njc110381 Posted February 22, 2008 Report Share Posted February 22, 2008 Hey guys. I was hoping you'd be able to give me some advice on what to do now I know my chamber length (or whatever it is you call it). With Speer 140grn soft points, I'm getting a measurement of 3.170. Lee State min OAL to be 3.030 with Varget. So, my question is, what do I do now? Is there a standard measurement I should be making my rounds to, or is there some testing involved? I understand the bullet should be taken back from the lands of the rifling slightly otherwise you get higher pressures? How far back? Thanks in advance for any advice Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 22, 2008 Report Share Posted February 22, 2008 if you got a factory gun then just seat them at saami length like it was designed for if its a custom with custom spec chamber then find out what bullet it was cut for and what fill of what powder and come back with what you found and i will punch numbers and math for you Link to comment Share on other sites More sharing options...
njc110381 Posted February 23, 2008 Author Report Share Posted February 23, 2008 Don't you measure it because every gun is slightly different? If you just seat to SAAMI length, what's the point finding out what size the chamber is? I've heard factory guns are machined to pretty sloppy tollerances, so can vary a lot depending on how worn the cutter is? Surely theres a reason people measure their guns, or have I got it wrong? I'm a bit lost on this one now Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 23, 2008 Report Share Posted February 23, 2008 ok the reason a guy with a custom chamber will measure it is because if he/she finds best accuracy say 5thou off or say 10 thou in the lands then he/she will need to keep a close eye on their loadings as the throat wears and they will want to adjust seating depth to keep with that accuracy area as the throat wears and lengthens its worth mentioning that many people buy a factory rig with a saami spec chamber and they automatically start loading out to near the lands as they read to do so without giving the saami industry standard a go, if they did they might be supprised I and others on this site now load back at saami length in a standard factory gun as this has proven better for many reasons if you have a factory stick then its still worth checking the throat measurement as when time goes on and you have shot a number of rounds you can check to get an idea of how much it has grown when checking growth of two rifles one seated at saami and the other seated at near,on or in the lands you can bet that the saami length one will have grown the least factory guns do have more chamber run out compared to custom rigs, this is the price paid by mass production if you can get access to a dial indicator then its worth checking your fired cases to get an idea of your run out if run out is more then 1.5 thou then I would recommend that you full length size only as trying to index a neck sized loaded round in the same orientation as the chamber run out is nearly impossible if you havent got access but would like to know your run out then just post me a fired case and I will check it for you as I have a guage that reads tenths of a thou if you are happy as you are then just check two five shot groups neck sized compared to two five shot groups full lengthed and this will give you what will be best in your gun for accuracy what length have you been loading to? Link to comment Share on other sites More sharing options...
njc110381 Posted February 23, 2008 Author Report Share Posted February 23, 2008 So far the best loads I've fired were made for me by my mentor. They were 120grn Nosler ballistic tips seated to the minimum length stated in the Lee book (3.000). How do you find out the SAAMI length? Thanks for the offer of measuring my cases, that's very kind of you. I have been advised to full length size my brass, is that because it's likely to cause feed problems if I don't? I have some Federal cases that were fired in my gun, but will be using Lapua from now on. If I was to send you a Federal case to work with would that be ok, or do you need a Lapua one? Thanks again for the offer of help, I'm really grateful. Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 23, 2008 Report Share Posted February 23, 2008 if the measurement came from the lee book then it will be saami spec as will all reloading manuals they get their accuracy from predicted pressures. seating at saami you get x pressure, seating out longer the pressure drops until it near the lands then pressure starts to rise again it is impossible in reality to seat into the lands but its a term used instead of soft seating what this means is the bullet is seated longer than the lands so when the round is chambered the bullet pushes up against the stell of the rifling and the brass neck being the softer and weaker of the three (lands,bullet and brass neck) gives way and allows the bullet to get pushed back into the case and this gives more uniform pressure build and let off lee in their wisdom created the lee factory crimp and this gives the saami spec reloader the same benifits you will see the lee factory crimp being used in bullet manufacturing companies around the world neck tension can vary from case to case even in hand turned necks and the lee crimp applies the same pressure every time to lesson the shot to shot variation and allows the case to HANG on to the bullet a little longer leading to a slightly increased and more even pressure shot to shot Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 23, 2008 Report Share Posted February 23, 2008 any case fired in your gun will do but it has got to be one that has been fired and the more times its been fired the better as the brass looses elastis after being fired more than once but a once fired will do if thats all you have Link to comment Share on other sites More sharing options...
