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Thread: It was going too well to last!

  1. #1

    It was going too well to last!

    Hi all

    Been working on my 1st load development lately. I settled on a load of N140 at 43.4 with a group just under half inch, very happy with that. 8 development loads had been under and two loads just over an inch. Today I went to zero that load as it was not quite on bulls eye at 100y and then I was going to see what the drop was out further.

    I shot one group at 2inch and a second at 2 1/2 inches. Not happy! I have some hand loads from Bisley, which have been shooting sub inch so I thought I would try them. Even from them I had a bad group just over two inches and a second at an inch, which is border line acceptable to me. All groups 5 shots, Packed up and went home before I kicked my teddy in the corner!

    Only thing I can think I have done differently was to leave a thin coating of oil in the barrel when I last cleaned it, which I don't normally do. Today I put a bore snake thought it before shooting, which may not of got all the oil out as I did notice some of my cases where unusually black when ejected.

    Could excess oil in the barrel affect group size? We are taking a lightly coated patch when I did it after cleaning.

    Needless to say I wont be making that mistake again. I've given the rifle a cleaning tonight and checked screws etc, all good. This has now made me question my whole load dev process. Ill be out tomorrow to try and correct things, hurry up daylight!

    Butchs bore shine. I've been using that to clean my new barrel during the break in process and load dev, says it removes everything from the barrel. No reason to think it hasn't, Ive followed the instructions to the letter.

    Thanks J

  2. #2
    The simple answer is Yes.
    Anything left in the bore (oil etc.) will adversely affect accuracy. Years ago I was out stalking in the morning and it was hammering it down.Water was dripping out of the magazine once back at the lodgings. I wd 40'd the barrel to stop rusting as I was out later that day. Teatime stalking first shot was a clear miss but the second dropped the deer on the spot.

    Lesson learned; dry pull through from then on in this situation!

    Clear your barrel and then rely on your data.

  3. #3
    Surely for no more than the first shot?

  4. #4
    Sooty cases are an indication of failure to obturate. Usually caused by low pressure.
    Were your loads developed in warmer times? In summer higher temperature can increase pressure. Frezing cold bullets lower it - could be you were only just achieving enough pressure in the warm - now failing in the cold.
    What calibre are you shooting & what bullet weight? & what velocity are you getting?
    An oily barrel won't have helped, but may not be the cause of your poor groups. Low pressure could.
    If you oil your barrel, it is a good idea to swab out the barrel with alcohol & drying it before shooting.
    It sounds like you may need to rework your loads bearing this in mind.

    Ian

  5. #5
    A meths soaked patch & a dry follow up patch should ensure a clean, dry bore.

    Yorric has touched on the sooty cases, perhaps loaded one too many times without annealing & as a result failing to obturate (seal correctly) causing poor consistency.
    Last edited by deeangeo; 26-12-2016 at 19:59.
    Blaser K95 Luxus Kipplaufbüchse .25-06Rem. Schmidt & Bender 8x56, 110gn Nosler Accubond = Game Over!

  6. #6
    A thin layer of oil in the barrel will affect the first shot but clear immediately after that. If both groups were off it's unlikely to be the answer.

    Before you start rebuilding all your recipes are you sure your technique was spot on? No likelihood of any human error and no wind that could have effected it? I would want to absolutely rule these factors out before I started to mess with a recipe that had worked previously.

    Something off with the scope would be next, but you have checked that. Wooden stock? has it got wet and moved so the barrel is no longer free floating? Is the action Marine-Tex bedded? Could that have moved in a plastic stock?

    Rule out everything else before you start redeveloping a load that was once working.
    So much to learn and so little time left

  7. #7
    Many thanks for all the replies.

    Its a PSE composite stock, very pleased with it. Gunsmith fitted it recently so should of been done correctly hopefully. I have checked the scope and mounts and rechecked, all appears correct.

    The sotty cases were happening on my Bisley rounds too, made by Fultons. My load dev was done over the last few weeks, so no significant temp change, today was 8'c with me. Might of been a few degrees warmer on some previous days. Its a .308 heavy barrel 26in, with 165g SST bullets. No wind to worry about today, quite sheltered, there was a head breeze.

    During pressure testing I started at 41g went up to 45.1g of N140 in gradual increments. I didn't have any stiffness when unloading and I didn't notice and flattered primers. I did noticed marks on the case at 44.7, 44.9 and 45.1 and was getting some noticeably stronger recoil with those loads. Likewise at 41g I noticed the recoil felt too light. So I decided 43.9 was my max load to allow for warmer temps in summer etc. Load dev was from 42.6 to 44. And 43.4 shot the most accurate which is why I choose that weight.

