James 1 Posted October 8, 2017 Report Share Posted October 8, 2017 is anyone finding that seating there bullets longer there velocities are low. cheers James Link to comment Share on other sites More sharing options...
DaveT Posted October 8, 2017 Report Share Posted October 8, 2017 Natural consequence of increasing the combustion capacity of the cartridge and so lowering pressure. Link to comment Share on other sites More sharing options...
James 1 Posted October 8, 2017 Author Report Share Posted October 8, 2017 should i reduce seating or just be happy with the good groups and low pressure as the brass wont be worked as hard. Link to comment Share on other sites More sharing options...
DaveT Posted October 8, 2017 Report Share Posted October 8, 2017 Depends on your mv, range expectations etc etc....but if you are happy with current grouping and the range that you are achieving then why force pressures? Link to comment Share on other sites More sharing options...
James 1 Posted October 8, 2017 Author Report Share Posted October 8, 2017 im not happy with the low mv Link to comment Share on other sites More sharing options...
DaveT Posted October 9, 2017 Report Share Posted October 9, 2017 Your choices (within normal safe reloading bounds and calibre limitations) are therefore to increase powder load watching out for pressure signs and / or to reduce COL keeping in mind both calibre COL book min / max recommendations .....also knowing what your chamber can accomodate having measured it with a Hornady lock and load tool or similar to keep your bullet off of the rifling which could elevate pressures. Would help if you state all components , lengths and loads etc. Link to comment Share on other sites More sharing options...
James 1 Posted October 9, 2017 Author Report Share Posted October 9, 2017 Lapua brass trimmed to book Sierra 140 spbt N560 viht CCI large primer Max load 44.8grn Start load 41grns Link to comment Share on other sites More sharing options...
M99 Posted October 9, 2017 Report Share Posted October 9, 2017 Which of the 6.5 calibres are you loading for? Might need to give us a clue. Link to comment Share on other sites More sharing options...
DaveT Posted October 9, 2017 Report Share Posted October 9, 2017 As Mike / M99 says we need calibre and your actual load and COL to advise further. Eg....If you are loading for , say, a 260 Rem then 46g of N560 will be fairly 'hot' even at extended COL. Link to comment Share on other sites More sharing options...
James 1 Posted October 9, 2017 Author Report Share Posted October 9, 2017 Sorry m99 it’s a .260rem Link to comment Share on other sites More sharing options...
James 1 Posted October 9, 2017 Author Report Share Posted October 9, 2017 My powder charge is 44.8 grains and seated to the lands 2.900 coal Link to comment Share on other sites More sharing options...
DaveT Posted October 9, 2017 Report Share Posted October 9, 2017 You are about at realistic limits with that load....perhaps another grain headroom depending on your rifle/ chamber / freebore.... but beware pressures created by being on / close to the lands at 2.9 col. Unless you have a very short barrel you should be sniffing around 2800fps? What is your mv? Link to comment Share on other sites More sharing options...
James 1 Posted October 9, 2017 Author Report Share Posted October 9, 2017 My mv is 2625fps with a 24” barrel doesn’t make sense. Cheers James Link to comment Share on other sites More sharing options...
DaveT Posted October 9, 2017 Report Share Posted October 9, 2017 Agreed sounds low....I will tinker with Quickload tomorrow and think on it. Link to comment Share on other sites More sharing options...
James 1 Posted October 9, 2017 Author Report Share Posted October 9, 2017 Thanks dave I’m at my witts end I’m on my 3rd lot of different powder. Cheers James Link to comment Share on other sites More sharing options...
James 1 Posted October 9, 2017 Author Report Share Posted October 9, 2017 Ok thank you dave Link to comment Share on other sites More sharing options...
DaveT Posted October 9, 2017 Report Share Posted October 9, 2017 Just checking here....Are you confident on your Chrono figures? Link to comment Share on other sites More sharing options...
gbal Posted October 10, 2017 Report Share Posted October 10, 2017 2750 fps is about the median velocity for SAAMI 260 commercial ammo.None is over 2800,and some is 2700. Those velocities of course do not mean good grouping,but do mean acceptable pressures and barrel life-though less fps generally means more barrel life. There are some options for your rather low reported velocities of 2625,down about 100 fps on above. Have you checked your powder measure is actually dispensing the weight of powder the book data say gives your desired velocity? Have you checked your velocity with a valid and reliable chrono-magnetospeed/lad radar? Screen ones can be chronic,not chrono. What performance do you need for your uses? 100 fps may not be a big deal-eg for target shooting to 600y,better accuracy than velocity.Will 25 ft lb more put pressure on your freezer? As you say,there may be advantages in brass life too,with a reduction in velocity (of little consequence). As your own question-is adequate with accuracy better than velocity without validity? Or even velocity with equal groups? If you are shooting at 1000y,you might want a bit more velocity-actually you need quite a bit more ,really,in another cartridge if at all serious (start with 6.5x84...better yet, just 284....or.... :-) gbal Link to comment Share on other sites More sharing options...
