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270win
@ 02:17 am (GMT) |
Trevor WilkesHi Nathen,I have some mild loads listed here that when I try work them up they go awol,well out to about inch. 130gr sst,57grs-2213sc groups .570 at 100yds-.710 at 200yds consistant. 130gr nosler ballistic,52.5grs-2209 groups .460at 100yds. consistant. Just curious if its the rifle may be recoil lug related or bedding or just me. The 90g HPBT Sierras with 60grs of 2209 shoot-.223 at 100 yds the rifle is a tikka T3 stainless laminate stock. Also is the 22 inch barrel to short for 2213sc as it seems to like 2209,I realise its a factory rifle am I just expecting to much from it. Cheers. |
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@ 04:27 pm (GMT) |
Nathan FosterRe: 270winHi Trevor, its a tough call for me. It is certainly easier when I can look over the rifle myself. Regardless,you have raised a point that is always good to discuss.Quite often, a shooter will bring me a rifle, stating that as loads are increased the accuracy wanes, leaving the shooter with an established sweet spot at a low velocity. I then take on the rifle and do my thing. Quite often, I find that as loads are increased, the loss of accuracy was due to the client's inability to manage the increased recoil. This is not a bad thing at all because after discovering this, its a case of correcting shooter technique, practice and eventually, everything comes together. The irony is, technology is advancing allowing the creation of ultra light rifles yet although we have achieved this level of engineering, due to the light weight platforms, shooting technique is now far more critical than it ever was. Felt recoil of modern rifles may well be light, but the actual recoil inertia and its effects on accuracy are utterly immense. This is so important to remember. So I believe you are on the right track looking at your own technique, even utilizing the laminated Tikka which is heavier than the T3 Lite. OK,so thats one factor. It may however be that the rifle is not capable of optimum accuracy at higher velocities. Occasionally a Tikka will have a sensitive bore and will suffer such limitations. On the other hand, it could be a case of having not reached the upper sweet spot. Most rifles do have two, sometimes more sweet spots. You may have found the low sweet spot, but have not yet loaded high enough (sometimes past the manual listed maximum in the manuals if the rifle requires it) to find the high sweet spot. As an example, typical sweet spots for the .270 Win with 130 grain bullets can be up around 56.5gr ADI 2209 / 4350 and 54.5gr with 150 grain bullets. Thats about 5.5 grains past the listed maximums and I have gone higher. But you have to know how to read the brass, thats the key. What we are talking about here (regarding powder charges) is not hot loading, its about getting the rifle up to its actual optimum pressure range, often due to loose tolerances that have inhibited optimum pressures with standard loads. There is a high possibility that your rifle is well under loaded. Keep this in mind. Bedding of the T3 can be an issue occasionally but I would like you to view this as a last resort in this case. Work on the factors above to begin with. Bullet jump for the SST .2mm. Bullet jump for the Nosler either .5mm or 1mm. Yes, 2209/4350 is perfect for the .270. The rifles that really did well with 2213sc / 4831 were the old Finnbears and likes with super long throats and 24" barrels. We really don't see rifles like these anymore, bit of a shame. When you get a chance, please experiment with the 150gr SST and if you find an accurate load, experiment with projectile annealing. Keep us posted. |
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@ 01:16 pm (GMT) |
Trevor WilkesRe: 270winHi Nathen,Thank you for the reply and very detailed at that makes it easy for people like me to understand that are new to reloading we are a lucky bunch to have your help. You are right I havnt loaded past max but am getting more confident as time goes by and my knowledge grows so I will start at max with the 130s as I have already done these with no preassure sighns. Im happy with the accuracy that Im getting just think there is better to be had out of this rifle so why not find it I say,I dont actualy have a purpose for this rifle where I reside so was thinking of using it to practice shooting longer distances well as far as its capable of shooting accurately to aid me when the 300 rum rocks up. So I shall keep an eye on my technique and see how it goes and thanks again Nathen I slip you another donation next week. Cheers.z |