    Yes there may well of been some human error today but if I say so myself its unlikely the cause of the all the groups and given the previous groups over last few weeks. The rifle was supported by a front and rear been bag.

    Starting over is the last thing I want to do. I don't know my MV. Obviously I've a rough idea of expected bullet drop at given ranges so that was/is the next step to see what the drop was like and gauge if the round is/was performing correctly. Its a new barrel, (and I know theres 100 opinions on breaking it in or not) I broke it in religiously took me two days, as per manufactures instructions, Sassen engineering, formally border barrels.

    Ill head out tomorrow and hopefully it was just a bad day today. Thanks Again. Cases are all new lapua brass.
    Last edited by purdeydog; 26-12-2016 at 20:49.

  8. #8
    Quote Originally Posted by purdeydog View Post
    Many thanks for all the replies.

    Its a PSE composite stock, very pleased with it. Gunsmith fitted it recently so should of been done correctly hopefully. I have checked the scope and mounts and rechecked, all appears correct.

    The sotty cases were happening on my Bisley rounds too, made by Fultons. My load dev was done over the last few weeks, so no significant temp change, today was 8'c with me. Might of been a few degrees warmer on some previous days. Its a .308 heavy barrel 26in, with 165g SST bullets. No wind to worry about today, quite sheltered, there was a head breeze.

    During pressure testing I started at 41g went up to 45.1g of N140 in gradual increments. I didn't have any stiffness when unloading and I didn't notice and flattered primers. I did noticed marks on the case at 44.7, 44.9 and 45.1 and was getting some noticeably stronger recoil with those loads. Likewise at 41g I noticed the recoil felt too light. So I decided 43.9 was my max load to allow for warmer temps in summer etc. Load dev was from 42.6 to 44. And 43.4 shot the most accurate which is why I choose that weight.

    Yes there may well of been some human error today but if I say so myself its unlikely the cause of the all the groups and given the previous groups over last few weeks. The rifle was supported by a front and rear been bag.

    Starting over is the last thing I want to do. I don't know my MV. Obviously I've a rough idea of expected bullet drop at given ranges so that was/is the next step to see what the drop was like and gauge if the round is/was performing correctly. Its a new barrel, (and I know theres 100 opinions on breaking it in or not) I broke it in religiously took me two days, as per manufactures instructions, Sassen engineering, formally border barrels.

    Ill head out tomorrow and hopefully it was just a bad day today. Thanks Again. Cases are all new lapua brass.
    Great barrel, great stock, great brass. Was the stock fitted after your initial load development? 43.4 grains of N140 isn't too soft a load, should be about 2700 fps, perhaps a tad more with a 26" barrel. All sounds a bit odd. Nothing irregular you could have done when you loaded your batch following initial load development? Seating depth?
    So much to learn and so little time left

  9. #9
    I agree with NigelM---- sounds odd. It should work.

    Assuming COAL is standard SAAMI of 2.800" theoretically you should be achieving 2720ft/sec & 55978psi with your 26" barrel.

    I'd now advise checking bedding & stock attachment bolt torque is ensuring fitting is secure. Being newly fitted, it could have settled a little & come loose
    Also if a moderator is being used, is that in perfect condition & securely fitted? -- I just had a failure of a PES moderator baffle which resulted in bullets clipping the loose parts & giving me poor groups with my 243.
    I am wondering whether the brass, although new, may be a bit hard & if you anneal the once fired cases the situation may improve.
    Other things to query are --- Is the powder the same batch as your original? Have you changed primers? Are you achieving identical neck tension?
    Did you size the new cases before loading them & are they the same batch? Are you now using the rifle in the same configuration - same stock/ Same moderator or muzzle brake? -- Changing any of these can upset groups due to changing resonance in the system.
    I would also check headspace length of the new unfired brass & compare it to fired examples.

    Ian

    p.s. Last year I bought some Seller & Belliot 308 fmj factory bullets for plinking on the range & despite them being very accurate, I had smokey cases when firing them in my Sako. - I felt they were a "soft" load & never chronographed them - I sold them to a mate with a different make of rifle & he never had a problem.

  10. #10
    Ive not got my note book with me. I seated the bullets to fit the magazine which was some way off the lands a good few mm. When I made my 1st round I was well cuffed, I'd made it to fit just off the lands, then I realised it didn't fit in mag lol. So redid to fit mag at COAL 3.155 using hornady gauge. The Lapua brass should be good, FL sized from new, uniformed primer pockets, etc etc. Used a bushing die too. Everything has been the same batches and anally retentive process.

    What baffles me is the match ammo from Fultons at bisley was off to, which makes me think it was something to do the the barrel/rifle. Its a new mod, barrel and stock, 90 odd shots through it now so should be well worn in.

    Tomorrow is a new day, ill recheck it all and see how we get on. Cheers

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