On the approach to landing

[Oly]

OK, I was just wondering what people's opinons were on the distance jumped from the reloaded round to the lands of the rifling.

 

I'm currently setting all my rounds (Rem 700VLS .243 Win) to have a 0.030 jump to the lands - however, this is a factor I havent played with much as yet. So, my question is - if my groups get tighter at, say, 0.040 (as per Redfox's advice http://ukvarminting.com/forums/index.php?showtopic=1553 ) with one particular bullet weight/type (e.g. 75gn Nosler BT) - would the same distance (0.040) also be the right distance for other types/weights of bullet (e.g. 75gn Honady HP, or 105gn AMax)? OR, will each type/weight of bullet have it's preferred jump distance to the lands?

 

Basically, I think a concise way of putting the above is; is the jump to the lands rifle/calibre specific or bullet weight/type specific?

 

Many thanks in anticipation of your response.

[Vermincinerator]

Oly,

It would be great if it was so easy but alas its not.

Every different bullet weight, style and make will have its own preferred amount of jump at which it performs at its best, this could even be true about bullets of the same style and weight from the same maker but a different batch.

 

Ian.

[Ronin]

From my own experiences, and I load for a few calibres you really have to play with seat depth once you find a reasonably accurate load (powder charge)

 

Say my pet load for the 25-06,

 

53g Vit 160 under a 100 Speer Hotcore SP and Fed Gold primer - accuracy = .75" if bullet seated .0100" off lands -(similar seat depth to spec Factory loads).

 

Now if I move the bullet out towards the lands, the accuracy gets better untill the best is achieved at .010" off the lands.

 

Accuracy here is sub .5"

 

I also use the same load for a friends 25-06, different barrel, different manufacturer.

 

Now the rifle actally likes a charge of 52.5g Vit 160 and the same bullet seated to .020" off the lands to achieve similar accuracy.

 

My point being, you can "generalise" a little by saying "you may get best results at xxx off the lands or xx off the lands BUT unless you ACTUALLY shoot and record the results with YOUR rifle / powder / bullet combination, you will never achieve the best you can out of it.

 

Every rifle / barrel is different, even if they are made the same day on the same production line - to get the best out of yours, you experiment with it.

[Orka Akinse]

if bullet seated .0100" off lands -(similar seat depth to spec Factory loads).

 

untill the best is achieved at .010" off the lands.

 

 

Ronin is that a typo buddy??? or is my brain up my ass again I aint as bright as you

[foxing2night]

Load your rounds just touching the rifling!!!!!

 

Shoot for group?????

 

Then move bullet in 3thou at a time

 

And see what gives you the best results????

 

But i will bet you that best accuracy will be when they touch the rifling?

 

Doing it this way, Is the easyest and the most controlled way that i know???

 

Do you have all the relevant gages to messure these distances properly??

 

If you get stuck!!!! Pm me!!!

 

Darrel

[Oly]

Cheers Darrel, yep got all the stuff...like you say, just need to try a variety of distances.

[silentsoulsleave308holes]

oh well

[Oly]

oh well

 

Ehh ???

[silentsoulsleave308holes]

Ehh ???

 

just a joke for those that know me so dont worry, just ignore me

 

wont go into it cause I would be typing 4 ever

 

have you tried loading to saami spec and keeping everything as tight as poss????

 

oh oh ah ouch that will start it off

[eldon]

Oh, I get it ......... you are the one who loads to saami spec aren't you ( I read it somewhere)

 

After all this fannying about with lenghts, do you think that saami spec as a generalisation is the best ? Have you backed this up using a variety of rifles including long throated remingtons ?

 

Please expand a little?

[Oly]

Oh, I get it ......... you are the one who loads to saami spec aren't you ( I read it somewhere)

 

After all this fannying about with lenghts, do you think that saami spec as a generalisation is the best ? Have you backed this up using a variety of rifles including long throated remingtons ?

 

Please expand a little?

 

I think the can of worms is now officially opened?!?

[325WSM]

Oly.

 

Loading can be dangerous and advice may or may not be from folk with actual hands on experience.

 

As a newcomer to reloading I must advise you that loading closer than 20thou to the start of the rifling may well be inadvisable from a safety point of view until you are 101% conversant with all aspects of reloading and the consequences of each of your actions.

 

For field shooting and as a beginner stay close to SAAMI specs and you are unlikely to encounter problems.

 

Better still find someone with a few years experience of reloading various cals for all types of shooting and do some reloading with them - your knowledge will expand at a far greater rate and the chances of a mishap reduce proportionally.