njc110381 Posted February 23, 2008 Author Report Share Posted February 23, 2008 I'm not sure when I'll be able to get to the range again, but I'll load one of the Federals again and fire it. I could even take the press with me and load it again if it helps? How many times can I fire it before it needs a trim? Me being a bit of a tit only ordered the case cutter and lock stud, I didn't realise the guide and holder is seperate Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 23, 2008 Report Share Posted February 23, 2008 once fired is ok but twice fired is better you could get away with two firings before trim for sure but on the third you wanna check before loading it Link to comment Share on other sites More sharing options...
charly hunter Posted February 23, 2008 Report Share Posted February 23, 2008 I have a .243 which I couldn't get to shoot, even with berger bullets I could only get 1.75 - 2 inch groups. I tried everything and eventualy I was ready to beat the rifle over a wall. Then Silent give me a load to try, I couldn't believe the groups I was getting. On three occasions I shot a 5 round group and the largest group was just over 1/4 inch at 100 m and the best was just .157 of an inch. Don't question what this guys says just try it and see what works. Come to find out the load he gave me was sammi loads, I won't use anything other now. Link to comment Share on other sites More sharing options...
crispacket Posted February 24, 2008 Report Share Posted February 24, 2008 Whats the load then charly Link to comment Share on other sites More sharing options...
njc110381 Posted February 24, 2008 Author Report Share Posted February 24, 2008 Well I've had some good luck with the loads so far. I had some I'd made to 30thou off the lands, with 33grns and 35grns of Varget. I figured I may as well try them rather than push them shorter. Both shoot under 5p groups at 50 yards, and I'm not a great shot! I bought some reloder 19 at the club, so have now made some up to the same length with 43 and 45grn charges to see what they do. If they work then great, if not I'll make some shorter ones. I'm really enjoying this. My groups are 1/2 of the size I can get with Federal premium, and I've only just started Link to comment Share on other sites More sharing options...
charly hunter Posted February 25, 2008 Report Share Posted February 25, 2008 Whats the load then charly Sorry I have been so long replying pard, the load I use is; 41.5grn N140 90g Nosler Balistic Tip OAL 2.200 And that is in a 24 inch sporting barrled CZ Link to comment Share on other sites More sharing options...
eddieb Posted February 26, 2008 Report Share Posted February 26, 2008 Charly I think you have got the wrong OAL there. That looks more like a 223 measurement. I have also used the VIT 140 for 80 grain spitzer bullets but 39.6 was my max load. Cheers Eddie Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 26, 2008 Report Share Posted February 26, 2008 yes he has a 223 as well and he's got them mixed up it should be 2.650 for that booooolet me thinks Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 26, 2008 Report Share Posted February 26, 2008 when he has a bad day with the 243 we just dont tell him he has loaded 223 in the bugger Link to comment Share on other sites More sharing options...
charly hunter Posted February 26, 2008 Report Share Posted February 26, 2008 Charly I think you have got the wrong OAL there. That looks more like a 223 measurement. I have also used the VIT 140 for 80 grain spitzer bullets but 39.6 was my max load. Cheers Eddie Sorry guys and well spotted it should be 2.650 I can't help it I'm just a dumb arse Link to comment Share on other sites More sharing options...
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