varmartin Posted February 18, 2010 Report Share Posted February 18, 2010 Went to the range today with Dave aka.. `onehole` to do a bit of load testing. I had made up my usual load of 155 Amax over 44 grns Varget in Lapua brass with a BR2 primer. I had two lots of loads , same components but 2x different seating depths to test. 20 rounds loaded to SAAMI length of 2.810. Av velocity 2720fps 30 rounds loaded to 0.015 off the lands. Av velocity 2737 My old Musgrave chambered in 7.62 loved to be loaded at 2.810 so i was eager to test my TRG at the same length and also loaded 0.015 thou off the lands. I think the test target tells a few stories... As i also tested the velocity and `ES-extreme spread` from both loads I am now wondering what you guys think would be the best load to test at long range. I am aware this is a `light` load for the .308/ 155 Amax but it is supremely accurate @100m A...The 0.015 off the lands load, that shoots the tightest groups at 100m with an ES of 60 fps..or B... the SAAMI load that gave bigger groups at 100m ,but gave an ES of 26fps .? Link to comment Share on other sites More sharing options...
Cornishman Posted February 18, 2010 Report Share Posted February 18, 2010 Martin Cracking groups from both loads and good shooting too. At longer range points are mainly lost on windage and there would be very little score difference between either load looking at the groups. You mention the extreme spread on velocities but what was the SD? If your ES was down to a single round that might just be a rogue round. I think you need to test again! Link to comment Share on other sites More sharing options...
varminter Posted February 18, 2010 Report Share Posted February 18, 2010 Very interesting test Martin , But also shows how accurate the 308 is!!!! As for your question , the spring is nearly here so best we go out with Jamie and stretch that TRG and get the results!!! my rifle is specked as 7.62 ( and loaded to SAMI ) and you have seen how that shoots at the longer ranges just as Jamie's!!! A fruit slayer meeting is imminent in the near future!!! :D Have a good holiday with the Mrs too!!!! ;) All the best............ RAY.............................. Link to comment Share on other sites More sharing options...
varmartin Posted February 18, 2010 Author Report Share Posted February 18, 2010 Martin Cracking groups from both loads and good shooting too. At longer range points are mainly lost on windage and there would be very little score difference between either load looking at the groups. You mention the extreme spread on velocities but what was the SD? If your ES was down to a single round that might just be a rogue round. I think you need to test again! Its a shame I did not get the SD from the crono before it was packed away..but i did write down the velocities as i went ...see below SAAMI load 2.810 to bullet tip 2721 2709 2737 2716 2720 2712 2730 2722 2705 2758 0.015 off the lands @ 2.280 to the ogive 2723 2738 2742 2717 2766 2717 2725 2749 2752 2738 2775 Link to comment Share on other sites More sharing options...
varmartin Posted February 18, 2010 Author Report Share Posted February 18, 2010 Very interesting test Martin ,But also shows how accurate the 308 is!!!! As for your question , the spring is nearly here so best we go out with Jamie and stretch that TRG and get the results!!! my rifle is specked as 7.62 ( and loaded to SAMI ) and you have seen how that shoots at the longer ranges just as Jamie's!!! A fruit slayer meeting is imminent in the near future!!! :D Have a good holiday with the Mrs too!!!! ;) All the best............ RAY.............................. Are... yes I can feel some fruit bashing is in order ... Link to comment Share on other sites More sharing options...
Streeker59 Posted February 19, 2010 Report Share Posted February 19, 2010 Damn you Martin...... I had convinced myself that i didn't need a TRG and that i would be better off customising my own 75. New trueflite, new Robertson, new scope. The whole package would shoot the pants off a TRG..... And you go and post pics of groups like these with test loads...... How could you be so cruel !!!!! By the way.. The best loads that were 15 thou off the lands.. Did they still fit in the mag or did you have to single load em ? Grant.. Link to comment Share on other sites More sharing options...
Ronin Posted February 20, 2010 Report Share Posted February 20, 2010 Martin lovely groups I think I would look at lowering the ES of the .015" off the lands load. Essentially, and quickly, the SAAMI load with 26 fps ES will give you a vertical spread of 8 inches (at 1000 yds) The load that is .015" off the lands has the higher ES of 60 fps, and potentilly will display a vertical spread of 18" (at 1000 yds) The .015 load is displaying better grouping. I would look at a light nck turn, flash hole de-bur, trimm all to length and sort by weight. Be interested to see if this made any difference. Also consider a primer change to Fed Match? It may alsobe interesing to see what effct using the new 308 small primer cases would have...... Hell, if my new 308 shoots that well I will be chuffed..... Link to comment Share on other sites More sharing options...
