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Posted: 8/10/2008 5:33:21 PM EDT
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One day, my DPMS LR-308B will come in. I'd like to load some rounds for it and have some ammo ready for it when it comes in. I'll be breaking it in with mil surp, but once that's done, time to test for accuracy. I'll be using Ramshot's Tac and the 168gr SMK. Now then, in my load books, there is a minimum and maximum load. Will the minimum load cycle the gun? Or should I start in the middle and go from there? Laugh if you will, but I load in 100 round lots. At the end of that 100 rounds, I know what the gun will do, dirty and clean. I just don't want to load up 100 rounds that won't cycle the gun. Any advice would be appreciated. |
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I know you don't like this plan, but I think you could accelerate your program quite a bit. Load 5 each of the longest you can get in the mag, minus a bit, in .1 or .2 grn increments. Take 50 out the range, and you will learn alot. Once you pick out something that feels right, tinker with the load and test reliability. I will be using tac for my builk loads but I have heard varget works great for precision 308. |
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I don't think I want to call DPMS. Most manufacturers say not to use reloads. The shells for my bolt gun are on their 5th load. FC nickel plated brass. Don't really want to start with them. I have some once fired MG brass by LC-06 that I bought. Gonna start with that. The Sierra book has separate listings for the 223. One for bolt guns and one for the AR-15. They don't have that for the 308. All they say is if using military brass, reduce the load by 1 to 2 grains. |
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+1 on the 5 rounds of each. Why does it have to be 100 round lots? Thats alot of $$ to spend on a load, just to satisfy your curiosity that the load shoots like crap or several loads that arn't what your looking for. $11-$12 for powder $30 for bullets $3 for primers = about $45 for 100 rounds that are not the load you want. X 5 different loadings = $225 just to find a load that is close may need tweeking. Start all over again tweeking the load and you could easily spend $450-$500 on load development by loading 100 at a time. I'm not being a smart@ss. Most rifle bbls have a limited life (be it 1000 rounds or 20,000 rounds). Maybe we just have a different take on things and you like the experimentation part of it, which is fine. But you stated not wanting to waste 100 rounds that won't cycle. Can't see loading 100 rounds that won't group better than MOM, minute of milkjug. |
| I'm not that great a shot. I could probably tell in 5 rounds the potential for a load, but in my AR-15s, in 223, after 100 rounds, I know exactly what I have. One AR-15 seems to like to run a little dirty. Groups start to tighten after 5 rounds. Then they settle in. The other doesn't seem to make any difference if it runs clean or dirty. I just want this gun to cycle when I start out. Then I'll go from there. It'll probably be a couple more months before the gun comes in. I just want some ammo ready for it after I break it in with the cheap stuff. |
Sir, FWIW I bought an LR-308 back in May. I broke it in with some factory Remington 150gr ammo the seller gave me when I bought the rifle. It didn't like my standard M1A reloads, the extractor ripped the case rim from the shell and I had to use a ram rod to remove the stuck shell from the chamber. It worked with factory M852 but accuracy was not great. My best advise is the same as already mentioned. Work up some loads in groups of five and determine what your rifle likes best. My current plan with this rifle is to do exactly that but I can tell the process will not be complete in a single range outing. Since you already mentioned it, most rifle manufacturers warn against using reloads. DPMS says using reloads voids their factory warrenty. I spoke with them last week in their store on commercial row at Camp Perry. Everything I've done to the rifle to make it shoot better voided their warrenty, including the new Geiselle trigger. Who cares? HTH, 7zero1. |
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The ammo I'll be breaking it in with isn't great. OFW from '79. Got about 200 rounds of that left. Were the loads for the M1A on the high or low side? 40.5grs of 748 caused problems? That's below minimum in my 2nd edition Sierra book. I used to use 44grs of 748 for the 168gr bullet in my bolt gun. Looks like I'm on my own for this gun. If I ever get it. |
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One of the problems I have observed in the LR-308 is that the action appears to open too soon, resulting in what looks like overpressure signs on the fired cases. More specifically: the rim is pulled (bent) back a bit by the extractor, and there are scuff marks on the case head indicating the bolt is rotating while there is still chamber pressure. I have even seen a heck of a burr scraped up by the ejector recess on a reasonable reload (with 4895). This issue makes it difficult to work up reloads for this rifle. There are two possible fixes: - A heavier buffer with little or no rattle-room for the weights (see ARFCOM user "slash" for heavy buffers an/or weights). - An adjustable gas block (several makers out there). I have decided on VARGET for 308 reloading, and will probably use bullets in the 150-168 grain weight range. |
Your surplus ammo may or may not work in the DPMS. Mine is about 50% with various types of surplus ammo. It will usually chamber and if it does chamber, it will fire. It will often leave the case stuck in the chamber. The strange thing is that it takes almost no effort to push the case out with a rod. I suspect that chamber pressure is still on the high side when the bolt is trying to open. Perhaps this is due to the short gas system. If yours is like mine, I think you will find that the chamber is very tight. My chamber was also quite rough with quite a few machining marks left in it. I had to pollish the chamber and use small base dies to get it to function nproperly. Anyway, I think if all's well, the rifle should function with light loads, if that's your concern. |
| I'm setting brass up with the RCBS X-Die, a small base die. I have two boxes of Black Hills 168gr match ammo. That will be the ammo I base my reloads on for accuracy. anyone have any idea if the Black Hills ammo is loaded hot or light? Starting to sound like the DPMS might be a little hard to reload for until it has a lot fired through it. |
Sir, I'm going to qualify my answer to your question by first mentioning that my M1A loads were developed using a 1985 edition of the Sierra reloading manual. I haven't bought a reloading manual since then but suspect not only are there more powders available but the charge weights for the same powders have changed. I've used 41.5 gr of IMR4895 with a Sierra 168gr MK and WLR primers for years. The load closely duplicates all of the properties of the formerly popular match M852 cartridges that I could measure. According to my Sierra reloading book 42.1 gr of powder is the max for this bullet so my loads are below the max charge. As previously mentioned the rifle tears the case rim off with this load so there are some limitations in the gas system. I haven't discussed this with my gun smith yet but suspect a heavier buffer and spring may be in order. Perhaps some form of gas block alteration may be needed, I don't know at this point. As a competitive high power rifle shooter so far I'm somewhat less than pleased with the properties of this rifle. I've already purchased a new AR10 upper and lower receiver from Armalite the last day they stayed open at Camp Perry, yet another rifle in the making! HTH, 7zero1. |
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