 

By the way most of my ammo for 10 different calibers is loaded 20thou and further from the lands and all shoots less than 1" at 100yds (sorry, except the 30-30) - so get some reasonable loads and enjoy shooting them for a while.

[silentsoulsleave308holes]

just an example: lapua match 308 in a good stick can shoot sub 1/4" @ 100

 

an improvement the reloader can make to this saami spec round would be to turn necks so each case has exact same tension, weigh each case and sort so case volumes are the same to give better shot to shot, weigh and sort bullets and load to a more concentric seating

 

just think what that good stick would shoot then

 

factory saami sticks are made to shoot saami spec rounds, buy a good stick and good loads and allready you will have a guaranteed good shooter

 

buy a lesser stick and that which promotes growth and vigour ammo and your gonna have problems

 

remy sticks have been known to shoot sub.5 consistantly with top factory loads and their not top sticks

 

done over four lonely years or so of testing saami vs this saami vs that and all my centre fire are loaded to that

 

I regularly shoot my 7.62 with its massive jump to the lands out to and past 1000, have had three one shot kills past 800 on small rabbits (I think I have only had a few pops at live stuff at this range anyhows)

 

wasted a few barrels testing over them years

 

my custom 300wm with its custom chamber and throat which has been cut for 210vlds has been made to shoot saami spec length

 

I got xxxxx vel from xxx bullet seated at xxxxx length with the old bbl, done the math and came up with a 32 " bbl loaded with a min powder would give the same vel as a 26" at top load, give a 95% case by seating well back and had the throat cut so bullet would touch lands when seated well back and so I seat out 15thou so bullet gets pushed back to saami

 

this has been done because that bullet needs it like that but it ends up saami length just because I wanted a touch fit to lands with full case of chosen powder at min load to give max vel ( a true custom chamber) also been cut at min spec head space

 

most rpa's, for example, are off the shelf and so have min spec saami spec chamber, they have custom bbl's that given the chance would shoot excellent at saami spec but most, myself included, have got or are wrapped up in the seating the bullet out as long as you can to look cool

 

she has a 32" x 32mm thick bbl and shoots top velocity with min load because of two reasons 1) long bbl 2) bullets are seated well back into the case with a case fill of about 95%

 

tests I have done have shown that a round touch produces almost identical pressure as a round seated back at saami and same vel

 

tests have also shown that rounds loaded somewhere in the middle shot worse groups and greater vel spread

 

there are more benifits to seating at saami

 

oh yeh the 300 gives me sub 1/4" and has proved itself at 1270 yards

 

mostly and prob 80+ % off accuracy come from a good bbl and a good shooter

 

all the other little bits and peices are just add ons

 

my 223 cz shot a screamer group last week, with weather conditions taken into account, at saami spec length

 

trust me when I say its no good saying well ok I will try seating back a little, it dont work, its got to be all the wayback or very close

 

I have had and still have (well kind of) remington sticks and can tell you that their jump to the lands is nothing compared to ph 7.62 yet others on here will tell you of how she shoots and its not a fluke coz I sourced one for a friend and his shoots the same (his can produce a group at 800 that you would be happy with at 100

 

the remingtons are just throated for the longest heaviest bullet that that twist will allow

 

[Oly]

325WSM - been reloading a little while now from the advice of a good friend who reloads in the 1000's/yr, only now getting into more detailed stuff though - but thanks for the words of caution, it's always worth reminding others reading this too.

 

silentsoulsleave308holes - interesting points you make there. I will try a saami spec length and see how she goes.

 

With the 9 1/8 twist in the Rem 700 VLS in .243Win, what do you think will be the heaviest, longest round that it has been throated for?

[Guest varmartin]

105 Amax

 

I had exact same rifle...107`s would tumble and not hit a board at 100 yards

 

If you shoot it above 6000 feet you may get away with it ....but then again all rifles are different .

 

Martin

[Ronin]

Ronin is that a typo buddy??? or is my brain up my ass again I aint as bright as you

 

 

Typo mate

 

 

sorry should read 0.100" - one hundred thou off lands

 

and

 

 

0.010" - ten thou off lands.

[Oly]

105 Amax

 

I had exact same rifle...107`s would tumble and not hit a board at 100 yards

 

If you shoot it above 6000 feet you may get away with it ....but then again all rifles are different .

 

Martin

 

Cheers Martin

[millpool]

just a joke for those that know me so dont worry, just ignore me

 

wont go into it cause I would be typing 4 ever

 

have you tried loading to saami spec and keeping everything as tight as poss????

 

oh oh ah ouch that will start it off

 

 

he has yet to dabble in the "black art" of saami spec!!!!