Cornishman Posted February 21, 2010 Report Share Posted February 21, 2010 Martin Your numbers show extreme spreads of 53 and 58 respectively for the 2.810 an 15 thou loads. I see there are 10 shots in the first load and 11 in the second but the SDs work out at 15.5 and 19.3 respectively which I'd say is not sufficient to draw any general conclusions. You're measuring the COLs in two different ways here - what's the difference in overall length between the two loads you tested? Having low extreme spreads is of course really important at 1000 yards but if you're shooting only up to, say, 500 yards I don't think you're going to notice the difference. How far are you proposing to take this thing? Link to comment Share on other sites More sharing options...
skany Posted February 21, 2010 Report Share Posted February 21, 2010 Went to the range today with Dave aka.. `onehole` to do a bit of load testing.I had made up my usual load of 155 Amax over 44 grns Varget in Lapua brass with a BR2 primer. I had two lots of loads , same components but 2x different seating depths to test. 20 rounds loaded to SAAMI length of 2.810. Av velocity 2720fps 30 rounds loaded to 0.015 off the lands. Av velocity 2737 My old Musgrave chambered in 7.62 loved to be loaded at 2.810 so i was eager to test my TRG at the same length and also loaded 0.015 thou off the lands. I think the test target tells a few stories... As i also tested the velocity and `ES-extreme spread` from both loads I am now wondering what you guys think would be the best load to test at long range. I am aware this is a `light` load for the .308/ 155 Amax but it is supremely accurate @100m A...The 0.015 off the lands load, that shoots the tightest groups at 100m with an ES of 60 fps..or B... the SAAMI load that gave bigger groups at 100m ,but gave an ES of 26fps .? MArtin awsome shooting mate bloody awsome rifle to mate if i ddint know better id have thought u had a parker hale:-P how consistant!!!! were u set up off bags or bipod? cheers Andy Link to comment Share on other sites More sharing options...
varmartin Posted February 21, 2010 Author Report Share Posted February 21, 2010 Ok guys ..thanks for posting ...Ive got some work to do to answer some of your Q`s...( just got back from a weekend away in London )..so will get back to this with a fresh head on ...bit knackered at the mo... Andy... Off bipod 6-9S...with rear caldwell bag... Link to comment Share on other sites More sharing options...
varmartin Posted February 21, 2010 Author Report Share Posted February 21, 2010 Damn you Martin...... I had convinced myself that i didn't need a TRG and that i would be better off customising my own 75. New trueflite, new Robertson, new scope. The whole package would shoot the pants off a TRG..... And you go and post pics of groups like these with test loads...... How could you be so cruel !!!!! By the way.. The best loads that were 15 thou off the lands.. Did they still fit in the mag or did you have to single load em ? Grant.. sorry about that Grant... ps. They still fitted in the mag, but they were single loaded on the day ... Link to comment Share on other sites More sharing options...
varmartin Posted February 21, 2010 Author Report Share Posted February 21, 2010 Martin Your numbers show extreme spreads of 53 and 58 respectively for the 2.810 an 15 thou loads. I see there are 10 shots in the first load and 11 in the second but the SDs work out at 15.5 and 19.3 respectively which I'd say is not sufficient to draw any general conclusions. You're measuring the COLs in two different ways here - what's the difference in overall length between the two loads you tested? Having low extreme spreads is of course really important at 1000 yards but if you're shooting only up to, say, 500 yards I don't think you're going to notice the difference. How far are you proposing to take this thing? Damn...got a tired head but cant leave it ... sorry for the confusion .. The 2.810 load was actually 2.185` to the ogive...so approx 0.097` difference. how far am i going to take this rifle ...well.... 1000yards before I load some 208 Amax/R17 ..or get a bigger gun ! Ronin... Essentially, what I am aiming for is a velocity of 2900+ with as low as possible ES.. I have some fettled cases and Fed Match primers, so onwards and upwards we go ... Link to comment Share on other sites More sharing options...