@ 11:45 pm (GMT) |
Jesse sullyRe: 270winThank you for this post. Ive been trying to develop a 150g load for a rem 700 in 270 using 150g speer hot cores. I was worried about going higher than 54.5g and so far only finding a sweet spot at 53g 2209 at velocity of 2790 fps. At 54.5g my velocity is 2880 fps with accuracy going from .2" to 1.4". Based on Nathan's comments it looks like i need to go 1g higher to find the upper sweet spot. The COAL with 150g SST is 90.0 mm suggesting i have one of those 'other' rifles like the old finbar with a super long throat. For the SST im not sure what the best seating depth is but considering 87.0mm. Any recommendations welcome. Thanks again. These forums contain a wealth of knowledge |
@ 07:06 am (GMT) |
Nathan FosterRe: 270winHi Jesse, it sounds like the throat is either out of spec or worn out. The OAL should not really be much longer than 87mm with the SST. With the HC in a max spec throat, you should be around 83 to 84mm.From what you are describing, the Speer 150gr, whether HC or BTSP may be the best choice as it tends to handle this type of situation well - a good bearing surface, non-finicky ogive design, cheap to experiment with and an effective killing bullet. While I may work up to 54.5gr 2209 in a max spec throat (150gr projectile), I seldom go past this. But yours appears to have an extra long throat and we can see the velocities are fairly mild at 2880 with 54.5gr so as you say, there may be room for some experimentation. The brass will of course tell you what you need to know. As mentioned elsewhere, make sure the bedding platform is up to the task. In some cases, wide groups at high charge rates come as a result of stress within a sub-optimal bedding platform. The two factors of increased recoil - that which effects the shooter vs stress to the bedding platform. If using the flat based Hotcor, make sure your dies do not make the case neck too narrow resulting in poor concentricity when seating. Best to use either the Lee neck die or a Redding bushing die with a gentle neck bushing. If nothing shows up at the high node, you do at least have a good load at 2790fps. |
@ 05:06 pm (GMT) |
Mike DavisRe: 270winTrevor...I read that above and say to myself...and where is the problem?????you have a good safe load thats not going to be hard on ears,shoulder ,brass or barrel...its shooting tiny bughole groups.....its a 130grn in .270 so you obviously ARENT thinking long range..assumably sub 350yards which means you wont be twiddlin n fiddlin so where was the issue again???? one really good point I see NO readout from a chronicgraph...excellent. to recap,you have a good accurate load...LEAVE IT ALONE AND BE HAPPY. Jesse along similar lines...if perchance you arent looking for a long range dinosaur slayer..consider a round nose projectile and IF you can find them,a heavy round nose...the reason I say that is my old rifle had very long and or worn throat and it loved 160 lapua megas and speer 170grn..... luckily my new Howa likes the 170s too...seated at mag length they must be very close to rifling . 2790fps with a 150grn is not to be sneazed at...... but thats bush hobbit talking..WHEN I can actually find a deer to shoot its normally under a hundred yards away. |
@ 04:29 am (GMT) |
Tim LuteRe: 270winHey fellas, Love the info available and thanks for sharing. I have always been an accuracy nut and good enough was never good enough. I have found that most rifles I own will group well at lower velocity levels with most load recipes. Because I hunt primarily Mule Deer and Coyotes in western US I have always looked towards the upper end of the velocity range when working up loads. As I increase charge weight (.5 gr increments) I use a micrometer to check for case expansion just above ejection groove. My most accurate loads have been found above "max" in the manual. All but one. 110 gr. Barnes ttsx. Note: 130 gr. and under. I have not gone to any heavier bullets. My .243 follows the same program. Don't be afraid to experiment slowly. Also worth mentioning velocity deviation is much tighter as case capacity is reduced. Why???? Any ideas ? |
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