25-06 Ackley Improved reloads

Old 31

My Father had this gun built on a Win. Model 70 action with a Blue Marlin barrel, in the 1950's & he never really shot it much or at all. Since his passing my son & I decided to get it out & use it. We tried factory Win. super X ammo with a 90gr. bullet just to form the case shoulders. To our suprise it shoots 5/8" groups @ 100 yds. just shooting out the shoulders with this ammo. We now are trying to work up a reload & can not get the bullet to fly true (punching oval holes & no good grouping). We are using a 100 gr, boatail bullet & have tried 4350 & 4832 podwers with various loads & still the same results. We are guessing it has a high twist rate but I don't know what it is. The gunsmith that built the rifle has also passed away. Any sugeestions?

JustC

what loads were you using?? it sounds like an understabilized projectile,....were you way low on the load weight??

if not, have you tried a lighter bullet?? you may have a slow twist rate which will not stabilize the heavier/longer projectiles. Try loading some 70-80gr loads just to see if the holes "round out".

try the cleaning rod trick to get a guestimate of the twist rate, that may answer the question straight away.

Old 31

We did try a near max load (don't remember what it was right now & my data is in another state), but will try a max. load. I also thought about getting a lighter gr. bullet as that worked well in the factory load.

I am very new to reloading & don't know what the cleaning rod trick is. Can you "pass" that on?

perry shooter

hello bullet over all length is the factor on rifleing twist the longer the bullet not heavier the the quicker the twist needs to be . [:0][:p] Just my thought but if I had a rifle that would shoot 5/8 groups I would be tempted to pull one of the bullets and then see if I could buy that exact same bullet. thru MIDWAYUSA to reload .

JustC

put a tight patch on the rod with the appropriate jag. place a mark on the side of the rod up at the handle, and place a mark on the rod shaft right where it enters the action at the rear where to bolt shround would normaly be when the bolt is in. This has to be done JUST AS THE ROD HAS HIT THE RIFLING. As the rod is pushed into the rifling, it will rotate with the rifling. When that mark at the handle comes all the way around 1X, mark the rod AGAIN where it enters the action at the rear portion where the bolt shroud would be if the bolt were in the rifle. Remove the rod, and measure the distance from mark to mark where you marked the rod both when it entered the rifling and when you stopped pushing when the mark at the handle came all the way around 1X.

lets say your marks on the rod were 10" apart. Thus, to make the rod revolve 1X fully, the rod travelled down 10" of bore. Therefore your twist rate is 1:10 (one full bullet revolution per 10" of barrel)

crude method but will work in a pinch.

and yes length of the bullet is what determines the needed twist rate. However, in a given bore dia, in order to make a bullet heavier,..it HAS TO be longer. The length/weight are directly related to one another. longer/heavier means faster twist needed to stabilize properly and visa versa.

Old 31

We did pull a bullet & it is not a boatail. We also checked how many grains of powder was in the factory load, but do not know what powder Win. is using. I'll try matching the factory bullet & increasing the load.

We have shot the gun 3 diferant times at the range & each time it is shooting 5/8" grups. ? Maybe I should just shoot the factory loads?!

Thanks,

JustC

actually it sounds like you should weigh the bullet, and use something close to that while working a powder charge of an appropriate powder. However, finding the twist rate will give you a lot of info on where to start.

perry shooter

I respect JustC but must disagree one one point THERE IS difference on length between bullets of the SAME weight. depending #1 on boat tail vs flat base. #2 thickness of jacket as to related to size of lead core lead weighs more then jacket material. #3 the ogive shape of the point "ever wonder why most factory bullets of the heaviest weight are round nose" shorter for given weight then a long spire point. I know these are very small items but if you are on the verge it WILL cause problems.

sandwarrior

Old 31,

What JustC is saying about the twist is correct. So is perry shooter in the point about O/A bullet length. Since you said your dad had this built in the '50's I'll pass a few factoids. Most of the bigger .25 cal bullets back then were roundnose or semi-round nose therefore shorter and therefore more easily stabilized by a slower twist. Also, in the 50's the thinking was 1-12" twist in everything except the little varmint rounds. I have come across so many old .257's of the day with a 1-12" twist I thought there must have been mercury in their water. Turns out the real radical thinking of the time was the .243 by Winchester and making it a 1-10". Keep in mind too that the 25-06 at the time was not a proprietary cartridge until 1969 So, it was at least a decade before Remington standardised the cartridge. I have found most of the standard or customized rifles in .25 cal of that day were 1-14" or 1-12" twist. I don't know when the 117's became the most prevalent bullet choice, but that is when 1-10" twists became more popular.

EDIT:

Sorry, long story short. 1-14" won't stabilize a .257 cal 100 gr. bullet at approximately .995" It will stabilize an 87 gr. at .887. A 1-12 will handily stabilize the 100 gr. But it really takes a 1-10" to stabilize the 120/130 gr. bullets.

Old 31

Thank you all for the advicee & suggestions. I have a direction to go now & feel more positive on a good outcome.

Thanks,

JustC

I agree on the length vs weight when related to round nose or flat base pills. neither of these I use, so my information is 95% based on match grade or boat tailed bullets. They vary much less between them as the only slight variances come from the ogive either being a secant or tangent and some will have the boattail a little longer and some will use a slightly shorter boat tail,..but then you place 3-4 different match or Boat tail pills by as many manuf, side by side, their lengths will seem almost identical with the obvious differences being those I mentioned. that should have been specified when I was talking about length and weight being relative to one another.

round nose, flat base were infact made so short to be able to stabilize in the "all around" factory twists they were offering. I have no experience with these types as my interest is mainly focused on accuracy and round nose bullets are no good for this kind of work. The flat base I use vary rarely as well due to the better performance in the wind after 300yds of the boat tail pills. I should have explained that earlier as Perry Shooter brought up info that I didn't even consider since I don't use those types of projectiles.[B)]