onehole Posted February 21, 2010 Report Share Posted February 21, 2010 Probably gonna get slammed for this but surely this rifle/barrel is in "tune" with the "15thou off" it is not in best tune or some other condition when at "sammi"The groups are larger and will get larger in comparison as we go further out.I think the ES seems to be insignificant in this rifle/ammo combo? Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 22, 2010 Report Share Posted February 22, 2010 if only it were that simple some guns or should I start with a gun that groups awsome at 100 yards does not necessarily shoot well at 1000 for example my 223 shoots a lot better at 100 with 52 amax rather than 75 amax but at longer range the 75 are a lot better also the test was 20 saami and 30 15thou the gun/chamber is designed to shoot saami spec as its the industry standard and also the gun is designed to be used or is aimed at the sniping world and they will have to use top factory match loads as their sniping round so the outfit will be tuned to perform its best with these rounds as the dont have the luxury of being aloud to load their own whats interesting is that top rifle builders that make for the sniping world, such as gap/ g a precision and many more will build rigs that are designed to shoot top factory match loads as these are only what a sniper will be able to shoot, and many many guns they make will shoot well bellow sub 1/4moa with this in mind a home load that clones these rounds closely in terms of length and powder amounts etc but benefits from the fact that the home loader being able to be more precise in charge weights, selected weighed brass better primers etc etc will only aid to better grouping over the top factory load given martins choice of rifle I would hope that it would shoot sub 1/4's with top factory match loads as it was designed to do and if he clones them and improves on them it will only shoot better just last week ray and I found something very interesting in that at 100 yards my 223 with 75 was shooting very poor so after one group of five being very very large we played and wasted the rest at just under 350 yards and we were hitting every little stone we aimed at on the backstop mound pasted from my other post...................... right just done the math as others seem to have missed your point bud and thought you would find this interesting because my pda was already set at 2650 fps for the old girl, I left it at that but input your ES for both load types to see what would happen at a 1000 yards ................................................................................ .............................. saami spec @2810 av fps 2650 +/- 13fps to give give your recorded oa/es spread of 26 fps so 2650+13fps = 2663fps requires 40.25moa elev, 5.5moa wind @1000 yards 2650-13fps = 2637fps requires 41.25moa elev, 5.5moa wind total of 1moa difference ................................................................................ .................................. 15 thou off av fps 2650+/- 30fps to give your recorded oa/es spread of 60fps so 2650+ 30fps = 2680fps requires 39.75moa elev, 5.5moa wind @ 1000 yards 2650-30fps = 2620fps requires 42moa elev, 5.5moa wind total of 2.25moa difference now that tells the story you were after now try saami with either crimp or 3thou pinch to get the es down a bit lower ....................... hope that helps, I will load you something to try Link to comment Share on other sites More sharing options...
TC Posted February 22, 2010 Report Share Posted February 22, 2010 now try saami with either crimp or 3thou pinch to get the es down a bit lower I understood lower neck tension to be linked to lower ES - have you found different ? I ask as I have a similar situation with a load I am working up at the moment and am looking at how to reduce the ES on a load that is spot on at 100 yds... TC Link to comment Share on other sites More sharing options...
onehole Posted February 22, 2010 Report Share Posted February 22, 2010 Now I am confused and Ronin started it?Cornishman got it right? Silent do the maths again on the correct ES for each load,I,m sure 5 fps is not a factor or is it? I admit to never even looking at ES perhaps I should. Link to comment Share on other sites More sharing options...