[charly hunter]

I dabb;ed in the black art of SAMMI Spec and bloody glad I did too Give it a try all you have to loose is a bit of time reloading and a few rounds, but you may just gain more than you loose Go on be a devil Just think about it all the worlds military snipers use SAMMI Spec and there lives depend on it, it's got to be worth a few rounds

[millpool]

I dabb;ed in the black art of SAMMI Spec and bloody glad I did too Give it a try all you have to loose is a bit of time reloading and a few rounds, but you may just gain more than you loose Go on be a devil Just think about it all the worlds military snipers use SAMMI Spec and there lives depend on it, it's got to be worth a few rounds

 

 

 

SPOT ON NIGE!!!!!!!!!!!!!!!!!!!!!!!!

[silentsoulsleave308holes]

took a chap out from this site today for some shooting

 

ok weather was that which promotes growth and vigour so only shop paper at 100 and a pheasent at 330

 

223 loaded at saami shot good though (didnt want to get others wet

 

got her outof box, put three rounds into clover, let ben shoot her, asked him how did it go, he replied I cant see where they are shooting

 

so we walked down to target and his three rounds had punched the middle out of my clover

 

put gun away

[Oly]

OK - so I'm going to have a go at Saami spec - like you say, all I have to lose it a bit of time & rounds! So...a couple of questions:

 

a.) Is the ogive the same point on all rounds (I think remembering reading that it was), and if not;

b.) Given that the figures I have for Saami spec .243Win rounds are total length, and not to the ogive, how can I transfer this measurement to a measurement to the ogive of my rounds (I prefer the accuracy of measuriing to the ogive rather than - for example - the fine tip of a plastic ballistic tip)?

c.) I presume (and from measuring one) that factory ammo is not loaded to Saami spec length?

 

From my calculations so far Saami spec will mean that the distance jumped to the lands for my rifle will be 0.042 (and therefore an increase of 0.012 on my current rounds, and also over the 0.040 as I said that Redfox had mentioned previously, and referenced in this thread initially).

[Redfox]

.02" wont beggar things up Oly

Have two friends with Sako 243s I have measured them all including mine ( when new) and they are all within .001" of each other, So I can pass one of my rounds to any of them and it shoots exactly the same with my scope put on their rifle, says something for Sako as a maker, one is a 579 like mine and one is a 591 which is the next model. I have taken the scope of that and my others and replaced them , never had to re zero, using the Sako rings and bases.

I basically like Sakos alright?

Redfox

[duey]

First of all I would like to say that advising anyone to load 'touching the lands' can be very dangerous and cause massive pressure problems so unless you know extactly how to do this DONT

 

I tried loading SAMMI spec for my Remmy 308 and was lucky to get a four inch group at 100yds. found out that this was because at that length the bullet was 0.090 off the lands and had to push them out to within .020 and solved the accuracy problem, but then they wouldn't fit in the Mag box, That was a few years back now and have since had the barrel rechambered a lot tighter (palmer match chamber I think) and now shoots great 0.5" or less at 100yds if i concentrate, with my hunting round.

 

I have heard from a couple of sources that sierra 155 match kings quite often work well at 0.050" but not with my 308

 

I generally seat 30 cal at about 0.020 and find that that works fine for my rifles

 

My 22-250 I've had to get the 52gr A-max out to .0050 to get any sort of group, rifle doesnt like 55 BT noslers, but have some 60gr HP hornadays to try out when i can get around to it but so far the 52's work fine on old charley

 

Ian

[silentsoulsleave308holes]

I bet I could load them to saami length and get them to shoot

 

my 7.62 has a lot lot bigger jump than that

 

to make saami length work ya gotta realise a few things and one thing is the pressure has to be right

 

if I had a gun that shot 4" at 100 then it would go straight back and changed

 

I doubt very much a gun that shot 4" would suddenly shoot tight groups when presented to the lands

 

what you are proberbly experiencing is accuracy on a pressure spike so if the saami spec didnt work then its prob down to you werent reaching the rigth pressure

 

 

your remy is almost guaranteed to shoot at least 1" 100 or 1moa with top factory loads such as lapua match, if it doesnt then it is faulty

 

many remys shoot around .5moa to .75

 

matches are won on lapua match boxed 308

 

I suspect you didnt try top of the range factory match and you reloaded the home loads incorrectly

 

the easiest thing to do is take a top range match factory load designed for your twist and crono it

 

I have been a reloader of touching or near for some years and spent four to five years doing lonely testing every opurtunity I had doing tests

 

in the summer months this often meant every evening was spent out on the bench doing tests

 

then home load using the best components and keep everything as tight and concentric as pos and take time in weighing poweders brass bullets etc as thats something the factory cant do as its too time consuming