James 1 Posted October 10, 2017 Author Report Share Posted October 10, 2017 I had my rifle built in feb and still being developing a load to get 2750fp so I can get out to the range and push out to as far as I can go, the Viht load data with 140grn bullets is saying 2700fps with an 18 3/4” test barrel. Link to comment Share on other sites More sharing options...
triggersqueezer Posted October 10, 2017 Report Share Posted October 10, 2017 this is one of those things that could really wind you up but in reality if you run it though an app you will see small difference from 100 fps on wind call ,which will probably be the reason for missing. if you could get past it and enjoy shooting it with good accuracy life is so much easier .chasing that extra 100-150 fps will probably get expensive . Link to comment Share on other sites More sharing options...
gbal Posted October 10, 2017 Report Share Posted October 10, 2017 James,SAAMI data given is for 24" test barrel. DEpendig on cartridge/velocity range/etc shortenng a barrel will reduce MV 20/25 fps per inch shortened,innthe 'normal' range normal range velocities and barrels (26"-20" Accuracy etc maywell be just as limiting for 600y plus distances,but here is an idea of what fps translates as: Nosler Part125g BC .45 MV 2950/2875 200 zero drop at. 600y 71/75. 800y 163/173. 1000y 316/335 drift is 1,2,3 inch more Rem 140g core lokt UB/PSP BC.457/.436 @2750 drop 60082/84. 800 189/196. 1000 367/382. Drift is 2,4,15 more for lower BC (Wind is 10 mph,and actual drigts at 800 are 57" for hi BC 125,and 62" for hi BC 140g) NOte small effects of 75 fps velocity increase,and .2 BC improvement (these are hunting bullets,not best BC target bullets,but the differntials make the point-thee really isn't a lot in it...precision/accuracy may be just as important,and gowith the less zippy loads-or not,of course. But ballistics don't make much of a case for losing sleep if casual/club level plinking! S0...just enjoy,see how it goes. Whatever the load,it won't get competitive...but so what- you didn't buy a (hot) 7mm......:-) gbal Link to comment Share on other sites More sharing options...
James 1 Posted October 10, 2017 Author Report Share Posted October 10, 2017 Yeah I no what you mean trigger squish I was just hopeful of a bit better velocity, Suppose you can’t have good accuracy and velocity without a really long tube or a bigger caliber. Cheers James Link to comment Share on other sites More sharing options...
gbal Posted October 10, 2017 Report Share Posted October 10, 2017 James,I meant to be more positive-if you have an accurate load,you won't gain much by another 150 fps-unless you are doing something with the cartridge,on the edge of it's design potential (and therfore has to give best to bigger cartridges anyhow). WAY better an xbull than a super fast bullet zipping through the 9 ring....and likewise all down the line. As you will be dialling in anyhow,two more clicks for your velocity will not have any discernible effect on scores. Enjoy it. (Another 200fps would just mean you are less behind the good 7s anyhow.....plus ca change,plus ces't la meme chose...not all good 7s are created equal either.... :-) g Link to comment Share on other sites More sharing options...
DaveT Posted October 10, 2017 Report Share Posted October 10, 2017 Quickload projects 2650 fps out of 24" barrel, 44.8g N560 and col 2.9 but also shows barely 90% powder charge burnt and pressure barely 45k psi. Its only a projection but you appear to have a bullet which creates lowish pressure...I dont have a diagram to check if it has a short bearing surface.....and a barrel which is too short to properly / efficiently use the slow burning N560. You could up the powder charge but would need to go over 46g to reach 2700+ and may hit pressures. Dropping the col to 2.8 as well as 46g N560 sees about 2772fps....same caveats. Alternatively N550 at around 42g shows 2761fps and near 100% burn....so better powder choice if pressures dont appear.......normally I would only use N550 with 123 / 130g class bullets but in this short barrel case it might be worth a go. Also consider 123g Scenar or SMK......EASILY A 1000 YARD choice with N550. Link to comment Share on other sites More sharing options...
James 1 Posted October 10, 2017 Author Report Share Posted October 10, 2017 I thought I would of been ok with a 24” barrel I am getting some eld-x bullets wen they come in the post, does it show any better with them daveT, if not I will at the n550 the Viht site and data is abit poor not as Gud as quickload. Cheers James Link to comment Share on other sites More sharing options...
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