6mmBR Posted February 22, 2010 Report Share Posted February 22, 2010 how far am i going to take this rifle ...well.... 1000yards before I load some 208 Amax/R17 ..or get a bigger gun ! Don't waist your time with reloader 17 and 208 Amax, we've tried it in my match rifle and velocities are very dissapointing, over 100 fps down on what N550 will give. Seems you can't get enough in the case to get correct velocity, best over chrono was 2650fps with a 210 Sierra, whilst 49 grains of N550 gives 2730 fps and 49.5 gives 2750fps but accuracy not as good. You need to have a chamber with a long throat to use these loads as a SAAMI spec will give serious pressure issues as the bullets will be seated very deep in the case. Cheers Dave Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 22, 2010 Report Share Posted February 22, 2010 if seating in/near the lands then yes less is better, if seating at saami then tight is better but more than 3 thou is not good because a) neck can start to shave copper off the bullet. can work the brass too hard and the effect wears off the important thing to remember is that saami spec.................. the bullet is seated well back into the case just as we see in factory loads, there is a large jump to the lands so the load info available from the industry is based on estimated or tested pressure to achiev accuracy. the round is seated back and will vary in length from bullets type's ie lighter bullets appear to be seated further in than heavy bullets take two cases or loads that are designed to jump as in saami spec, ones a light bullet and ones a heavy bullet, now the industry has tested and found what pressures produce what speeds so load the cases with the same amount of powder and seat the bullets so that the air gap between the back of the bullets and the loaded powder in the case are equal, if both bullets are going to jump to the lands then the pressure build up is going to be produced mainly whilst the bullets are still in the case it all happens in a blink of an eye but the pressure builds rapidly until the csae neck holding the bullet in place can no longer hold the bullet and so the bullet is pushed out of the case and into the lands and the bullet begins its travel down the barrel the greater the hold the case neck has on the bullet the greater the pressure will be and so the faster the bullet will travel( to a point) but their is only so much tension that case neck will ever have on the bullet. if you can apply more pressure at a very small area of the neck then the theory is (and its proven) then the more uniform the pressure let off will be and thats why lee designed the lee factory crimp that is used by bullet manufacturer's lee understanding that if you are not going to seat near the lands and depend on saami industry standard load data you may want to use the lee factory crimp that they have proven to work, and this would give you the little extra hold on the bullet to make pressures more uniform (they do have millions and millions more $'s or £'s to use in load developement unlike the hobbie reloader so they should know a thing or two) around three thou however as a reloader they know (as do other die makers) that you may want to seat bullets near the lands so a 3thou pinch on sized brass and the pinch that the bullet seated on the lands simulates (will explain in a mo)will be too much pressure and so most set dies will close to give a around 2thou pinch any way they can estimate velocity based on pressure so the two cases I was talking about that have a light and a heavy bullet with different oal's actually have very similar air space when seated in the cases with the same charge andso when jumping to the lands will actually give almost the same speads minus a tiny bit on the heavier bullet for increase friction so a way of making the standard die/ saami spec load more consistant apart from the obvious like more consistant charges would be to increaes the hold on the bullet by turning die mandrel/button to achieve 3thou pinch or crimp (I preffer 3thou pinch instead of crimp although testing over the chrono did confirm that the lee crimp does infact reduce extreme spread near or on the lands............................. this method of bullet seating uses a different process in that instead of the neck holding the bullet tight until certain pressures are achieved and then the bullet is released to travel down the barrel and a better hold on the bullet gives increased pressure or higher speads or simply put 1) primer ignites powder 2) powder burns 3) neck holds bullet until it cant hold on anymore so neck lets go of bullet 4)bullet has built up speed now its left the neck and jumps to the lands and begins its spiraling travel down the barrel and out with the bullet on/near the lands the bullet is allready through to stage 4 of the saami spec so its process is as follows 1) primer ignites powder 2) powder burns 3) pressure builds but the bullet is allready at the lands or hasnt left the neck before engaging lands and there is a momentary pause until the pressure forces the bullet down the rifling whilst fire is still burning and the bonfire still growing behind the bullet allready travelling down the barrel and this explains why seating near/on the lands causes the throat to wear quicker but more importantly explains to you why neck tensions is not required to be as high for this method as the rifling produces the pause which allows pressure to build for velocity hope that helps Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 22, 2010 Report Share Posted February 22, 2010 Now I am confused and Ronin started it?Cornishman got it right?Silent do the maths again on the correct ES for each load,I,m sure 5 fps is not a factor or is it? I admit to never even looking at ES perhaps I should. the math was done based on what varmartin posted as his es's on both loads and given a +/- over the average the es on the 15thou was higher so gave greater moa difference at 1000 also the math info was taken from martins post elsewhere Link to comment Share on other sites More sharing options...
