seat to the middle of the cannelure or slightly above if you want to use a roll crimp. If that results in a length that you want to use, but you don't want to crimp, leave the length right there. The location of the cannelure is variable, even on bullets from the same manufacturer but made at different times, so you may need to readjust the seater after buying a new batch of bullets. One detail that is critical is confirming that the cartridge will function in the firearms magazine at a certain length. In my experience 3 or 4 test cartridges are needed so they are down inside the magazine body. Up high near the feed lips a cartridge that is slightly long may feed fine because the front of the magazine is below the case. There aren't any stupid questions here. Sometimes the answers are stupid, but everyone gets to have their say unless it's dangerous. The number 1 reason for the forum is to help people. |
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Here are a couple of pic (sorry about the quaility) They are seated to 2.725" the Speer #14 book has a BTSP @ 2.700" for a 150g and a FMJBT @ 2.800" , if I seat to the the 2.800 the cannelure is not even close but if I run it to the middle of the cannelure a Dillon suggested it comes in at 2.725" The bullet measures 1.126" total 0.386" to bottom of cannelure 0.430" to the top the bullet looks more like a FMJBT but I don't know bullets either My big concern is a big bad explosion if i seat it wrong Thanks for all your help   |
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Bullets vary. Trim lengths vary. COAL will vary. Q.C. is what everyone wants for consistency, though it comes at a price. Accept some amount of variation and move on. Hey, it's your first time.......re-loading bullets in the cannelure in this case, is "good enough." I ASSUME that you've done your case preps, safely loaded with known load data (starting low and working your way up), it chambers and extracts without problems...........IMHO, what you have looks "good enough," to go shooting. How about? IF you're still up to it, next time, start experimenting with COAL and crimps. BTW, my 168 gr BTHP (no cannelure) measures 2.80" it fits the magazine of my M1A. It's accurate so, IMHO, it's GTG. IF I experimented. I may find that 2.75" or 2.82" (or anything in between) may be "better." But, who knows? Every rifle is different. What works for me, may not for you. As you gain more experience you'll be more comfortable with what you're doing. Go shooting. Aloha, Mark PS.....BTW as you're loading more of these bullets (miliatry style FMJ).............don't be surprised IF you start seeing the case neck ending up higher or lower in the cannelure. Sometimes, the bullet cannelure placement on the bullet isn't consistant. Q.C. problems with the bullet mfn. or diffent lots thrown together in a "bulk box." Or, your trimming of your brass wasn't consistant. |
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Military style FMJ ? , where can these be purchased or for that matter 150g FMJBT 308 bullets at a decent price, i just ordered a couple of thousand 9mm 124's from Precision Delta I did not think they were a bad price. I would like to get several thousand FMJBT 308 in the 150g range for range plinking. I looked in my Speer Book at the list, a 150g FMJBT is 2.800" so I will ask can I seat these to that OAL even though the cannelure is not even close to being covered, I did some searching on the net and they look like Win 308 bulk is what i have and others have reported that the cannelure does not match the OAL for that round |
Taken from....... www.speer-bullets.com/default.asp?s1=5&s2=30 Aloha, Mark PS........the military wants (not in any particular order) the cannelure (AKA: bullet crimp groove) because, 1) The bullet likes (especially, in the 5.56mm) to "fragment" at the crimp groove. 2) Knowing that military cartridges are subjected to adverse handling and recoil forces. The crimp when placed in the cannelure of the bullet, helps to maintain the cartridge's OAL. Better for consistency and safety. |
Well, 2.80" is the COAL spec. for M80 and M59. So, don't worry so much. Go shooting. www.inetres.com/gp/military/infantry/rifle/762mm_ammo.html Your shorter COAL w/ bullet crimped in the cannelure, may be due to a mfn decision, of where they wanted to place the cannelure for that lot of bullets. Or, a Q.C. issue. Or, it could reflect the difference in length between, your trimmed cases vs. what is spec'ed for the mfn's new brass cases. I doubt that for this particular bullet (150 gr FMJBT) the COAL (be it 2.70" or 2.80" and everywhere in between) will matter too much. Not having it exactly 2.80" isn't THE END OF THE WORLD.  NOTE: Some bullets are longer (or shorter) and sometimes made of different materials, which can affect the pressures and performance of the cartridge. Thus, not all data for a particular grain weight bullet will interchange for another mfn bullet of the same weight. It's always best to use load data from reliable sources (and components matter). Start low and work your way up.Aloha, Mark PS...........handloading involves some amount of RISK and at times some amount of experimentation. |
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Well I have loaded my first 20 and will get to the range soon I hope to see how they function They are 150 FMJBT Fed 210 primer 40g of IMR 4895 LC MG Brass sized and trimmed to 2.005 OAL is at @2.775" ( These are not seated to the cannelure) used the Sierra Data for this info. They load fine in the mag and all extract without any problems will just have to se how they do at the range |
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