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7mm-08 loads
@ 08:15 pm (GMT) |
DaveHi Nathan,I must say I have enjoyed reading the articles posted on your site. Reading the page on the 7mm-08 has left me a little confused however. I would like to develop a load for my 7mm-08 that is suitable for the longest range that a 7mm-08 can be reliably used on for Red Deer (although I wouldn't class my self as a trophy hunter after big stags) and Chamois. I currently load a 120 grain Noslier which runs at 3230fps and I have been concerned about its knock down power and have been think about heading up in projectile weight. I guess the obvious answer is to change to a different calibre however currently this isn't and option so getting the best out of what I have is the way I'm going. So my questions are: 1. What projectile would you recommend? 3. Do you have a load you can recommend ? 2. What range would you consider this is suitable out too? (and is there a minimum range under which it would be less effective) Hoping you can shed some light on these questions Cheers Dave Scobie |
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@ 09:50 pm (GMT) |
Nathan FosterRe: 7mm-08 loadsHi Dave, great to hear from you and thanks for the kind comments. Hard case: Man writes knowledge base to inform hunters, man overwhelms reader with too many choices, reader contacts man to ask about loads. I definitely understand.A lot comes down to the ranges you hunt at. If you find that the vast majority of your shooting is at close ranges and out to say 300 yards, a bullet like the 140 or 150 grain Nosler Partition is quite simply outstanding. I am constantly amazed by the Partition. People are always wanting a violent bullet, like the bullet you currently use, yet also want deep penetration. The Partition does this in spades yet it never gets much press which is absolutely beyond me. As for which is better, the 140 or 150 grain Partition, that depends on what velocities your rifle is capable of. If you have a fast barrel, then take advantage of the 150 grain Partition (More on this below). Both bullets create immensely wide, fast bleeding wounds down at 2200fps and do very well down at 2000fps which is a big ask of a small bore hunting bullet. If your hunting is predominantly at longer ranges, starting at say 200 yards, open country, shooting as far as you can, then I really stand behind the 162 grain Amax. Really, you have to draw on your past experience regarding how and where your animals are encountered, then set about matching a bullet to the job. Relative to your own rifle, the best way to work out potential velocities, is to the use the data you already have on your current pet load: 120gr BT 3230fps 140gr bullet will have a sweet spot at around 3000fps with 2 grains less powder 150gr bullet will be 2900fps with 3 grains less powder 160gr bullet will 2800fps with 4 grains less powder 162gr bullet will be 2780fps with 4 grains less powder. You will still have to experiment with incremental loads, working up and down in .2 or .5 grain Increments. All of the above velocities sound too hot for a 7mm-08, including your 3230fps load. Many 7mm-08 rifles will only achieve 3000fps with the 120gr BT, thats a huge difference and shows why it is impossible to suggest one generic powder charge that suits all. The reasons why your rifle may be faster than others (for the benefit of other visitors here) may be: a long barrel, a loose dimension bore, generous head space, overloading (some folk are happy to sacrifice brass after a couple of loads) or finally, a faulty chronograph. I am going to assume that your load habits are safe, your chrony is fine and that the results simply are what they are, based on generous chamber or bore dimensions. OK, so getting down to the nuts and bolts of it all, lets play with some examples. The 140gr Partition at 3000fps breaks 2200fps at 390 yards and 2000fps at 500 yards. The 140gr Accubond at 3000fps (pretty popular bullet these days) breaks 2400fps at 320 yards, wounding gradually deteriorates from there, adequate but not emphatic on Reds which can run a long way when hit as you will know very well. The 150gr Partition at 2900fps breaks 2200fps at 365 yards, producing excellent wounding at this range. The load will break 2000fps at 480 yards and this is roughly its limit for wide wounding if reasonably fast killing is to be expected. The 162gr Amax at 2780fps is violent down to 1800fps or 745 yards in your rifle- yeah thats a hell of a long way for a 7mm-08. Adequately wide wounding occurs down at 1600fps or 925 yards, deteriorating at 1400fps or 1135 yards (trajectory and wind are now major factors so you do have to excersize more attention to detail than when using a magnum)). Your rifle is too fast to allow the 162 grain Amax to be the deep penetrating projectile that it can be when driven at 2600fps in bush hunting situations, quartering shots are fine but tail on shots are off the menu for you. I am sure you won't mind though, considering the potential of this load at long range! One other compromise is the 154 grain SST (your rifle 2850fps). That said, I don't want to send you into a melt down LOL. I hope that gives you some starting points. Here we are, twiddling our thumbs while Christchurch is levelled to the ground and we can't help as outside help only threatens to add to their troubles at this stage. Hell its horrible and frustrating. Cheers, Nathan. |
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@ 10:38 pm (GMT) |
Nathan FosterRe: 7mm-08 loadsOne other thing, twist rate of your rifle will have an effect on the velocity accuracy relationship. Regardless of stated twist, testing firing is the only way to discover potential. |
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@ 10:56 am (GMT) |
Dave ScobieRe: 7mm-08 loadsHi Nathan,Thanks for the info. The laod I am using isn't showing any signs of over pressure (flatten primers, extractor mark or difficulty opening the bolt) and is very accurate (1/4 of an inch groups at 100yards). My gun is a Tikka T3 and I think it has an unusually long or loose chamber. As I can't seat the projectiles so they touch or are close to the lands. My O.A.L. for this load is 2.825" any longer and I can't get them in the mag. The powder is 46.5 grains of ADI AR2208. |
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@ 10:54 pm (GMT) |
Nathan FosterRe: 7mm-08 loadsThanks for the stats. Definitely sounds like a safe load. Plenty of freebore and only 1.5 grains over max using a good powder that isn't prone to pressure troubles.Don't hink you will have to worry about trading to a more powerful rifle, thats for sure. Good luck with your projectile experimentation. If you get a chance, please give us a follow up. Some wounding pics would be great too. Cheers, Nathan. |
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@ 09:05 pm (GMT) |
tim woodillRe: 7mm-08 loadsHi Nathan, regarding factory loads, when you say that the Federal 150 grain Speer Hotcor bullet is very good medium game loading, what weight range is this round suitable for? Is it a suitable round for red deer for example? |
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@ 10:18 pm (GMT) |
Nathan FosterRe: 7mm-08 loadsHi Tim- hope you have been enjoying the .308 article.....finally. Very sorry about the delay.Yes, the Federal Hotcor is very good for Red Deer, as options go. When I was testing, I was quite surprised that the Fusion load could not best it. The Federal Hotcor is not available to hand loaders. In hand load form, its the 145gr Hotcor but differs not just in weight, but also, the Federal load features a cannelure that I found helped arrest expansion and allowed the frontal area to shed, allowing deep penetration. As far as open country work goes, killing out at 300 yards is slightly delayed but clean. Think most of my notes on this are actually in the knowledge base. |
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@ 08:11 am (GMT) |
tim woodillRe: 7mm-08 loadsThanks Nathan. Yes I've been absorbing the .308 article and expect to be trying some Hornady 165gr SST SF in my .308 at the earliest opportunity... Once again, this site is brilliant resource. Cheers. |
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