TC Posted February 23, 2010 Report Share Posted February 23, 2010 if seating in/near the lands then yes less is better, if seating at saami then tight is better but more than 3 thou is not good because a) neck can start to shave copper off the bullet. can work the brass too hard and the effect wears off the important thing to remember is that saami spec.................. the bullet is seated well back into the case just as we see in factory loads, there is a large jump to the lands so the load info available from the industry is based on estimated or tested pressure to achiev accuracy. the round is seated back and will vary in length from bullets type's ie lighter bullets appear to be seated further in than heavy bullets take two cases or loads that are designed to jump as in saami spec, ones a light bullet and ones a heavy bullet, now the industry has tested and found what pressures produce what speeds so load the cases with the same amount of powder and seat the bullets so that the air gap between the back of the bullets and the loaded powder in the case are equal, if both bullets are going to jump to the lands then the pressure build up is going to be produced mainly whilst the bullets are still in the case it all happens in a blink of an eye but the pressure builds rapidly until the csae neck holding the bullet in place can no longer hold the bullet and so the bullet is pushed out of the case and into the lands and the bullet begins its travel down the barrel the greater the hold the case neck has on the bullet the greater the pressure will be and so the faster the bullet will travel( to a point) but their is only so much tension that case neck will ever have on the bullet. if you can apply more pressure at a very small area of the neck then the theory is (and its proven) then the more uniform the pressure let off will be and thats why lee designed the lee factory crimp that is used by bullet manufacturer's lee understanding that if you are not going to seat near the lands and depend on saami industry standard load data you may want to use the lee factory crimp that they have proven to work, and this would give you the little extra hold on the bullet to make pressures more uniform (they do have millions and millions more $'s or £'s to use in load developement unlike the hobbie reloader so they should know a thing or two) around three thou however as a reloader they know (as do other die makers) that you may want to seat bullets near the lands so a 3thou pinch on sized brass and the pinch that the bullet seated on the lands simulates (will explain in a mo)will be too much pressure and so most set dies will close to give a around 2thou pinch any way they can estimate velocity based on pressure so the two cases I was talking about that have a light and a heavy bullet with different oal's actually have very similar air space when seated in the cases with the same charge andso when jumping to the lands will actually give almost the same speads minus a tiny bit on the heavier bullet for increase friction so a way of making the standard die/ saami spec load more consistant apart from the obvious like more consistant charges would be to increaes the hold on the bullet by turning die mandrel/button to achieve 3thou pinch or crimp (I preffer 3thou pinch instead of crimp although testing over the chrono did confirm that the lee crimp does infact reduce extreme spread near or on the lands............................. this method of bullet seating uses a different process in that instead of the neck holding the bullet tight until certain pressures are achieved and then the bullet is released to travel down the barrel and a better hold on the bullet gives increased pressure or higher speads or simply put 1) primer ignites powder 2) powder burns 3) neck holds bullet until it cant hold on anymore so neck lets go of bullet 4)bullet has built up speed now its left the neck and jumps to the lands and begins its spiraling travel down the barrel and out with the bullet on/near the lands the bullet is allready through to stage 4 of the saami spec so its process is as follows 1) primer ignites powder 2) powder burns 3) pressure builds but the bullet is allready at the lands or hasnt left the neck before engaging lands and there is a momentary pause until the pressure forces the bullet down the rifling whilst fire is still burning and the bonfire still growing behind the bullet allready travelling down the barrel and this explains why seating near/on the lands causes the throat to wear quicker but more importantly explains to you why neck tensions is not required to be as high for this method as the rifling produces the pause which allows pressure to build for velocity hope that helps That was a lot of typing, much appreciated. The load I am working on is well in to the lands before the base leaves the neck but I may well have an experiment! Cheers Tony Link to comment Share on other sites More sharing options...
varmartin Posted February 23, 2010 Author Report Share Posted February 23, 2010 Thanks to all you guys for taking the time to read / and post...especially Jamie whose fingers are probably bleeding stumps by now .... I think what is called for is another` round` of load development , some at SAAMI and some at a new load of 46 grns either Varget or VV N140. I may get the velocity up and then start 10% lower and substitute the BR2 for a Fed Match primer and log the results again. I know using Jamie`s recipe...of 2650fps/44grns Varget @SAAMI works ...always has ...always will...But I am looking for more velocity to give me as big an advantage in the wind with this cal as possible ...so im thinking 2900fps little tiny bugholes at 100m and as low an ES as poss. We shall see..... Link to comment Share on other sites More sharing options...
silentsoulsleave308holes Posted February 23, 2010 Report Share Posted February 23, 2010 I got something in mind for you based on your needs and something I tried a long while ago , have you got twenty spare bullets 155's ??? I got the other bullets and the rest when you got a weekend day spare? I will get the field loading gear together and we can save a lot of waisted rounds and barrel life you fire and I load Link to comment Share on other sites More sharing options...
varmartin Posted February 24, 2010 Author Report Share Posted February 24, 2010 Got plenty 155`s mate...I will let you know when i have sufficient time off.... Link to comment Share on other sites More sharing options...
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